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74,157,080 | https://en.wikipedia.org/wiki/3C%20345 | 3C 345 is a blazar/flat spectrum radio quasar located in the constellation of Hercules. It is noted for hosting a superluminal jet and its variability in almost all wave bands.
Characteristics
3C 345 has an active galactic nucleus that has been categorised as a blazar or as a flat spectrum radio quasar. The host galaxy of 3C 345 is an E3 elliptical galaxy without prominent peculiar characteristics.
Superluminal jet
When observed in radio waves, 3C 345 features a compact region with a radio jet emanating from it for 3 arcseconds and ending at a hot spot. The jet appears straight for 4 milliarcseconds (mas) but then curves northwards. Hot spots are visible at the counterjet direction in radio images. There is also a faint halo. The jet has been found to emit X-rays, up until 0.2 arcseconds from a radio hot spot, which could be in reality a bend of the jet.
The components of the jet have been found to move by about 0.25–0.42 mas, which at the distance of the jet represent apparent speeds that are 5 to 15 times faster than the speed of light. The radio jet exhibits superluminal motion for 0.12 to 12 mas, with apparent speeds that accelerate from ~5c to ~15c within 0.3 mas. Within the jet lies a stationary feature ~0.1 mas (with corresponds to about 0.7 pc at the distance of 3C 345) from the core, which has also been found in other blazars. The viewing angle between the jet axis and the line of sight is calculated to be about 5°.
Variability
3C 345 has been known to fluctuate in brightness. For example, it brightened from magnitude 17.2 to 16.0 between 10 April 2018 and 8 May 2018 when observed in R band. A bright GeV gamma-ray flare was observed by the Fermi Gamma-ray Space Telescope on 31 May 2017, as the flux increased by 40 times above average. The flares in 2009 were observed simultaneously in γ-rays, X-rays and optical/UV, while there was a lag before they were observed in radiowaves. A long term variability study indicates flares every 3.5 to 4 years, coinciding with the appearance of new features in the radio jets.
It has been suggested that the source of the fluctuation is the presence of a binary supermassive black hole, with the two similar black holes with masses about which are separated by around 0.33 pc and orbit each other with a period of 480 years. The second black hole perturbates the accretion disk, resulting to fluctuations in activity. The X-rays observations indicate that the nuclear region is hidden behind a compton thick absorber with a column density of NH ≃ 1025 cm−2 that covers 75% to 85% of the X-rays source.
References
External links
3C 345 on SIMBAD
OVV quasars
Blazars
Hercules (constellation)
345 | 3C 345 | [
"Astronomy"
] | 636 | [
"Hercules (constellation)",
"Constellations"
] |
74,157,832 | https://en.wikipedia.org/wiki/Dreams%20in%20analytical%20psychology | Dream psychology is a scientific research field in psychology. In analytical psychology, as in psychoanalysis generally, dreams are "the royal road" to understanding unconscious content.
However, for Swiss psychiatrist Carl Jung, its interpretation and function in the psyche differ from the Freudian perspective. Jung explains that "the general function of dreams is to try to re-establish our psychological equilibrium by means of dream material which, in a subtle way, reconstitutes the total equilibrium of our entire psyche. This is what [he] calls the complementary (or compensatory) function of dreams in our psychic constitution". In this sense, dreams play a part in the development of the personality, at the same time as linking the subject to the vast imaginary reservoir that is the collective unconscious. According to analyst Thomas B. Kirsch, "Jung regards the dream as a natural and normal psychic phenomenon, which describes the dreamer's inner situation [and makes it a] spontaneous self-portrait, in symbolic form, of the present state of his unconscious".
Jung and his followers, such as Marie Louise von Franz (for whom dreams are "the voice of human instinct") and James Hillman, made a significant contribution to the science of dreams. Carl Gustav Jung proposed a dual reading of the dream in terms of object and subject, while representing the dream as a dramatic process with phases that shed light on its meaning, always individual but also reducible to cultural and universal issues. His method of interpretation, "amplification", allows us to compare dream messages with myths and cultural productions from all eras. Marie Louise von Franz has studied dream symbols, while James Hillman is more interested in what this other world represents for the dreamer.
As a nocturnal theater of symbols, dreams are for Jung a natural production of the unconscious, as well as the locus of personality transformation and the path to what Jung calls "individuation". The dream is therefore at the heart of Jungian psychotherapy, which aims, through its study and the method of amplification, to relate each dream motif to the human imagination, and thus develop its meaning for the dreamer.
Dreams in analytical psychology
In analytical psychology, the dream is a natural process emanating from the unconscious. As such, it has several functions, which Jung explores in two major works: Man's Discovery of His Soul and On the Interpretation of Dreams. According to Jacques Montanger, for Jung, the dream is "an organ of information and control with a dual function": a compensatory and a prospective function, as well as being a physiological regulator.
Physiological function
In his early writings on dreams, Jung considered the biological and physiological utility of dreams. He speaks of "functional automatisms which, like cellular reactions, necessarily find their justification" in the dream process. Some dreams even enable the body to express feverish or sickly states, and herald future biological disorders. Dreams can in fact have somatic causes, a fact which, as Jung points out, has long been recognized by traditional and shamanic medicine and, more recently, by experimental psychology. Similarly, certain physical and environmental events, such as noise, heat or cold, can provoke dreams. Finally, some dreams have a traumatic, haunting content, constituting "an attempt by the unconscious to integrate the shock psychically".
Compensatory and psychic balance function
According to Jung, the main function of dreams is to contribute to psychic equilibrium, just as they contribute to biological equilibrium. Recalling the role of compensation mentioned by Alfred Adler, he notes that not everything we experience during the day reaches our consciousness. Some phenomena remain subliminal. In dreams, the hidden, unconscious aspect of a concept can be put into images. The human psyche is made up of conscious and unconscious parts, the latter of which are expressed in dreams, linking them together to safeguard psychic balance. To restore mental and even physiological stability (Jung speaks of the "compensatory biological function" of dreams), consciousness and unconsciousness must be integrally linked, in order to evolve in parallel. This compensatory function is found throughout his theory.
In On the Interpretation of Dreams, Jung distinguishes four meanings of the dream process in terms of its psychic balancing function. Firstly, it represents the unconscious reaction to a conscious situation, and thus reacts either by restoring the daytime content or by compensating for it. Secondly, the dream reveals a situation arising from the conflict between consciousness and the unconscious. Through compensation, the dream represents the unconscious' tendency to transform the conscious attitude. Finally, the unconscious processes inherent in the dream have no relation whatsoever to the conscious situation. Jung's conception of the unconscious sees dreams as "indispensable messengers, transmitting information from the instinctive to the rational part of the human mind". To represent this non-rational instinctive part, Jung takes into account the relationship between the personal unconscious and the collective foundations of the human imagination. For him, this collective unconscious produces meaning and compensates for the attitude of the ego, in order to maintain or re-establish psychic equilibrium; indeed, the "dream is a spontaneous and symbolic self-representation of the current situation of the unconscious". For Jung, the dream is therefore an expression of the overall psychic situation, which is as much a representation of the momentary state of consciousness as it is of the collective dimension of the unconscious, making it an energy regulator that compensates for daytime life.
Prospective function
Dreams have a foresight function, enabling us to find a way out of an immediate conflict. To reduce the polysemy of the term, Jung sometimes speaks of the "intuitive function" of dreams. This prospective function is not in fact a premonitory dream, but teaches the dreamer a path to follow. As the unconscious possesses absolute knowledge enabling it to anticipate the future, Jung sees this dream function as the key to explaining certain "psychic" faculties such as telepathy. Nevertheless, Jung only really considers dreams that forecast future transformations in the dreamer's personality, and explains that "it would be unjustified to call them prophetic, for they are, basically, as little prophetic as a medical or meteorological prognosis". These dreams therefore take their place within individuation, a central concept for Jung. He considers the prospective function to have two meanings: it is both integrative and synthetic (or "reductive").
Within this prospective function, Jung includes a category of dreams: those in which certain psychic events penetrate the unconscious sphere. This is the case of dreams announcing the death of a loved one. Jung notes that these cases are close to a "situational instinct". In his latest work, the Swiss psychiatrist sees this category of dreams as examples of synchronicity, i.e. acausal relationships between a real event on the one hand and a psychic and emotional state on the other. Conversely, dreams can evoke past events, both known and unknown to the subject. Jung likens them to the phenomenon of cryptomnesia.
Dream interpretation
Jung took his cue from Freud's psychoanalysis and his seminal work, The Interpretation of Dreams (Traumdeutung in German), and believed that dreams could be deciphered. However, Freudian concepts such as latent content and manifest content do not enable him to derive a meaning in line with the subject's equilibrium. Jung therefore developed various notions and practices specific to his theory, based on his particular approach to the symbol.
Dreams and symbols: the language of dreams
For Jung, the dream is the "theater of symbols", in the sense that a "symbol", as distinct from a "sign", is an image that combines contradictory contents, one conscious and the other unconscious. For Jung, "the symbol is endowed with a subjective dynamism that exerts a powerful attraction on the individual, acting as a transformer of psychic energy", explains Thomas B. Kirsch. Monstrous motifs remain significant in this respect: "the presence in dreams of monstrous or hybrid figures often points to an incursion of the non-homogenous, of independent motifs that are not part of the dream context". Moreover, symbols are natural, spontaneous products of the unconscious, obeying the principle of psychic economy. Thus, dream symbolism obeys the law of the smallest force necessary, bringing together in a single object several important clues, as Yves Delage already noted in his book Le Rêve (1921).
However, the same symbol does not necessarily have the same meaning from one dream to the next. This is why Jung has always opposed the possibility of interpreting dreams by means of manuals. Recurring motifs (such as falling, flying, chasing etc.) require individual interpretations, because their meaning depends on the context and life of the dreamer. In Julian theory, "dream teachings" are always personal. Thus, the explanation of the dream is complete when we succeed in indicating "the dreamer's distance from the realization of the demands of the collective unconscious". Knowing the collective unconscious and its hold on the subject is the crucial phase of Julian psychotherapy. In the course of treatment, there always comes a point when the patient's imaginations change character, and interpretation can no longer be based (solely) on repressed personal elements. These particular materials must then be compared from a collective angles, in order to amplify the interpretation. This "mythic shift" characterizes the Julian approach.
Amplification
"Amplification is a kind of delimited, coherent and directed work of association, which always leads back to the quintessence of the dream and seeks to elucidate it by illuminating it from every possible angle," explains Jolande Jacobi, an analyst close to Jung. This approach reveals the point of divergence between Freudian analysis, on the one hand, which presents itself "as a monologue", and Jung's, in which the dream is an "object of examination", according to Charles Baudouin. Jung also warns against over-interpretation, which is sterile and dangerous even for the dreamer. Jung's French translator, psychiatrist Roland Cahen, also stresses the danger of unrestrained amplification. Moreover, amplification aimed at "arousing in the analyst a richer understanding of his dream" is less widely used today, as experience has shown that it avoids confronting complexes.
In practice, the method of amplification (which Jung explains in the second part of On the Interpretation of Dreams, made up of seminar notes from 1938 and 1939) consists in getting the dreamer to express what immediately comes to mind from a dream scene. In this way, the analyst can explore a maximum number of possible meanings that make up the patient's imaginary world, revolving around a "central core of meaning". For Jung, this method enables the analyst to identify the archetype(s) constellated, i.e. excited, in the subject's unconscious. Jung's approach is therefore exhaustive in terms of symbolic motifs, whereas Freud, with his method of free associations, develops the same motif, moving away from an initial association by an association on this association, and so on. While the analyst helps and guides the amplification, it is imperative that the patient approves and even validates the conclusions in some way, and "Jung insists on the necessity of obtaining the patient's assent to the proposed interpretation".
The method of amplification must also be applied to each element of the dream. The "lion" motif, for example, evokes the subject's thirst for power; then the analyst asks him again what the word power means to him, and so on. This is personal amplification, which Jung extends (and this is specific to his theory) through collective and cultural amplification. Children's dreams are part of this. The analyst must then conduct bibliographical research and possess a broad cultural background in order to identify symbolic correspondences between motifs.
Interpretation on three levels: subject, object and transference
Jung introduced schematic analysis to dream interpretation. He distinguished between the "subject level" and the "object level". As the dream compensates for the dreamer's daytime life, the analyst can interpret the dream production on the object level, enabling the subject to confront archetypes, or on the subject level, giving him/her the opportunity to reappropriate the libidinal energy contained in the projections he/she has made onto the object.
The object level is an interpretation that refers each motif and symbol to external elements. The method breaks down dream elements in order to discover their meaning according to the dreamer. The subject level concerns the dreamer's own self. Jung relates an example of interpretation to the person's own experience, as in this example: "A patient wants to cross a river when she sees herself held back by the foot by a crab. This patient is in a homosexual relationship with a friend and, by association, comes to think that the crab's claws represent her friend's monopolizing affection. This is the interpretation from the object perspective, but it does not exhaust the material in relation to the subject itself, for the crab is an animal that moves backwards - evidence of a regressive disposition - and is associated with cancer, suggesting that the root of homosexuality is terribly dangerous. The aim of this approach is to dissociate the dream elements, retaining only what concerns the dreamer. In this way, a subject-oriented interpretation reduces the patient's projections by bringing unconscious images to the fore, while the assimilation of complexes is, for analytical psychology, a matter of becoming aware of them.
Nevertheless, the dream can be considered on either of these two levels, since it is constantly immersed in a milieu of primitive, "adualistic" (duality-free) thought. The phenomenon of mystical participation leads to the fusion of object and subject in the dream image. Jung adds a third level of interpretation, that of transference, which takes into account the other two levels, as well as the transferential relationship between the dreamer and the analyst, in the context of psychotherapy.
Dream series and dramatic structure
In On the Method of Dream Interpretation, Jung writes that "the dream series can be compared to a kind of monologue that takes place unbeknownst to consciousness. This monologue, perfectly intelligible in dreams, sinks into the unconscious during periods of wakefulness, but in reality never ceases. It's likely that we are in fact constantly dreaming, even in the waking state, but that consciousness produces such a din that the dream is no longer perceptible to us. Indeed, a single dream is not enough; the unconscious always uses a series of dreams to influence the conscious, even if "the series which (...) appears chronological is not the true series". The analyst must therefore interpret continuous sets of dreams in which a dynamic of representations is revealed. Jung gives two significant examples of the value of studying dream series, through the cases of "Miss Miller" (in Métamorphoses de l'âme et ses symboles) and physicist Wolfgang Pauli (whom Jung also had as a patient) in Psychologie et alchimie. As Jung points out, these series of dreams seem to point towards an unconscious desire for centrality and totality, which he calls individuation.
Moreover, when a dream is too complex, it makes sense to schematize it. For example, Jung sees a dream as a drama, comprising an exposition of the situation (place, time and dramatis personae) and the problem, followed by the adventures and finally the lysis or result of the dream, which is also the compensatory representation of the dream action. In fact, most dreams follow a similar dramatic structure, which the ritual also reproduces at the conscious level. The specificity of analytical psychology lies in the fact that dreams are seen as dramatic personifications of complexes.
Concentric method and ethical principles of interpretation
While the free association method proceeds by arborescence, gradually moving away from the primitive dream image, Jung's method is "concentric", tending to return to the dream image. The Freudian method is considered too defensive, as it allows for a reduction to the original figure. Jung therefore prefers a circular, circumambulatory method that is found in spiritual traditions such as alchemy and Gnosticism, and which he calls amplification. But it's not just a technical approach, it's also an ethical position for the practitioner in relation to the dream and the dreamer.
The analyst must assume that he or she knows nothing about the dream and cannot form a preconceived or theoretical opinion. Indeed, Jung explains that, given the "infinite variability of dreams", it is best to "treat the dream as a totally unknown object ". Marie Louise von Franz puts it this way: "We should observe dreams as objectively as possible (...). The dream brings a new message that neither the analyst nor the subject can know in advance ". The analyst also has a role to play in this interpretation. The analyst is there to guide the dreamer in the initial interpretative work of amplifying the dream. On the other hand, certain images can be harmful, and the analyst has a duty, particularly through transference, to genuinely help the patient make them conscious. For Jung, transference, in contrast to Freud, has a useful purpose in treatment: by becoming the object of the dreamer's projections, the analyst enables him or her to make certain unconscious contents conscious.
Genesis of the concept
Philosophical and psychoanalytical heritage
Dream interpretation before Jung
As in the Jewish Kabbalah, for Jung, the dream carries its own meaning. Nevertheless, in his various seminars, Jung often traces his scientific interest in dreams back to early Christian theological figures. Thus, in his seminar notes of 1936 and 1937, forming the first part of his synthesis work On the Interpretation of Dreams, he draws up a historical panorama ranging from Artemidorus of Daldis (2nd c.) with his Five Books on the Art of Interpreting Dreams, to Macrobius (b. c. 370), through his Commentary on the Dream of Scipio, and Synesios of Cyrene (4th-5th c., with Traité sur les visages du rêve) and more modern figures such as Caspar Peucer (1525 - 1602), author of De somniis, Abbé Richard (18th c.) and his Théorie des songes, Franz Splittgerber (Schlaf und Tod, 1866) and, in the 20th century, Yves Delage (1854 - 1920) with Le rêve (1920). In the third part of the same work, corresponding to the seminar notes from 1940 - 1941, Jung devotes a long, practical study to the dreams of Jerome Cardan, then to the visions of Saint Perpetua (died 203), applying the method of amplification. In this way, Jung attempts to show that these thinkers, before psychoanalysis and often in curiously similar terms, were interested in dreams as sensible productions of the mind. For Françoise Parot, Jung is the heir to the mystics and Romantics, Carl Gustav Carus and Gotthilf Heinrich von Schubert in particular.
Freud's "science of dreams": influence and extension in Jung's work
Apart from this philosophical and theological heritage, it was above all Freud and his science of dreams that most influenced the young Jung, then a psychiatrist at the University Psychiatric Clinic in Zurich. Indeed, Freud's contribution is fully acknowledged by Jung: "Freud was essential for me, especially through his fundamental research into the psychology of hysteria and dreams", he says in his autobiography. Nevertheless, while Freud saw dreams as a condensation of repressed unconscious processes, Jung saw them as revealing complexes, a notion he developed during his experiments with word associations, with Franz Riklin, at the University Psychiatric Clinic in Zurich. Like Freud, however, dreams - to which Jung added daydreams, fantasies and visions - remained the preferred material for analysis. Freud insisted that "any key to dreams", i.e., any list of symbolic equivalences of general value, should be excluded. He does, however, admit a few universal symbols, carried by culture, and certain "typical dreams" whose paradigms can be found in many dreamers.
Freud, however, sees dreams as a repetition of obsessive past events: for him, dreams are merely "the veiled expression of a complex, whether this complex be linked to lust, power or sexuality". Jung called this approach reductio in primam figuram, and contrasted it with his own concentric approach, which he called amplification. The first notion Jung criticized was censorship. He refused to speak of the "facade" of the dream, just as he rejected the classic Freudian distinction between latent and manifest content, because he considered that "dreams do not delude, lie, distort or disguise; on the contrary, they naively announce what they are and what they think. (...) Their inability to be any clearer corresponds to the inability of consciousness to understand, or to want to understand, the point in question". "The fundamental difference with Freud is that, for Jung, "the dream is entirely what it is"; here, the dream is its own interpretation. What's more, whereas Freud sees the dream as an aimless assemblage of images, a façade, Jung sees it as a moralizing message (concerning the dreamer's ethics and behavior) and, as such, with a purpose. As he repeatedly emphasizes, his finalist conception is fundamentally opposed to Freud's causalist one. The dream is what it is, not an anthropomorphic construct," explains Charles Baudouin. His theory of dream-compensation develops Freud's theory of dream-desire.
Jung's dream research: from psychoanalysis to analytical psychology
It was while still a student at the Burghölzli in Zurich that Jung read Freud's Interpretation of Dreams. He then reported on it to the other students in his psychiatry course, and in particular to his supervisor, Eugen Bleuler. Jung joined the psychoanalytical movement after meeting Freud in 1907. At the time, his psychiatric practice focused mainly on the collection and study of patients' dreams. As early as 1906, Jung had praised the Freudian method in his book Psychologie de la démence précoce (Psychology of Premature Dementia), a copy of which he sent to Freud, who welcomed it. Yet Jung had already referred to Freud's interpretation of dreams in his 1902 psychiatric thesis, Psychologie et pathologie des phénomènes dits occultes. As soon as he embraced psychoanalysis, Jung began to multiply his theoretical studies on dreams. In 1908, he published the article "The Freudian Theory of Hysteria", followed in 1909 by a synthesis in "The Analysis of Dreams", in which he used all Freud's concepts, such as censorship and latent and manifest content. The study even closes with a recommendation, not only to psychiatrists and neurologists, but also to psychologists, to use the psychoanalytic method.
It was with his study "On the Meaning of Numerical Dreams" in 1910 that Jung began to distance himself from Freudian thought, a separation that would culminate in 1912, after their official break. In the same year, he published a final plea, "On the Critique of Psychoanalysis", before gradually introducing and developing his own theory. Indeed, Jung began to develop his own ideas on the meaning of dreams shortly after his break with Freud, in 1912 and 1913. During this period, he experienced what Henri F. Ellenberger called a "creative illness", which brought him into direct contact with unconscious images, which he drew and compiled in his Red Book. Volume 5 of The Theory of Psychoanalysis, entitled "The Fantasies of the Unconscious", from 1912, sets out the postulates of the newly created analytical psychology, which he defines as a method of investigating the unconscious that does not rely on sexuality as Freud perceived it. Jung explains that the unconscious is the key to the etiology of neuroses. He also shows that there are clear parallels between the imaginary contents of the unconscious and those of mythology, parallels that dreams express in symbolic terms.
In 1916, Carl Gustav Jung published Allgemeine Gesichtspunkte zur Psychologie des Traumes (General Viewpoints on the Psychology of Dreams), in which he developed his own understanding of dreams, which differed greatly from that of Freud. From then on, dreams became material for comparative study, enabling Jung to advance other concepts and hypotheses such as the collective unconscious, in Metamorphosis and Symbols of the Libido, and archetypes. Later, when he turned to alchemy and its allegories as working material, he would nevertheless continue to illuminate their motifs by comparing them with patients' dreams. Throughout his career, Jung amassed a considerable number of dreams, enabling him to declare his method empirical. In 1928, he outlined his method in an article entitled "On Dreams", which was reprinted in Man Discovering His Soul (1948) and constitutes his most synthetic introduction to his conception of the dream process.
Dream and unconsciousness
Archetypes and dreams
For Jung, dreams express archetypes, the unconscious structures that shape the human imagination. Freud had also noted, in The Interpretation of Dreams, the existence of "typical dreams" made by a large number of people that do not designate personal imperatives. But "Freud paid little attention to these dream motifs", explains Claire Dorly. Jung, on the other hand, linked them to the notion of the collective unconscious, which he developed as early as 1912, and which refers to the imaginal reservoir of human representations. Marie Louise von Franz states that "fairy tales, like archetypal dreams, reflect slow, profound processes taking place within the collective unconscious". Mythological themes are rich in such images, which dreams use. These images, through the medium of the symbol, allow us to go beyond consciousness and inform the subject of an underlying problem or future evolution of the unconscious personality. If the dream's content is too shocking for the conscious mind, the latter immediately awakens in order to avoid its revelation. On the other hand, when the dream emphasizes a completely conscious problem, this also provokes awakening. These images "have a function of their own by virtue of their historical character [and are] the link between the rational universe of consciousness and the world of instinct ". Thus, the unconscious is represented in dreams by the land of the dead, symbolizing the unknowable.
The connection between dream images and those of mythologies, cultures and religions enables Jung to speculate on the origin of consciousness. In Man Discovering His Soul, he explains that "the similarities between typical dream motifs and mythological themes make it possible to suppose (...) that dream thought is an earlier phylogenetic form of our thought ". Consciousness would thus have gradually emerged from the unconscious psyche, notably through attention and volition. The warning function that dreams retain, warning the subject of immediate danger and making it a "timely reaction ", testifies to the proximity of the dream process to the instincts. The dream is therefore a psychic process close to that undifferentiated state between the unconscious and the conscious which, in particular, enables the body's needs to be expressed.
The Anima and Animus
The archetypes of the male anima and female animus, depicted in the guise of the opposite sex, are the relational functions of the conscious mind with the unconscious psyche in analytical psychology. Thus, Athena for the Greeks, Beatrice for Dante or Helen in Goethe's Faust, are cultural representations of the anima for the man, who acts as a guide for the sleeping ego, in the depths of the unconscious, while for the woman, the animus is often personified by a male assembly issuing categorical judgments and made up of figures ranging from father to brother to lover. These complexes, which Jung calls "contra-sexual", are relatively autonomous within the psyche, and thus influence the conscious, through the dream. Thus: "The anima, in man, is always part of a system of relationships. We can even speak of a system of erotic relationships, whereas the animus in women does not represent this at all: it appears as an intellectual problem, a system of understanding". The first step in Jungian psychotherapy is therefore to objectify the anima or animus through the study of dream series.
The use of these concepts in the study of dreams was continued by Gaston Bachelard, who re-used them in La poétique de la rêverie (1987). The psychoanalytical philosopher explains that "pure dreaming, filled with images, is a manifestation of the anima". Although he is mainly concerned with daydreams, Bachelard seeks to show that poetry is concerned with the revelation of archetypal patterns, which in turn derive from the world of dreams, the aim being to uncover a "phenomenology of the soul".
Children and big dreams
From 1936 to 1941, Jung was interested in children's dreams, and in particular in a class of dream productions he called "big dreams", i.e. those that come from the depths of the collective unconscious. His studies gave rise to the three-volume work Les Rêves d'enfants (Children's Dreams). Different cultures also experienced great dreams. The collective dream, in fact, pours out images that concern a group of individuals, or even an entire society. Jung takes the example of a Kenyan tribe in which it is customary to recount one's great dreams, which thus concern and belong to the entire community. These dreams seem to have nothing to do with the dreamer's conscious situation and environment. They are sometimes indicative of the onset of a neurosis or other mental illness, and are characterized by the presence of archetypes that are difficult to explain by experience or culture. Jungian analyst Michael Fordham studied these dreams in L' me enfantine et la psychanalyse, notably through a compilation of children's drawings.
This type of dream also has a more cultural influence. Marie Louise von Franz has studied the influence of great dreams on historical figures. In Rêves d'hier et d'aujourd'hui: de Thémistocle à Descartes et à C.G. Jung (1990), Jung's successor argues that certain scientific theories and worldviews have dream origins. This same interview was published in book form in 1987, with the same title. According to her, fairy tales are also dreams about an entire community, which have become narratives over time.
The study of dreams in analytical psychology after Jung
The study of dreams is central to analytical psychology, and many Jungian authors and analysts refer to it. Carl Alfred Meier studies the use of patients' dreams in ancient Greek sanctuaries, and in particular the dream motif of incubation. Mario Jacoby, with Das Tier im Traum (The Animal in Dreams, 1967), Verena Kast, Peter Schellenbaum, Barbara Hannah, Katrin Asper (with Inner Child in Dreams, 2001), Helmut Barz and Adolf Guggenbühl-Craig, among others, also use dreams as the material of choice for their investigations. Other analysts, such as James A. Hall in Jungian Dream Interpretation, have revisited the epistemological contribution of the Jungian vision of dreams. Hall with Jungian Dream Interpretation (1983), Mary Ann Matoon in Understanding Dreams (1978), Strephon Kaplan-Williams (Durch Traumarbeit zum eigenen Selbst in 1981), E. G. Whitmont and S. B. Perera's Dreams, A Portal to the Source (1989) and Harry Wilmer's How Dreams Help (1999) shed new light on analytical psychology. The study of dreams after Jung is mainly represented by three major figures: Alphonse Maeder, James Hillman and Étienne Perrot in France.
Alphonse Maeder and the dream's foresight function
A close friend of Jung since 1906, Swiss analyst Alphonse Maeder devoted himself to studying the prospective function in dreams in two works: Sur la formation des symboles dans les rêves (Zur Entstehung der Symbolik im Traum) in 1910 and La Fonction des rêves (Funktion des Traumes) in 1912. Despite his adherence to analytical psychology, he also supported a theory that diverged from those of Jung and Freud. According to Maeder, the dream is a set of self-seeking activities with a cathartic function. Maeder also showed that the sexual interpretation of a dream is not immediate, and that the dream is always richer in meaning if the analyst does not read it as a libidinal drive. Finally, Maeder's contribution relates above all to the prospective capacity of dreams, which he believes to be unconscious, and which goes "from sketch to sketch, preparing the solution of conflicts and actual problems that the subject seeks to represent himself by means of gropingly elected symbols", and which he sets out in his article "On the psycho-analytical movement", in Chapter VII entitled "The playful theory of dreams". Dreams are therefore anticipations, not to be confused with prophetic abilities.
Dreams and archetypal psychology: James Hillman
According to American analyst James Hillman, the dreaming self is not the same as the waking self. The two selves have a twin relationship and are, in Jungian parlance, "each other's shadows", as he explains in The Beauty of Psyche, The Soul and its Symbols. In The Dream and the Underworld, Hillman explains that the ego is an image, "a completely subjective figure, a phantom, a shadow emptied of the 'I' who surrenders to sleep". The dream does not belong to the dreamer; he or she only plays a role in it, within a dream dramaturgy. The ego must therefore relearn to familiarize itself with the dream and its world, to create an intimacy with it, to speak its language, without seeking to distort it through abusive interpretations. James Hillman uses the expression "underworld", a reference to the world of Hades in Greek mythology, to designate this dream world, which is the place of the symbolic death of the self. Animals are thus soul carriers, enabling us to enter the unconscious world. Steeped in Jungian analytical practice, Hillman rejects symbolic and cultural interpretation alone, preferring to focus solely on the image itself, and the emotion it arouses in the patient. His archetypal psychology is thus both an extension of Jung's theory and a practice in its own right, concerned solely with the patient's imagination.
Étienne Perrot and the language of dreams
Étienne Perrot, following in Jung's footsteps, sees the language of birds and the interplay of sonorities as a dream's ability to express a parallel psychic reality: "These inner and outer listenings, these double readings, we learn first and foremost from dreams. Dreams teach us to decipher reality. It's well known that dreams often take material from daytime life, but they teach us to read it differently. This reading contains a very important element, which is the deciphering of words according to laws that are not causal, but phonetic laws, following the formation mode of puns. This is what we call the 'language of birds', and it's precisely what the alchemists called the 'gaia science'. Perrot recognizes that dreams have a certain motivation, independent of consciousness, and even a certain humor, which is reflected in the language of birds. By deconstructing the word, through the sounds it contains, the dream gives us another meaning. For example, a dream evoking a "parchment", against all logic, could be interpreted by the expression "by the path" following the language of birds, an expression that refers to symbols of freedom, open-mindedness and personal development.
Bibliography
1899 The Interpretation of Dreams by Sigmund Freud
1917 A Metapsychological Supplement to the Theory of Dreams by Sigmund Freud
1920 Supplements to the Theory of Dreams by Sigmund Freud
1922 Dreams and Telepathy by Sigmund Freud
Critique of the Jungian concept of dreams
The criticisms of Jungian dreaming and analytical psychology are of two kinds: those made by other Jungian analysts, and those not specifically related to the dream process.
Two Jungian-inspired analysts are the main critics of the amplification method of interpretation. Patricia Berry and James Hillman criticize this method for losing the primary, instinctual meaning of the dream, by dint of symbolic developments. For Berry, the amplification method shifts the image from the dreamer's personal space to a collective and cultural space, and thus loses precision by distancing itself from the original image, due to haphazard analogies. Hillman criticizes the symbolist conception of dreams for abstracting images from their context and transforming them into fixed hypostases that then deliver only literal meanings.
The criticism that Jung's thinking is more akin to mysticism than to official psychology is recurrent, and concerns the concepts of dreams and the collective unconscious as well, as Françoise Parot sums up. Freudian psychoanalysts initiated the debate, notably Karl Abraham, who denounced the Swiss psychiatrist's "delaying of the unconscious", which his conception of dreams accuses him of doing. The "religious tinge" of the concept of the unconscious, which then becomes a "mystical background", makes Jung a "theologian" and no longer a psychoanalyst, in his view. Abraham continues: "Jung's elucidations of the dream shock us. Here, too, Jung fails to take account of Freudian theory when he says that the technique of interpretation consists in remembering "where the fragments of the dream come from". The originality of the Jungian vision is made up of impasses, in his view; thus "the 'prospective tendency' is not an original discovery by Jung or Maeder, but simply a new name for an impasse that Freud avoided in advance".
General criticism
The idea that Freudian free association provides access to the latent content of dreams has been invalidated by experimental work which has concluded that this method is arbitrary.
See also
Carl Jung
Sigmund Freud
Dream
Dreamwork
Dreaming (journal)
Lucid dreaming
Oneirology
Oneiromancy
Oneironautics
Unconscious mind
International Association for the Study of Dreams (IASD)
Notes
References
Carl Gustav Jung, L'Homme à la découverte de son ameCarl Gustav Jung, Sur l'interprétation des reves
Françoise Parot, Presses Universitaires de France, coll. « Premier cycle », 1995, 186 p.
Other references
Carl Jung
Sigmund Freud
Oneirology
Dream
Lucid dreams
Analytical psychology
Psychoanalytic theory
Symbols
Sleep physiology | Dreams in analytical psychology | [
"Mathematics",
"Biology"
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74,158,384 | https://en.wikipedia.org/wiki/Short%20circuit%20ratio%20%28electrical%20grid%29 | In an electrical grid, the short circuit ratio (or SCR) is the ratio of: the short circuit apparent power (SCMVA) in the case of a line-line-line-ground (3LG) fault at the location in the grid where some generator is connected, to: the power rating of the generator itself (GMW).
Since the power that can be delivered by the grid varies by location, frequently a location is indicated, for example, at the point of interconnection (POI):
SCR is used to quantify the system strength of the grid (its ability to deal with changes in active and reactive power injection and consumption). On a simplified level, a high SCR indicates that the particular generator represents a small portion of the power available at the point of its connection to the grid, and therefore the generator problems cannot affect the grid in a significant way. SCMVA is defined as a product of the voltage before the 3LG fault and the current that would flow after the fault (this worst-case combination will not happen in practice, but provides a useful estimation of the capacity of the circuit). SCMVA is also called a short circuit level (SCL), although sometimes the term SCL is used to designate just the short-circuit current.
Grid strength
The term grid strength (also system strength) is used to describe the resiliency of the grid to the small changes in the vicinity of the grid location (“grid stiffness”). From the side of an electrical generator, the system strength is related to the changes of voltage the generator encounters on its terminals as the generator's current injection varies. Therefore, the quantification of the system strength can be done through finding the equivalent (Thévenin) electrical impedance of the system as observed from these terminals (the strength is inversely proportional to the resistance). SCR and its variations provide a convenient way to calculate this impedance under normal or contingency conditions (these estimates are not intended for the actual short-circuit state).
Strong grids provide a reliable reference for power sources to synchronize. In a very stiff system the voltage does not change with variations of the power injected by a particular generator, making its control simpler. In a traditional grid dominated by synchronous generators, a strong grid with SCR greater than 3.0 will have the desired voltage stability and active power reserves. A weak grid (with SCR values between 2.0 and 3.0) can exhibit voltage instability and control problems. A grid with SCR below 2.0 is very weak.
Importance of overcurrent
Grid strength is also important for its overcurrent capabilities that are essential for the power system operations. Lack of overcurrent capability (low SCR) in a weak grid creates a multitude of problems, including:
transients during the large load changes will cause large variations of the grid voltage, causing problems with the loads (e.g., some motors might not be able to start in the undervoltage condition);
the grid protection devices are designed to be triggered by a sufficient level of overcurrent. In a weak system the short circuit current might be hard to distinguish from a normal transient overcurrent encountered during the load changes;
during a black start operation after a power outage, large inrush current might be needed to energize the system components. For example, if some loads in a weak system remain connected, an inverter-based resource might not be able to start.
Presence of inverter-based resources
Large penetration of the inverter-based resources (IBRs) reduces the short circuit level: a typical synchronous generator can deliver a significant overcurrent, 2-5 p.u., for a relatively long time (minutes), while the component limitations of the IBRs result in overcurrent limits of less than 2 p.u. (usually 1.1-1.2 p.u.).
The original SCR definition above was intended for a system with predominantly synchronous generation, so multiple alternative metrics, including weighted short circuit ratio (WSCR), composite short circuit ratio (CSCR), equivalent circuit short circuit ratio (ESCR), and short circuit ratio with interaction factors (SCRIF), have been proposed for the grids with multiple adjacent IBRs to avoid an overestimation of the grid strength (an IBR relies on grid strength to synchronize its operation and does not have much overcurrent capacity).
Henderson et al. argue that in case of IBRs the SCR and system strength are in fact decoupled and propose a new metric, grid strength impedance.
Integrating renewable energy sources often raises concerns about the system's strength. The ability of different components in a power system to perform effectively depends on the system's strength, which measures the system variables' sensitivity to disturbances. The short circuit ratio (SCR) is an indicator of the strength of a network bus about the rated power of a device and is frequently used as a measure of system strength. A higher SCR value indicates a stronger system, meaning that the impact of disturbances on voltage and other variables will be minimized. A strong system is defined as having an SCR above three, and the SCRs of weak and very weak systems range between three and two and below two, respectively.
Power electronic applications often encounter issues related to SCR, particularly in renewable energy systems that use power converters to connect to power grids. When connecting HVDC/FACTs devices based on current source converters to weak AC systems, particular technologies must be employed to overcome SCR of less than three. For HVDC, voltage-source-based converters or capacitor-commutated converters are utilized in applications with SCR near one. Failing to use these technologies will require special studies to determine the impact and take measures to prevent or minimize the adverse effects, as low levels of SCR can cause problems such as high over-voltages, low-frequency resonances, and instability in control systems.
Wind farms are commonly linked to less robust network sections away from the main power consumption areas. Problems with voltage stability that arise from incorporating large-scale wind power into vulnerable systems are crucial issues that require attention. Some wind turbines have specific minimum system strength criteria. GE indicates that the standard parameters of their wind turbine model are appropriate for systems with a Short Circuit Ratio (SCR) of five or higher. However, if connecting to weaker systems, it is necessary to carry out further analysis to guarantee that the model parameters are adequately adjusted. Specifically designed control methods for wind turbines or dynamic reactive compensation devices, such as STATCOM, are required to ensure optimal performance.
Example
An experience at ERCOT in early 21st century provides a prime example of how the wind turbine's performance is affected by a weak system strength. The wind power plant, linked to the ERCOT grid through two 69kV transmission lines, worked efficiently when the SCR was around 4 during normal operations. However, when one of the 69kV lines was disconnected, the SCR dropped to 2 or less, leading to unfavorable, poorly damped, or un-damped voltage oscillations that were documented by PMUs at the Point of Interconnection (POI) of the wind plant. After a thorough investigation, it was determined that the aggressive voltage control used by the WPP was not appropriate for a weak grid environment and was the primary cause of the oscillatory response. Due to the low short circuit level detected by the wind generator voltage controller and the high voltage control gain, the oscillation occurred. When compared to the normal grid with high SCR, the closed loop voltage control would have a faster response under weak grid conditions. To replicate the oscillatory response, the event was simulated using a detailed dynamic model representing the WPP.
Impact on grid
The SCR can be calculated for each point on an electrical grid. A point on a grid having a number of machines with an SCR above a number between 1 and 1.5 has less vulnerability to voltage instability. Hence, such a grid is known strong grid or power system. A power system (grid) having a lower SCR has more vulnerability to grid voltage instability. Hence such a grid or system is known as a weak grid or a weak power system.
Grid strength can be increased by installing synchronous condensers.
References
Sources
Power engineering
Electrical grid | Short circuit ratio (electrical grid) | [
"Engineering"
] | 1,764 | [
"Power engineering",
"Electrical engineering",
"Energy engineering"
] |
74,158,460 | https://en.wikipedia.org/wiki/Short%20circuit%20ratio%20%28synchronous%20generator%29 | In a synchronous generator, the short circuit ratio is the ratio of field current required to produce rated armature voltage at the open circuit to the field current required to produce the rated armature current at short circuit. This ratio can also be expressed as an inverse of the saturated direct-axis synchronous reactance (in p.u.):
Effects of SCR values
Higher SCR requires lower reactance that in practice means a larger air gap.
Both high and low levels of SCR have their benefits:
low SCR:
in case of a short circuit, the current is proportional to SCR, therefore generators with low SCR require less protection and thus are cheaper;
low SCR allows shorter air gap and lower excitation field, both decreasing the size (an cost) of the generator;
with low SCR the amounts of iron and copper are reduced, lowering the cost;
high SCR:
generator with high SCR provides more power when overloaded, improving the system stability in case of a contingency;
high SCR inherently provides lower voltage variations in case of an oscillatory load, thus contributing to system stability;
high-SCR generator has more synchronizing power, making it easier to operate generators in parallel.
Therefore, in practice the design of a generator is seeking an SCR that balances benefits and drawbacks for a particular application.
SCR is a measure of the electrical stiffness (also known as a synchronizing coefficient) of the machine. Synchronization coefficient is proportional to the SCR. A stiff machine has a higher SCR, is more loosely coupled to the network and thus is slower in following. A less stiff machine with lower SCR (a typical situation for modern h=generators) will follow the grid faster. Stiffness is a ratio of the change in power output to the change of power angle. For example, if the system frequency decreases, the stiffer generator provides more power thus contributing to the system stability.
Effects of construction
The larger the SCR, the smaller is alternator reactance (Xd) and inductance Ld. This is the result of larger air gaps in generator design (As in Hydro generators or Salient Pole Machines). It results into Machine loosely coupled to the grid, and its response will be slow. This increases the machines’ stability while operating on the grid, but simultaneously will increase the short circuit current delivery capability of the machine (higher short circuit current) and subsequently larger machine size and its cost. Typical values of SCR for Hydro alternators may be in the range of 1 to 1.5.
Conversely, the smaller the SCR, the larger is alternator's reactance (Xd), the larger is Ld. It results from small air gaps in machine design (As in Turbo generators or Cylindrical rotor Machines). Machines are tightly coupled to the grid, and their response will be fast. This reduces the machine's stability while operating on the grid and will reduce the short circuit current delivery capability (lower short circuit current), smaller machine size, and lower cost subsequently. Typical values of SCR for turbo alternators may be in the range of 0.45 to 0.9.
References
Sources
Electromechanical engineering | Short circuit ratio (synchronous generator) | [
"Engineering"
] | 670 | [
"Electrical engineering",
"Electromechanical engineering",
"Mechanical engineering by discipline"
] |
72,716,690 | https://en.wikipedia.org/wiki/HD%20101917 | HD 101917, also designated as HR 4509, or rarely 34 G. Chamaeleontis, is a solitary star located in the southern circumpolar constellation Chamaeleon. It has an apparent magnitude of 6.38, placing it near the limit for naked eye visibility. The object is located relatively close at a distance of 185 light years based on Gaia DR3 parallax measurements but is receding with a heliocentric radial velocity of . At its current distance, HD 101917's brightness is diminished by 0.28 magnitudes due to interstellar dust. It has an absolute magnitude of +2.69.
HD 101917 has a stellar classification of K0 III/IV, indicating that it is an evolved K-type star with the blended luminosity class of a subgiant and a giant star. Gaia DR3 models it to be 3.9 billion years old, enough time for it to cool and expand to 4.01 times the radius of the Sun. At present it has 126% the mass of the Sun and now radiates 9.04 times the luminosity of the Sun from its enlarged photosphere at an effective temperature , giving it a yellow hue. HD 101917 has an iron abundance 22% below solar levels, making it slightly metal deficient. It spins slowly with a projected rotational velocity lower than .
References
K-type giants
K-type subgiants
Chamaeleon
Chamaeleontis, 34
CD-78 00476
101917
057137
4509 | HD 101917 | [
"Astronomy"
] | 325 | [
"Chamaeleon",
"Constellations"
] |
72,717,145 | https://en.wikipedia.org/wiki/Sonia%20Arriaga | Sonia Lorena Arriaga García is a Mexican is a Mexican environmental biotechnologist, professor, and researcher. She is a Senior Researcher B at the Potosino Institute of Scientific and Technological Research (IPICYT) and a Level III member of the National System of Researchers (SNI). Her research focuses on the treatment of volatile organic compounds, mathematical modeling of biofiltration processes, and the treatment of bioaerosols emitted by biofilters through advanced oxidation processes.
Education and career
She earned a bachelor's degree in chemical engineering from the Faculty of Chemical Sciences at the Universidad Autónoma de San Luis Potosí in 1999. Later, she pursued a master's degree in sciences at the same university, graduating in August 2001.
She completed her PhD studies in Chemical Engineering at the Metropolitan Autonomous University in Iztapalapa. During her doctoral studies, she conducted a research stay at Lund University in Sweden, where she studied the biodegradation of hydrophobic volatile organic compounds in two-phase partitioning bioreactors. Her doctoral thesis focused primarily on the operation of biofilters for the biodegradation of volatile organic compounds. She graduated with her PhD in 2005, and that same year, she joined the Potosino Institute of Scientific and Technological Research (IPICYT) as a postdoctoral researcher, working on the project Anaerobic Co-digestion of Organic Waste for the Production of Methane and Hydrogen.
In September 2006, she joined the Environmental Sciences Division of IPICYT as a senior professor and researcher. Later, in 2014, she undertook a research stay at Aalborg University in the Microbial Communities Center, where she studied culture-independent techniques for the identification of microorganisms. Since 2019, she has been an associate professor at the National Institute of Scientific Research (INRS) in Quebec.
Since 2021, she has been on a sabbatical at the National University of Ireland, where she is working on indoor bioaerosol monitoring.
Research lines
Her main research areas are biotechnology and environmental engineering, including the mathematical modeling of biofiltration processes. In her lab, they work on biofiltration of indoor air pollutants such as formaldehyde. Another of her research areas includes the treatment of bioaerosols using advanced oxidation processes. Additionally, using single-phase biological bioreactors, she studies the emissions of volatile organic compounds to produce high-value extracellular proteins and biopolymers like polyhydroxyalkanoates.
Her main research and collaborative projects include:
Monitoring of air in furnaces (2019)
Mexico-Quebec Course (2018)
Degradation of emissions of volatile organic compounds in a hybrid UV/O3/TiO2 oxidation system coupled with a biological system. Project supported by the National Council of Science and Technology (CONACYT) in the Sectoral Funds SEP call (2011 and 2015).
Identification and biodegradation of volatile organic compounds, hydrocarbons, and pesticides emitted in the State of Guanajuato using a biofiltration system packed with microstructured reusable materials. Project funded by CONACYT under the Mixed Funds call (2007).
Removal of air pollutants
Her research laboratory at IPICYT monitors indoor air pollutants, particularly studying suspended biological material, commonly known as bioaerosols. This includes spores, viruses, bacteria, pollen, fungi, endotoxins, and cellular fragments that can cause respiratory diseases and allergies. As part of this research, monitoring was conducted within a pediatric office, where bioaerosol concentrations were found to be 10,000 times higher than the levels accepted by the World Health Organization.
In addition to monitoring and identifying bioaerosols, she also works on developing treatment systems for these bioaerosols. These treatment systems consist of photocatalytic systems operated in continuous flow, which are being optimized through the synthesis of catalysts to function under visible radiation, making them more environmentally friendly. Similarly, these technologies aim to valorize the emissions and transform them into high-value products such as biopolymers or proteins.
Research related to COVID-19
In 2020, during the COVID-19 pandemic, she began disseminating information through Mexican mass media to raise awareness about the viability of the SARS-CoV-2 virus in the air for up to three hours. She explained that scientific evidence demonstrates the persistence and existence of the SARS-CoV-2 virus in the air for up to three hours and on surfaces such as plastic and stainless steel for up to 72 hours. This suggests that the virus can be transmitted through the air, so to prevent its spread, the use of masks and proper ventilation in areas with infected patients should be implemented.
Awards and recognition
Throughout her career, she has been recognized on multiple occasions.
2000: Award for the best student of the 1994 Chemical Engineering cohort, Autonomous University of San Luis Potosí.
2005: Medal for University Merit, Metropolitan Autonomous University-Iztapalapa.
Since 2007: Member of the National System of Researchers (Level III since 2022).
Since 2016: Regular member of the Mexican Academy of Sciences.
2019: Premio Potosino de Ciencia y Tecnología en la categoría joven investigadora, modalidad investigación científica del área ciencias de la ingeniería.
2022: Promotion to level 3 of the Sistema Nacional de Investigadores, its highest rank.
References
External links
Mujeres en la Ciencia: Doctora Sonia Arriaga García (52-minute audio interview, Radioteca)
Year of birth missing (living people)
Living people
Mexican engineers
Mexican women engineers
Bioengineers
Women bioengineers
Members of the Mexican Academy of Sciences
Mexican scientists | Sonia Arriaga | [
"Engineering",
"Biology"
] | 1,189 | [
"Bioengineers",
"Biological engineering"
] |
72,719,782 | https://en.wikipedia.org/wiki/Polynomial%20root-finding | Finding polynomial roots is a long-standing problem that has been the object of much research throughout history. A testament to this is that up until the 19th century, algebra meant essentially theory of polynomial equations.
Principles
Finding the root of a linear polynomial (degree one) is easy and needs only one division: the general equation has solution For quadratic polynomials (degree two), the quadratic formula produces a solution, but its numerical evaluation may require some care for ensuring numerical stability. For degrees three and four, there are closed-form solutions in terms of radicals, which are generally not convenient for numerical evaluation, as being too complicated and involving the computation of several th roots whose computation is not easier than the direct computation of the roots of the polynomial (for example the expression of the real roots of a cubic polynomial may involve non-real cube roots). For polynomials of degree five or higher Abel–Ruffini theorem asserts that there is, in general, no radical expression of the roots.
So, except for very low degrees, root finding of polynomials consists of finding approximations of the roots. By the fundamental theorem of algebra, a polynomial of degree has exactly real or complex roots counting multiplicities.
It follows that the problem of root finding for polynomials may be split in three different subproblems;
Finding one root
Finding all roots
Finding roots in a specific region of the complex plane, typically the real roots or the real roots in a given interval (for example, when roots represents a physical quantity, only the real positive ones are interesting).
For finding one root, Newton's method and other general iterative methods work generally well.
For finding all the roots, arguably the most reliable method is the Francis QR algorithm computing the eigenvalues of the companion matrix corresponding to the polynomial, implemented as the standard method in MATLAB.
The oldest method of finding all roots is to start by finding a single root. When a root has been found, it can be removed from the polynomial by dividing out the binomial . The resulting polynomial contains the remaining roots, which can be found by iterating on this process. However, except for low degrees, this does not work well because of the numerical instability: Wilkinson's polynomial shows that a very small modification of one coefficient may change dramatically not only the value of the roots, but also their nature (real or complex). Also, even with a good approximation, when one evaluates a polynomial at an approximate root, one may get a result that is far to be close to zero. For example, if a polynomial of degree 20 (the degree of Wilkinson's polynomial) has a root close to 10, the derivative of the polynomial at the root may be of the order of this implies that an error of on the value of the root may produce a value of the polynomial at the approximate root that is of the order of
For avoiding these problems, methods have been elaborated, which compute all roots simultaneously, to any desired accuracy. Presently the most efficient method is Aberth method. A free implementation is available under the name of MPSolve. This is a reference implementation, which can find routinely the roots of polynomials of degree larger than 1,000, with more than 1,000 significant decimal digits.
The methods for computing all roots may be used for computing real roots. However, it may be difficult to decide whether a root with a small imaginary part is real or not. Moreover, as the number of the real roots is, on the average, proportional to the logarithm of the degree, it is a waste of computer resources to compute the non-real roots when one is interested in real roots.
The oldest method for computing the number of real roots, and the number of roots in an interval results from Sturm's theorem, but the methods based on Descartes' rule of signs and its extensions—Budan's and Vincent's theorems—are generally more efficient. For root finding, all proceed by reducing the size of the intervals in which roots are searched until getting intervals containing zero or one root. Then the intervals containing one root may be further reduced for getting a quadratic convergence of Newton's method to the isolated roots. The main computer algebra systems (Maple, Mathematica, SageMath, PARI/GP) have each a variant of this method as the default algorithm for the real roots of a polynomial.
The class of methods is based on converting the problem of finding polynomial roots to the problem of finding eigenvalues of the companion matrix of the polynomial, in principle, can use any eigenvalue algorithm to find the roots of the polynomial. However, for efficiency reasons one prefers methods that employ the structure of the matrix, that is, can be implemented in matrix-free form. Among these methods are the power method, whose application to the transpose of the companion matrix is the classical Bernoulli's method to find the root of greatest modulus. The inverse power method with shifts, which finds some smallest root first, is what drives the complex (cpoly) variant of the Jenkins–Traub algorithm and gives it its numerical stability. Additionally, it has fast convergence with order (where is the golden ratio) even in the presence of clustered roots. This fast convergence comes with a cost of three polynomial evaluations per step, resulting in a residual of , that is a slower convergence than with three steps of Newton's method.
Finding one root
The most widely used method for computing a root is Newton's method, which consists of the iterations of the computation of
by starting from a well-chosen value
If is a polynomial, the computation is faster when using Horner's method or evaluation with preprocessing for computing the polynomial and its derivative in each iteration.
Though the convergence is generally quadratic, it may converge much slowly or even not converge at all. In particular, if the polynomial has no real root, and is real, then Newton's method cannot converge. However, if the polynomial has a real root, which is larger than the larger real root of its derivative, then Newton's method converges quadratically to this largest root if is larger than this larger root (there are easy ways for computing an upper bound of the roots, see Properties of polynomial roots). This is the starting point of Horner's method for computing the roots.
When one root has been found, one may use Euclidean division for removing the factor from the polynomial. Computing a root of the resulting quotient, and repeating the process provides, in principle, a way for computing all roots. However, this iterative scheme is numerically unstable; the approximation errors accumulate during the successive factorizations, so that the last roots are determined with a polynomial that deviates widely from a factor of the original polynomial. To reduce this error, one may, for each root that is found, restart Newton's method with the original polynomial, and this approximate root as starting value.
However, there is no warranty that this will allow finding all roots. In fact, the problem of finding the roots of a polynomial from its coefficients can be highly ill-conditioned. This is illustrated by
Wilkinson's polynomial: the roots of this polynomial of degree 20 are the 20 first positive integers; changing the last bit of the 32-bit representation of one of its coefficient (equal to –210) produces a polynomial with only 10 real roots and 10 complex roots with imaginary parts larger than 0.6.
Closely related to Newton's method are Halley's method and Laguerre's method. Both use the polynomial and its two first derivations for an iterative process that has a cubic convergence. Combining two consecutive steps of these methods into a single test, one gets a rate of convergence of 9, at the cost of 6 polynomial evaluations (with Horner's rule). On the other hand, combining three steps of Newtons method gives a rate of convergence of 8 at the cost of the same number of polynomial evaluation. This gives a slight advantage to these methods (less clear for Laguerre's method, as a square root has to be computed at each step).
When applying these methods to polynomials with real coefficients and real starting points, Newton's and Halley's method stay inside the real number line. One has to choose complex starting points to find complex roots. In contrast, the Laguerre method with a square root in its evaluation will leave the real axis of its own accord.
Finding roots in pairs
If the given polynomial only has real coefficients, one may wish to avoid computations with complex numbers. To that effect, one has to find quadratic factors for pairs of conjugate complex roots. The application of the multidimensional Newton's method to this task results in Bairstow's method.
The real variant of Jenkins–Traub algorithm is an improvement of this method.
Finding all roots at once
The simple Durand–Kerner and the slightly more complicated Aberth method simultaneously find all of the roots using only simple complex number arithmetic. Accelerated algorithms for multi-point evaluation and interpolation similar to the fast Fourier transform can help speed them up for large degrees of the polynomial. It is advisable to choose an asymmetric, but evenly distributed set of initial points. The implementation of this method in the free software MPSolve is a reference for its efficiency and its accuracy.
Another method with this style is the Dandelin–Gräffe method (sometimes also ascribed to Lobachevsky), which uses polynomial transformations to repeatedly and implicitly square the roots. This greatly magnifies variances in the roots. Applying Viète's formulas, one obtains easy approximations for the modulus of the roots, and with some more effort, for the roots themselves.
Exclusion and enclosure methods
Several fast tests exist that tell if a segment of the real line or a region of the complex plane contains no roots. By bounding the modulus of the roots and recursively subdividing the initial region indicated by these bounds, one can isolate small regions that may contain roots and then apply other methods to locate them exactly.
All these methods involve finding the coefficients of shifted and scaled versions of the polynomial. For large degrees, FFT-based accelerated methods become viable.
For real roots, see next sections.
The Lehmer–Schur algorithm uses the Schur–Cohn test for circles; a variant, Wilf's global bisection algorithm uses a winding number computation for rectangular regions in the complex plane.
The splitting circle method uses FFT-based polynomial transformations to find large-degree factors corresponding to clusters of roots. The precision of the factorization is maximized using a Newton-type iteration. This method is useful for finding the roots of polynomials of high degree to arbitrary precision; it has almost optimal complexity in this setting.
Real-root isolation
Finding the real roots of a polynomial with real coefficients is a problem that has received much attention since the beginning of 19th century, and is still an active domain of research. Most root-finding algorithms can find some real roots, but cannot certify having found all the roots. Methods for finding all complex roots, such as Aberth method can provide the real roots. However, because of the numerical instability of polynomials (see Wilkinson's polynomial), they may need arbitrary-precision arithmetic for deciding which roots are real. Moreover, they compute all complex roots when only few are real.
It follows that the standard way of computing real roots is to compute first disjoint intervals, called isolating intervals, such that each one contains exactly one real root, and together they contain all the roots. This computation is called real-root isolation. Having an isolating interval, one may use fast numerical methods, such as Newton's method for improving the precision of the result.
The oldest complete algorithm for real-root isolation results from Sturm's theorem. However, it appears to be much less efficient than the methods based on Descartes' rule of signs and Vincent's theorem. These methods divide into two main classes, one using continued fractions and the other using bisection. Both method have been dramatically improved since the beginning of 21st century. With these improvements they reach a computational complexity that is similar to that of the best algorithms for computing all the roots (even when all roots are real).
These algorithms have been implemented and are available in Mathematica (continued fraction method) and Maple (bisection method). Both implementations can routinely find the real roots of polynomials of degree higher than 1,000.
Finding multiple roots of polynomials
Numerical computation of multiple roots
Multiple roots are highly sensitive, known to be ill-conditioned and inaccurate in numerical computation in general. A method by
Zhonggang Zeng (2004), implemented as a MATLAB package, computes multiple roots and corresponding multiplicities of a polynomial accurately even if the coefficients are inexact.
The method can be summarized in two steps. Let be the given polynomial. The first step determines the multiplicity structure by applying square-free factorization with a numerical greatest common divisor algorithm. This allows writing as
where are the multiplicities of the distinct roots. This equation is an overdetermined system for having variables on equations matching coefficients with (the leading coefficient is not a variable). The least squares solution is no longer ill-conditioned in most cases. The second step applies the Gauss-Newton algorithm to solve the overdetermined system for the distinct roots.
The sensitivity of multiple roots can be regularized due to a geometric property of multiple roots discovered by William Kahan (1972) and the overdetermined system model maintains the multiplicities .
Square-free factorization
For polynomials whose coefficients are exactly given as integers or rational numbers, there is an efficient method to factorize them into factors that have only simple roots and whose coefficients are also exactly given. This method, called square-free factorization, is based on the multiple roots of a polynomial being the roots of the greatest common divisor of the polynomial and its derivative.
The square-free factorization of a polynomial p is a factorization where each is either 1 or a polynomial without multiple roots, and two different do not have any common root.
An efficient method to compute this factorization is Yun's algorithm.
References
Polynomials | Polynomial root-finding | [
"Mathematics"
] | 2,936 | [
"Polynomials",
"Algebra"
] |
72,719,794 | https://en.wikipedia.org/wiki/BrainChip | BrainChip (ASX:BRN, OTCQX:BRCHF) is an Australia-based technology company, founded in 2004 by Peter Van Der Made, that specializes in developing advanced artificial intelligence (AI) and machine learning (ML) hardware. The company's primary products are the MetaTF development environment, which allows the training and deployment of spiking neural networks (SNN), and the AKD1000 neuromorphic processor, a hardware implementation of their spiking neural network system. BrainChip's technology is based on a neuromorphic computing architecture, which attempts to mimic the way the human brain works. The company is a part of Intel Foundry Services and Arm AI partnership.
History
Australian mining company Aziana acquired BrainChip in March 2015. Later, via a reverse merger of the now dormant Aziana in September 2015 BrainChip was put on the Australian Stock Exchange (ASX), and van der Made started commercializing his original idea for artificial intelligence processor hardware. In 2016, the company appointed former Exar CEO Louis Di Nardo as CEO; Van Der Made then took the position of CTO. In October 2021, the company announced that it was taking orders for its Akida AI Processor Development Kits, and in January 2022, that it was taking orders for its Akida AI Processor PCIe boards. In April 2022, BrainChip partnered with NVISO to provide collaboration with applications and technologies. In November 2022, BrainChip added the Rochester Institute of Technology to its University AI accelerator program. The next month, BrainChip was a part of Intel Foundry Services. In January 2023, Edge Impulse announced support for BrainChip's AKD processor.
MetaTF
The MetaTF software is designed to work with a variety of image, video, and sensor data, and is intended to be implemented in a range of applications, including security, surveillance, autonomous vehicles, and industrial automation. The software uses Python to create spiking neural networks (or convert other neural networks to SNNs) for use on the AKD processor hardware. The software is also capable of SNN deployment on normal processors.
The AKD processor
The Akida 1000 processor is an event-based neural processing device with 1.2 million artificial neurons and 10 billion artificial synapses. Utilizing event-based processing, it analyzes essential inputs at specific points. Results are stored in the on-chip memory units.
The processor contains 80 nodes that communicate over a mesh network. Each node consists of four either convolutional or fully connected Neural Processing Units (NPUs), coupled with individual memory units. Akida runs an entire neural network executing all neuron layers in parallel. The design elements are meant to allow inference and incremental learning on edge devices with lower power consumption.
On January 29, 2023, BrainChip announced that it has completed the design of its AKD1500 reference chip.
On March 6, 2023, BrainChip announced the second generation of its Akida platform. BrainChip added support for 8-bit weights and activations, Vision Transformer (ViT) engine, and hardware support for a Temporal Event-Based Neural Net (TENN).
On March 12, 2023, BrainChip announced that the Akida processor family integrates with the Arm® Cortex®-M85 processor.
See also
Cognitive computer
Spiking neural network
S&P/ASX 200
Neuromorphic engineering
References
External links
Brainchip-empowers-next-generation-technology
edge-impulse-and-brainchip-partner-to-further-ai-development-with-support-for-the-akida-platform
Brainchip-joins-technology-partners-during
MegaChips Forms Strategic Partnership with BrainChip
BrainChip Adds Rochester Institute of Technology to Its University AI Accelerator Program
BrainChip Introduces a Powerful Neural Network Converter
markets for Brainchip
"BrainChip’s founder takes chips off the table"
"BrainChip Readies 2nd Gen Platform For Power-Efficient Edge AI"
"Brainchip Extends AI, Machine Learning In Space And Time With Bio-Inspired Neural Networks"
Computer hardware companies
Application-specific integrated circuits
AI accelerators
Artificial neural networks
Hardware acceleration
Australian companies established in 2004
Companies based in Sydney
Companies listed on the Australian Securities Exchange | BrainChip | [
"Technology",
"Engineering"
] | 894 | [
"Hardware acceleration",
"Computer engineering",
"Computer hardware companies",
"Computer systems",
"Application-specific integrated circuits",
"Computers"
] |
72,721,049 | https://en.wikipedia.org/wiki/Jedi1 | Jedi1 (IUPAC name: 2-methyl-5-phenylfuran-3-carboxylic acid) is a chemical compound which acts as an agonist for the mechanosensitive ion channel PIEZO1, and is used in research into the function of touch perception.
See also
Yoda1 and Jedi2
References
Furans
Carboxylic acids | Jedi1 | [
"Chemistry"
] | 81 | [
"Pharmacology",
"Carboxylic acids",
"Functional groups",
"Medicinal chemistry stubs",
"Pharmacology stubs"
] |
72,721,591 | https://en.wikipedia.org/wiki/National%20Academy%20of%20Engineering%20of%20Korea | The National Academy of Engineering of Korea (NAEK; ) is a Korean nonprofit, non-governmental organization founded to support engineering and technology development in academia, industry, and national institutions; and to contribute to the development and sustainable development of engineering technology through academic research. The Academy was founded in 1996 in accordance with Article 40 of the Industrial Technology Innovation Promotion Act.
History
The Korean Association for Engineering Deans petitioned the government to establish the National Academy of Engineering of Korea in December 1993. The Association was included in the Industrial Technology Innovation Promotion Act and then approved by the Ministry of Industry and Energy. The Board of Directors, chairman, and initial members were determined in April 1996 followed by the first president two months later.
Objectives
There are four stated objectives of the National Academy of Engineering of Korea:
Conduct research and propose policies in regards to engineering technologies
Strengthen international activities of engineering technologies through international network of the International Council of Academies of Engineering and Technological Sciences (CAETS), the East Asia Round Table Meetings, etc.
Create and promote engineering culture
Acknowledge and honor engineers who brought about innovation for society
Membership
Membership is divided into members, associate members, emeritus members, and foreign members both in academia and the private sector. Engineering divisions include electrical and electronic engineering; mechanical engineering; architectural, civil and environmental engineering; chemical and biological engineering; material and energy engineering; technology, management and policy; computer science and engineering; and biomedical engineering.
Leadership
Chairmen
Rieh Chong Hun (April 1996–September 1998)
(September 1998–February 2005)
Huh Chin Gyu (February 2005–June 2015)
Kwon Oh Joon (June 2015–June 2015)
Kim Kinam (June 2019–current)
Presidents
(June 1996–January 2005)
(January 2005–December 2010)
(December 2010–June 2011)
Chung Joon-yang (June 2011–January 2015)
(January 2015–January 2017)
Kwon Oh-Kyong (January 2017–current)
Awards
The NAEK Award was started in 1996 to honor engineers who have made significant contributions to the development of the engineering and technology field at universities, institutions, and industries. It is awarded annually to one or formerly two recipients for the primary award and also two young engineers. Other awards include the Iljin Award, Haedong Award and Wonik Award.
References
Non-profit organizations based in South Korea
National academies of engineering
Research institutes in South Korea
1996 establishments in South Korea | National Academy of Engineering of Korea | [
"Engineering"
] | 486 | [
"National academies of engineering"
] |
72,722,473 | https://en.wikipedia.org/wiki/2023%20FAA%20system%20outage | On January 11, 2023, U.S. flights were grounded or delayed as the Federal Aviation Administration (FAA) attempted to fix a system outage. FAA paused all flight departures between 7:30 a.m. and 9 a.m. ET. Flights already in the air were allowed to continue to their destinations. Around 8:30 am. ET, flights were beginning to resume departures. The outage was the first time since September 11, 2001, that the FAA issued a nationwide ground stop in the United States.
A preliminary investigation of the incident demonstrated to FAA investigators that a "damaged database file" may have caused the outage of the FAA's Notice to Air Missions (NOTAM) system, responsible for notifying pilots of safety hazards. The FAA told CNN that there was "no evidence of a cyberattack" on its NOTAM system.
Incident
On January 10, 2023, NOTAM system stopped processing updates at 3:28 p.m. ET, and FAA issued the first Air Traffic Control System Command Center Advisory about this incident at 7:47 p.m. ET.
At 7:30 a.m. ET on January 11, the FAA ordered airlines to pause all domestic departures after its pilot-alerting Notice to Air Missions (NOTAM) system went offline overnight, causing extensive disruption. Around 8:30 a.m. ET, flights were beginning to resume departures after the FAA terminated the NOTAM outage advisory, and departures at other airports were expected to resume by 9 am. ET. However, the airlines were free to implement their own ground delay programs subsequent to the ground stop being lifted, potentially leading to further timetable issues.
Aftermath
A total of 32,578 flights were delayed within, into or out of the United States as of 8:07 a.m. ET, and another 409 within, into or out of the country were also canceled.
After the incident, shares of U.S. carriers fell in the premarket trading: Southwest Airlines was down 2.4%, while Delta Air Lines Inc, United Airlines and American Airlines were down about 1%.
Delta Air Lines reported that it had a working backup to the FAA system, but decided not to use it. Delta Air Lines CEO Ed Bastian stated that they didn't use the backup system "out of deference" to the FAA and allowing the FAA to make the decisions.
The FAA adopted new procedures for maintenance of the NOTAM system to prevent future outages.
Investigation
On January 13, 2023, the FAA stated that preliminary analysis of the outage indicates that it was caused by the failure of FAA personnel to follow proper procedures. The incident happened during routine scheduled maintenance. According to the FAA, one engineer mistakenly "replaced one file with another", not realizing that a mistake had been made. FAA officials stated that it was an "honest mistake that cost the country millions." It was later determined that the contractor from Spatial Front, Inc. unintentionally deleted files while "working to correct synchronization between the live primary database and a backup database."
Reactions
President Joe Biden was briefed on the FAA system outage. The White House said there was no evidence of a cyberattack in relation to the system outage, but the president has asked for an investigation.
House Transportation Committee Chair Sam Graves (R-MO) and Rick Larsen (D-WA) stated that the committee intended to conduct vigorous oversight of the Department of Transportation's plan to prevent such disruption from happening again. A group of more than 120 U.S lawmakers also told the FAA that such incidents were "completely unacceptable."
See also
2023 Philippine airspace closure, a similar incident that occurred ten days prior.
References
Aviation accidents and incidents in the United States in 2023
January 2023 events in the United States
Federal Aviation Administration
Technological failures | 2023 FAA system outage | [
"Technology"
] | 794 | [
"Technological failures"
] |
72,723,176 | https://en.wikipedia.org/wiki/Lightware | Lightware Visual Engineering (or simply Lightware, ) is a Hungarian privately owned company, manufacturer and distributor of audiovisual automation and integration equipment based in Budapest, Hungary, founded in 1998. Lightware is Europe's largest manufacturer of AV management products in both fixed installation market areas (e.g. in theaters, in the entertainment industry, for medical applications, in the education sector, in smart homes as well as for all types of corporate applications such as collaboration and conferencing) and in the extensive segment of live events. Since its founding numerous projects have been planned and carried out in many countries around the world. The company develops and produces all products at the headquarters in Budapest, Hungary. The company is privately owned by the founder Árpád Gergely Vida. To this day he is CEO and head of the development department.
History
Lightware was founded by Árpád Gergely Vida, Miklós Debreczeni, Attila Nagy and György Németh in 1998. In its early years, two employees worked for the company, and they repaired only projectors and plasma TVs.
In 2006 the engineers of Lightware invented the EDID Manager as the very first product, helping the users to handle the different predefined video signal resolutions. After this, the company appeared at the ISE exhibition in Brussels, Belgium. A year later, the first hybrid eight-input and eight-output fully digital video-multiplexer matrix supporting HD resolution, the 32x32 DVI and HDMI Matrix Switcher was completed. This device eliminated the need for multiple devices by combining DVI and HDMI connectivity ports on a large crosspoint size.
In 2011 Lightware opened its first two offices outside Hungary, in the United Kingdom and in the United States of America, two years later followed by the ones in Australia, Italy and Singapore, and in 2015 in the Netherlands, India and in the Middle East.
It was 2020, when Lightware announced the arrival of the Taurus UCX, using USB-C technology to send video, audio, control and Ethernet signals through a single cable for enhanced collaborations.
Activity
Lightware focuses on audiovisual technology, develops and manufactures data transmission devices. The products of the company are used in rental events, such as concerts and shows.
Lightware is Europe's biggest AV manufacturer company. The product range includes AV-over-IP products, presentation switchers, HDMI switchers and extenders. The Taurus UCX range offers the latest technology for boardrooms incorporating USB-C, HID USB, room control and video distribution and switching with Cisco certified class leading technology.
High-tech meeting room systems that support hybrid work are also operated with the company's devices, for example at Google, Microsoft, Apple, Netflix or Facebook, where the entire control and automation of the meeting rooms, the power, turning on and off of the lighting can be solved from a single touch screen. In addition, Lightware's products can be found in 3D simulation rooms of car factories, in the controls of oil platforms, in the control centers of well-known buildings, as well as on airplanes, yachts and submarines.
The company develops and manufactures all its products at its headquarters in Budapest. Since the company has offices and distribution points worldwide, more than 99% of sales revenue comes from export.
Product lines
Taurus UCX/TPX/TPN
UBEX (Ultra Bandwidth Extender)
VINX (Video Network Extender)
Gemini GVN
TPS extenders
HDMI-TPX extenders
HDMI-TPN extenders
MX2 series
MX2M series
MX series
MMX series
MMX2 series
OPTC/OPTJ extenders
HDMI/USB/USB-C cables
Event Manager
LARA (Lightware Advanced Room Automation)
Monitoring Webtool
Lightware software
Sales network
The company has opened offices on four continents so far. In the countries, where Lightware hasn't established an office yet, they allot the products thanks to the distribution network, or serve the customers by the HQ from Budapest, Hungary.
Lightware offices:
References
Manufacturing companies based in Budapest
Manufacturing companies established in 1998
Home automation companies
Building automation
Remote control
Video equipment manufacturers | Lightware | [
"Technology",
"Engineering"
] | 863 | [
"Home automation",
"Home automation companies",
"Building engineering",
"Automation",
"Building automation"
] |
72,723,612 | https://en.wikipedia.org/wiki/Chloral%20cyanohydrin | Chloral cyanohydrin is the cyanohydrin derivative of chloral (trichloroacetaldehyde). It was historically used as a source of hydrogen cyanide for medicinal purposes. Chloral cyanohydrin is toxic by inhalation.
See also
Chloral hydrate
References
Blood agents
Cyanohydrins
Trichloromethyl compounds | Chloral cyanohydrin | [
"Chemistry"
] | 86 | [
"Blood agents",
"Chemical weapons"
] |
72,723,628 | https://en.wikipedia.org/wiki/Calonarius | Calonarius is a genus of fungi in the family Cortinariaceae.
Taxonomy
The genus was created in 2022 when the family Cortinariaceae, which previously in then-recent phylogenetic studies contained only the one genus of Cortinarius, was reclassified based on genomic data and split into the genera of Cortinarius, Aureonarius, Austrocortinarius, Calonarius, Cystinarius, Hygronarius, Mystinarius, Phlegmacium, Thaxterogaster and Volvanarius.
The genus is further divided with subgenus and section classifications:
Calonarius subgenus Calonarius includes the sections: Calonarius, Humolentes and Rufoolivacei.
Calonarius subgenus Calochroi includes the sections: Calochroi, Nymphicolores, Platypodes and Sodagniti.
Calonarius subgenus Fulvi includes the sections: Fulvi, Atrovirentes, Aureopulverulenti, Dibaphi and Splendentes.
Etymology
The name Calonarius derives from the combination of the genus name Cortinarius and the section name Calochroi in which these species were placed prior to the reclassification.
Species
As of January 2023, Species Fungorum accepted 133 species of Calonarius.
Calonarius adonis (Bojantchev & Ammirati) Niskanen & Liimat. (2022)
Calonarius albertii (Dima, Frøslev & T.S. Jeppesen) Niskanen & Liimat. (2022)
Calonarius albidolilacinus (Ammirati, Bojantchev, Beug, Liimat., Niskanen & Garnica) Niskanen & Liimat. (2022)
Calonarius alcalinophilus (Rob. Henry) Niskanen & Liimat. (2022)
Calonarius alnobetulae (Kühner) Niskanen & Liimat. (2022)
Calonarius amabilis (Bojantchev, Ammirati & Pastorino) Niskanen & Liimat. (2022)
Calonarius amnicola (A.H. Sm.) Niskanen & Liimat. (2022)
Calonarius anaunianus (Fellin & R.J. Ferrari) Niskanen & Liimat. (2022)
Calonarius anetholens (Ammirati, Garnica, Bojantchev, Beug, Liimat. & Niskanen) Niskanen & Liimat. (2022)
Calonarius arcuatorum (Rob. Henry) Niskanen & Liimat. (2022)
Calonarius arenicola (A.H. Sm.) Niskanen & Liimat. (2022)
Calonarius atrovirens (Kalchbr.) Niskanen & Liimat. (2022)
Calonarius aureocalceolatus (M.M. Moser & Peintner) Niskanen & Liimat. (2022)
Calonarius aureofulvus (M.M. Moser) Niskanen & Liimat. (2022)
Calonarius aureopulverulentus (M.M. Moser) Niskanen & Liimat. (2022)
Calonarius aurora (M.M. Moser & Ammirati) Niskanen & Liimat. (2022)
Calonarius barbaricus (Brandrud) Niskanen & Liimat. (2022)
Calonarius barbarorum (Bidaud, Moënne-Locc. & Reumaux) Niskanen & Liimat. (2022)
Calonarius bigelowii (Thiers & A.H. Sm.) Niskanen & Liimat. (2022)
Calonarius cacodes (M.M. Moser & Ammirati) Niskanen & Liimat. (2022)
Calonarius caesiocinctus (Kühner) Niskanen & Liimat. (2022)
Calonarius caesiolatens (Rob. Henry ex Bidaud & Reumaux) Niskanen & Liimat. (2022)
Calonarius callochrous (Pers.) Niskanen & Liimat. (2022)
Calonarius calojanthinus (M.M. Moser & Ammirati) Niskanen & Liimat. (2022)
Calonarius caroviolaceus (P.D. Orton) Niskanen & Liimat. (2022)
Calonarius caryae (Lebeuf, A. Paul, J. Landry & Y. Lamoureux) Niskanen & Liimat. (2022)
Calonarius catharinae (Consiglio) Niskanen & Liimat. (2022)
Calonarius cedretorum (Maire) Niskanen & Liimat. (2022)
Calonarius chailluzii (Frøslev & T.S. Jeppesen) Niskanen & Liimat. (2022)
Calonarius cisticola (Frøslev & T.S. Jeppesen) Niskanen & Liimat. (2022)
Calonarius citrinipedes (A.H. Sm.) Niskanen & Liimat. (2022)
Calonarius citrinus (J.E. Lange ex P.D. Orton) Niskanen & Liimat. (2022)
Calonarius claroflavus (Rob. Henry) Niskanen & Liimat. (2022)
Calonarius cobaltinus (Kytöv., Liimat. & Niskanen) Niskanen & Liimat. (2022)
Calonarius coniferarum (M.M. Moser) Niskanen & Liimat. (2022)
Calonarius corrosus (Fr.) Niskanen & Liimat. (2022)
Calonarius cupreorufus (Brandrud) Niskanen & Liimat. (2022)
Calonarius dalecarlicus (Brandrud) Niskanen & Liimat. (2022)
Calonarius dibaphus (Fr.) Niskanen & Liimat. (2022)
Calonarius elegantiomontanus (Garnica & Ammirati) Niskanen & Liimat. (2022)
Calonarius elegantio-occidentalis occidentalis (Garnica & Ammirati) Niskanen & Liimat. (2022)
Calonarius elegantior (Fr.) Niskanen & Liimat. (2022)
Calonarius elegantissimus (Rob. Henry) Niskanen & Liimat. (2022)
Calonarius elotoides (M.M. Moser & McKnight) Niskanen & Liimat. (2022)
Calonarius elotus (Fr.) Niskanen & Liimat. (2022)
Calonarius evosmus (Joachim ex Bidaud & Reumaux) Niskanen & Liimat. (2022)
Calonarius flavaurora (M.M. Moser & McKnight) Niskanen & Liimat. (2022)
Calonarius flavipallens (Kytöv., Liimat. & Niskanen) Niskanen & Liimat. (2022)
Calonarius flavoaurantians (Boccardo, Cleric. & Vizzini) Niskanen & Liimat. (2022)
Calonarius flavobulbus (Ammirati & M.M. Moser) Niskanen & Liimat. (2022)
Calonarius flavomirus Guinberteau, Armada & Bellanger (2022)
Calonarius flavovirens (Rob. Henry) Niskanen & Liimat. (2022)
Calonarius frondosophilus (Bidaud) Niskanen & Liimat. (2022)
Calonarius fulvoarcuatorum (Garnica & Ammirati) Niskanen & Liimat. (2022)
Calonarius fulvocitrinus (Brandrud) Niskanen & Liimat. (2022)
Calonarius fulvoincarnatus (Joachim ex Bidaud, Moënne-Locc. & Reumaux) Niskanen & Liimat. (2022)
Calonarius glaucescens (Jul. Schäff.) Niskanen & Liimat. (2022)
Calonarius glaucoelotus (Brandrud, Dima, Krisai, Ballarà & Peintner) Niskanen & Liimat. (2022)
Calonarius haasii (M.M. Moser) Niskanen & Liimat. (2022)
Calonarius hildegardiae (Schmidt-Stohn, Brandrud & Dima) Niskanen & Liimat. (2022)
Calonarius humolens (Brandrud) Niskanen & Liimat. (2022)
Calonarius insignibulbus (Bidaud & Moënne-Locc.) Niskanen & Liimat. (2022)
Calonarius intricatus (Bojantchev, Ammirati & N. Siegel) Niskanen & Liimat. (2022)
Calonarius ionochlorus (Maire) Niskanen & Liimat. (2022)
Calonarius jardinensis (Garnica, Ammirati & Halling) Niskanen & Liimat. (2022)
Calonarius juxtadibaphus (Rob. Henry) Niskanen & Liimat. (2022)
Calonarius kristiniae (Brandrud) Niskanen & Liimat. (2022)
Calonarius laberiae (Münzmay, B. Oertel & Saar) Niskanen & Liimat. (2022)
Calonarius langeorum (Frøslev & T.S. Jeppesen) Niskanen & Liimat. (2022)
Calonarius lavandulochlorus (Eyssart.) Niskanen & Liimat. (2022)
Calonarius lentus (Boccardo, Cleric., Dovana & Vizzini) Niskanen & Liimat. (2022)
Calonarius lilacinovelatus (Reumaux & Ramm) Niskanen & Liimat. (2022)
Calonarius lilaciotinctus (Garnica & Ammirati) Niskanen & Liimat. (2022)
Calonarius luteicolor (Ammirati, Bojantchev, Niskanen & Liimat.) Niskanen & Liimat. (2022)
Calonarius luteolus (M.M. Moser) Niskanen & Liimat. (2022)
Calonarius mariekristinae (Brandrud & Dima) Niskanen & Liimat. (2022)
Calonarius meinhardii (Bon) Niskanen & Liimat. (2022)
Calonarius metarius (Kauffman) Niskanen & Liimat. (2022)
Calonarius mikedavisii (Bojantchev) Niskanen & Liimat. (2022)
Calonarius molochinus (Bidaud & Ramm) Niskanen & Liimat. (2022)
Calonarius moseri (E. Horak) Niskanen & Liimat. (2022)
Calonarius murellensis (Cors. Gut., Ballarà, Cadiñanos, Palazón & Mahiques) Niskanen & Liimat. (2022)
Calonarius napus (Fr.) Niskanen & Liimat. (2022)
Calonarius natalis (D. Antonini & M. Antonini) Niskanen & Liimat. (2022)
Calonarius nymphicolor (Reumaux) Niskanen & Liimat. (2022)
Calonarius ochraceopallescens (Moënne-Locc. & Reumaux) Niskanen & Liimat. (2022)
Calonarius odoratus (Joguet ex M.M. Moser) Niskanen & Liimat. (2022)
Calonarius odorifer (Britzelm.) Niskanen & Liimat. (2022)
Calonarius olearioides (Rob. Henry) Niskanen & Liimat. (2022)
Calonarius olivaceolamellatus (Lebeuf, A. Paul & J. Landry) Niskanen & Liimat. (2022)
Calonarius oliveopetasatus (M.M. Moser) Niskanen & Liimat. (2022)
Calonarius olympianus (A.H. Sm.) Niskanen & Liimat. (2022)
Calonarius osloensis (Brandrud, T.S. Jeppesen & Frøslev) Niskanen & Liimat. (2022)
Calonarius osmophorus (P.D. Orton) Niskanen & Liimat. (2022)
Calonarius parasuaveolens (Bon & Trescol) Niskanen & Liimat. (2022)
Calonarius piceae (Frøslev, T.S. Jeppesen & Brandrud) Niskanen & Liimat. (2022)
Calonarius platypus (M.M. Moser) Niskanen & Liimat. (2022)
Calonarius praetermissus (Bergeron ex Reumaux) Niskanen & Liimat. (2022)
Calonarius prasinus (Schaeff.) Niskanen & Liimat. (2022)
Calonarius pseudocisticola (Boccardo, Dovana, Dima, L. Albert, Borovička, Mikšík, Saar & Vizzini) Niskanen & Liimat. (2022)
Calonarius pseudocupreorufus (Niskanen, Liimat. & Ammirati) Niskanen & Liimat. (2022)
Calonarius pseudoglaucopus (Jul. Schäff. ex M.M. Moser) Niskanen & Liimat. (2022)
Calonarius pseudoparvus (Bidaud) Niskanen & Liimat. (2022)
Calonarius quercilicis (Chevassut & Rob. Henry) Melot (2022)
Calonarius rapaceoides (Bidaud, G. Riousset & Riousset) Niskanen & Liimat. (2022)
Calonarius rapaceotomentosus (Delaporte & Eyssart.) Niskanen & Liimat. (2022)
Calonarius rufo-olivaceus olivaceus (Pers.) Niskanen & Liimat. (2022)
Calonarius sancti-felicis felicis (Frøslev & T.S. Jeppesen) Niskanen & Liimat. (2022)
Calonarius sannio (M.M. Moser) Niskanen & Liimat. (2022)
Calonarius saporatus (Britzelm.) Niskanen & Liimat. (2022)
Calonarius saxamontanus (Fogel) Niskanen & Liimat. (2022)
Calonarius selandicus (Frøslev & T.S. Jeppesen) Niskanen & Liimat. (2022)
Calonarius sodagnitus (Rob. Henry) Niskanen & Liimat. (2022)
Calonarius spectabilis (M.M. Moser) Niskanen & Liimat. (2022)
Calonarius speculum (Moënne-Locc.) Niskanen & Liimat. (2022)
Calonarius splendens (Rob. Henry) Niskanen & Liimat. (2022)
Calonarius splendidior (Bidaud) Niskanen & Liimat. (2022)
Calonarius splendificus (Chevassut & Rob. Henry) Niskanen & Liimat. (2022)
Calonarius suaveolens (Bataille & Joachim) Niskanen & Liimat. (2022)
Calonarius subgracilis (Moënne-Locc.) Niskanen & Liimat. (2022)
Calonarius sublilacinopes (Bidaud, Moënne-Locc. & Reumaux) Niskanen & Liimat. (2022)
Calonarius subpurpureophyllus (A.H. Sm.) Niskanen & Liimat. (2022)
Calonarius subsulfurinus (Ammirati, Dima, Liimat., Niskanen & Garnica) Niskanen & Liimat. (2022)
Calonarius sulfurinus (Quél.) Niskanen & Liimat. (2022)
Calonarius typicus (Liimat.) Niskanen (2022)
Calonarius verrucisporus (Thiers & A.H. Sm.) Niskanen & Liimat. (2022)
Calonarius vesterholtii (Frøslev & T.S. Jeppesen) Niskanen & Liimat. (2022)
Calonarius violaceipes (Bidaud & Consiglio) Niskanen & Liimat. (2022)
Calonarius viridicarneus (Lebeuf, A. Paul & J. Landry) Niskanen & Liimat. (2022)
Calonarius viridirubescens (M.M. Moser & Ammirati) Niskanen & Liimat. (2022)
Calonarius xanthochlorus (Rob. Henry) Niskanen & Liimat. (2022)
Calonarius xanthodryophilus (Bojantchev & R.M. Davis) Niskanen & Liimat. (2022)
Calonarius xanthophyllus (Cooke) Niskanen & Liimat. (2022)
Notes
References
Agaricales genera
Cortinariaceae | Calonarius | [
"Biology"
] | 4,076 | [
"Fungus stubs",
"Fungi"
] |
72,724,569 | https://en.wikipedia.org/wiki/TOI-700%20e | TOI-700 e is the second outermost known exoplanet orbiting TOI-700, a red dwarf star in the constellation of Dorado.
Host star
TOI-700 is a red dwarf of spectral class M that is about 40% the mass and radius, and very roughly 50% of the temperature of the Sun. The star is bright with low levels of stellar activity. Over the 11 sectors observed with TESS, the star does not show a single white-light flare. The low rotation rate is also an indicator of low stellar activity.
Orbit
TOI-700 e orbits its host star with an orbital period of 27.8 days, comparable with the Moon's orbital period of 27.5 Earth days. It has an orbital radius of about , less than half of that of Mercury to the Sun in the Solar System. It receives about 127% of Earth's sunlight from its host star.
TOI-700 e is in a near 4:3 orbital resonance with TOI-700 d.
Discovery
In November 2021, a fourth possible planet, Earth-sized and receiving approximately 30% more flux from TOI-700 than Earth does from the Sun, was found at the inner edge of the habitable zone of TOI-700. In January 2023 the existence of this planet, designated TOI-700 e, was confirmed.
Discovered in 2023, TOI-700 e is terrestrial exoplanet that NASA claims to be an "earth-like" planet, with 95 percent of the Earth’s radius. Discovered by NASA's TESS (Transiting Exoplanet Survey Satellite), TOI-700 e has mass of about 0.818 Earths and takes 27.8 days to orbit once around its star. The planet is in a habitable zone distance from the M-type star TOI-700 it orbits, leading NASA scientists to believe that there is potential for liquid water on its surface. Ten percent smaller than its neighboring planet TOI-700 d, both are at a distance from their sun to be considered habitable, however, TESS requires an additional year to acquire more data about the exoplanets. Being one in only about a dozen habitable zone planets known, further research and data collection of the TOI-700 solar system are important for understanding Earth-like planets.
References
Dorado
Exoplanets discovered in 2023
Exoplanets discovered by TESS
Transiting exoplanets
Near-Earth-sized exoplanets in the habitable zone | TOI-700 e | [
"Astronomy"
] | 517 | [
"Dorado",
"Constellations"
] |
72,726,482 | https://en.wikipedia.org/wiki/Leslie%20Schoop | Leslie Mareike Schoop is a German-American materials chemist who is an associate professor at Princeton University. Her research considers the realization of new materials for quantum technologies. She has identified several new topological materials, including ZrSiS, a non-toxic, air-stable topological semi-metal.
Early life and education
Schoop grew up in Germany close to the border with Belgium. She has said that her mother was a strong independent woman. She was an undergraduate student at the Johannes-Gutenberg Universitaet in Mainz. She completed her doctoral research at Princeton University, where she worked on exotic properties in condensed matter with Robert Cava. She was unsure whether to pursue a career in academia or industry, and turned to her grandfather for her advice, who said, “You know, Leslie, money should never be a reason why you make a career decision. If you’re good at your job, the money will come”.
Research and career
After her PhD, Schoop remained at Princeton for a postdoctoral position, during which she worked on superconductivity. She was awarded a Minerva program fellowship and moved to the Max Planck Institute for Solid State Research to work alongside Bettina Lotsch, where she found the first non-toxic air-stable topological semi-metal, ZrSiS.
In 2017, Schoop established her own research group at Princeton, where she identified new topological semimetals and predicted their crystal properties. She was supported by the Beckman Foundation to investigate new magnetic topological materials low-power computation.
In 2022, she identified a new quantum state in twisted bilayer tungsten ditelluride. In confined electrons, twisted bilayer graphene are strongly correlated, forming one-dimensional linear arrays of conductive channels. The observation of Luttinger liquids in two-dimensional materials was expected to be very challenging to achieve experimentally, but Schoop and co-workers observed it in a Moiré super lattice.
Awards and honors
2015 Minerva Fast Track Fellowship, Max Planck Society
2019 EPiQS Materials Synthesis Investigator – Gordon and Betty Moore Foundation
2019 Beckman Young Investigator Award
2020 Packard Fellowship in Science and Engineering
2021 Office for Naval Research (ONR) Young Investigator Award
2021 Sloan Fellowship
2022 National Science Foundation CAREER Award
Selected publications
Large, non-saturating magnetoresistance in WTe2
Dirac cone protected by non-symmorphic symmetry and three-dimensional Dirac line node in ZrSiS
A new form of Ca3P2 with a ring of Dirac nodes
References
Living people
Johannes Gutenberg University Mainz alumni
Princeton University alumni
Princeton University faculty
American materials scientists
21st-century American chemists
21st-century American women scientists
German emigrants to the United States
Year of birth missing (living people)
Women materials scientists and engineers | Leslie Schoop | [
"Materials_science",
"Technology"
] | 566 | [
"Women materials scientists and engineers",
"Materials scientists and engineers",
"Women in science and technology"
] |
72,726,720 | https://en.wikipedia.org/wiki/Lundgreni%20Event | The Lundgreni Event, also known as the Mid-Homerian Biotic Crisis, was an extinction event during the middle Homerian age of the Silurian period. Evidence for the event has been observed in Silurian marine deposits in the Iberian Peninsula, Bohemia, and Poland.
Timing
In the Kosov quarry in Bohemia, the extinction is observed during the latest lundgreni biozone and over the course of the flemingii biozone interval. The following parvus biozone, corresponding to the nassa, the parvus-nassa, or dubious-nassa biozones in other localities, represents a post-extinction interval, which is in turn followed by the frequens, praedeubeli-deubeli, and ludensis-gerhardi biozones that mark the period of recovery from the extinction.
Causes
Eutrophication and anoxia coeval with abrupt ecological changes have been implicated as extinction mechanisms bringing about the Lundgreni Event. Immediately after the extinction event, geological records from Bartoszyce evidence a sharp slowdown of ocean mixing. The Lundgreni Event has been hypothesised to have occurred during a period of global marine transgression, a proposed explanation cohering with the relative lack of effect this biotic crisis had on benthic fauna due to the fact that anoxia would likely not have spread into shallow, epicontinental seas.
Isotopic effects
The extinction is marked by the start of a double-peaked positive carbon isotope excursion beginning in the lundgreni graptolite biozone. The first peak spans from the uppermost portion of the lundgreni biozone all the way to the praedeubeli-deubeli graptolite biozone, with a particularly sharp trend towards increasingly positive δ13C values observed during the flemingii and parvus graptolite biozones, corresponding to the extinction interval. The second peak’s start is close to the base of the ludensis-gerhardi graptolite biozone, during the recovery interval.
Biotic effects
The crisis primarily affected graptolites, benthic organisms, and microphytoplankton.
Graptolite species richness reached a worldwide minimum during the extinction event. Cyrtograptids were rendered extinct by the event, while monograptids managed to survive. The genus Monograptus and the family Monoclimacidae were driven to near-extinction. The recovery of graptolites was dominated by retiolitids, and novel graptolite morphological innovations, such as hooded, hooked, lobate, and spinose thecal apertures, sicular cladia, and S-shaped rhabdosomes, have been documented to have evolved among graptolites during the adaptive radiation following the environmental perturbations of the Lundgreni Event.
In Bartoszyce, benthic faunas did not experience an extinction synchronous with the graptolite crisis, and experienced a spike in abundance during the post-extinction period believed to be related to the decline in eutrophication.
In Kosov, the benthic fauna of the lundgreni biozone, dominated by epibyssate cardiolid bivalves (Cardiola, Isiola) and rare reclining bivalves (Slava, Dualina), along with atrypid brachiopods and crinoids, was replaced with the Decoroproetus–Ravozetina fauna, dominated by trilobites, hyolithids, machaeridians, and the linguliform brachiopod Paterula during the parvus biozone.
Acritarchs and prasinophytes suffered no extinction during the crisis, although their relative frequencies and abundances did vary over the course of the extinction event as marine environments were perturbed.
Pelagic cephalopods, other than a drop in overall abundance, were unaffected by the biotic crisis, and saw no meaningful decrease in diversity.
See also
Ireviken event
Mulde event
Lau event
References
Extinction events
Silurian events | Lundgreni Event | [
"Biology"
] | 858 | [
"Evolution of the biosphere",
"Extinction events"
] |
72,727,446 | https://en.wikipedia.org/wiki/Water%20supply%20and%20sanitation%20in%20Angola | Water supply and sanitation is an ongoing challenge in the nation of Angola.
Background
Angola has historically had issues with corruption and instability hindering its water infrastructure development.
Recent developments
Despite being a relatively poor country, water access has improved in recent history. The percentage of Angolans with access to a stable water supply grew from 42% in 1990 to 54% in 2012.
References
Water supply
Health in Angola | Water supply and sanitation in Angola | [
"Chemistry",
"Engineering",
"Environmental_science"
] | 80 | [
"Hydrology",
"Water supply",
"Environmental engineering"
] |
72,728,137 | https://en.wikipedia.org/wiki/Lexipafant | Lexipafant (BB-882, Zacutex) is a drug which acts as a potent and selective inhibitor of the phospholipid mediator platelet-activating factor (PAF). It was developed in the 1990s by British Biotech with several potential applications, including HIV-associated neurocognitive disorder and acute pancreatitis. Initial results were encouraging and it progressed as far as Phase III clinical trials, but final analysis of trial results showed that it failed to improve survival rates in pancreatitis despite some symptomatic improvement, and it was ultimately discontinued from development as a medicine, though it continues to be used as a model PAF inhibitor for pharmacology research.
References
Sulfonamides
Ethyl esters
Imidazopyridines | Lexipafant | [
"Chemistry"
] | 166 | [
"Pharmacology",
"Pharmacology stubs",
"Medicinal chemistry stubs"
] |
72,728,570 | https://en.wikipedia.org/wiki/HD%20224355 | HD 224355, also known as V1022 Cassiopeiae, HR 9059 and (in early publications) Boss 6148, is an eclipsing binary star in the constellation Cassiopeia. It ranges in apparent magnitude from 5.57 to 5.68, which means it is faintly visible to the naked eye for an observer located well away from city lights. It is one of the few binaries known to be an astrometric, spectroscopic and eclipsing binary, a combination that allows the parameters of the stellar system to be calculated with high accuracy. HD 224355 lies west of the 5th-magnitude σ Cassiopeiae.
HD 224355 was discovered to be a spectroscopic binary by Harry Hemley Plaskett of the DAO, in 1919. Many additional spectra were obtained at the DAO in 1922, and orbital elements of the binary were first published in 1923. The orbit was found to have a significant eccentricity of 0.278. Because the physical separation of spectroscopic binaries is often relatively small, they are good candidates to be eclipsing binaries. For that reason, in 1924 Joel Stebbins included HD 224355 in an early photo-electric photometry study, and observed a "suspect eclipse". That led to the star being listed in the New Catalogue of Suspected Variable Stars as NSV 14773. Hipparcos data confirmed that HD 224355 is an Algol-type eclipsing binary. In 2008 it was given the variable star designation V1022 Cassiopeiae.
From 2014 through 2017, HD 224355 was observed with the CHARA optical interferometer. Those observations allowed the orbit to be directly traced from the changes of the stars' relative positions on the sky. That orbit, when combined with radial velocity information, provided a distance measurement to the star. The value obtained, , agrees well with the value of measured by the Gaia spacecraft using the completely independent method of stellar parallax.
Both components of the HD 224355 system are slightly more massive than the Sun, F5 or F6 stars 1.9 billion years old and right at the end of their main sequence lives. Each is about 2.5 times the radius of the Sun and 9 or 10 times as luminous, and they have effective temperatures around .
References
Algol variables
Cassiopeia (constellation)
118077
224355
Durchmusterung objects
Cassiopeiae, V1022 | HD 224355 | [
"Astronomy"
] | 512 | [
"Cassiopeia (constellation)",
"Constellations"
] |
72,728,867 | https://en.wikipedia.org/wiki/CCTV%20drain%20camera%20%28plumbing%29 | CCTV drain cameras, also known as sewer cameras or pipe inspection cameras, are a line of waterproof, high definition cameras that have become a widely popular technology in the plumbing profession. These cameras are advanced diagnostic tools that allow plumbers to execute plumbing inspections, called CCTV Drain Surveys with heightened accuracy.
These cameras can vary; the main difference being the size of the pipe the camera ca inspect. The total distance they can travel within the pipeline is also a common difference between models.
Purpose
CCTV drain cameras are used to uncover any damages or obstructions within the plumbing system. They provide a non-invasive and efficient way to assess the internal condition of drainage pipes and sewer systems, ensuring that issues are accurately identified and addressed without the need for disruptive excavation or guesswork.
These advanced cameras are equipped with high-resolution imaging and flexible cables that allow them to navigate through various pipe sizes and shapes, capturing clear, real-time footage of the inside of the drainage network. As modern-day technology, they are specifically designed for surveying and assessing the working condition of water pipes and sewer lines, making them an invaluable tool for both residential and commercial applications.
In the plumbing world, CCTV drain cameras are commonly used to detect and locate potential problems, such as debris buildups, collapsed pipe sections, root infestations, and pipe offsets. By providing a clear visual of the interior of the drainage system, these cameras help professionals diagnose issues accurately and plan effective solutions. This level of precision eliminates the need for trial-and-error methods, reducing repair time and cost for property owners.
Moreover, CCTV inspections are often conducted as part of routine maintenance to prevent serious drainage problems from developing. Early identification of minor defects, such as hairline cracks or corrosion, allows plumbers to recommend proactive repairs, extending the lifespan of the drainage system. Consequently, CCTV drain cameras contribute significantly to maintaining the overall health and functionality of plumbing networks.
Usage
The camera, attached to a long, flexible cable, is fed through an access point on the property, such as a drain cover or cleanout. It is then carefully maneuvered through the pipes until it reaches the point of damage or obstruction. As the camera moves through the plumbing system, the captured footage is transmitted directly to a monitor or screen, giving the plumber a real-time view of the affected area. This live feed allows the professional to inspect the condition of the pipework, identify issues, and determine the exact location of any problem spots, such as blockages, cracks, or root intrusions.
The camera can also be used in tandem with a plumber’s snake (also known as a drain auger). After the camera has pinpointed the position of a blocking object, such as a buildup of debris or a foreign object, the plumber’s snake can be fed into the same access point. The snake's flexible design allows it to navigate bends and tight spaces within the pipe, where it can then be used to break up or remove the blockage. This combination of tools ensures a highly efficient process, minimizing disruption and avoiding unnecessary excavation or pipe removal.
Additionally, CCTV drain cameras are often paired with hydro-jetting equipment. Once the camera has identified the extent of the obstruction, high-pressure water jets can be used to thoroughly clean the pipe interior, effectively removing any stubborn residues or buildup. This step is especially useful for clearing out grease, scale, or other accumulations that may restrict water flow.
Through the use of these modern technologies, plumbers can achieve accurate diagnoses and perform targeted repairs, reducing the need for extensive digging or structural disruptions. The combination of CCTV drain cameras, plumber’s snakes, and hydro-jetting provides an integrated solution to maintaining and repairing plumbing systems efficiently and cost-effectively.
See also
Pipeline video inspection
References
Plumbing
Piping | CCTV drain camera (plumbing) | [
"Chemistry",
"Engineering"
] | 794 | [
"Building engineering",
"Chemical engineering",
"Plumbing",
"Construction",
"Mechanical engineering",
"Piping"
] |
72,730,996 | https://en.wikipedia.org/wiki/Graham%20Farquharson | Graham Farquharson (1940–2022) was a Canadian mining engineer and executive who was inducted into the Canadian Mining Hall of Fame in 2011 and the Order of Canada in 2021. He is known for his work in the development of underground mining methods.
Career
Farquharson began his career as a mining engineer, gaining experience in underground mines in Canada and South Africa. He later joined Inco Limited (now Vale), where he held various roles, including Vice President of Underground Mining. In this capacity, he oversaw the design and construction of several underground mines. Farquharson is credited with implementing Inco's "room-and-pillar" mining technique, which enhanced the efficiency and safety of underground operations. During his tenure, Inco's Copper Cliff Deep Mine emerged as one of the more productive underground mines in the worlds.
Farquharson was a director of the Mining Industry Human Resources Council. He was inducted into the Canadian Mining Hall of Fame in 2010 in recognition of his contributions to the mining industry.
Philanthropy
In addition to his accomplishments in the mining industry, Graham Farquharson is also known for his philanthropy. He was actively involved in supporting education and community development and donated significant time and resources to a variety of charitable causes.
One of Farquharson's major philanthropic efforts was his support of education. He was involved with a number of educational institutions and served on the boards of several universities and colleges. He was also a major donor to educational institutions and scholarship funds, with a particular focus on supporting students pursuing careers in the mining industry.
Farquharson was also actively involved in supporting community development, particularly in Northern Ontario. He was a strong advocate for the development of sustainable communities in the region and provided financial support and leadership to a number of community development projects.
His contributions to community development have also been recognized by various organizations. He received the Paul Harris Fellow Award from Rotary International in recognition of his philanthropic efforts. He has also been honored by the Ontario government with a prestigious Northern Ontario Heritage Award for his contributions to economic development in the region.
Farquharson's philanthropic work shows a deep understanding of the importance of education and the role it plays in the sustainable development of communities. His contributions have had a positive impact on education and community development in Canada and his legacy continues to be felt through the work of the organizations and initiatives he supported.
References
1940 births
2022 deaths
Members of the Order of Canada
Mining engineers
21st-century Canadian engineers
Engineers from Ontario
Canadian mining businesspeople | Graham Farquharson | [
"Engineering"
] | 511 | [
"Mining engineering",
"Mining engineers"
] |
72,731,078 | https://en.wikipedia.org/wiki/Aureonarius | Aureonarius is a genus of fungi in the family Cortinariaceae.
Taxonomy
The genus was created in 2022 when the family Cortinariaceae, which previously contained only the one genus of Cortinarius was reclassified based on genomic data and split into the genera of Cortinarius, Aureonarius, Austrocortinarius, Calonarius, Cystinarius, Hygronarius, Mystinarius, Phlegmacium, Thaxterogaster and Volvanarius.
The genus is further divided with subgenus and section classifications:
Aureonarius subgenus Aureonarius includes the section: Aureonarius.
Aureonarius subgenus Callistei includes the sections: Callistei and Collybiani.
Etymology
The name Aureonarius derives from the Latin word 'aureus' meaning golden and the suffix of the previous genus name Cortinarius. The name refers to the golden colour of the mushrooms in this genus.
Species
As of January 2023, Species Fungorum accepted 18 species of Aureonarius.
Aureonarius armiae (Soop) Niskanen & Liimat. (2022)
Aureonarius aurantiobrunneus (Ammirati, Halling & Garnica) Niskanen & Liimat. (2022)
Aureonarius austrolimonius (M.M. Moser & E. Horak) Liimat. & Niskanen (2022)
Aureonarius callisteus (Fr.) Niskanen & Liimat. (2022)
Aureonarius caryotis (Soop) Niskanen & Liimat. (2022)
Aureonarius caryotoides (Soop) Niskanen & Liimat. (2022)
Aureonarius collybianus (Soop) Niskanen & Liimat. (2022)
Aureonarius controversus (Gasparini) Niskanen & Liimat. (2022)
Aureonarius eucollybianus (Soop) Niskanen & Liimat. (2022)
Aureonarius infucatus (Fr.) Niskanen & Liimat. (2022)
Aureonarius kroegeri (Niskanen, Liimat., E. Harrower, Berbee, Garnica & Ammirati) Niskanen & Liimat. (2022)
Aureonarius limonius (Fr.) Niskanen & Liimat. (2022)
Aureonarius neocallisteus (Kranab., Ammirati, Liimat. & Niskanen) Niskanen & Liimat. (2022)
Aureonarius rubrimarginatus (Soop) Niskanen & Liimat. (2022)
Aureonarius rubrocastaneus (Soop) Niskanen & Liimat. (2022)
Aureonarius rubrodactylus (Soop) Niskanen & Liimat. (2022)
Aureonarius tofaceus (Fr.) Niskanen & Liimat. (2022)
Aureonarius viscilaetus (Soop) Niskanen & Liimat. (2022)
References
Agaricales genera
Taxa described in 2021
Cortinariaceae | Aureonarius | [
"Biology"
] | 726 | [
"Fungus stubs",
"Fungi"
] |
72,731,144 | https://en.wikipedia.org/wiki/European%20learning%20model | The European Learning Model is a semantic standard used to describe metadata about learning. It is openly licensed, and intended to be used by any stakeholder, in any education, training and employment context, that needs to describe learning data. Available in 29 languages of the European Education Area and candidate country languages, the model can be used in a wide variety of applications, which may include, but not be limited to, describing information on:
· qualifications and learning opportunities (including individual learning accounts);
· qualifications standards such as core vocational profiles;
· credentials awarded to individuals describing their learning activities, achievements, entitlements and/or associated assessments;
· accreditation and licensing of courses, programmes and institutions;
· recognition of qualifications and credentials;
· person identity information and student membership/enrolment in educational institutions.
History
Over the past years, the commission has put in place a range of open standards, reference frameworks and semantic assets to increase data quality and interoperability. While the model was originally aimed to serve as a basis for the European Commission's own applications, the latest version (ELM v3), to be released in Q1-2023, brings together the learning opportunities and qualifications model, the qualifications dataset register model and the European digital credentials model, into a unified structure.
Cloud standards | European learning model | [
"Technology"
] | 265 | [
"Computer standards",
"Cloud standards"
] |
72,731,171 | https://en.wikipedia.org/wiki/Austrocortinarius | Austrocortinarius is a genus of fungi in the family Cortinariaceae.
Taxonomy
The genus was created in 2022 when the family Cortinariaceae, which previously contained only the one genus of Cortinarius was reclassified based on genomic data and split into the genera of Cortinarius, Aureonarius, Austrocortinarius, Calonarius, Cystinarius, Hygronarius, Mystinarius, Phlegmacium, Thaxterogaster and Volvanarius.
Etymology
The name Austrocortinarius derives from 'austro' meaning South and Cortinarius. Currently the genus is only known from the Southern Hemisphere and so it is named in reference to this.
Species
As of January 2023, Species Fungorum accepted 2 species of Austrocortinarius.
Austrocortinarius australiensis (Cleland & Cheel) Liimat. & Niskanen (2022)
Austrocortinarius victoriaensis (Liimat.) Niskanen (2022)
References
Agaricales genera
Cortinariaceae | Austrocortinarius | [
"Biology"
] | 226 | [
"Fungus stubs",
"Fungi"
] |
72,731,240 | https://en.wikipedia.org/wiki/Cystinarius | Cystinarius is a genus of fungi in the family Cortinariaceae.
Taxonomy
The genus was created in 2022 when the family Cortinariaceae, which previously contained only the one genus of Cortinarius was reclassified based on genomic data and split into the genera of Cortinarius, Aureonarius, Austrocortinarius, Calonarius, Cystinarius, Hygronarius, Mystinarius, Phlegmacium, Thaxterogaster and Volvanarius.
The genus is further divided with subgenus and section classifications:
Cystinarius subgenus Cystinarius includes the section: Cystinarius.
Cystinarius subgenus Crassi includes the section: Crassi.
Etymology
The name Cystinarius derives from cystidia and Cortinarius. This is in reference to the cystidia found in this genus.
Species
As of January 2023, Species Fungorum lists six accepted species of Cystinarius.
Cystinarius crassus (Fr.) Niskanen & Liimat. (2022)
Cystinarius eutactus (Soop) Niskanen & Liimat. (2022)
Cystinarius paurigarhwalensis (Semwal, Dima & Soop) Niskanen & Liimat. (2022)
Cystinarius rubicundulus (Rea) Niskanen & Liimat. (2022)
Cystinarius rubiginosus (Ammirati, Bojantchev, Niskanen & Liimat.) Liimat. & Niskanen (2022)
Cystinarius subgemmeus (Soop) Niskanen & Liimat. (2022)
References
Agaricales genera
Cortinariaceae | Cystinarius | [
"Biology"
] | 384 | [
"Fungus stubs",
"Fungi"
] |
72,731,277 | https://en.wikipedia.org/wiki/Hygronarius | Hygronarius is a genus of fungi in the family Cortinariaceae.
Taxonomy
The genus was created in 2022 when the family Cortinariaceae, which previously contained only the one genus of Cortinarius was reclassified based on genomic data and split into the genera of Cortinarius, Aureonarius, Austrocortinarius, Calonarius, Cystinarius, Hygronarius, Mystinarius, Phlegmacium, Thaxterogaster and Volvanarius.
The genus is further divided with subgenus and section classifications:
Hygronarius subgenus Hygronarius includes the section: Hygronarius.
Hygronarius subgenus Viscincisi includes the sections: Austroduracini and Viscincisi.
Etymology
The name Hygronarius derives from the word hygrophanous and Cortinarius. This is in reference to the hygrophanous caps of the species within this genera which display colour variations depending on moisture content.
Species
, Species Fungorum accepted 5 species of Hygronarius.
Hygronarius austroduracinus (M.M. Moser) Liimat. & Niskanen (2022)
Hygronarius parahumilis (Garnica) Liimat. & Niskanen (2022)
Hygronarius renidens (Fr.) Niskanen & Liimat. (2022)
Hygronarius viridibasalis (M.M. Moser) Liimat. & Niskanen (2022)
Hygronarius viscincisus (Soop) Niskanen & Liimat. (2022)
References
Agaricales genera
Cortinariaceae | Hygronarius | [
"Biology"
] | 379 | [
"Fungus stubs",
"Fungi"
] |
72,731,309 | https://en.wikipedia.org/wiki/Mystinarius | Mystinarius is a genus of fungi in the family Cortinariaceae.
Taxonomy
The genus was created in 2022 when the family Cortinariaceae, which previously contained only the one genus of Cortinarius was reclassified based on genomic data and split into the genera of Cortinarius, Aureonarius, Austrocortinarius, Calonarius, Cystinarius, Hygronarius, Mystinarius, Phlegmacium, Thaxterogaster and Volvanarius.
The genus is further divided with subgenus and section classifications:
Mystinarius subgenus Mystinarius.
Etymology
The name Mystinarius derives from the Latin word 'mysticus' meaning mystical and Cortinarius.
Species
As of January 2023, the genus is monotypic with only one species of Mystinarius accepted by Species Fungorum.
Mystinarius lustrabilis (Moënne-Locc.) Niskanen & Liimat. (2022)
References
Agaricales genera
Cortinariaceae | Mystinarius | [
"Biology"
] | 221 | [
"Fungus stubs",
"Fungi"
] |
72,731,437 | https://en.wikipedia.org/wiki/Volvanarius | Volvanarius is a genus of fungi in the family Cortinariaceae.
Taxonomy
The genus was created in 2022 when the family Cortinariaceae, which previously contained only the one genus of Cortinarius was reclassified based on genomic data and split into the genera of Cortinarius, Aureonarius, Austrocortinarius, Calonarius, Cystinarius, Hygronarius, Mystinarius, Phlegmacium, Thaxterogaster and Volvanarius.
The genus is further divided with subgenus classifications:
Volvanarius subgenus Thaumasti.
Volvanarius subgenus Volvanarius.
Etymology
The name Volvanarius derives from the word volva and Cortinarius. This is in reference to the volva which many species in this genus present with.
Species
As of January 2023, Species Fungorum accepted eight species of Volvanarius.
Volvanarius chlorophanus (M.M. Moser) Niskanen & Liimat. (2022)
Volvanarius chlorosplendidus (Furci, Niskanen, San-Fabian, Liimat. & Salgado Salomón) Niskanen & Liimat. (2022)
Volvanarius coleopus (M.M. Moser & E. Horak) Niskanen & Liimat. (2022)
Volvanarius cosmoxanthus (M.M. Moser) Niskanen & Liimat. (2022)
Volvanarius olivaceovaginatus (Niskanen, San-Fabian, Liimat. & E. Horak) Niskanen & Liimat. (2022)
Volvanarius subcosmoxanthus (Liimat., San-Fabian & Niskanen) Niskanen & Liimat. (2022)
Volvanarius thaumastus (Soop) Niskanen & Liimat. (2022)
Volvanarius vaginatus (E. Horak & M.M. Moser) Niskanen & Liimat. (2022)
References
Agaricales genera
Cortinariaceae | Volvanarius | [
"Biology"
] | 459 | [
"Fungus stubs",
"Fungi"
] |
66,934,710 | https://en.wikipedia.org/wiki/Leslie%20Leiserowitz | Leslie Leiserowitz (, born 1934 in Johannesburg) is an Israeli chemist and crystallographer.
Leiserowitz studied electrical engineering at the University of Cape Town with a bachelor's degree, and then worked briefly as an electrical engineer and received a master's degree in physics (X-ray crystallography, under Reginald William James). In 1959 he joined the X-ray crystallography department at the Weizmann Institute under Gerhard Schmidt, a student of Dorothy Crowfoot-Hodgkin. The group at the Weizmann Institute has an international reputation in solid-state chemistry. From 1966 to 1968 he set up the organic chemistry X-ray crystallography department at the University of Heidelberg at the invitation of Heinz Staab. There he developed and installed computer programs using the direct method of Nobel Laureates Herbert Hauptman and Jerome Karle.
Back at the Weizmann Institute, Leiserowitz worked on the synthesis of molecules for the investigation of various molecular interactions using X-ray crystallography (crystal engineering). In collaboration with Danish scientists, he also used X-ray diffraction to investigate thin molecular films with synchrotron radiation at DESY in Hamburg.
He and Meir Lahav have been working together for many years on the stereochemical control of crystal formation and growth with targeted impurities.
He is also active in malaria research, studying malaria pathogens using X-ray microscopy (fluorescence images of iron after X-ray exposure in infected red blood cells) and studying antimalarial drugs such as quinoline compounds. The malaria pathogen breaks down hemoglobin, producing a poisonous heme that docks in hemozoin crystals. Quinolines hinder the growth of the hemozoin crystals. Leiserowitz and Ronit Buller modeled the growth of the hemozoin crystals using computer simulation and found that their crystal surfaces were ideal for the docking of the quinolines. This explained the action of certain antimalarial agents and gave direction for improved drug design.
In 1987 he received the Prelog Medal and lecture, in 2002 the Gregori Aminoff Prize together with Meir Lahav, the Israel Prize in 2016, the EMET Prize in 2018 and the Wolf Prize in Chemistry in 2021 jointly with Meir Lahav. In 1997 Leiserowitz was elected to the Leopoldina.
Publications
Literature
• Oral History Interview with Ute Deichmann, Jacques Loeb Centre for History and Philosophy of the Life Sciences, Ben-Gurion Universität, 2013
References
Israeli chemists
Crystallographers
1934 births
Living people
University of Cape Town alumni
Scientists from Johannesburg
Members of the German National Academy of Sciences Leopoldina
Israeli people of South African-Jewish descent
Academic staff of Weizmann Institute of Science | Leslie Leiserowitz | [
"Chemistry",
"Materials_science"
] | 573 | [
"Crystallographers",
"Crystallography"
] |
66,934,841 | https://en.wikipedia.org/wiki/Fluazifop | Fluazifop is the common name used by the ISO for an organic compound that is used as a selective herbicide. The active ingredient is the 2R enantiomer at its chiral centre and this material is known as fluazifop-P when used in that form. More commonly, it is sold as its butyl ester, fluazifop-P butyl with the brand name Fusilade.
History
In the 1970s, a number of agrochemical companies were working to develop new herbicides to be complementary to the auxin phenoxyacetic acid types such as 2,4-D, which had activity on broad-leaved weeds but were safe to grass crops such as the cereals. Thus the aim was to find materials which would selectively control grass weeds in broad-leaved crops such as cotton and soybean.
In 1973, Hoechst AG filed patents on a new class of compound, the aryloxphenoxypropionates, which showed such selectivity and led to the commercialisation of diclofop. Then the Japanese company Ishihara Sangyo Kaisha (ISK) found improved biological activity in an analogue, chlorazifop, which replaced the aryloxy portion of diclofop with a pyridine ring containing the same two chlorine substituents. This area of research became very competitive and within three weeks of one another in 1977 ISK, Dow Chemicals and Imperial Chemical Industries (ICI) all filed patents covering another group of analogues, with a trifluoromethyl (CF3) group in place of one of the chlorine atoms in the pyridine. Subsequently, ISK and ICI cross-licensed their intellectual property and first marketed fluazifop as its butyl ester in 1981 under the brand name Fusilade while Dow marketed haloxyfop as its methyl ester.
All these compounds have an additional oxygen-linked aromatic group in the para position of the phenyl ring with its OCH(CH3)COOH group and as a class are called "fops", referring to their common fenoxy-phenoxy [sic] feature. (In other words, fops are a subtype of ACCase herbicides, specifically the aryloxyphenoxypropionates.)
Synthesis
The preparation of fluazifop butyl ester as a racemate was disclosed in patents filed by ICI and ISK. Hydroquinone is combined to form ethers with 2-chloro-5-trifluoromethyl pyridine and the butyl ester of 2-bromopropionic acid: these nucleophilic substitution reactions can be performed in either order. The compound is now sold in its single-enantiomer form by Syngenta and other manufacturers. It is produced from chiral starting materials such as alanine and lactic acid.
Mechanism of action
Fluazifop and other similar herbicides act by inhibiting plant acetyl-CoA carboxylase (ACCase). Their selectivity for grasses arises because they target the plastid isoform of the enzyme present only in these species, making them ineffective on broad-leaved weeds and other organisms including mammals. When applied as an ester, metabolism in the target plant leads to the parent acid which is responsible for the herbicidal action.
Usage
The estimated annual use of fluazifop in US agriculture is mapped by the US Geological Service and shows that in 2018, approximately were applied — almost exclusively in soyabean. The earlier much higher figure is partly because the compound was initially used as its racemate. The herbicide is also registered for use in the European Union under EC Regulation 1107/2009.
Human safety
The LD50 of fluazifop-P butyl is 2451 mg/kg (rats, oral), which means that it has low toxicity by oral ingestion. It metabolises in plants and soil to the parent acid, fluazifop-P. The World Health Organization (WHO) and Food and Agriculture Organization (FAO) joint meeting on pesticide residues has determined that the acceptable daily intake for fluazifop is 0-0.004 mg/kg bodyweight.
The Codex Alimentarius database maintained by the FAO lists the maximum residue limits for fluazifop in various food products, some of which are set at its 0.01 mg/kg limit of detection while others are much higher, including soyabean at 15 mg/kg.
Effects on the environment
The environmental fate and ecotoxicology of fluazifop-P are summarised in the Pesticide Properties database and a very extensive risk assessment of the compound was made by the USDA Forest Service.
Resistance Management
There are many reports of individual weed species becoming resistant to fluazifop and other ACCase inhibitors. These are monitored by manufacturers, regulatory bodies such as the EPA and the Herbicides Resistance Action Committee (HRAC). In some cases, the risks of resistance developing can be reduced by using a mixture of two or more herbicides which each have activity on relevant weeds but with unrelated mechanisms of action. HRAC assigns active ingredients into classes so as to facilitate this.
References
Further reading
Herbicides
Pyridines
Ethers
Trifluoromethyl compounds | Fluazifop | [
"Chemistry",
"Biology"
] | 1,116 | [
"Herbicides",
"Functional groups",
"Organic compounds",
"Ethers",
"Biocides"
] |
66,936,728 | https://en.wikipedia.org/wiki/Electromaterials | In physics, electrical engineering and materials science, electromaterials are the set of materials which store, controllably convert, exchange and conduct electrically charged particles. The term electromaterial can refer to any electronically or ionically active material. While this definition is quite broad, the term is typically used in the context of properties and/or applications in which atomic electronic transition is pertinent. The word electromaterials is a compound form of the Ancient Greek term, ἤλεκτρον ēlektron, "Amber", and the Latin term, materia, "Matter".
Properties
Electromaterials enable the transport of charged species (electrons and/or ions) as well as facilitate the exchange of charge to other materials. For atomic and molecule systems, this is observed as atomic electronic transition between discrete orbitals, while for bulk semiconductor materials electronic bands determine which transitions may occur. Metals, in which the conduction band is permanently populated, may also be considered electromaterials, although this is typically outside the category compared to other conduction mechanisms such as for a degenerate semiconductor (transparent conductive oxides) or polaron hopping (organic conductor). Materials which can be ionised (i.e. electrons either added or stripped away) may also be considered electronically active.
Electromaterials have a number of properties broadly, including:
Opto-electronic properties
Photoelectric properties
Exotic phenomena such as super-conductive properties
Partial charge transfer, adsorption of species leading to change in electronic properties of material
Ion conductive materials
Applications
In the application of electromaterials, ions or electrons are used to carry out a specific function. For example, the oxidation or reduction (loss or gain of electrons, respectively) of another species. Materials such as metals, metal particles, conducting polymers, conducting carbon, e.g. CNTs, graphene, carbon fibres, electrodes, electrolytes, electrocatalysts, light harvesting materials (e.g. dyes for DSSCs) find applications in which electromaterials are critical to their functionality:
Batteries
Super-capacitors
Fuel cells
Photovoltaics
Artificial muscles
Chemical sensors
LEDs
Energy conversion/storage devices
Systems that interact with living tissue and soft robotics (prosthetics)
Characterisation
Electromaterials can be explored by techniques such as (but not limited to) absorption spectroscopy, photoluminescence spectroscopy, electrochemistry, FTIR, Raman spectroscopy or combinations of the above, such as raman spectroelectrochemistry.
See also
Metal
Electrolyte
Electrical conductor
Piezoelectricity
References
Electricity
Materials science | Electromaterials | [
"Physics",
"Materials_science",
"Engineering"
] | 544 | [
"Applied and interdisciplinary physics",
"Materials science",
"nan"
] |
66,938,719 | https://en.wikipedia.org/wiki/Chloroquine%20and%20hydroxychloroquine%20during%20the%20COVID-19%20pandemic | Chloroquine and hydroxychloroquine are anti-malarial medications also used against some auto-immune diseases. Chloroquine, along with hydroxychloroquine, was an early experimental treatment for COVID-19. Neither drug has been useful to prevent or treat SARS-CoV-2 infection. Administration of chloroquine or hydroxychloroquine to COVID-19 patients, either as monotherapies or in conjunction with azithromycin, has been associated with deleterious outcomes, such as QT prolongation. scientific evidence does not substantiate the efficacy of hydroxychloroquine, with or without the addition of azithromycin, in the therapeutic management of COVID-19.
Cleavage of the SARS-CoV-2 S2 spike protein required for viral entry into cells can be accomplished by proteases TMPRSS2 located on the cell membrane, or by cathepsins (primarily cathepsin L) in endolysosomes. Hydroxychloroquine inhibits the action of cathepsin L in endolysosomes, but because cathepsin L cleavage is minor compared to TMPRSS2 cleavage, hydroxychloroquine does little to inhibit SARS-CoV-2 infection.
Several countries initially used chloroquine or hydroxychloroquine for treatment of persons hospitalized with COVID-19 (as of March 2020), though the drug was not formally approved through clinical trials. From April to June 2020, there was an emergency use authorization for their use in the United States, and was used off label for potential treatment of the disease. On 24 April 2020, citing the risk of "serious heart rhythm problems", the FDA posted a caution against using the drug for COVID-19 "outside of the hospital setting or a clinical trial".
Their use was withdrawn as a possible treatment for COVID-19 infection when it proved to have no benefit for hospitalized patients with severe COVID-19 illness in the international Solidarity trial and UK RECOVERY Trial. On 15 June 2020, the FDA revoked its emergency use authorization, stating that it was "no longer reasonable to believe" that the drug was effective against COVID-19 or that its benefits outweighed "known and potential risks". In fall of 2020, the National Institutes of Health issued treatment guidelines recommending against the use of hydroxychloroquine for COVID-19 except as part of a clinical trial.
In 2021, hydroxychloroquine was part of the recommended treatment for mild cases in India.
In 2020, the speculative use of hydroxychloroquine for COVID-19 threatened its availability for people with established indications (malaria and auto-immune diseases).
Background
Chloroquine is an anti-malarial medication that is also used against some auto-immune diseases. Hydroxychloroquine is more commonly available than chloroquine in the United States. Hydroxychloroquine is used as a prophylactic in India.
Hydroxychloroquine and chloroquine have numerous, potentially serious, side effects, such as retinopathy, hypoglycemia, or life-threatening arrhythmia and cardiomyopathy. Both drugs have extensive interactions with prescription drugs, affecting the therapeutic dose and disease mitigation. Some people have allergic reactions to these drugs. The NIH recommended against the use of a combination of hydroxychloroquine and azithromycin because of the resulting increased risk of sudden cardiac death. Widespread administration of chloroquine or hydroxychloroquine, either alone or in combination with azithromycin, among COVID-19 patients, has been associated with increased mortality due to adverse effects, including QT prolongation.
In October 2021 a large network of companies selling hydroxychloroquine and ivermectin has been disclosed in the US, targeting primarily right-wing and vaccine hesitant groups through social media and conspiracy videos by anti-vaccine activists such as Simone Gold. The network had 72,000 customers who collectively paid $15 million for consultations and medications.
Timeline
Chloroquine was initially recommended by Indian, Chinese, South Korean and Italian health authorities for the treatment of COVID-19, although these agencies and the US CDC noted contraindications for people with heart disease or diabetes. In February 2020, both drugs were shown to effectively reduce COVID-19 illness, but a further study concluded that hydroxychloroquine was more potent than chloroquine and had a more tolerable safety profile.
On 18 March 2020, the World Health Organization (WHO) announced that chloroquine and the related hydroxychloroquine would be among the four drugs studied as part of the multinational Solidarity clinical trial.
On 19 March 2020, US president Donald Trump encouraged the use of chloroquine and hydroxychloroquine during a national press conference. These endorsements led to massive increases in public demand for the drugs in the United States. Beginning in March 2020, Trump began promoting hydroxychloroquine to prevent or treat COVID-19, citing small numbers of anecdotal reports. Trump stated in June that he was taking the drug as a preventive measure, stimulating unprecedented worldwide demand and causing shortages of hydroxychloroquine for its prescribed purpose of preventing malaria.
New York governor Andrew Cuomo announced that New York State trials of chloroquine and hydroxychloroquine would begin on 24 March. On 28 March, the US Food and Drug Administration (FDA) authorized the use of hydroxychloroquine sulfate and chloroquine phosphate under an Emergency Use Authorization (EUA), which was later revoked due to the risk of cardiac adverse events. The drug was authorized under the EUA as an experimental treatment for emergency use in hospitalized patients.
In late March 2020, an Arizona man died of cardiac arrest and his wife was hospitalized after the couple ingested a version of chloroquine used as a parasite treatment for aquarium fish. The couple had incorrectly believed that the parasite treatment would have the same effects as the medication form of chloroquine. The surviving wife stated that the couple self-administered the chemical after listening to speeches by President Donald Trump that touted chloroquine as an effective treatment against COVID-19.
Beginning in March 2020, New Jersey state senator Joe Pennacchio began publicly calling for the use of hydroxychloroquine to combat the spread of COVID-19 based on a French study which showed a decrease in "viral shedding." He received support from over 60 doctors and advocacy groups across the United States, including Sheila Page and Marilyn Singleton from the Association of American Physicians and Surgeons, Niran Al-Agba from Physicians for Patient Protection and Frank Alario of the American College of Physicians.
On 28 March 2020, the FDA authorized the use of hydroxychloroquine and chloroquine under an emergency use authorization (EUA). The experimental treatment was first authorized only for emergency use for people hospitalized but unable to receive treatment in a clinical trial.
On 1 April 2020, the European Medicines Agency (EMA) issued guidance that chloroquine and hydroxychloroquine are only to be used in clinical trials or emergency use programs.
On 9 April 2020, the National Institutes of Health began the first clinical trial to assess whether hydroxychloroquine is safe and effective to treat COVID-19. A Veterans Affairs study released results on 21 April suggesting COVID-19-hospitalized patients treated with hydroxychloroquine were more likely to die than those who received no drug treatment at all, after correcting for clinical characteristics.
On 24 April 2020, the FDA cautioned against using the drug outside a hospital setting or clinical trial after reviewing case reports of adverse effects including ventricular tachycardia, ventricular fibrillation and in some cases death. According to Johns Hopkins' ABX Guide for COVID-19, "Hydroxychloroquine may cause prolonged QT, and caution should be used in critically ill COVID-19 patients who may have cardiac dysfunction or if combined with other drugs that cause QT prolongation". Caution was also recommended as to the combination of chloroquine and hydroxychloroquine with treatments which might inhibit the CYP3A4 enzyme (by which these drugs are metabolized). As such, combination might indirectly result in higher plasma levels of chloroquine and hydroxychloroquine, and thus enhance the risk for significant QT prolongation. CYP3A4 inhibitors include Azithromycin, ritonavir, and lopinavir.
On 27 April 2020 the Association of American Physicians and Surgeons wrote a letter, signed by Jane Orient and Michael Robb, to Arizona governor Doug Ducey asking to rescind his executive order forbidding the use of hydrochloroquine as a treatment for COVID-19. The executive order was signed on 2 April 2020.
On 5 June 2020, use of hydroxychloroquine in the UK RECOVERY Trial was discontinued when an interim analysis of 1,542 treatments showed it provided no mortality benefit to people hospitalized with severe COVID-19 infection over 28 days of observation.
On 15 June 2020, the FDA revoked the emergency use authorization for hydroxychloroquine and chloroquine, stating that although the evaluation of both these drugs under clinical trials continues, the FDA (after interagency consultation with the Biomedical Advanced Research and Development Authority (BARDA)) concluded that, based on new information and other information discussed "... it is no longer reasonable to believe that oral formulations of hydroxychloroquine (HCQ) and chloroquine (CQ) may be effective in treating COVID-19, nor is it reasonable to believe that the known and potential benefits of these products outweigh their known and potential risks".
On 23 July 2020, results were published from a multicenter, randomized, open-label, three-group, controlled trial of 667 participants in Brazil which found no benefit from using hydroxychloroquine, alone or with azithromycin, to treat mild-to-moderate COVID-19. In July, the U.S. President Donald Trump once again promoted the use of the drug contradicting various public health officials, including National Institute of Allergy and Infectious Diseases director Dr. Anthony Fauci.
In November 2020, a U.S. National Institutes of Health clinical trial evaluating the safety and effectiveness of hydroxychloroquine for the treatment of adults with COVID-19 formally concluded that the drug provided no clinical benefit for COVID-19 treatment and recommended against its use.
A Cochrane review from February 2021 came to the conclusion, that hydroxychloroquine has little or no effect on the risk of death. Besides, adverse events are tripled compared to placebo. The authors came to the conclusion that no further trials of hydroxychloroquine or chloroquine for treatment of COVID-19 should be carried out.
On 26 April 2021, in its amended clinical management protocol for COVID-19, the Indian Ministry of Health lists hydroxychloroquine for use in patients during the early course of the disease.
In August 2022, a meta-analysis led by Harvard epidemiologist Miguel Hernán found that the aggregate of pre-exposure prophylaxis trials with hydroxychloroquine suggested a reduction of around 28% in COVID-19 infections. Evidence of effectiveness in this setting was also provided by a large multicenter study led by the Centre for Tropical Medicine and Global Health at the University of Oxford, published only in 2024, which found a 15% decrease in symptomatic infections with prophylaxis. Both studies argued that the controversies surrounding the drug early in the pandemic led to the premature closure of studies and to difficulties in trial recruitment, ultimately hurting scientific enquiry about its effectiveness.
A French study published in 2024 found that the use of hydroxychloroquine may have been associated with 17,000 deaths in Belgium, Turkey, France, Italy, Spain, and the United States. This study was ultimately retracted on August 22, 2024, after "the Editor-in-Chief found the conclusions of the article to be unreliable".
Combined with zinc and another antibiotic
Due to the properties of zinc as a cofactor in the immune response for producing antibodies during viral infections, as of May 2020 it was being included among multiple-agent "cocktails" for investigating potential treatment of people hospitalized with COVID-19 infection. One such cocktailhydroxychloroquine combined with a high dose of zinc (as a sulfate, 220 mg (50 mg elemental Zn) per day for five days, a zinc dose ~4 times higher than the reference daily intake level) and an approved antibiotic, either azithromycin or doxycyclinebegan in May as a PhaseIV trial in New York State. However, caution was recommended about the combination of chloroquine or hydroxychloroquine with CYP3A4 inhibitors, such as azithromycin, a treatment combination found to be ineffective for preventing death in hospitalized people with COVID-19. There was preliminary evidence that combining hydroxychloroquine and azithromycin for treating non-hospitalized ("outpatient") people with COVID-19 infection with multiple comorbidities was effective, but this evidence was not confirmed by later studies: co-administration of chloroquine or hydroxychloroquine with azithromycin has been associated with increased mortality due to adverse effects, including QT prolongation.
Zinc deficiencywhich decreases immune capacity to defend against pathogensis common among elderly people, and may be a susceptibility factor in viral infections. The mechanism for any potential benefit of including zinc in a cocktail treatment for recovery from severe COVID-19 or any viral infection is unknown.
Prophylaxis
Drugs used for treatment of infectious diseases may also be considered for use for post-exposure prophylaxis. On 22 May, The Lancet published a response to criticism of the Indian government's decision to allow chemoprophylaxis with hydroxychloroquine for some high risk persons who may have had exposure to COVID. Researchers supporting prophylactic administration of hydroxychloquine note that results from human trials have suggested that hydroxychloroquine may decrease the duration of both viral shedding and symptoms if the drug is administered early.
On 3 June, results were published from a randomized, double-blind, placebo-controlled trial of 821 participants which found that hydroxychloroquine did not prevent symptomatic COVID-19 illness when used for post-exposure prophylaxis. A randomized, multicenter, placebo-controlled trial amongst healthcare workers found that oral hydroxychloroquine did not help prevent COVID-19 infections when used as pre-exposure prophylaxis.
British researchers are studying whether the drug is effective when used for prevention. 10,000 National Health Service (NHS) workers, along with 30,000 additional volunteers from Asia, South America, Africa, and other parts of Europe are participating in the global study. Results are expected by 2021.
WHO trial
Due to safety concerns and evidence of heart arrhythmias leading to higher death rates, the WHO suspended the hydroxychloroquine arm of the multinational Solidarity trial in May 2020. The WHO had enrolled 3,500 patients from 17 countries in the Solidarity trial. The research surrounding this suspension, provided by a company called Surgisphere based in Chicago, came into question due to errors in the underlying data set. The authors of the study corrected errors in the data later but initially remained firm on their conclusions. Subsequently, a retraction of the study by three of its authors was published by The Lancet on 4June 2020. The authors stated that their reason behind the retraction was because Surgisphere had failed to cooperate with an independent review of the data used for the study by not allowing any such review to take place.
The WHO decided to resume the trial on 3June, after reviewing the safety concerns which had been raised. Speaking at a press briefing, WHO's director-general, Tedros Adhanom Ghebreyesus stated that the board had reviewed the available mortality data and had found "no reasons to modify the trial".
On 4 July, the WHO discontinued the hydroxychloroquine trial based on evidence presented at the July WHO Summit on COVID-19 research and innovation. The WHO stated that "These interim trial results show that hydroxychloroquine and lopinavir/ritonavir produce little or no reduction in the mortality of hospitalized COVID-19 patients when compared to standard of care."
See also
COVID-19 drug repurposing research
Ivermectin during the COVID-19 pandemic
References
COVID-19 drug development
Antimalarial agents
Chloroarenes
Quinolines
Health-related conspiracy theories | Chloroquine and hydroxychloroquine during the COVID-19 pandemic | [
"Chemistry",
"Technology"
] | 3,677 | [
"COVID-19 drug development",
"Health-related conspiracy theories",
"Drug discovery",
"Science and technology-related conspiracy theories"
] |
66,939,063 | https://en.wikipedia.org/wiki/STARS-EC | STARS-EC (Space Tethered Autonomous Robotic Satellite Elevator of CubeSat, COSPAR 1998-067SE, SATCAT 47928) was a nanosatellite developed by Shizuoka University, for the purpose of demonstrating space elevator tether technology. It was a 3U-size CubeSat, and could split into three separate satellites, connected via tethers. STARS-EC was launched on 20 February 2021, and was deployed from the International Space Station (ISS). The deployment service of STARS-EC was provided by Mitsui Bussan Aerospace.
The satellite decayed from orbit on 15 April 2022.
Mission
STARS-EC's mission was to demonstrate space elevator tether technology using a 3U CubeSat. After deployment from the ISS, the satellite split into three separate spacecraft, each the size of a 1U CubeSat. The spacecraft on each end was connected to the center satellite by an space tether, thus putting the satellites on the ends 22 m apart from one another. The satellite in the center moved back and forth along the tether, demonstrating the orbital space elevator technology. Each spacecraft was equipped with a camera to monitor the elevator demonstration.
See also
STARS
STARS-II
STARS-C
OPUSAT-II
RSP-01
WARP-01
References
External links
Official project site
STARS Space Service
Space elevator
Satellites of Japan
2021 in Japan
Spacecraft launched in 2021
Spacecraft which reentered in 2022
Satellites deployed from the International Space Station | STARS-EC | [
"Astronomy",
"Technology"
] | 298 | [
"Exploratory engineering",
"Astronomical hypotheses",
"Space elevator"
] |
66,939,284 | https://en.wikipedia.org/wiki/Panus%20purpuratus | Panus purpuratus is a fungus in the family, Panaceae, first described by Greta Stevenson in 1964. The type species was collected from fallen wood in a coastal forest in Waikanae in 1949. The species is endemic to New Zealand.
References
External links
Panus purpuratus: images and occurrence data from GBIF
Polyporales
Fungi of New Zealand
Taxa named by Greta Stevenson
Fungi described in 1964
Fungus species | Panus purpuratus | [
"Biology"
] | 88 | [
"Fungi",
"Fungus species"
] |
66,941,160 | https://en.wikipedia.org/wiki/Trichosphaerella%20buckii | Trichosphaerella buckii is a species of lichenicolous fungus in the family Niessliaceae. It was described as a new species in 2016 by Richard Harris and James Lendemer. The type was found growing immersed in a moribund thallus of the lichen Punctelia rudecta, which itself was on the trunk of a maple tree. This tree was in the Alligator River Game Land, in the Coastal Plain region of eastern North Carolina. Although at the time of publication the fungus was known only from the type locality, it was suspected to have a larger distribution, considering its lichen host has a widespread North American distribution.
References
Hypocreales
Fungi described in 2016
Fungi of the United States
Lichenicolous fungi
Fungi without expected TNC conservation status
Taxa named by James Lendemer
Fungus species
Taxa named by Richard Clinton Harris | Trichosphaerella buckii | [
"Biology"
] | 176 | [
"Fungi",
"Fungus species"
] |
66,944,870 | https://en.wikipedia.org/wiki/Fascaplysin | Fascaplysin is a marine alkaloid based on 12H-pyrido[1–2-a:3,4-b′]diindole ring system. It was first isolated as a red pigment from the marine sponge Fascaplysinopsis reticulata that was collected in the South Pacific near Fiji in 1988. Fascaplysin possesses a broad range of in vitro biological activities including analgesic, antimicrobial, antifungal, antiviral, antimalarial, anti-angiogenic, and antiproliferative activity against numerous cancer cell lines.
Synthesis
The first total synthesis of fascaplysin was performed in seven steps from indole in 1990. Fascaplysin and its derivatives can be synthesized from tryptamine, beta-carboline, indoleketones, and indigo.
References
Alkaloids
Heterocyclic compounds with 5 rings
Nitrogen heterocycles
Quaternary ammonium compounds | Fascaplysin | [
"Chemistry"
] | 201 | [
"Organic compounds",
"Biomolecules by chemical classification",
"Natural products",
"Alkaloids"
] |
66,944,962 | https://en.wikipedia.org/wiki/Acarospora%20citrina | Acarospora citrina is a lichen in the family, Acarosporaceae, first described as Urceolaria citrina by
Thomas Taylor in 1847. It was assigned to the genus, Acarospora, in 1913 by Alexander Zahlbruckner.
This lichen has been found in all mainland states of Australia, on rocks in sclerophyll woodland.
References
External links
Acarospora citrina: images and occurrence data from GBIF
Taxa named by Thomas Taylor (botanist)
Lichen species
citrina
Lichens described in 1847
Lichens of Australia | Acarospora citrina | [
"Biology"
] | 126 | [
"Fungus stubs",
"Fungi"
] |
66,944,978 | https://en.wikipedia.org/wiki/Crepidotus%20applanatus | Crepidotus applanatus is a species of fungus in the family Crepidotaceae. It was first described in 1796 by Christiaan Hendrik Persoon and renamed by Paul Kummer in 1871. It is inedible.
Description
Like other Crepidotus, it has brown spore powder. It grows on deciduous wood, to which it is attached at the side by at most only a rudimentary stem (it is "pleurotoid"). The cap grows up to 5 cm across and is hygrophanous, white to ochraceous when damp and drying whitish. The spores, around 5 - 6 μm, are almost spherical and warty. It is distinguished from the very similar Crepidotus stenocystis by the shape of the Cheilocystidia (clavate and unbranched) and the habitat on broad-leaf timber.
References
Crepidotaceae
Inedible fungi
Fungus species | Crepidotus applanatus | [
"Biology"
] | 201 | [
"Fungi",
"Fungus species"
] |
66,945,372 | https://en.wikipedia.org/wiki/Mustapha%20Ishak%20Boushaki | Mustapha Ishak-Boushaki is a theoretical physicist, cosmologist and professor at the University of Texas at Dallas. He is known for his contributions to the studies of cosmic acceleration and dark energy, gravitational lensing, and testing alternatives to general relativity; as well as his authorship of Testing General Relativity in Cosmology, a review article published in Living Reviews in Relativity.
He was elected as a fellow of the American Association for the Advancement of Science (AAAS) in 2021 and as a fellow of the American Physical Society (APS) with the quote: "For distinguished contributions to the field of theoretical cosmology, particularly for testing modifications to general relativity at cosmological scales, and for sustained excellence in teaching and mentoring of students."
Education and academic background
Mustapha Ishak-Boushaki was born in Algeria (North Africa), where he grew up and completed his pre-university studies in the city of Bouira.
He moved to Montreal in 1987. In 1994, he received an undergraduate degree in computer science at the University of Quebec at Montreal, followed by an additional undergraduate degree in physics from the University of Montreal in 1998.
He then attended Queen's University at Kingston where in 2003 he completed his PhD in general relativity and theoretical cosmology.
His graduate work included studies on inhomogeneous cosmologies, wormholes, exact solutions in general relativity of compact objects (such as neutron stars), and an inverse approach to the Einstein field equations.
Following the completion of his graduate studies, Ishak-Boushaki began work as a research associate at Princeton University until later entering a professorship at the University of Texas at Dallas in 2005.
While at the University of Texas at Dallas, he formed an active group of cosmologists and astrophysicists, and received the Outstanding Teacher of the Year Award in the years 2007 and 2018, as well as the University President's Excellence in Teaching Award and the University of Texas System Regents Outstanding Teacher Award in 2022
He is an active member of the Dark Energy Science Collaboration and the Dark Energy Spectroscopic Instrument.
Research and career
Mustapha Ishak-Boushaki's work involves research in the subjects of the origin and cause of cosmic acceleration and the dark energy associated with it, testing general relativity at cosmological scales, the application of gravitational lensing to cosmology, intrinsic alignment of galaxies, and Large-scale structure of the Universe.
In 2005, Ishak-Boushaki and collaborators proposed a procedure to distinguish between dark energy and modification to general relativity at cosmological scales as a cause of cosmic acceleration.
The idea was based on the fact that cosmic acceleration affects both the expansion rate and the growth rate of large-scale structures in the universe.
These two effects must be consistent one with another since they are based on the same underlying theory of gravity.
The publication was one of the first to: (1) contrast dark energy versus modified gravity as cause of cosmic acceleration, (2) use inconsistencies between Lambda-CDM model cosmological parameters to test gravitational theory at cosmological scales.
He and collaborators wrote then a series of publications on testing general relativity at cosmological scales (see Bibliography), and his work on the subject was recognized by an invitation to write in 2018 a review article on the current state of research in the field of testing general relativity in the journal Living Reviews in Relativity.
Ishak-Boushaki and collaborators made a first detection of the large-scale intrinsic alignment of galaxies of type "intrinsic shear – gravitational shear" using a spectroscopic galaxy sample from the Sloan Digital Sky Survey.
He and collaborators also made a first detection of these intrinsic alignments using a self-calibration method in the photometric galaxy sample in Kilo-Degree Survey.
Ishak-Boushaki and collaborator wrote a review article on the intrinsic alignment of galaxies and its impact on weak gravitational lensing.
Ishak-Boushaki and a collaborator proposed a new mathematical measure of inconsistency between cosmological datasets called the index of inconsistency (IOI) as well as a novel Bayesian interpretation of the level of significance of such measures.
Awards and honors
References
External links
Mustapha Ishak-Boushaki's personal website
Mustapha Ishak-Boushaki's papers recorded in INSPIRE-HEP
Kabyle people
American astrophysicists
American cosmologists
Algerian astrophysicists
21st-century American physicists
1967 births
Living people
Theoretical physicists
Algerian emigrants to Canada
Algerian expatriates in the United States
Université du Québec à Montréal alumni
Université de Montréal alumni
Queen's University at Kingston alumni
Princeton University alumni
Princeton University faculty
University of Texas at Dallas faculty
20th-century Algerian physicists
21st-century Algerian physicists
Algerian science writers
Mustapha
Naturalized citizens of the United States
Algerian inventors
Fellows of the American Physical Society
21st-century inventors
21st-century Algerian people | Mustapha Ishak Boushaki | [
"Physics"
] | 1,012 | [
"Theoretical physics",
"Theoretical physicists"
] |
66,946,131 | https://en.wikipedia.org/wiki/Danielle%20Dixson | Danielle L. Dixson was previously an Associate Professor of Marine Ecology in the School of Marine Science and Policy at the University of Delaware. Her research focusses on how human-induced change to marine ecosystems impacts animal behaviour. Her work, now known to be fraudulent, was about understanding how ocean acidification affects the behaviour of coral reef fishes.
Academic career
Dixson studied Marine Science at the University of Tampa in Florida, obtaining her B.S. in 2005. She went on to obtain her Ph.D. in 2012 under the supervision of Philip Munday, Geoffrey Jones, and Morgan Pratchett at James Cook University, Australia. From 2011, she worked as postdoctoral researcher at Georgia Institute of Technology until her appointment as an Assistant Professor in 2013. In 2015 she began as an assistant professor at the University of Delaware before becoming an associate professor in 2019.
Dixson is the author of Sea Stories, a children's book series based on scientific literature that aims to promote awareness of marine conservation, STEM subjects, and visibility of minorities from an early age. She is a member of the International Society of Chemical Ecology and was the recipient of their Early Career Award in 2019.
Research
Dixson's research broadly focuses on the relationship of how marine animals sense their environment and how this influences their decisions. Her major research areas include the role of chemical cues in corals and coral reef fishes, and the influence of ocean acidification on fish behaviour.
Misconduct allegations
Dixson has been accused of fabricating primary data by other researchers in the field and is the subject of ongoing institutional investigations. On August 9, 2022, Science published a piece announcing that an investigation by the University of Delaware found Dixson guilty of scientific misconduct, including data fabrication and falsification related to her work on coral reef fish behaviour. A separate investigation is reportedly being conducted by the Georgia Institute of Technology.
Honours and awards
International Society of Chemical Ecology Early Career Award
National Science Foundation (NSF) Faculty Early Career Development Award
James Cook University Outstanding Alumni Award
See also
Oona Lönnstedt See misconduct case of Oona Lönnstedt who was also found to have conducted discredited fish research at James Cook University
Selected publications
References
Living people
University of Delaware alumni
University of Tampa alumni
Georgia Tech faculty
University of Delaware faculty
American LGBTQ scientists
Year of birth missing (living people)
21st-century American LGBTQ people
People involved in scientific misconduct incidents
Ecologists
James Cook University alumni
Women ecologists
Women marine biologists | Danielle Dixson | [
"Environmental_science"
] | 505 | [
"Ecologists",
"Environmental scientists"
] |
66,946,224 | https://en.wikipedia.org/wiki/Gamma%20ray%20cross%20section | A gamma ray cross section is a measure of the probability that a gamma ray interacts with matter. The total cross section of gamma ray interactions is composed of several independent processes: photoelectric effect, Compton (incoherent) scattering, electron-positron pair production in the nucleus field and electron-positron pair production in the electron field (triplet production). The cross section for single process listed above is a part of the total gamma ray cross section.
Other effects, like the photonuclear absorption, Thomson or Rayleigh (coherent) scattering can be omitted because of their nonsignificant contribution in the gamma ray range of energies.
The detailed equations for cross sections (barn/atom) of all mentioned effects connected with gamma ray interaction with matter are listed below.
Photoelectric effect cross section
The photoelectric effect phenomenon describes the interaction of a gamma photon with an electron located in the atomic structure. This results in the ejection of that electron from the atom. The photoelectric effect is the dominant energy transfer mechanism for X-ray and gamma ray photons with energies below 50 keV. It is much less important at higher energies, but still needs to be taken into consideration.
Usually, the cross section of the photoeffect can be approximated by the simplified equation of
where k = Eγ / Ee, and where Eγ = hν is the photon energy given in eV and Ee = me c2 ≈ 5,11∙105 eV is the electron rest mass energy, Z is an atomic number of the absorber's element, α = e2/(ħc) ≈ 1/137 is the fine structure constant, and re2 = e4/Ee2 ≈ 0.07941 b is the square of the classical electron radius in barns.
For higher precision, however, the Sauter equation is more appropriate:
where
and EB is a binding energy of electron, and ϕ0 is a Thomson cross section (ϕ0 = 8πe4/(3Ee2) ≈ 0.66526 barn).
For higher energies (>0.5 MeV) the cross section of the photoelectric effect is very small because other effects (especially Compton scattering) dominates. However, for precise calculations of the photoeffect cross section in high energy range, the Sauter equation shall be substituted by the Pratt-Scofield equation
where all input parameters are presented in the Table below.
Compton scattering cross section
Compton scattering (or Compton effect) is an interaction in which an incident gamma photon interacts with an atomic electron to cause its ejection and scatter of the original photon with lower energy. The probability of Compton scattering decreases with increasing photon energy. Compton scattering is thought to be the principal absorption mechanism for gamma rays in the intermediate energy range 100 keV to 10 MeV.
The cross section of the Compton effect is described by the Klein-Nishina equation:
for energies higher than 100 keV (k>0.2). For lower energies, however, this equation shall be substituted by:
which is proportional to the absorber's atomic number, Z.
The additional cross section connected with the Compton effect can be calculated for the energy transfer coefficient only – the absorption of the photon energy by the electron:
which is often used in radiation protection calculations.
Pair production (in nucleus field) cross section
By interaction with the electric field of a nucleus, the energy of the incident photon is converted into the mass of an electron-positron (e−e+) pair. The cross section for the pair production effect is usually described by the Maximon equation:
for low energies (k<4),
where
.
However, for higher energies (k>4) the Maximon equation has a form of
where ζ(3)≈1.2020569 is the Riemann zeta function. The energy threshold for the pair production effect is k=2 (the positron and electron rest mass energy).
Triplet production cross section
The triplet production effect, where positron and electron is produced in the field of other electron, is similar to the pair production, with the threshold at k=4. This effect, however, is much less probable than the pair production in the nucleus field. The most popular form of the triplet cross section was formulated as Borsellino-Ghizzetti equation
where a=-2.4674 and b=-1.8031. This equation is quite long, so Haug proposed simpler analytical forms of triplet cross section. Especially for the lowest energies 4<k<4.6:
For 4.6<k<6:
For 6<k<18:
For k>14 Haug proposed to use a shorter form of Borsellino equation:
Total cross section
One can present the total cross section per atom as a simple sum of each effects:
Next, using the Beer–Lambert–Bouguer law, one can calculate the linear attenuation coefficient for the photon interaction with an absorber of atomic density N:
or the mass attenuation coefficient:
where ρ is mass density, u is an atomic mass unit, a A is the atomic mass of the absorber.
This can be directly used in practice, e.g. in the radiation protection.
The analytical calculation of the cross section of each specific phenomenon is rather difficult because appropriate equations are long and complicated. Thus, the total cross section of gamma interaction can be presented in one phenomenological equation formulated by Fornalski, which can be used instead:
where ai,j parameters are presented in Table below. This formula is an approximation of the total cross section of gamma rays interaction with matter, for different energies (from 1 MeV to 10 GeV, namely 2<k<20,000) and absorber's atomic numbers (from Z=1 to 100).
For lower energy region (<1 MeV) the Fornalski equation is more complicated due to the larger function variability of different elements. Therefore, the modified equation
is a good approximation for photon energies from 150 keV to 10 MeV, where the photon energy E is given in MeV, and ai,j parameters are presented in Table below with much better precision. Analogically, the equation is valid for all Z from 1 to 100.
XCOM Database of cross sections
The US National Institute of Standards and Technology published on-line a complete and detailed database of cross section values of X-ray and gamma ray interactions with different materials in different energies. The database, called XCOM, contains also linear and mass attenuation coefficients, which are useful for practical applications.
See also
Cross section (physics)
Gamma ray
Linear attenuation coefficient
Mass attenuation coefficient
Neutron cross section
Nuclear cross section
External links
XCOM Database
References
Atomic physics
Physical quantities
Measurement
Nuclear physics
Gamma rays
Radiation | Gamma ray cross section | [
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"Mathematics"
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"Waves",
"Radiation",
"Gamma rays",
" molecular",
"Atomic physics",
"Atomic",
"Ph... |
66,948,337 | https://en.wikipedia.org/wiki/Turkmenistan%20Memorial%20Capsule | The Turkmenistan Memorial Capsule is a memorial satellite which was launched in 2005 to a Sun-synchronous orbit by a Ukrainian Dnepr rocket
The capsule is bolted to the Dnepr 3rd stage and it contains a flag of Turkmenistan and the book of Ruhnama.
References
Satellites of Turkmenistan
2005 in Turkmenistan
Spacecraft launched by Dnepr rockets
Spacecraft launched in 2005 | Turkmenistan Memorial Capsule | [
"Astronomy"
] | 75 | [
"Astronomy stubs",
"Spacecraft stubs"
] |
75,542,521 | https://en.wikipedia.org/wiki/Quercus%20%C3%97%20harbisonii | Quercus × harbisonii, commonly known as Harbison's oak and Harbison oak, is a rare hybrid species of oak in the family Fagaceae.
Description
It is a medium-sized deciduous to semi-evergreen tree.
Taxonomy
The Harbison oak is a naturally occurring hybrid of the post oak and live oak. It was originally described by Sargent as Quercus stellata var. margaretta × Quercus virginiana var. geminata. Some taxonomists regard Quercus margarettae and Quercus geminata as separate species. EJ Palmer noted that some Quercus × harbisonii were of the typical subspecies. Thus, Quercus × harbisonii is easily said as a hybrid of the post oak and live oak in the broad sense.
Distribution
The tree is found in the southeastern United States. It is known from the states of Florida, North Carolina, South Carolina, Georgia, Texas and Oklahoma.
References
Hybrid plants
harbisonii
Plants described in 1918
Flora of Florida
Flora of North Carolina
Flora of South Carolina
Flora of Texas
Flora of Georgia (U.S. state)
Flora of Oklahoma | Quercus × harbisonii | [
"Biology"
] | 234 | [
"Hybrid plants",
"Plants",
"Hybrid organisms"
] |
75,545,505 | https://en.wikipedia.org/wiki/Happy%20corner | Happy corner, also known as aluba (), is a form of prank, game, or bullying that primarily occurs in mainland China, Hong Kong, Macau and Taiwan, generally among male students, in which the victim is lifted up by several perpetrators who subsequently bump his groin against a pole-shaped object.
Prevalence and effects
In a 2004 survey of students from 8 universities by Hong Kong's U-Beat Magazine, 46% of the students surveyed have subjected someone else to happy corner, of whom 98% are males. 58% of male students reported having subjected someone else to happy corner, and one in ten respondents reported suffering injury as a result of happy corner. Nine in ten respondents who had engaged in happy corner reported experiencing greater affinity with both the person subjected to happy corner and other participants afterwards.
Injuries and incidents
In 2007 a Taiwanese middle school student suffered injuries after being subjected to aluba by four classmates. According to TVBS, this was first incident in which aluba led to a civil suit in Taiwan.
In 2009, a Taiwanese middle school student suffered injuries that required surgery after being subjected to aluba. The matter was settled out of court for NT$500,000.
CUHK Medical Centre urologist Chen Longwei indicates that happy corner carries a risk of injuries to the genitals. Chen points out that men may receive injuries to the penile tunica albuginea or suffer a bent penis, while women may receive injuries to the vulva, vagina, urethra, or hymen.
Motives
Rough play and homosocial interactions
A 2017 research paper that interviewed 45 Taiwanese men found that common motives for engaging in aluba include celebrating special occasions, punishing other students, and resolving disputes. The researchers indicate that aluba often occurs without regard to disparities in power or popularity and, in spite of the apparent violation of the target's autonomy, generally occurs between close friends and with implicit consent.
Summarizing previous research, Li Peiwen notes that aluba allows school-aged boys to build intimacy with each other in a societal context in which gentler forms of physical affection may be perceived as indicators of homosexuality or effeminacy.
Bullying and hazing
In their 2017 paper, Bih Herng-dar, Huang Haitao, Hung Wen-lung, and Pan Bo-han dispute scholarly works and legislative efforts that have categorized aluba as a form of bullying. In a 2011 research paper, Bih and Huang also dispute the claim that aluba is a form of hazing, noting that in contrast to secretive initiation rituals, the practice generally occurs in the open.
Nevertheless, Bih and Huang link aluba to "ritualistic games of initiation" involving vulnerability, noting that it involves a symbolic attack on the male genitals. The game serves to test the risk-taking ability of the person subjected to aluba as well as his trust in those conducting aluba, and also serves to separate those who belong in a peer group from those to be excluded.
Reinforcement of gender roles
Bih Herng-dar and Huang Haitao note that aluba is an overwhelmingly male activity, and that the activity reinforces and confirms the masculinity of the participants. They cite one interviewee who indicated that aluba is more appropriate for boys as a celebratory activity in contrast to more "girlish" activities like cutting birthday cakes, and also note that the protestations of the person subjected to aluba serves as a "symbolic verification" that he has a penis. Bih and Huang indicate that both female students and gay men often perceive aluba as an immature activity.
Responses
Taiwan's Ministry of National Defense and Ministry of Education issued directives forbidding the practice in 2004.
References
Harassment and bullying
Practical jokes | Happy corner | [
"Biology"
] | 764 | [
"Harassment and bullying",
"Behavior",
"Aggression"
] |
75,546,387 | https://en.wikipedia.org/wiki/Mortimer%20Rogoff | Mortimer Alan Rogoff (May 2, 1921 – August 1, 2008) was an American inventor, businessman, and author as well as an amateur photographer and radio operator. He is recognized for his work in spread spectrum technology which is the technology that modern cell phones and GPS systems are based on. He is also considered the grandfather of the electronic navigation chart.
Early life
Rogoff was born in Brooklyn, New York. He earned his B.S.E.E. from Rensselaer Polytechnic Institute in 1943 and his M.S.E.E. from Columbia University in 1948. While at Rensselaer he was a member of Kappa Nu fraternity and the Features Editor for the student newspaper.
During World War II, he enlisted in the United States Navy and worked on developing radio communication and aerial navigation systems. One of the techniques he developed was undetectable by Axis forces because its power was below that of the background noise and its frequency varied in random ways. This secure transmission was the beginning of spread spectrum technology which would become the basis for GPS and CDMA cellular telephone systems. Although he was never able to patent the technology because it was a military secret he did get some recognition for it almost forty years later when he received the Institute of Electrical and Electronics Engineers’ Pioneer Award in 1981.
Career
Rogoff worked for twenty-two years (1946 to 1968) for ITT Laboratories in New Jersey. In 1958, he became their deputy director of Engineering. He was Vice President of ITT Laboratories from 1962 to 1963. From 1963 to 1968, he was promoted to the corporate staff where he became head of European operations. In 1968 he left ITT to work for the Diebold Group where he became an Executive Vice President.
After leaving the Diebold Group he founded several technology and automation businesses, including his own consulting firm, and Teletext Communications Corporation. Later in the 1970s, he was a Principal with Booz Allen Hamilton. In 1979, his book ‘’Calculator Navigation’’ was published. This book demonstrated practical methods for calculating precise ship locations using radio navigation with a consumer calculator.
In 1981, he founded a new company, Navigation Sciences Inc., in Bethesda, Maryland. With this company he patented a method for marine navigation that combined radar maps with electronic charts in 1986. This was a major advancement in field. Today, this system is known as the Electronic Chart Display and Information System (ECDIS). Rogoff had seen the need for a new charting system in 1968 from his apartment at 180 East End Avenue in New York City. From there, he saw a boating accident where a life was lost and decided there had to be a way to automate navigation.
Rogoff then became of member of the International Maritime Organization’s (IMO) sub-committee on Safety of Navigation, a representative to the International Electrotechnical Commission, and became the chairman of the Radio Technical Commission for Maritime Services Special Committee 109 on Electronic Charts. He was able to use his influence on these boards to push through a proposal of ECDIS standards in 1989 where none has been before. As his friend Giuseppe Carnevali said, “Although nobody could argue against the need for a standard, no one was ready to endorse one; however, nobody was brave enough to oppose it.” A Test Bed project on these proposals was conducted by the United States Coast Guard. The amended standards were accepted by the IMO in November, 1995.
In 2000, he was named as a Fellow of the Institute of Navigation. He was also a Fellow of the Institute of Electrical and Electronics Engineers. During this time, he was also president of the Navigational Electronic Charts System Association.
Personal
In 1979, he moved to Washington, D.C. and bought a home in Nantucket, Massachusetts. He married Sheila Zunser in 1943 and they were together for sixty-five years. They had three daughters: Louisa Thompson, Alice Rogoff, and Julia Peach. His sister was sociologist Natalie Rogoff Ramsøy of the University of Oslo. He was a member of the Cosmos Club and President of The Navigational Electronic Chart System Association (NECSA). He was a very good amateur photographer and liked amateur radio (call sign W2EE). He died in Nantucket from bladder cancer.
Patents
Patent number: 4176316 – Secure Communication System – November 27, 1979
With Louis A. DeRosa
Patent number: 4590569 – Electronic Navigation System – May 20, 1986
With Peter M. Winkler and John N. Ackley
Patent number: RE34004 – Secure Communication System – July 21, 1992
With Louis A. DeRosa
Publications
September 1957. Automatic Analysis of Infrared Spectra. Annals of the New York Academy of Sciences; vol. 69: no. 1: 27–37.
Gen. P.C. Sandretto and Mortimer Rogoff. 1958 “A Novel Concept for Application to the Control of Airways Traffic.” NAVIGATION: Journal of The Institute of Navigation; vol. 6: no. 2: 102–107
1979. Calculator Navigation; ISBN 0-393-03192-6. Published by W.W. Norton & Company (New York and London).
December 1985. Electronic Charting. Yachting; vol. 158: no. 6: 54–57.
Winter 1990. Electronic Charts in the Nineties. NAVIGATION: Journal of The Institute of Navigation; vol. 37: no. 4: 305–318.
References
1921 births
2008 deaths
Businesspeople from Brooklyn
Inventors from Brooklyn
Writers from Brooklyn
Diebold
Booz Allen Hamilton people
Rensselaer Polytechnic Institute alumni
Telecommunications
Navigation | Mortimer Rogoff | [
"Technology"
] | 1,149 | [
"Information and communications technology",
"Telecommunications"
] |
75,547,310 | https://en.wikipedia.org/wiki/Kirbee%20Kiln%20Site | The Kirbee Kiln Site is a 19th-century kiln ruin located in Montgomery County, Texas, where stoneware was manufactured by the Kirbee family. It is one of the largest groundhog kilns ever recorded in the American South. The exact location of the site is restricted. It was listed on the National Register of Historic Places in 1973.
History
The Kirbee Kiln was founded and operated by James Kirbee, who was originally from Edgefield, South Carolina, and had relatives and acquaintances who were also potters. One of his acquaintances might have been David Drake, a potter who was enslaved by Kirbee's associate Rev. John Landrum. By 1830, Kirbee and his family had relocated to Georgia; and by 1840, they had migrated to Montgomery County, Texas. The kiln itself was likely built around 1849, as it appeared in the 1850 Schedule of Industry and Manufacture. James was likely assisted by his sons M.J. and Louis. The annual value of the stoneware produced did not exceed $500, much lower than other local kilns. The kiln likely ceased operations in the 1860s.
The site was one of several kilns surveyed by the Texas Historical Commission between 1973 and 1974. It was listed on the National Register of Historic Places on August 28, 1973. It was the first site from in the area to be added to the NRHP.
Architecture and pottery
At the time of the archaeological surveys in the 1970s, the Texas Historical Commission named the Kirbee Kiln Site as the largest groundhog kiln that had then been excavated in Texas, and it remains one of the largest ever recorded in the American South. It measured across and 8 to 10 inches wide and was constructed of brick. The kiln was rectangular in shape, consisting of an opening at the very front for loading and firing, a depressed firebox, the loading shelf in the middle, and a fireplace-shaped chimney at the very back. A unique feature of this kiln was the presence of a second firing box located midway along the loading shelf; a side door would have provided access. The chimney is believed by the excavators to have decreased in width towards its top. The buttresses of the Kirbee Kiln were large and angled but also included several smaller ones, a rare feature that could have functioned to support its size, offer resistance against the sloped ground, and double as a retaining wall. The entire floor of the kiln was sandy soil.
Kirbee's stoneware had similarities to techniques observed elsewhere in Georgia and South Carolina, particularly the alkaline glaze that was characteristic of contemporary Edgefield stoneware; and the vessels were also comparable in features such as their handles and shape. This style of pottery is very similar to Catawba Valley Pottery, which was developed in nearby North Carolina. The trademarks on the Kirbee stoneware were a round stamp resembling the letter "O".
References
Kilns
American pottery
Industrial buildings and structures on the National Register of Historic Places in Texas
National Register of Historic Places in Montgomery County, Texas
1849 establishments in Texas
Industrial buildings completed in 1849 | Kirbee Kiln Site | [
"Chemistry",
"Engineering"
] | 644 | [
"Chemical equipment",
"Kilns"
] |
75,547,946 | https://en.wikipedia.org/wiki/AzTECC71 | AzTECC71 is a dusty star-forming galaxy discovered by the James Webb Space Telescope, reported by NASA in early December 2023. This red ghost-like galaxy has been optically invisible to other telescopes including the Hubble Space Telescope; astronomers referred to them as “Hubble-dark galaxies”.
This object has been identified as a dusty star-forming galaxy by the astronomers with the COSMOS-Web collaboration and the team published its findings in The Astrophysical Journal. “This thing is a real monster,” said Jed McKinney, a postdoctoral researcher at The University of Texas at Austin. “Even though it looks like a little blob, it’s actually forming hundreds of new stars every year. And the fact that even something that extreme is barely visible in the most sensitive imaging from our newest telescope is so exciting to me. It’s potentially telling us there’s a whole population of galaxies that have been hiding from us.”
References
Discoveries by the James Webb Space Telescope
Galaxies discovered in 2023 | AzTECC71 | [
"Astronomy"
] | 208 | [
"Galaxy stubs",
"Astronomy stubs"
] |
75,548,094 | https://en.wikipedia.org/wiki/Central%20compact%20object | A central compact object (CCO) is an x-ray source found near the center of a young, nearby supernova remnant (SNR). Given the observed x-ray flux and spectra observed from these objects, the almost certain conclusion is that CCOs are the remnant neutron stars which resulted from the recent supernova. Unlike most pulsars, CCOs generally lack pulsed radio emission or variation in the observed x-rays due to such phenomena being either nonexistent or difficult to detect. The weaker magnetic fields than most other detected neutron stars means that most of the detected x-rays are due to blackbody radiation. Confirmation that the CCO is associated with the past supernova can be done using the kinematics of the objects and matching them to the age and kinematics of the host SNR.
The detection in 1980 of 1E 161348-5055 at the center of SNR RCW 103 using the Einstein Observatory was once touted as the first CCO discovery, but is now classified as a slow-rotating magnetar due to magnetar outburst detection. Since that object's discovery, ten CCOs have been positively identified with a further two as candidates.
List of CCOs
The following list of confirmed CCOs and their associated supernova remnants is curated by Andrea De Luca, astronomer at the National Institute for Astrophysics.
RX J0822.0-4300 (center of Puppis A) (pulsations detected)
CXOU J085201.4-461753 (center of RX J0852.0−4622)
1E 1207.4-5209 (center of PKS 1209−51/52) (pulsations detected)
CXOU J160103.1-513353 (center of G330.2+1.0)
1WGA J1713.4-3949 (center of G347.3−0.5)
XMMU J172054.5-372652 (center of G350.1−0.3)
XMMU J173203.3-344518 (center of G353.6−0.7)
CXOU J181852.0-150213 (center of G15.9+0.2)
CXOU J185238.6+004020 (center of Kesteven 79) (pulsations detected)
CXOU J232327.9+584842 (center of Cassiopeia A)
References
External links
List of CCOs maintained by A. De Luca
Neutron stars
Supernova remnants
X-ray astronomy | Central compact object | [
"Astronomy"
] | 558 | [
"Astronomy stubs",
"Astronomical sub-disciplines",
"X-ray astronomy"
] |
75,548,895 | https://en.wikipedia.org/wiki/Leigh%20Signal | Tracey Leigh Signal is a New Zealand academic, and is a full professor at Massey University, specialising in fatigue and sleep, especially in relation to the aviation industry, and in women and children.
Academic career
Signal trained as a commercial pilot before completing a Master's degree on shiftwork in air traffic services at Massey University,and a PhD in public health at the University of Otago. Her doctoral thesis was titled Scheduled napping on the night shift: consequences for the performance and neurophysiological alertness of air traffic controllers, and was supervised by Philippa Gander. Signal then joined the faculty at Massey, rising to full professor in 2021.
Signal works in the Fatigue Management and Sleep Health group of the Sleep/Wake Centre at Massey University. Her research interests cover two areas, She studies sleep and fatigue avoidance, identification and management in the workplace, particularly in the aviation industry, and in relation to workplace deaths and accidents. She also researches healthy sleep in women and children, changes in sleep that occur at different life stages, and the relationship between sleep and sporting performance. She published a book Sleeping better in pregnancy after experiencing problems sleeping during her own second pregnancy.
Signal has been an invited member of two International Civil Aviation Organisation Fatigue Risk Management Task Forces, and has contributed to national and global standards on civil aviation. She has provided expert advice to the Coroner's Office, WorkSafe New Zealand and to the Transport Accident Investigation Commission.
Selected works
References
External links
Youtube video of Signal talking about pregnancy and post-partum sleep changes in women
New Zealand academics
New Zealand women academics
Massey University alumni
University of Otago alumni
Academic staff of Massey University
Sleep researchers | Leigh Signal | [
"Biology"
] | 332 | [
"Sleep researchers",
"Behavior",
"Sleep"
] |
75,549,316 | https://en.wikipedia.org/wiki/Alexander%20Mihailovich%20Zamorzaev | Alexander Mihailovich Zamorzaev (; 27January 1927 – 1November 1997) was a Soviet mathematician and crystallographer. In 1953 Zamorzaev was the first to derive the complete list of magnetic space groups (Shubnikov groups). In 1957 Zamorzaev founded the field of generalised antisymmetry by introducing the concept of more than one kind of two-valued antisymmetry operation.
Life
Career
Zamorzaev was born on 23 January 1927 in Leningrad. In 1953 at the University of Leningrad, under the supervision of A.D. Aleksandrov, he gained the M.A. degree with the dissertation Generalization of Fedorov groups, in which he developed the general theory of antisymmetry. In this work he derived for the first time the 1651 antisymmetry space groups, and named them "Shubnikov groups", after A.V. Shubnikov the pioneer of antisymmetry.
In 1953 he became a mathematics lecturer at the newly opened University of Kishinev (Chișinău). Besides teaching the regular mathematics curriculum, and supervising graduate students, Zamorzaev devised and taught new courses in the areas of discrete geometry, theoretical crystallography, and antisymmetry and its generalisations.
In 1971 he gained his doctoral degree with a thesis entitled Theory of Antisymmetry and its Different Generalizations. The thesis was based on his new theories of geometry and mathematical crystallography, 1) multiple antisymmetry; 2) similarity and conformal symmetry; and 3) P-symmetry, including generalisations of A. V. Shubnikov's antisymmetry and N. V. Belov's color symmetry.
In 1973 a department of higher geometry was established within the university and Zamorzaev was appointed as professor and head of the department. A history of the personnel and achievements of Zamorzaev's school of geometry is available online.
Works
The majority of Zamorzaev's works were published in Russian. Books published by Zamorzaev:
Theory of simple and multiple antisymmetry (1976)
Theory of discrete symmetry groups (1977)
Color symmetry, its generalizations and applications (1978)
P-symmetry and its further development (1986)
Zamorzaev published 110 papers. Selected papers available in English:
Similarity symmetric and antisymmetric groups (1964).
Quasisymmetry (p-symmetry) groups (1968)
Color-symmetry space groups (1969)
Antisymmetry, its generalizations and geometrical applications (1980)
Generalized antisymmetry (1988).
Honours and awards
E. S. Fedorov Prize of the Russian Academy of Sciences for his contributions to the theory of symmetry (1973)
State Prize of the Moldovan SSR in Science and Technology for his contributions in the field of discrete geometry (1974)
Honored Worker of Science of the Moldovan SSR for his achievements in science and education (1977)
Elected Corresponding Member of the Academy of Sciences of Moldova (1989)
References
1927 births
1997 deaths
Soviet mathematicians
Crystallographers
Scientists from Saint Petersburg | Alexander Mihailovich Zamorzaev | [
"Chemistry",
"Materials_science"
] | 648 | [
"Crystallographers",
"Crystallography"
] |
75,551,391 | https://en.wikipedia.org/wiki/Tylvalosin | Tylvalosin, sold under the brand name Aivlosin, is a macrolide antibiotic used for the treatment of bacterial infections with Mycoplasma hyopneumoniae in swine, that causes enzootic pneumonia. It is used as tylvalosin tartrate.
Mechanism of Action
Macrolides are generally considered to be bacteriostatic agents that exert their antibiotic effect by reversibly binding to the 23S rRNA of the 50S ribosomal subunit, thereby inhibiting bacterial protein synthesis.
Medical uses
Tylvalosin is indicated for the control of porcine proliferative enteropathy associated with Lawsonia intracellularis infection in groups of swine intended for slaughter and female swine intended for breeding in buildings experiencing an outbreak of PPE. Not for use in male swine intended for breeding; and for the control of swine respiratory disease associated with Bordetella bronchiseptica, Glaesserella (Haemophilus) parasuis, Pasteurella multocida, Streptococcus suis, and Mycoplasma hyopneumoniae in groups of swine intended for slaughter and female swine intended for breeding in buildings experiencing an outbreak of swine respiratory disease. Not for use in male swine intended for breeding.
References
Macrolide antibiotics
Veterinary drugs
Sugar alcohols
Acetate esters
Tertiary amines
Methoxy compounds
Conjugated dienes
Ketenes | Tylvalosin | [
"Chemistry"
] | 309 | [
"Carbohydrates",
"Sugar alcohols",
"Functional groups",
"Ketenes"
] |
75,551,560 | https://en.wikipedia.org/wiki/Velagliflozin | Velagliflozin, sold under the brand name Senvelgo, is an antidiabetic medication used for the treatment of cats. Velagliflozin is a sodium-glucose cotransporter 2 (SGLT2) inhibitor. It is taken by mouth.
Medical uses
Velagliflozin is indicated to improve glycemic control in otherwise healthy cats with diabetes not previously treated with insulin.
References
Cat medications
SGLT2 inhibitors
Nitriles
Cyclopropyl compounds
Sugar alcohols
Veterinary drugs | Velagliflozin | [
"Chemistry"
] | 111 | [
"Carbohydrates",
"Nitriles",
"Sugar alcohols",
"Functional groups"
] |
75,552,808 | https://en.wikipedia.org/wiki/Blue%20food | Blue foods, also known as aquatic foods, are plants and animals sourced from aquatic environments and are suitable for human consumption. More than 2500 species of marine and freshwater animals, aquatic plants, and algae have been identified as relevant to the human diet.
Origin of the term
The term was coined in the Blue Transformation Strategy of the Food and Agriculture Organization of the United Nations. Blue Foods are therefore linked to the blue economy principle. Blue food is the first internationally applicable term which, by definition, includes animal and plant foods from the sea and freshwater. The latter also distinguishes it from the English term seafood, for which there is no equivalent in many other languages.
Background
The social and political discussions regarding food systems have predominantly revolved around terrestrial agriculture and livestock farming, overlooking the significance of blue foods. Blue foods such as fish, invertebrates, algae, and aquatic plants, which are caught or bred in freshwater and marine ecosystems, have been excluded from broader food system conversations. Initiatives such as the UN Food and Agriculture Organization (FAO)´s roadmap for the blue transformation stress the important role of blue food for feeding a growing world population, and at the same time underscore the necessity of integrating sustainable practices into aquatic food production for long-term viability.
The role of blue foods is among others described in the Blue Food Assessment. The report is backed by more than 100 scientists from 25 universities, including Stanford University, the Stockholm Resilience Center and the Potsdam Institute for Climate Research.
Sustainability evaluation
Economic factor
Blue foods are obtained using a range of different methods - from large deep-sea trawlers to small carp ponds, which date back to 2,500 years in areas such as the Mediterranean and China. Economically, blue food systems significantly contribute to global trade and livelihood support, benefiting millions of people worldwide directly or indirectly. Local adaptation strategies enhance the resilience of these systems to external stressors, fostering economic stability in coastal and riparian communities. The FAO estimates that the livelihoods of approximately 800 million people rely on blue food systems, either directly or indirectly. In countries of the global South, the net income generated by blue food trade exceeds that of all other agricultural commodities. Overall, fish and seafood are among the world's most traded goods, generating an estimated 151 billion US dollars a year.
Complex global supply chains with limited transparency can pose just as much of a challenge to the sustainable production of blue food as taking the rights of indigenous peoples or traditional coastal fishing into consideration. Certification programmes and the associated controls along the supply chain can be an important step towards greater transparency, although they meet their limits in autocratic countries.
Nutrition
Blue foods are valued for their nutritional richness, providing essential proteins, vitamins, micronutrients and fatty acids vital for human health.
They play a crucial role in addressing dietary deficiencies prevalent in regions with limited access to diverse food sources: In many African and South American countries, a higher consumption of blue foods is suggested as compensation for the lack of vitamin B12 and omega-3. In many countries of the global North, the rates of cardiovascular disease, which are associated with a high consumption of red meat, among other things, are considered to be reduced by switching to an alternative, moderate but regular consumption of seafood.
Environment
From an environmental perspective, blue foods often have a smaller ecological footprint compared to terrestrial protein sources. For example, the pelagic fishing of herring or anchovies, or the cultivation of carp, have a significantly lower carbon or climate footprint than the farming of chickens, the most environmentally friendly of all terrestrial animal foods. There are examples of how the aquacultures of algae or mussels even improve the water quality of their location. Additionally, blue foods often have a low to zero consumption of lifestock feed and agrochemicals; wild caught fish and seafood do also consume zero freshwater and land.
In other areas, the environmental impact of blue food can also be high if fisheries and aquaculture operations do not follow rigid sustainability criteria. A third of the world's fish stocks are considered to be overfished, and unsustainable fisheries and aquaculture have a negative impact on the ecosystem and pose a threat to marine biodiversity. Examples of this include the destruction of fauna and flora on the seabed by bottom trawlers fishing in sensitive marine areas, the deforestation of mangrove forests for fish farms and the transfer of diseases and pharmaceutical residues into wild waters by unsustainable aquaculture operations.
Greenhouse gas emissions can also be higher with some farming or fishing methods than with others.
In light of these risks, the United Nations considers ending overfishing and making global fisheries and aquaculture more sustainable to be one of the core tasks of the Blue Transformation Strategy - and an essential prerequisite for the long-term preservation of blue food and healthy ecosystems. Stronger intergovernmental regulation and control mechanisms for fishing and aquaculture, as well as voluntary certification programmes and environmental labels, such as that of the Marine Stewardship Council, offer solutions here.
See also
The Blue Economy
Fishery
Human food
Food sources
References
External links
Blue Food Assessment
Blue Transformation Roadmap (FAO)
The Blue Food Revolution
Sustainable agriculture
Aquaculture
Marine biology | Blue food | [
"Biology"
] | 1,052 | [
"Marine biology"
] |
75,552,883 | https://en.wikipedia.org/wiki/Marek%20Kowalkiewicz | Marek Kowalkiewicz (born 21 July 1978) is a Polish-Australian computer scientist. He is a Professor and Chair in Digital Economy at Queensland University of Technology (QUT) where he focuses on artificial intelligence (AI) and digital transformation strategies for government and industry. He performs all of his research in 30-day "research innovation sprints", an award-winning concept he pioneered at QUT in 2015. Kowalkiewicz's research sprints are designed to create and accelerate industry-focused research outcomes by combining the commercial philosophy of Google's five-day design sprint with the rigour of academic research.
Kowalkiewicz joined QUT from Silicon Valley where he led global innovation teams for SAP. He was a Research Manager at SAP's Machine Learning Lab in Singapore, Global Research Program Lead at SAP Research Australia, and a Research Fellow at Microsoft Research Asia.
He is the author of the book The Economy of Algorithms: Rise of the Digital Minions, published by La Trobe University Press in March 2024. The book has received multiple awards for its contribution to the rapidly evolving field of AI.
Education
Poznań University of Economics and Business
Kowalkiewicz received a Master of Business Information Systems from Poznań University of Economics and Business (PUEB) in Poland in 2002. He completed his PhD in Information Systems at PUEB in 2006, graduating summa cum laude. Kowalkiewicz's research area was in extracting content from websites; his dissertation was titled "Information Extraction and Aggregation for Business Entities".
Career and research
Poznań University of Economics and Business
From 2002 - 2006, while completing his PhD, Kowalkiewicz held the position of Assistant Professor in the Department of Information Systems at Poznań University of Economics and Business.
Microsoft Research Asia
Before receiving his PhD in 2006, Kowalkiewicz relocated to Beijing to become a Research Fellow at Microsoft Research Asia where he built a location detection system for Windows Live Spaces, a functionality that was later introduced in blog searches.
SAP Research Australia
In 2007, he joined SAP Research Australia as Senior Researcher and Development Expert leading teams of developers and researchers in various projects including the 2010 launch of the first SAP app in the AppStore, AUS Traffic, which led to SAP's focus on mobile apps and Apple partnership. He also led the IdeaWall project (previously known as InnoBoard), a remote collaboration app that helped distributed teams work with physical and virtual post-it notes, a concept still used in some internal SAP applications.
While at SAP Research, Kowalkiewicz was appointed Global Research Program Manager, User Experience, where he established a global user experience research team and program.
He also led a global series of SAP InnoJam hackathons which promoted the use of SAP technologies by startups, and won SAP TechEd DemoJams in Las Vegas and Bangalore with demonstrations of augmented reality (AR) in enterprise systems.
SAP Singapore
In April 2012, Kowalkiewicz moved to Singapore to help establish SAP Research's Asia-Pacific Japan (APJ) headquarters. As Research Manager and Head of Developer Outreach for APJ, he created SAP's first Machine Learning research lab.
SAP Americas
In 2014, he was appointed Senior Director, Products and Innovation, at SAP Americas in Palo Alto, California. Kowalkiewicz was global content and strategy lead for SAP's largest internal conference series, d-kom, where he designed and launched its annual, global developer kick-off event for more than 25,000 attendees. He also built a network of makerspaces for SAP developers, introducing AR/VR, 3D printing, and robotics.
Kowalkiewicz was a SAP Mentor in their SAP Influencer Program from 2013 - 2018. According to SAP's website, SAP Mentors are "Top influencers in the SAP ecosystem, representing customers, partners, and consultants."
QUT and Chair in Digital Economy
In 2015, Kowalkiewicz was appointed Professor and PwC Chair in Digital Economy at Queensland University of Technology (QUT). This joint venture between QUT, PwC, Brisbane Marketing and the Queensland Government was a five-year research initiative that enabled collaboration between industry, academia and government and was tasked with "designing digital transformation strategies for complex economic and social challenges".
In 2016, Kowalkiewicz was a member of the Opportunities for Personalised Transport Review Taskforce guiding the Queensland Government on developing new ride-sharing regulation. The newDemocracy Foundation ranked the regulation, dubbed "Legalising Uber," as one of the leading evidence-based policy initiatives of the year following reports by Per Capita and the Institute of Public Affairs.
From 2016 - 2019, Kowalkiewicz was Research Theme Lead: Embracing the Digital Age.
In 2020, Kowalkiewicz co-founded his Queensland AI Hub in collaboration with Queensland's government, universities and industry leaders. The AI Hub was established during the COVID-19 crisis to improve Queensland's AI capability.
In 2020, Kowalkiewicz established a QUT Centre for the Digital Economy, as its founding director. In 2022, the Centre was merged with the very similar QUT's Centre for Future Enterprise, and Kowalkiewicz carries out its "Algorithmic Enterprise" research.
Boards, fellowships, memberships
Board Member, State Library of Queensland, 2017 - 2023
Founder and Member of the Board Of Advisors, Queensland AI Hub, 2020 - 2023
Fellow, On Deck, 2020 - present
Member of Ministerial ICT Advisory Council, Queensland Government, 2019 - present
Keynotes
Kowalkiewicz has delivered more than 100 keynotes to academia and industry. He primarily speaks on the rapidly evolving field of artificial intelligence and the challenges and opportunities it presents to organisations. Keynote topics include digital economy, digital transformation, economy of algorithms, innovation sprints, artificial intelligence, natural language processing, technology management, and business information systems.
Awards and Recognition
2024 - Good Design Award - Gold Winner (for Research Innovation Sprints)
2011 - Winner SAP TechEd DemoJam Las Vegas
2011 - Winner SAP TechEd DemoJam Bangalore
Publications
Books
The Economy of Algorithms: Rise of the Digital Minions was published in March 2024.
Awards
2024 - Winner of the Australian Business Book Awards' technology category
2024 - Silver medal at the Independent Publisher Book Awards for the book's contribution to current events (social and humanitarian issues)
Editions
Chinese translation published in September 2024
Audiobook published in June 2024
Articles
Kowalkiewicz is the author or co-author of more than 140 publications.
Online news sites
Kowalkiewicz is a regular contributor to:
Harvard Business Review
The Conversation not-for-profit media outlet
Online publishing platform Medium
Digital newsletter platform Substack
Patents
Workflow task re-evaluation, United States US 8429668 B2, Issued June 11, 2009
Workflow Modeling With Flexible Blocks, United States US 20090281777 A1, Issued November 12, 2009
Composing and executing service processes, United States US 20100088701 A1, Issued April 8, 2010
Method and system to effectuate recovery for dynamic workflows, United States US 20110246991 A1, Issued October 6, 2011
Systems and Methods for Augmenting Physical Media from Multiple Locations, United States US 20120324372 A1, Issued December 20, 2012
Creating parallel control flows in business process models, United States US 8365136 B2, Issued January 29, 2013
Systems and methods for data aware workflow change management, United States US 8413150 B2, Issued April 2, 2013
Timer patterns for process models, United States US 8683436 B2, Issued March 25, 2014
Work flow model processing with weak dependencies that allows runtime insertion of additional tasks, United States US 8719826 B2, Issued May 6, 2014
Multi-media collaborator, United States US 20140152665 A1, Issued June 5, 2014
Creating parallel control flows in business process models, Europe EP 2101292 A1, Issued September 16, 2009
Method, system and computer program product for composing and executing service processes, Europe EP 2175403 A1, Issued April 14, 2010
Method and system to effectuate recovery for dynamic workflows, Europe EP 2372620 A1, Issued October 5, 2011
References
External links
Kowalkiewicz's publications indexed by Google Scholar
Kowalkiewicz's QUT profile
1978 births
Living people
Artificial intelligence researchers
Computer scientists
Australian computer scientists
Polish computer scientists
Polish emigrants to Australia | Marek Kowalkiewicz | [
"Technology"
] | 1,723 | [
"Computer science",
"Computer scientists"
] |
75,552,978 | https://en.wikipedia.org/wiki/Tremella%20erythrina | Tremella erythrina is a species of fungus in the family Tremellaceae. It produces orange to red, lobate to foliaceous, gelatinous basidiocarps (fruit bodies) and is parasitic on other fungi on wood of broad-leaved trees. It was originally described from China.
Taxonomy
Tremella erythrina was first published in 2019 by Chinese mycologists Xin-Zhan Liu and Feng-Yan Bai based on collections made in Guangxi Province, China. The species is considered to be close to Tremella mesenterica, the type species of the genus, and hence belongs in Tremella sensu stricto.
Description
Fruit bodies are gelatinous, red to brownish orange, up to 18 mm across, cerebriform (brain-like) to foliaceous, with undulating, hollow lobes. Microscopically, the basidia are tremelloid (globose to broadly ellipsoid, with oblique to vertical septa), 4-celled, 12 to 18 by 13 to 19 μm. The basidiospores are ellipsoid, smooth, 7 to 10 by 5 to 7 μm.
Similar species
Tremella dysenterica and T. rubromaculata are similarly coloured, but were described from Brazil and Guatemala respectively. Tremella samoensis, described from Samoa, and T. flammea, described from Japan, are also similar in colour, but differ microscopically.
Habitat and distribution
Tremella erythrina is a parasite on lignicolous fungi, but its host is unknown. It was originally described from wood of a deciduous tree.
The species is currently only known from China.
References
erythrina
Fungi described in 2019
Fungi of Asia
Fungus species | Tremella erythrina | [
"Biology"
] | 378 | [
"Fungi",
"Fungus species"
] |
75,555,324 | https://en.wikipedia.org/wiki/Israeli%20bombing%20of%20Cairo | The Israeli Air Force bombarded a residential neighborhood near Qasr al-Qubba in Cairo on July 15, 1948, during the international phase of the 1948 Palestine war. The attack was carried out during the breaking of the fast of Ramadan and killed 30 civilians and destroyed many homes. It led to an angry march on the Jewish quarter.
Background
Before the establishment of the State of Israel, the Haganah had ordered three Boeing B-17 Flying Fortress planes from the United States through US Mahal operative Al Schwimmer. The heavy bomber planes were prepared for combat by Mahal recruit Ray Kurtz. They were acquired during the truce and smuggled from Czechoslovakia in violation of an arms embargo.
Attacks on Egyptian targets
The 69 Squadron of the Israeli Air Force was flying the planes, which were ordered to strike Egyptian targets on the way from Czechoslovakia. The air operation attempted to bomb King Farouq's Abdeen Palace. One plane went to Cairo but failed to hit the palace. The bombing struck a residential neighborhood during Iftar, killing 30 Egyptians and striking a rail line. According to Al-Ahram the following day, the bombardment happened at 7:55 pm.
The two other planes were supposed to strike el-ʻArīsh but bombed Rafah instead.
Results
The bombardment killed 30 Egyptians, struck a rail line, and led to an angry march on a Jewish quarter in Cairo.
The bombardment raised morale in Tel Aviv.
References
1948 in Egypt
Airstrikes conducted by Israel
Airstrikes in Egypt
Battles and operations of the 1948 Arab–Israeli War
Egypt–Israel military relations
Military history of Cairo
1940s in Cairo
Explosions in Cairo
Building bombings in Egypt
Attacks on railway systems
Mass murder in 1948
Mass murder in Cairo
20th-century mass murder in Egypt
Israeli war crimes
Attacks on buildings and structures in the 1940s
Cross-border operations of Israel
Egypt in the Arab–Israeli conflict | Israeli bombing of Cairo | [
"Technology"
] | 379 | [
"Railway accidents and incidents",
"Attacks on railway systems"
] |
75,556,122 | https://en.wikipedia.org/wiki/Ryan%20O%27Donnell%20%28computer%20scientist%29 | Ryan O'Donnell is a Canadian theoretical computer scientist and a professor at Carnegie Mellon University. He is known for his work on the analysis of Boolean functions and for authoring the textbook on this subject. He is also known for his work on computational learning theory, hardness of approximation, property testing, quantum computation and quantum information.
O'Donnell completed his B.Sc. in Mathematics and Computer Science at the University of Toronto. He then completed his Ph.D. at the Massachusetts Institute of Technology (MIT) in 2003, advised by Madhu Sudan.
Research
O'Donnell proved that the Goemans–Williamson approximation algorithm for MAX-CUT is optimal, assuming the unique games conjecture. The proof follows from two papers, one in 2004 with Subhash Khot, Guy Kindler, and Elchanan Mossel which reduced this statement to proving the Majority Is Stablest conjecture in analysis of Boolean functions, and one in 2005 with Elchanan Mossel and Krzysztof Oleszkiewicz which proves this conjecture. He later wrote an influential textbook on the analysis of Boolean functions.
O'Donnell's other notable contributions include participation in the first Polymath project, Polymath1, for developing a combinatorial proof to the density Hales–Jewett theorem, improved algorithms for problems in computational learning theory, and improved algorithms for the tomography of quantum states.
Recognition
He received the National Science Foundation CAREER Award in 2008 and a Sloan Research Fellowship in 2009. He gave an invited lecture at the International Congress of Mathematicians in 2014.
Service
O'Donnell served as the editor-in-chief for the journal ACM Transactions on Computation Theory from 2019 to 2023 and was an editor of the SIAM Journal on Discrete Mathematics from 2012 to 2017. He is on the scientific advisory board of the Simons Institute for the Theory of Computing
and on the scientific board of the Electronic Colloquium on Computational Complexity.
O'Donnell operates a YouTube channel, which has 10.2k+ subscribers and 680k+ views as of December 2023. On there, he delivers mathematics and computer science lectures on topics such as complexity theory, spectral graph theory, and analysis of boolean functions, as well as uploads lectures from his classes at Carnegie Mellon University. He has directed several course series, such as his "CS Theory Toolkit" series, where he explores mathematical areas applicable to the theoretical computer science field.
Selected publications
References
External links
Official website
Faculty page
YouTube channel
Living people
Quantum information scientists
Theoretical computer scientists
Date of birth missing (living people)
Computer scientists
Year of birth missing (living people) | Ryan O'Donnell (computer scientist) | [
"Technology"
] | 531 | [
"Computer science",
"Computer scientists"
] |
75,557,217 | https://en.wikipedia.org/wiki/Aitken%20Lectureship | The Aitken Lectureship is awarded by the New Zealand Mathematical Society to a research mathematician from New Zealand. The lectureship is named for New Zealander Professor Alexander Aitken, formerly of the University of Edinburgh. The lectureship was funded in 2009 by the London Mathematical Society and the New Zealand Mathematical Society, and is normally awarded every two years, alternating with the Forder Lectureship. Recipients of the lectureship will give a several-week lecturing tour of UK universities and a lecture at the annual meeting of the London society.
Recipients
The recipients of the Aitken Lectureship are:
2011: Geoff Whittle
2013: Robert Mclachlan
2015: Steven Galbraith
2017: Hinke Osinga
2019: Bakh Khoussainov
2022: Lisa Orloff Clark
See also
List of mathematics awards
References
Awards of the London Mathematical Society
Biennial events
University and college lecture series
Higher education in New Zealand
New Zealand–United Kingdom relations
2009 establishments in England
2009 establishments in New Zealand | Aitken Lectureship | [
"Technology"
] | 205 | [
"Science and technology awards",
"Science award stubs"
] |
75,557,877 | https://en.wikipedia.org/wiki/Geoffrey%20Gordon%20%28computer%20scientist%29 | Geoffrey Gordon was the creator of the popular GPSS simulation system language.
Career
In the early 1950s, Gordon began using analog computers for simulation in England. A few years later he began working with digital computers.
He moved to the United States in 1955 where he continued working with digital simulation at Westinghouse Electric Corporation. At the end of following year (1956) he began working at Bell Labs, writing simulation software for message switching systems.
In 1959, he started work on a project to digitally simulate what was seen across flow-chart style simulation sequence diagrams, instead of writing new software for each one. These diagrams used nodes to communicate the flow and operations of a simulation. The project, called the "Sequence Diagram Simulator" was completed at the end of that year.
In 1960, Gordon became manager of the Advanced Systems Development Division at IBM which experimented with new technology to design more efficient systems, especially in teleprocessing problems. Since the use of simulation was important in creating accurate models, Gordon suggested that a block diagram language be created similar to the Sequence Diagram Simulator. The new program and corresponding language, unofficially called the "Gordon Simulator", was developed in the IBM 704 symbolic assembly language. It became known throughout the company as a useful tool and became officially documented for internal use in the company on October 25, 1960. The use of the program outside of the company was soon recognized by the Cross Industry Marketing Group of IBM. On October 6, 1961, the program became available publicly outside of IBM as "GPSS I" after a complete rewrite. It was initially available for the IBM 704, 709, and 7090.
Gordon retired from IBM as a Consulting Systems Engineer and an IBM Fellow. He then became a professor at Kean University.
On December 19, 1989, he died in Washington, New Jersey.
References
1924 births
1989 deaths
Computer scientists | Geoffrey Gordon (computer scientist) | [
"Technology"
] | 378 | [
"Computer science",
"Computer scientists"
] |
75,558,170 | https://en.wikipedia.org/wiki/Charge%20based%20boundary%20element%20fast%20multipole%20method | The charge-based formulation of the boundary element method (BEM) is a dimensionality reduction numerical technique that is used to model quasistatic electromagnetic phenomena in highly complex conducting media (targeting, e.g., the human brain) with a very large (up to approximately 1 billion) number of unknowns. The charge-based BEM solves an integral equation of the potential theory written in terms of the induced surface charge density. This formulation is naturally combined with fast multipole method (FMM) acceleration, and the entire method is known as charge-based BEM-FMM. The combination of BEM and FMM is a common technique in different areas of computational electromagnetics and, in the context of bioelectromagnetism, it provides improvements over the finite element method.
Historical development
Along with more common electric potential-based BEM, the quasistatic charge-based BEM, derived in terms of the single-layer (charge) density, for a single-compartment medium has been known in the potential theory since the beginning of the 20th century. For multi-compartment conducting media, the surface charge density formulation first appeared in discretized form (for faceted interfaces) in the 1964 paper by Gelernter and Swihart. A subsequent continuous form, including time-dependent and dielectric effects, appeared in the 1967 paper by Barnard, Duck, and Lynn. The charge-based BEM has also been formulated for conducting, dielectric, and magnetic media, and used in different applications.
In 2009, Greengard et al. successfully applied the charge-based BEM with fast multipole acceleration to molecular electrostatics of dielectrics. A similar approach to realistic modeling of the human brain with multiple conducting compartments was first described by Makarov et al. in 2018. Along with this, the BEM-based multilevel fast multipole method has been widely used in radar and antenna studies at microwave frequencies as well as in acoustics.
Physical background - surface charges in biological media
The charge-based BEM is based on the concept of an impressed (or primary) electric field and a secondary electric field . The impressed field is usually known a priori or is trivial to find. For the human brain, the impressed electric field can be classified as one of the following:
A conservative field derived from an impressed density of EEG or MEG current sources in a homogeneous infinite medium with the conductivity at the source location;
An instantaneous solenoidal field of an induction coil obtained from Faraday's law of induction in a homogeneous infinite medium (air), when transcranial magnetic stimulation (TMS) problems are concerned;
A surface field derived from an impressed surface current density of current electrodes injecting electric current at a boundary of a compartment with conductivity when transcranial direct-current stimulation (tDCS) or deep brain stimulation (DBS) are concerned;
A conservative field of charges deposited on voltage electrodes for tDCS or DBS. This specific problem requires a coupled treatment since these charges will depend on the environment;
In application to multiscale modeling, a field obtained from any other macroscopic numerical solution in a small (mesoscale or microscale) spatial domain within the brain. For example, a constant field can be used.
When the impressed field is "turned on", free charges located within a conducting volume immediately begin to redistribute and accumulate at the boundaries (interfaces) of regions of different conductivity in . A surface charge density appears on the conductivity interfaces. This charge density induces a secondary conservative electric field following Coulomb's law.
One example is a human under a direct current powerline with the known field directed down. The superior surface of the human's conducting body will be charged negatively while its inferior portion is charged positively. These surface charges create a secondary electric field that effectively cancels or blocks the primary field everywhere in the body so that no current will flow within the body under DC steady state conditions.
Another example is a human head with electrodes attached. At any conductivity interface with a normal vector pointing from an "inside" (-) compartment of conductivity to an "outside" (+) compartment of conductivity , Kirchhoff's current law requires continuity of the normal component of the electric current density. This leads to the interfacial boundary condition in the form
for every facet at a triangulated interface. As long as are different from each other, the two normal components of the electric field, , must also be different. Such a jump across the interface is only possible when a sheet of surface charge exists at that interface. Thus, if an electric current or voltage is applied, the surface charge density follows.
The goal of the numerical analysis is to find the unknown surface charge distribution and thus the total electric field (and the total electric potential if required) anywhere in space.
System of equations for surface charges
Below, a derivation is given based on Gauss's law and Coulomb's law. All conductivity interfaces, denoted by , are discretized into planar triangular facets with centers . Assume that an -th facet with the normal vector and area carries a uniform surface charge density . If a volumetric tetrahedral mesh were present, the charged facets would belong to tetrahedra with different conductivity values. We first compute the electric field at the point , for i.e., just outside facet 𝑚 at its center. This field contains three contributions:
The continuous impressed electric field itself;
An electric field of the -th charged facet itself. Very close to the facet, it can be approximated as the electric field of an infinite sheet of uniform surface charge . By Gauss's Law, it is given by where is a background electrical permittivity;
An electric field generated by all other facets , which we approximate as point charges of charge at each center .
A similar treatment holds for the electric field just inside facet 𝑚, but the electric field of the flat sheet of charge changes its sign. Using Coulomb's law to calculate the contribution of facets different from , we find
From this equation, we see that the normal component of the electric field indeed undergoes a jump through the charged interface. This is equivalent to a jump relation of the potential theory. As a second step, the two expressions for are substituted into the interfacial boundary condition , applied to every facet 𝑚. This operation leads to a system of linear equations for unknown charge densities which solves the problem:
where is the electric conductivity contrast at the -th facet. The normalization constant will cancel out after the solution is substituted in the expression for and becomes redundant.
Application of fast multipole method
For modern characterizations of brain topologies with ever-increasing levels of complexity, the above system of equations for is very large; it is therefore solved iteratively. An initial guess for is the last term on its right-hand side while the sum is ignored. Next, the sum is computed and the initial guess is refined, etc. This solution employs the simple Jacobi iterative method. The more rigorous generalized minimum residual method (GMRES) yields a much faster convergence of the BEM-FMM. In either case, the major work is in computing the underbraced sum in the system of equations above for every at every iteration; this operation corresponds to a repetitive matrix-vector multiplication. However, one can recognize this sum as an electric field (times ) of charges to be computed at observation points. Such a computation is exactly the task of the fast multipole method, which performs fast matrix-by-vector multiplication in or even operations instead of . The FMM3D library realized in both Python and MATLAB can be used for this purpose. It is therefore unnecessary to form or store the dense system matrix typical for the standard BEM.
Continuous charge-based BEM. Near-field correction
The system of equations formulated above is derived with the collocation method and is less accurate. The corresponding integral equation is obtained from the local jump relations of the potential theory and the local interfacial boundary condition of normal electric current continuity. It is a Fredholm integral equation of the second kind
Its derivation does not involve Green's identities (integrations by parts) and is applicable to non-nested geometries. When the Galerkin method is applied and the same zeroth-order basis functions (with a constant charge density for each facet) are still used on triangulated interfaces, we obtain exactly the same discretization as before if we replace the double integrals over surfaces and of triangles and , respectively, by
where is the surface area of the triangle . This approximation is only valid when is much larger than a typical facet size i.e., in the "far field". Otherwise, semi-analytical formulae and Gaussian quadratures for triangles should be used. Typically, 4 to 32 such neighbor integrals per facet should be precomputed, stored, and then used at every iteration. This is an important correction to the plain fast multipole method in the "near field" which should also be used in the simple discrete formulation derived above. Such a correction makes it possible to obtain an unconstrained numerical (but not anatomical) resolution in the brain.
Applications and limitations
Applications of the charge-based BEM-FMM include modeling brain stimulation with near real-time accurate TMS computations as well as neurophysiological recordings. They also include modeling challenging mesoscale head topologies such as thin brain membranes (dura mater, arachnoid mater, and pia mater). This is particularly important for accurate transcranial direct-current stimulation and electroconvulsive therapy dosage predictions. The BEM-FMM allows for straightforward adaptive mesh refinement including multiple extracerebral brain compartments. Another application is modeling electric field perturbations within densely packed neuronal/axonal arbor. Such perturbations change the biophysical activating function. A charge-based BEM formulation is being developed for promising bi-domain biophysical modeling of axonal processes.
In its present form, the charge-based BEM-FMM is applicable to multi-compartment piecewise homogeneous media only; it cannot handle macroscopically anisotropic tissues. Additionally, the maximum number of facets (degrees of freedom) is limited to approximately for typical academic computer hardware resources used as of 2023.
See also
Computational electromagnetics
Boundary element method
Fast multipole method
Computational neuroscience
Transcranial magnetic stimulation
Transcranial direct-current stimulation
Electroencephalography
Magnetoencephalography
External links
A survey on integral equations for bioelectric modeling, preprint.
Flatiron Institute - Simons Foundation FMM3D GitHub Project Site.
References
Computational electromagnetics
Dimension reduction | Charge based boundary element fast multipole method | [
"Physics"
] | 2,235 | [
"Computational electromagnetics",
"Computational physics"
] |
75,558,350 | https://en.wikipedia.org/wiki/HIV%20latency | Human Immunodeficiency Virus (HIV) has the capability to enter a latent stage of infection where it exists as a dormant provirus in CD4+ T-cells. Most latently infected cells are resting memory T cells, however a small fraction of latently infected cells isolated from HIV patients are naive CD4 T cells.
Molecular Control of HIV Latency
HIV transcription is controlled by the 5' Long Terminal Repeat (LTR) region of the provirus, which serves as the key promoter.
LTR Structure
The LTR promoter has multiple upstream DNA regulatory elements: there are three SP1-binding sites, a TATA element, and an initiator sequence. The LTR has two NF-кB binding motifs that are capable of binding both NF-кB transcription factors as well as NFATs. The LTR promoter is very noisy and prone to large bursts of transcription. While signaling through the NF-кB enhancers has been shown to be necessary for re-activation of latent proviruses, mutations in these sites do not completely inhibit viral growth in cell line experiments.
Tat Control of HIV Transcription
The LTR of HIV is positively auto regulated by the Tat (transcription activator) protein, which is found towards the 3' end of the HIV genome. Without Tat activity, HIV transcription is restricted and often results in abortive transcripts. Tat activates the LTR through interactions with the elongation factor P-TEFb; Tat binds to cyclin T1, which is a unit of P-TEFb. Tat:P-TEFb directs RNA polymerases to the provirus genome by binding the HIV transactivation response (TAR) element, an RNA stem-loop structure.
Latency Regulation
The mechanisms underpinning HIV latency and proviral induction are not thoroughly understood, and two competing models attempt to explain how latency is controlled.
Cell-dependent control
In the cell-dependent model of latency regulation, host cell processes control provirus latency and induction. Generally, this model proposes that the relaxation of active CD4+ T-cells to a resting or quiescent state as memory T cells restricts proviral transcription and leads to latency.
Multiple host-cell processes have been experimentally linked to HIV latency regulation. Observations both in patient samples and in vitro experiments with T cell lines have correlated latency with the relaxation of activated T cells to a resting-memory state. Latency was initially thought to be due to HIV proviral genome integration into heterochromatin, but later it was found that latent proviral transcripts were still preferentially integrated into active genes. The main changes in cell state observed are epigenetic silencing of the HIV LTR as well as cytosolic sequestration of NF-кB and NFAST, which can activate HIV transcription if present in the nucleus. The LTRs of latent proviruses acquire heterochromatic structures instead of integrating into previously heterochromatic areas, and show high levels of deacetylated and methylated histones, which reinforces the role of chromatin restriction in latency regulation. Histone deacetylases (HDACs) are recruited to the proviral genome during latency establishment and methylate key Histone H3 Lysines, indicating a role of HDACs in latency regulation.
In addition to cytosolic sequestration of transcription factors, the P-TEFb complex is restricted in quiescent T cells through incorporation into an RNP complex. In latently infected cells, NF-кB induction and TNF-α have been shown to be necessary but not sufficient for viral induction. T-cell Receptor (TCR) activation has been shown to activate proviral transcription in latently-infected memory T cells, indicating some correlation between proviral induction and T cell state.
Cell-autonomous control
In contrast to the cell-dependent model, the cell-autonomous model proposes that HIV latency decisions are largely driven by the Tat-positive feedback loop and latency is therefore a probabilistic response due to intrinsically generated phenotypic heterogeneity rather than host-cell-determined.
Multiple studies have found that proviral induction is dependent on the Tat autoregulation response. In a study focused on understanding the diversity of roles of Sp1 and NF-кB binding elements in the LTR, authors noted that the Tat autoregulatory circuit resulted in a phenotypic bifurcation of genetically identical cells where viral gene expression was either off or highly induced. Additionally, primate studies of HIV latency have shown that latent cells emerge before the adaptive immune response is established, indicating that latency cannot entirely be dependent on T-cell relaxation after peak adaptive immune response. Latency is also established in cell-culture models with up to a 50% probability of establishment.
Some research has shown that the Tat positive-feedback loop in isolation has the ability to establish latency via stochastic noise, and that T-cell relaxation is not sufficient to drive latency. This model proposes to explain why many latent proviruses are not reactivated along with T-cell reactivation: instead of a deterministic mechanism, cellular activation or relaxation would probabilistically affect HIV latency decisions, which is consistent with other work showing that LTR regulatory sites have some influence on the frequency of phenotypic bifurcation of HIV transcription.
Bet-Hedging Hypothesis
One key hypothesis put forward is that latency allows HIV infection to persist past the initial mucosal stage; latently infected cells could allow HIV to disseminate from mucosal tissue to lymph nodes with much higher populations of the target CD4+ T cells. This hypothesis is supported by observations that HIV infections appear to expand from single founder sequences, indicating that the mucosal infection provides a bottleneck. A two-compartment model of HIV dissemination and transmission predicts that the probability of latency for an HIV provirus should be close to 50% to balance dissemination from the mucosal tissue and transmission inoculum.
Clinical Relevance
Latently infected cells are the key barrier to viral elimination by current antiretroviral therapies. A study focused on determining the frequency of latently infected cells in patients on combination antiretroviral therapy found that latently infected cells created a stable reservoir of virus with a half-life of 43 months. This latent reservoir forces patients to continuously take antiretroviral therapy to avoid viral re-emergence. An additional study found that actively infected cells and viremia re-emerge within weeks of antiretroviral therapy being discontinued.
Some work has been put into a "shock and kill" strategy to circumvent the challenge posed by latently infected reservoirs: before antiretrovirals, there is a "shock" phase that attempts to reactivate most latent proviruses. So far, these "shock" phases focus on drugs that stimulate P-TEFb nuclear mobilization and direct transcriptional activation of HIV. Further work is being done to understand LTR noise and more effectively activate or kill latently infected cells.
References
Virology
Viral life cycle | HIV latency | [
"Biology"
] | 1,500 | [
"Viral life cycle"
] |
71,233,584 | https://en.wikipedia.org/wiki/Act%201%20adaptor%20protein | Act 1 adaptor protein (Act 1) is an essential intermediate in the interleukin-17 pathway. The IL-17 protein is a pro-inflammatory cytokine important for tissue inflammation in host defense against infection and in autoimmune disease. It is produced by the CD4 + T cells, in particular the Th17 cells. There are 6 subtypes of IL-17, from IL-17A to IL17-F, these subtypes have nearly identical structures. We know that the cytokines are interacting homotypically, but IL-17A and IL-17F are capable do perform heterotypic interaction too.
Each cytokine has its own receptor, IL-17RA to IL-17F, and their pathways are still under investigation. It has been proven that these receptors are not using MyD88 and IRAK in their signaling pathways. They indeed use the adaptor Act1 protein, and TRAF family protein in order to activate the nuclear factor-kappa B (NF-κB), a transcription factor involved in the immunity response (see the pathways explanation below). This protein has different binding sites, which can physically attach the different components in order to activate them.
Act1 is crucial in the IL-17 signaling pathway. Moreover, this protein is only used in cells expressing CD40 and CD40L, which are also from the tumor necrosis receptor superfamily and more importantly expressed by B cells. It can also be expressed by other cell types such as epithelial cells, monocytes, basophils, dendritic cells, fibroblasts, smooth muscle cells, endothelial cells. Therefore, Act1 has a very wide impact on the immune system.
Act1 malfunction could induce autoimmunity (see below).
Structure
Some studies have been done in order to understand the structure of each subunit, and their importance in the protein function:
C-Terminal SEFIR domain (residues 394 to 574): This domain is shared by the Act1 protein and the IL-17R. It has been shown that the two components interact through this domain physically. It allows to start the IL-17 pathway by direct contact between the receptor and the adaptor.
U3-box: Site in which Act1 can perform the ubiquitination of other proteins.
TRAF domains (residues 35 to 42, and 333 to 337): Act1 has two TRAF domains. Act1 will interact with the TRAF family proteins, in particular, TRAF6 in order to activate the NF-κB pathway. Indeed, Act1 polyubiquitinates TRAF6. TRAF6 will then be activated and recruit TAK1 (TGFβ Activated Kinase 1 ), leading to the activation of NF-κB.
HLH-domain (residues 135 to 190): It is a helix-loop-helix (HLH) which allow the interaction with the IkB kinase protein (IKK). This protein allows the phosphorylation of IkB, which is part of a trimer of protein and sequestering the NF-κB. When IKK interacts with Act1, this one will be activated, phosphorylate IkB inducing the releasing of NF-κB which translocates into the nucleus and induces gene expression.
Act1 in the IL-17 pathway
When IL-17 binds to its receptor, IL-17R is activated and recruits Act1 adaptor through the SEFIR domain that they are both sharing.
NF-κB is kept inactive in the cytoplasm by the IkB subunits which is part of a complex composed of two other subunits: IKKγ and IKKα.
Subsequently, Act1 recruits TRAF6 through its TRAF domain and ubiquitinates this protein. Once this protein is ubiquitinated, it will recruit TAK1. It leads to the polyubiquitination of IkB which releases NF-κB, allowing its translocation inside the nucleus.
Act1 also recruits the IKK complex through its HLH domain. This complex phosphorylates the IkB protein which will release as well NF-κB and induce its activation.
Act1 used by CD40 receptor
Act1 activates NF-κB through the TAK1 and IKK proteins. Nevertheless, TRAF3 is also involved when the CD40 receptor is activated. When CD40 is stimulated by CD40L, Act1 binds to TRAF3, with the help of TRAF2 and 5 in order to activate the JNK proteins. The precise function of TRAF3 remains unknown. Indeed, depending on the TRAF variants involved, the protein has an activatory or inhibitory signal for NF-κB activation. It has been shown that there is mostly an inhibition in the NF-κB signaling when TRAF3 is activated. But, due to the splicing, some variants of TRAF3 have been identified to activate the NF-κB pathway, as well as the TRAF2 and 5. Furthermore, the activation of NF-κB induces the inhibition of the CD40L-induced apoptosis. The function of TRAF3 is complex and not yet fully understood.
Act1 adaptor and diseases
Act1 is an important protein for the immune system functions. Furthermore, its dysfunction is involved in autoimmunity or other diseases, such as allergic airway inflammation or psoriatic arthritis. When the Th17 cell number is enhanced, it leads to the over-production of IL-17, inducing Act1 activation and inflammation, and autoimmunity.
Given the fact that Act1 inhibits the CD40-40L stimulation, its loss would induce an accumulation of B cell population. This enhancement of cells number triggers lymphoma and antibody production, leading to auto-immunity.
Some studies have shown that Act1 could be involved in psoriatic arthritis due to SNP (single nucleotide polymorphism), but the mechanism in which it takes place is still under investigation.
Study this adaptor could be a way to treat the disease related to the IL-17 signaling and Th17 cells.
References
Human biology
Immune system process | Act 1 adaptor protein | [
"Biology"
] | 1,306 | [
"Human biology",
"Immune system process"
] |
71,233,927 | https://en.wikipedia.org/wiki/Psilocybe%20fasciata | Psilocybe fasciata is a species of fungus belonging to the psychedelic Psilocybe genus. It was first documented in 1957 by Japanese mycologist Tsuguo Hongo. It was found growing at the outskirts of a bamboo forest in Japan.
References
fasciata
Fungi of Japan
Fungi described in 1957
Fungus species | Psilocybe fasciata | [
"Biology"
] | 68 | [
"Fungi",
"Fungus species"
] |
71,234,420 | https://en.wikipedia.org/wiki/List%20of%20blockchains | This is a list of blockchains - decentralized, cryptographic databases - and other distributed ledgers.
List
See also
Category:Blockchains
List of cryptocurrencies
References
General refs
https://arxiv.org/pdf/1708.05665.pdf
Blockchains
Blockchains | List of blockchains | [
"Technology"
] | 69 | [
"Computing-related lists"
] |
71,238,169 | https://en.wikipedia.org/wiki/Read%27s%20conjecture | Read's conjecture is a conjecture, first made by Ronald Read, about the unimodality of the coefficients of chromatic polynomials in the context of graph theory. In 1974, S. G. Hoggar tightened this to the conjecture that the coefficients must be strongly log-concave. Hoggar's version of the conjecture is called the Read–Hoggar conjecture.
The Read–Hoggar conjecture had been unresolved for more than 40 years before June Huh proved it in 2009, during his PhD studies, using methods from algebraic geometry.
References
Conjectures that have been proved
Graph theory | Read's conjecture | [
"Mathematics"
] | 122 | [
"Graph theory stubs",
"Mathematical theorems",
"Graph theory",
"Mathematical relations",
"Conjectures that have been proved",
"Statements in graph theory",
"Mathematical problems"
] |
71,238,193 | https://en.wikipedia.org/wiki/Clear-Vision | Clear-Vision is a Japanese EDTV (Extended Definition TV) television system introduced in the 1990s, that improves audio and video quality while remaining compatible with the existing broadcast standard. Developed to improve analog NTSC, it adds features like progressive scan, ghost cancellation and widescreen image format. A similar system named PALPlus was developed in Europe with the goal of improving analog PAL broadcasts.
The initial version of the system was called IDTV (Improved Definition Television, or SuperNTSC) and was based on advanced signal processing on TV receivers. This allowed improvements such as progressive scan, ghost cancellation (reducing the effects of multipath propagation) and NTSC luminance and chroma crosstalk reduction (by way of filtering), without requiring any extra information being broadcast. These early studies were done by NTV, under the direction of the MPT (Ministry of Post and Telecommunications) and the BTA (Broadcasting Technology Association).
This early standard was published as ITU-R recommendation BT.797 - "CLEARVISION". Public broadcasting began on NTV in August 1989, under the name of EDTV-I or "Clear-Vision", ending on July 24, 2011.
Tests for an updated system known as EDTV-II or "Wide-aspect Clear-vision" started in 1994. EDTV-II supported 480p progressive scan, wide-screen and digital audio. Public broadcasting began in July 1995 by NTV. The standard was published as ARIB STD-B9 - "Direct Coding for EDTV-II Television Signal" in 1997 and as ITU BT.1298 - "Enhanced wide-screen NTSC TV transmission system".
EDTV-II broadcasts are displayed in letterbox format (with black bands on the top and bottom of the screen) on regular 4:3 NTSC receivers with no decoding ability. Information to reconstruct the original image signal is transmitted as helper signals - HH (horizontal high), VH (vertical high) and VT (vertical-temporal) - placed on the black bars. This solution is similar to the one used on PALplus, a comparable system to improve analog PAL broadcasts. On compatible TV sets, broadcasts are seen in 16:9 wide-screen retaining the full original 480 line resolution.
When introduced, EDTV-II was used on many shows by NTV such as Friday Road Show. At the time of TOKYO MX start in 1995, more than half of its broadcasts were in widescreen using EDTV-II, such as Tokyo NEWS. Interest was predicted to be high, with manufacturers such as Sony and Mitsubishi having 16 to 32'' widescreen EDTV-II compatible TVs available that same year. Yet, due to lack consumer interest, broadcasts returned to regular 4:3 over the years. NHK used the system occasionally, as it was more interested in promoting its own analog high-definition MUSE system. Widescreen EDTV-II broadcasts gradually disappeared, with World Heritage, broadcast by Sony, being the last show shown using the format.
Other than widescreen broadcasts, the system gave a limited improvement in image quality, mostly noticeable on larger TV sets. Yet these TVs benefited more from true HDTV broadcasts using the MUSE system, also available at the time. The system was replaced by ISDB digital broadcasts after 2012.
Technical details
The EDTV-II "Clear-Vision" transmission system is based on the following elements:
Vertical conversion of the original full resolution 480 lines widescreen image to a 360-line 16:9 letterbox picture. High and low-pass filters are used.
Recovery of original vertical image resolution using helper signals (VH, VT). Taking advantage of the letterbox black bands, these are modulated on the color subcarrier, with visibility minimized on regular 4:3 televisions. The vertical helper (VH) carries the missing vertical luminance details in motionless portions of the picture. The vertical temporal helper (VT) carries information allowing the receiver to reconstruct the original progressive scanning.
Recovery of original horizontal image resolution using a helper signal (HH), taking advantage of the “Fukinuki hole”. Horizontal luminance between 4.2 - 6 MHz is transmitted by frequency division multiplexing into the active area of the letterbox signal.
A wide-screen signaling system, according to recommendations EIAJ CPX1204 / ITU BT.1119;
The chrominance signal is transmitted in the active area of the letterbox (360 lines).
Some elements are optional, but the standard requires that at least one helper and the wide-screen signaling are used.
See also
PALplus (a similar system for PAL broadcasts)
Improved-definition television
Enhanced-definition television
MUSE
NTSC
Broadcast television systems
Widescreen television
Widescreen signaling
References
Audiovisual introductions in 1989
Audiovisual introductions in 1995
1989 establishments in Japan
1995 establishments in Japan
2011 disestablishments in Japan
Television technology
Television transmission standards
Video formats | Clear-Vision | [
"Technology"
] | 1,023 | [
"Information and communications technology",
"Television technology"
] |
71,238,570 | https://en.wikipedia.org/wiki/Journal%20of%20Clinical%20Virology | Journal of Clinical Virology is a scientific journal that covers the aspects of human virology that directly pertains to virus-induced clinical conditions. The journal is published by Elsevier.
Abstracting and indexing
The journal is abstracted and indexed in:
Current Contents - Clinical Medicine
Sociedad Iberoamericana de Informacion Cientifica (SIIC) Data Bases
PubMed/Medline
Embase
Elsevier BIOBASE
Scopus
According to the Journal Citation Reports, the journal has a 2021 impact factor of 14.481.
References
External links
Elsevier academic journals
English-language journals
Virology journals
ISSN needed
Publications with year of establishment missing | Journal of Clinical Virology | [
"Biology"
] | 135 | [
"Virus stubs",
"Viruses"
] |
71,240,373 | https://en.wikipedia.org/wiki/Leucoagaricus%20badhamii | Leucoagaricus badhamii is a species of fungus in the family Agaricaceae and genus Leucoagaricus. The flesh of this mushroom turns blood red when cut or bruised, hence its common name of blushing dapperling. These damaged areas may eventually turn brown or black and likewise the mushroom may discolour brown or black with age. All parts of the flesh display red staining aiding in identification.
Leucoagaricus badhamii is a species of mushroom belonging to the genus Leucoagaricus. It is commonly known as Badham's agaricus or sometimes as Badham's leucoagaricus. This mushroom is part of the family Agaricaceae. The cap color is typically white, and it can reach a diameter of about 3 to 8 centimeters (1.2 to 3.1 inches).
Taxonomy
This mushroom was first described by the British mycologists Miles Joseph Berkeley and Christopher Edmund Broome in 1854 who gave it the name Agaricus badhamii. In 1943 the French mycologist Marcel Locquin moved this species to the genus Leucocoprinus and some modern sources still refer to it as Leucocoprinus badhamii however in 1951 it was reclassified as a Leucoagaricus species by the German mycologist Rolf Singer.
Etymology
Leucoagaricus gets its name from the Greek Leucos meaning white and Latin or Greek Agaricus meaning 'of the country'. Badhamii is named for the British writer, physician, entomologist and mycologist Charles David Badham, author of the 1847 text Treatise on the Esculent Funguses of England.
Description
Leucoagaricus badhamii is a large dapperling mushrooms with white flesh that readily stains red-brown when damaged.
Cap: 5-8cm. Starts ovate/hemispherical before flattening with a slight umbo before finally becoming slightly depressed. Whitish background with brown to black scales or speckles. Turns red when cut or bruised with damaged areas ultimately turning brown or black. Discolours brown or black with age. Stem: 8-12cm. Tapers upwards from bulbous base with a persistent but fragile annulus. Stains red-brown when touched. Gills: White, free/collared, crowded. Staining red-brown when touched. Spore print: White. Spores: ovoid, smooth, dextrinoid. 6.5-8 x 4-4.5 μm. Taste: indistinct, may turn saliva red. Smell: fruity/acidic.
Habitat and distribution
Like other Leucoagaricus species, L. badhamii is a saprotroph, living on humus rich ground, growing in small groups in deciduous and mixed woodland and may be associated with beech trees. It may also grow on woodchips enabling it to appear outside of forest habitats. It has a widespread distribution and has been found in America, Britain, Europe and Africa but appears to be uncommon.
Similar species
Leucoagaricus erythrophaeus exhibits similar red staining.
See also
List of Leucoagaricus species
References
badhamii
Fungi described in 1854
Fungus species | Leucoagaricus badhamii | [
"Biology"
] | 669 | [
"Fungi",
"Fungus species"
] |
71,241,206 | https://en.wikipedia.org/wiki/Leucocoprinus%20ianthinus | Leucocoprinus ianthinus is a species of mushroom producing fungus in the family Agaricaceae. Like several other Leucocoprinus species it may have originated in a tropical climate but now finds a home in plant pots, greenhouses and compost piles in many countries. It is not seen in plant pots with the same kind of regularity as the well known Leucocoprinus birnbaumii and not seen in the wild as frequently as Leucocoprinus brebissonii.
Taxonomy
It was first described in 1888 by the English botanist and mycologist Mordecai Cubitt Cooke who classified it as Agaricus (Lepiota) ianthinus based on specimens collected in the hothouses of Kew Gardens (London, England) in 1888. In 1891 the Italian mycologist Pier Andrea Saccardo reclassified it as Lepiota ianthinus or Lepiota janthina in the original text. It was reclassified as Leucocoprinus ianthinus in 1945 by Marcel Locquin.
An additional basionym was classified as Lepiota lilacinogranulosa or Lepiota lilacino-granulosa by the German mycologist Paul Christoph Hennings in 1898. In 1934 the French botanists and mycologists Roger Heim and Henri Romagnesi reclassified it as a variant of Hiatula cepaestipes (now known as Leucocoprinus cepistipes). The species was reclassified as Leucocoprinus lilacinogranulosa by Locquin in 1943. This is now also considered a synonym of Leucocoprinus ianthinus however some mycologists do consider them as separate, but similar looking species.
Description
Leucocoprinus ianthinus is a small dapperling mushroom with thin white flesh.
Cap: 1.5-7cm, starting ovate/hemispherical before expanding to campanulate (bell shaped) with age with a prominent umbo and then plano-convex with age. The surface is whitish with a dark purple to reddish brown centre and purplish scales spreading across the cap but becoming sparse at towards the edges. The margins have striations that extend two thirds of the way across the cap or up to the umbo. They may split radially and discolour yellowish with age and it is common for them to curve inwards with age. Gills: Free, moderately crowded and white. Stem: 3.5-7cm long and 2-5mm wide tapering upwards from a slightly bulbous base and hollow interior. The surface is yellowish white towards the top of the stem, whitish below the ring and then with a violet to lilac fibrillose coating at the base and a white tomentous covering at the bulb. The white, ascending, stem ring has a purplish margin but may disappear. Spore print: White to pale lilac. Spores: A different range of sizes is given by different sources: 8–12 x 5.5–7.5 μm or 6.5–10 x 5.75–6.5 μm or 9.5-10.5 x 6.5-7 μm. Ellipsoid to amygdaliform with a thick wall and a germ pore that is covered with a hyaline cap. Dextrinoid, congophilous and cyanophilous. In cresyl blue a pink colouration is visible in the inner wall of the spore. Basidia: 17–42 x 8–11 μm. Four spored or rarely two spored. Smell: fungal, strong and astringent. Taste: fungal.
Similar species
Leucocoprinus brebissonii can appear similar but is distinguished by the darker brown colour of the centre disc and the white stem which lacks a purplish base. It is more commonly found in the wild rather than in plant pots.
Leucocoprinus heinemannii and some related, possibly undescribed species in the Heinemannii complex may appear similar but with black scales.
Leucocoprinus lilacinogranulosus is considered a synonym for L. ianthinus however some sources suggest they may be separate species.
References
Leucocoprinus
Fungi described in 1888
Fungus species | Leucocoprinus ianthinus | [
"Biology"
] | 902 | [
"Fungi",
"Fungus species"
] |
71,241,537 | https://en.wikipedia.org/wiki/Pollination%20of%20orchids | The pollination of orchids represents a complex aspect of the biology of this plant family, characterized by intricate flower structures and diverse ecological interactions with pollinator. Notably, the topic has garnered significant scientific interest over time, including the attention of Charles Darwin, who is recognized for his contributions to the theory of evolution by natural selection. In 1862, Darwin published his observations on the essential role of insects in orchid pollination in his work The Fertilization of Orchids. He noted that the various strategies employed by orchids to attract their pollinators are complex.
Adaptations of orchids to pollination by animals
Approximately 97% of orchid species rely on pollinator for the transfer of pollen from one plant to the pistils of another, which is essential for fertilization and seed formation. The pollen of orchids is organized into compact masses known as pollinia (singular: "pollinium"), preventing dispersal by wind and necessitating the presence of pollinators for sexual reproduction. These pollinators vary widely and may include flies, mosquitos, bees, wasps, butterflies, coleopterans, and birds, particularly hummingbirds.
The phenomenon of zoophily in orchids requires that pollinating animals frequently visit the flowers and remain long enough to contact both the anthers and stigma. For successful pollen transfer, it is crucial that the pollen adheres effectively to the pollinators, enabling it to reach the stigmas of other flowers. The effectiveness of zoophily depends on the ability of these animals to recognize flowers from a distance and their attraction to flowers of the same species. Consequently, zoophilous flowers typically possess "attractive products" such as pollen and nectar, "means of attraction" like scents and colors, and pollen that is viscous or adhesive.
Throughout the evolution of angiosperms, there has been significant differentiation in the means of attraction and flower morphology, allowing a broader range of animals to participate in pollination. This evolutionary process has led to the establishment of close relationships between pollinating animals and zoophilous flowers, benefiting both groups. For plants, this relationship has resulted in more precise attraction of specific pollinators, facilitating the transfer of pollen to the stigmas of other plants and reducing the overall production of pollen. In contrast to anemophilous plants, which may produce around one million pollen grains per ovule, orchids typically produce a one-to-one ratio. For specialized pollinators, this mutualism has reduced competition from other anthophilous animals, making targeted pollination advantageous.
The evolutionary development of zoophilous angiosperms and their adapting animal partners is best understood as a process of coevolution characterized by reciprocal relationships. In some cases, orchids and their pollinators have become so interdependent that their existence is mutually exclusive. Pollination mechanisms resulting from this coevolution generally benefit both parties: pollinators obtain nectar from the flowers, while orchids gain pollen transfer. However, in numerous instances, the attraction of pollinators to orchids may rely on deceptive strategies that do not offer any rewards.
Orchid flowers
Orchid flowers are predominantly hermaphroditic, with unisexual forms being rare, and they typically exhibit zygomorphic (bilateral) symmetry. Most genera feature three outer elements known as sepals—two lateral and one dorsal—and three inner elements called petals, with the lower petal often modified into a lip or labellum. This labellum is usually larger and more vividly colored than the other petals, often exhibiting a trilobed or uniquely shaped structure, sometimes adorned with fleshy bumps or ridges, and may feature a basal spur with distinct color patterns.
The androecium of orchids generally comprises one or two stamens, occasionally three, and is fused with the style and stigma to form a structure known as the column (or gynostema/gynostegium). The pollen is organized into masses called pollinia, which can vary in number from one to twelve, though two or four are most common. These pollinia, combined with a sticky stalk derived from the anther or stigma, form the transport unit during pollination. The gynoecium consists of three fused carpels and is situated below the calyx. It features a highly modified style that is solitary and terminal, forming a key component of the column. Near the apex, the stigma has an elongated lobe known as the rostellum, which is typically non-receptive and positioned above the stigmatic region. A part of the rostellum may develop into a sticky platform called the viscidium, which attaches to the pollinium stem.
Orchids generally produce nectar as a reward for pollinators, with nectaries varying in their location and type. They may be situated on the lip spur, at the tips of the sepals, or on the septa of the gynoecium. Additionally, some orchid species are capable of self-pollinatings or are apomictics, meaning they can produce seeds without the need for pollinators.
Attraction of pollinators by means of rewards
Many orchid species provide various rewards to pollinators, including nectar, food hairs, oils, and other compounds such as waxes, resins, and fragrances. These rewards serve to reinforce pollinator behavior, enhancing the likelihood of effective pollen transfer. Over time, this specialization on a single type of pollinator has led to increased morphological and structural adaptations in orchid flowers, aimed at attracting specific insect species.
This evolutionary aspect of the interspecific relationships between orchids and their pollinators was notably examined by Charles Darwin in his studies of both British and exotic orchid species. A prominent example is the Madagascar species Angraecum sesquipedale, which features a spur exceeding 30 cm in length that contains nectar. Darwin's attempts to extract the pollinia from this flower using needles were unsuccessful; he was only able to do so by inserting a cylinder with a diameter of 2.5 mm into the spur and pulling it out, causing the viscidium to adhere to the cylinder. Darwin proposed that when a butterfly reached the bottom of the spur to access the nectar, the pollinia would attach to its head as it withdrew its proboscis. Upon visiting another flower, the butterfly would then transfer the pollinia to its stigma. Based on this reasoning, Darwin suggested that the pollinator of Angraecum sesquipedale would need to have a proboscis longer than 30 cm, an idea that seemed implausible to contemporary biologists. However, this prediction was confirmed in 1903 with the discovery of the moth Xanthopan morganii praedicta in Madagascar, which possesses a proboscis of the predicted length. The subspecific epithet "praedicta" reflects the foretelling of its existence by Darwin.
The moth is attracted to Angraecum sesquipedale by its fragrance, particularly during the night. Upon approaching the flower, the moth unrolls its proboscis and inserts it into a crevice of the rostellum that leads to the spur. After accessing the nectar at the base of the spur, the moth lifts its head while withdrawing its proboscis, causing the viscidium to adhere to its head or another part of its body. The viscidium contains a small pedicel, known as the caudicle, which carries the pollinia. When the moth finishes feeding and moves to another flower, the caudicle dehydrates, altering its angle relative to the insect’s body. This positioning ensures that when the moth inserts its proboscis into the next flower, the pollinia are properly aligned to attach to the stigma. After successful pollination, the flowers stop producing fragrance, and their tepals wither shortly thereafter. Nonetheless, the processes of pollen transfer, fertilization, and the formation of numerous new individuals have already been secured.
Many orchids, including Angraecum sesquipedale, are pollinated by nocturnal butterflies and, as a result, tend to have light-colored or nearly white flowers that emit fragrance in the evening or night. Other examples of such orchids include Bonatea speciosa, Habenaria epipactidea, species in the genus Satyrium, Disa cooperi and D. ophrydea. In contrast, some orchid genera have evolved to be pollinated by diurnal butterflies, exhibiting bright colors and providing nectar as a reward.
Melitophilous orchids, which are pollinated by bees, typically produce a strong fragrance during the day and are robustly colored. Examples include Satyrium erectum and Disa versicolor. These bee-pollinated orchids often offer not only nectar but also oils—a relatively rare reward in the plant kingdom—used by various bee species to nourish their larvae. Notable genera that provide oil rewards include Disperis, Pterygodium, Corycium, Ceratandra, Evotella, Satyrium, and Pachites.
Pollination by flies, known as myophily, is the second most prevalent method of pollination among orchids, involving pollinators from twenty different dipteran families. These flowers typically emit scents reminiscent of decaying organic materials, excrement, or carrion, which attract flies seeking food or suitable sites for egg deposition. Various floral parts produce putrescent or carrion-like odors and often incorporate traps to retain the pollinators, alongside appendages and colors that may mimic flesh or other aspects of rotting matter. For example, species in the genus Bulbophyllum, which are daciniphilous, attract true fruit flies from the Dacini tribe (Tephritidae) using pleasant or spicy scents as floral synomones, establishing mutualistic relationships that confer reproductive benefits to both the orchids and the male flies. Notably, B. hortorum has coevolved with male fruit flies to develop a unique pollination mechanism that selects for optimal-sized individuals as potential pollinators.
Stelis hymenantha produces a strong aroma of sweet menthol. It secretes a sticky substance at the base of the labellum that resembles nectar. Another species, S. immersa, also emits a fragrance, described as melon-like, with its sticky substance located on both the petals and the labellum’s base. The primary visitors to these species are dipterans from various families. Typically, flies remain outside the flowers, investigating the viscous liquid on the petal surfaces. In the case of Stelis immersa, female flies from the genus Megaselia (Phoridae) are specifically adapted for effective pollen transfer. After inspecting the nectar-like substance, these insects enter the flower laterally and land on the downward-facing labellum. When this occurs, the labellum rises, pressing the fly against the viscid pollinium and trapping it. To exit, the fly backs up, causing the viscidium to adhere to its thorax. The labellum then returns to its original position, releasing the fly, which has now facilitated pollination.
Attraction and reward by means of perfumes
The flowers of the subtribes Stanhopeinae and Catasetinae exhibit specialized pollination mechanisms. These species are exclusively pollinated by male euglossine bees, which collect perfumes from the flowers. The reasons behind this behavior are not entirely understood, as the perfumes do not provide nutrition or protection but may play a role in the mating rituals of these bees.
The process of scent collection is quite similar across species. The male bee approaches the osmophore, the scent-producing part of the flower, and perches on the labellum. Using the long, dense hairs on its front legs, the bee gathers the aromatic substances, which are typically liquid but can also be found in crystalline form. If the scent compounds are solid, the bee dissolves them with secretions from its salivary glands. Once saturated with the aroma, the bee transfers the scents using its middle legs to storage cavities in its hind legs, where they can be preserved for extended periods. Different orchid genera attach pollinia to various parts of the bee’s body.
Orchids, like many plants, attract specific groups of male euglossine bees by producing species-specific scent mixtures, which likely act as reproductive isolation mechanisms. Some orchids exhibit morphological adaptations that ensure pollinia are only released upon visitation by particular bee species, depending on their size and behavior. Consequently, not all euglossine bees that visit a given orchid species are effective pollinators.
Additionally, certain species of Bulbophyllum attract specific male Dacini fruit flies through particular male attractants such as methyl eugenol (ME), raspberry ketone (RK), or zingerone (ZN). Methyl eugenol serves as a sex pheromone precursor for several quarantine pest species of Bactrocera, including the oriental fruit fly (B. dorsalis), B. carambolae, B. occipitalis, and B. umbrosa. Similarly, raspberry ketone and zingerone function as sex pheromone components for male fruit flies like Zeugodacus caudatus, Z. cucurbitae, and Z. tau.
Attraction of pollinators by means of deception
Many orchids employ various deceptive tactics to attract pollinators by mimicking scents, shapes, colors, or movements associated with resources of interest to the pollinators, without providing any actual rewards. The mechanisms of deception are diverse and can be categorized as follows:
Generalized Feeding Deception: Flowers mimic the shape and coloration of species that typically offer rewards to pollinators.
Feeding Deception Mediated through Floral Mimicry: In this case, flowers closely resemble a specific species that rewards pollinators, cohabiting in the same environment.
Mimicry of Nesting Sites: Flowers imitate the egg-laying sites of certain pollinators.
Mimicking Shelter Sites: Flowers provide potential shelter for pollinators, a strategy that may not be deceptive but can be mutually beneficial for both the insect and the orchid.
Pseudo-Antagonism: This mechanism attracts pollinators by invoking their innate defense responses. Flowers mimic the appearance of another insect species that the pollinator may perceive as a threat, prompting the pollinator to attack the flower. In doing so, the insect inadvertently transfers pollen to other flowers.
Rendezvous Attraction: Flowers imitate other flowers that are attractive to female pollinators.
Sexual Deception: In this scenario, flowers mimic the visual and olfactory mating signals of female pollinators.
Among these mechanisms, generalized feeding deception is the most commonly observed in orchids, reported in 38 genera, followed by sexual deception, which has been identified in 18 genera.
Attraction of pollinators by luring them for food
The ability to attract pollinators without offering rewards has evolved independently across several angiosperm lineages, although it typically occurs in only a few species within each family. In contrast, it is estimated that approximately one-third of orchid species employ a food-deceptive mechanism. This strategy involves signaling the presence of food, such as nectar or pollen, to attract pollinators without providing any actual reward. Orchids often achieve this by resembling species that do offer rewards and that cohabit in the same environment. Feeding deception commonly manifests as a general resemblance to rewarding species, with orchids featuring large, brightly colored flowers that exploit pollinators' innate preferences for such floral characteristics.
Imitation of other plants
Another method employed by orchids to attract pollinators involves mimicking the flowers of other plant species. A notable example is Epidendrum ibaguense, a terrestrial or lithophilous orchid found from Mexico to Bolivia and Brazil. This orchid features orange flowers with an intense yellow labellum, closely resembling the flowers of Asclepias curassavica, a member of the Asclepiadaceae family. The butterfly Agraulis vanillae, which typically visits Asclepias curassavica to collect nectar in exchange for pollen transport, is frequently drawn to the mimetic flowers of Epidendrum ibaguense. When the butterfly approaches the orchid, it inserts its proboscis into the narrow duct (gynostemium) of the flower. The small diameter of this duct can cause the butterfly's spiracles to become temporarily trapped. In its struggle to escape, the insect inadvertently picks up the orchid's pollinia. After being released, the butterfly may visit another Epidendrum flower, transferring the pollinia and facilitating pollination without receiving nectar for its efforts.
Attraction of pollinators by sexual luring
Certain orchids have evolved deceptive flowers that mimic the shape, hairiness, and scent of female wasps or bees to attract male pollinators. A well-known example is Ophrys insectifera, found in southern Europe, which is exclusively visited by two species of wasps from the genus Argogorytes. Male wasps emerge in spring, weeks before females, and are attracted to the fragrance of Ophrys flowers, which resembles the pheromones secreted by female wasps. Additionally, the labellum of Ophrys insectifera closely resembles the shape, color, and texture of female wasps. This interaction is referred to as pseudocopulation, as male wasps attempt to mate with the flower, during which they come into contact with the anther and transfer pollinia between flowers.
The phenomenon of pollination by pseudocopulation was first documented by A. Pouyanne and H. Correvon in 1916 and 1917 while studying the relationship between the orchid Ophrys speculum and the scoliidae wasp Campsoscolia ciliata in Algeria. Their findings initially went unnoticed until Robert Godfrey validated their observations in 1925, prompting increased interest in this area of study. Following this, Australian biologist Edith Coleman published numerous papers on the pollination of orchids from the genus Cryptostylis by males of the ichneumonoidea wasp Lissopimpla excelsa.
Several genera of terrestrial orchids employ this pseudocopulation mechanism, including Ophrys, Cryptostylis, Drakaea, Caladenia, Chiloglottis, Geoblasta, Arthrochilus, Calochilus, Leporella, and Spiculaea. Most terrestrial orchid genera utilizing pseudocopulation are found in Australia, with Ophrys being the largest and best-documented genus in Europe. This mechanism is not limited to a specific continent; it has also been observed in the South American species Geoblasta penicillata and in two South African orchids of the genus Disa.
A similar mechanism is found in Tolumnia henekenii, whose flowers mimic the female of the bee species Centris insularis. The resemblance is so convincing that male bees attempt to copulate with the flower, thereby facilitating its pollination.
In the genus Caleana, commonly known as the duck orchid due to its labellum resembling the head of a duck and the overall flower resembling a flying duck, a distinct mechanism of pseudocopulation has been observed. This species utilizes a spring mechanism to trap pollinating insects in a pouch, with their only means of escape being through the pollinium and stigma. When male insects land on the labellum, they activate a two-hinged relaxation mechanism involving the labellum-lamellum and the lamina-perianth, which flips the insect into the pouch containing the stigma and pollinia.
Pseudocopulation is not limited to pollinators from the Hymenoptera order (such as bees and wasps); it has also been documented in certain Diptera. For instance, male mosquitoes of the genus Bradysia have been observed to pseudocopulate with species of Lepanthes, a large genus of orchids found in neotropical rainforests.
In Ophrys orchids, the flowers not only mimic the shape, size, and color of female pollinators but also emit fragrances that include compounds found in female sex pheromones. This reinforces the sexual attraction of males to the flowers. Chemical and electrophysiological comparisons have been made between the volatile compounds emitted by Ophrys iricolor and the female pheromones of its pollinator, Andrena morio. More than 40 compounds have been identified, including alkanes and alkenes with 20 to 29 carbon atoms, aldehydes with 9 to 24 carbons, and two esters. Most of these compounds are present in similar proportions in both floral extracts of O. iricolor and extracts from the cuticular surface of A. morio females.
The biologically active volatile compounds in Ophrys species are largely similar to those utilized by other Ophrys species that engage in pseudocopulation with males of the genera Andrena and Colletes.
See also
Orchidaceae
Orchis
Notes
References
Orchids
Pollination
Botany
Flowers
Charles Darwin | Pollination of orchids | [
"Biology"
] | 4,357 | [
"Plants",
"Botany"
] |
71,241,698 | https://en.wikipedia.org/wiki/Regge%E2%80%93Wheeler%E2%80%93Zerilli%20equations | In general relativity, Regge–Wheeler–Zerilli equations are a pair of equations that describes gravitational perturbations of a Schwarzschild black hole, named after Tullio Regge, John Archibald Wheeler and Frank J. Zerilli. The perturbations of a Schwarzchild metric is classified into two types, namely, axial and polar perturbations, a terminology introduced by Subrahmanyan Chandrasekhar. Axial perturbations induce frame dragging by imparting rotations to the black hole and change sign when azimuthal direction is reversed, whereas polar perturbations do not impart rotations and do not change sign under the reversal of azimuthal direction. The equation for axial perturbations is called Regge–Wheeler equation and the equation governing polar perturbations is called Zerilli equation.
The equations take the same form as the one-dimensional Schrödinger equation. The equations read as
where characterizes the polar perturbations and the axial perturbations. Here is the tortoise coordinate (we set ), belongs to the Schwarzschild coordinates , is the Schwarzschild radius and represents the time frequency of the perturbations appearing in the form . The Regge–Wheeler potential and Zerilli potential are respectively given by
where and characterizes the eigenmode for the coordinate. For gravitational perturbations, the modes are irrelevant because they do not evolve with time. Physically gravitational perturbations with (monopole) mode represents a change in the black hole mass, whereas the (dipole) mode corresponds to a shift in the location and value of the black hole's angular momentum. The shape of above potentials are exhibited in the figure.
Remember that in the tortoise coordinate, denotes event horizon and is equivalent to i.e., to distances far away from the back hole. The potentials are short ranged as they decay faster than ; as we have and as , we have Consequently, the asymptotic behaviour of the solutions for is
Relations between the two problems
In 1975, Subrahmanyan Chandrasekhar and Steven Detweiler discovered a one-to-one mapping between the two equations, leading to a consequence that the spectrum corresponding to both potentials are identical. The two potentials can also be written as
The relations between and are given by
Reflection and transmission coefficients
Here is always positive and the problem is one of reflection and transmission of waves incident from to . The problem is essentially the same as that of a reflection and transmission problem by a potential barrier in quantum mechanics. Let the incident wave with unit amplitude be , then the asymptotic behaviours of the solution are given by
where and are respectively are the reflection and transmission amplitudes. In the second equation, we have imposed the physical requirement that no waves emerge from the event horizon.
The reflection and transmission coefficients are thus defined as
subjected to the condition Because of the inherent connection between the two equations as outlined in the previous section, it turns out
and thus consequently, since and differ only in their phases, we get
It is clear from the figure for the reflection coefficient that small-frequency perturbations are readily reflected by the black hole whereas large-frequency ones are absorbed by the black hole.
Quasi-normal modes
Quasi-normal modes correspond to pure tones of the black hole. It describes for arbitrary, but small, perturbations such as an object falling into the black hole, accretion of matter surrounding it, last stage of slightly aspherical collapse etc. Unlike the reflection and transmission coefficient problem, quasi-normal modes are characterised by complex-valued 's with the convention . The required boundary conditions are
indicating that we have purely outgoing waves with amplitude and purely ingoing waves at the horizon.
The problem becomes an eigenvalue problem. The quasi-normal modes are of damping type in time, although these waves diverge in space as (this is due to the implicit assumption that the perturbation in quasi-normal modes is 'infinite' in the remote past). Again because of the relation mentioned between the two problem, the spectrum of and are identical and thus it enough to consider the spectrum of The problem is simplified by introducing
The nonlinear eigenvalue problem is given by
The solution is found to exist only for a discrete set of values of This equation also implies the identity
See also
Chandrasekhar–Page equations
Teukolsky equations
References
Astrophysics
Eponymous equations of physics
General relativity
Ordinary differential equations | Regge–Wheeler–Zerilli equations | [
"Physics",
"Astronomy"
] | 928 | [
"Equations of physics",
"Eponymous equations of physics",
"Astrophysics",
"General relativity",
"Theory of relativity",
"Astronomical sub-disciplines"
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71,241,798 | https://en.wikipedia.org/wiki/Leucocoprinus%20straminellus | Leucocoprinus straminellus is a species of mushroom producing fungus in the family Agaricaceae. Like other Leucocoprinus species it may have originated in a tropical climate but now finds a home in plant pots, greenhouses and compost piles in many countries. Leucocoprinus straminellus is described as being similar to the more commonly known Leucocoprinus birnbaumii but it is smaller and a lighter shade of yellow with smaller spores that lack a germ pore. It is also described as being superficially similar to Leucocoprinus fragilissimus but slightly more robust with flesh that is less translucent.
Taxonomy
It was first described in 1865 by the Italian botanist Francesco Baglietto who classified it as Agaricus straminellus.
In 1887 the Italian mycologist Pier Andrea Saccardo classified it as Lepiota straminella.
It was reclassified as Leucocoprinus straminellus by the Italian mycologists Roberto Narducci and Vincenzo Caroti in 1995. However it is still sometimes referred to by its former name Leucocoprinus denudatus which it acquired in 1951 when classified by the German mycologist Rolf Singer.
In 1999 the variant Leucocoprinus straminellus var. albus was described by the mycologists Vincenzo Migliozzi & Marcello Rava. This is now considered a synonym.
Description
Leucocoprinus straminellus is a small dapperling mushroom with thin whitish to pale yellow flesh.
Cap: 1.5-2.5 cm wide, ovoid to campanulate (bell shaped) maturing to convex or almost flat with age but retaining the umbo. The surface is whitish yellow with a darker yellow centre and the margins are striated. Stem: 2.4–5 cm tall tapering upwards from a swollen base. The stem ring is located towards the top of the stem (median-superior) but quickly disappears. Gills: Free with a collar, distant and white-cream. Spore print: White. Spores: Ellipsoid to spherical and smooth. Dextrinoid. 5-6 x 4-4.5 μm. Taste: Indistinct. Smell: Indistinct.
The description of Leucocoprinus denudatus (now considered a synonym) from 1981 includes the following details:
Cap: 1.6-2.4 cm wide. Ovoid to campanulate or hemispheric and expanding with age to become convex or flat. Pale greenish-yellow in colour with the centre presenting with a deeper colour. The cap edges are paler and have striations. The centre of the cap is velvety in texture whilst the rest of the cap is covered in a fine powdery substance (pruinose) when examined under a lens. Gills: Crowded and free, tinted pale yellow or the same colour as the cap. Stem: 1.5-4.5 cm long and 2-3mm thick at the top, 4-6mm at the base. Paler yellow than the cap with a small, membranous stem ring that is high up (superior). The stem texture is smooth or very finely pruinose when examined with a lens and the base is often covered with soil. Spores: Globose to subglobose to broadly ovoid, with a minute apiculus, lacking a germ pore. 3.6-4.5 x (3.6) 4-4.8 μm and rarely up to 6-8 x 5.2μm. Pale yellow to rust yellow in Melzer's reagent. Basidia: 24-36 x 5-8μm, narrowly clavate to nearly cylindrical.
Dried specimens present with a brown umbo whilst the rest of the cap is yellow however dry immature specimens may develop brownish tones on the rest of the cap.
Due to the similarities with Leucocoprinus flavescens these species may often be confused resulting in inconsistencies in descriptions.
Habitat and distribution
Specimens studied in 1981 where found in June at the University of Michigan Botanical Garden. They were growing in dense clusters. This was the first observation of the species in North America but it is more commonly found in Europe.
Similar species
Leucocoprinus flavescens is described similarly with some sources suggesting they may be synonymous although they appear to have different sized spores and different coloured cap centres.
References
Leucocoprinus
Fungi described in 1865
Taxa named by Francesco Baglietto
Fungus species | Leucocoprinus straminellus | [
"Biology"
] | 949 | [
"Fungi",
"Fungus species"
] |
71,242,004 | https://en.wikipedia.org/wiki/Wiliot | Wiliot is a startup company developing Internet of Things technology for supply-chains and asset management, founded in 2017 and based in Caesarea, Israel, with customer operations in San Diego, US.
Wiliot develops battery-free printable sensor tags to monitor products like groceries, apparel and pharmaceuticals from their sources to stores and homes. The company's business model is to sell the use of its cloud software.
History
Wiliot was founded in 2017 by Tal Tamir, Yaron Elboim, and Alon Yehezkely, following the sales of their previous startup Wilocity to Qualcomm in 2014.
In 2019, Williot closed a $30 million series B round of funding from Amazon, Avery Dennison, Samsung and its previous series A investors Norwest Venture Partners, 83North Venture Capital, Grove Ventures, Qualcomm Ventures, and M Ventures. Other early investors include PepsiCo, NTT Docomo Ventures, and Vintage Investment Partners.
In 2021 Wiliot raised $200 million in a series C funding round led by SoftBank Vision Fund 2 and backed by all previous investors.
Technology
Wiliot's tags, called IoT Pixels, are a postage stamp-sized printed computer that powers itself by harvesting the energy from surrounding Wi-Fi, cellular and Bluetooth radio signals. The IoT Pixel tags have sensors for temperature, fill level, motion, location changes, humidity, and proximity. The tags cost less than 10 cents a piece.
The IoT Pixel includes an ARM Cortex-M0+ processor core, Bluetooth Low Energy connectivity, 1 kB of non-volatile memory, and antennas for Bluetooth and energy harvesting. Dual-band models include connectivity in the ISM bands.
In June 2022, Wiliot launched a business card-sized battery-assisted version of the IoT Pixel providing continuous connectivity.
Data from the sensors is fed into a Wiliot Cloud server, where algorithms help its customers make decisions through a software as a service subscription.
As of 2022, Wiliot is the assignee of 66 patents that relate to harvesting energy from very weak sources, running a computer element on tiny amounts of energy, producing a computer element in a thin, flexible form factor and the cloud services that enable sensing from such a system.
Applications
Wiliot's tags are designed for use in the many crates that agriculture shippers use to get their products to markets. The tags can provide information about the safety of the journey and the condition of perishable goods, to better manage inventory and reduce waste. Its first large public customer was Israeli supermarket chain Shufersal in June, 2022.
The has experimented with reducing food loss throughout the food supply chain from producers to stores and in consumers’ homes by visualizing product information using Wiliot's tags.
The company hopes to extend more broadly to sectors like pharmaceuticals and apparel Their tags can sense when a consumable is nearing end of life, or when a non-perishable consumable is almost used up, or how many washings a garment has been given.
Recognition
The industry recognition received by Wiliot include:
Winner of the 2019 CableLabs Innovation Showcase
Winner of the FDA’s Low- or No-Cost Food Traceability Challenge 2021
Frost & Sullivan’s 2022 North American Battery-free Bluetooth Low Energy Tag Technology Innovation Leadership Award
Frost & Sullivan's 2022 European Passive BLE-based IoT Solutions Customer Value Leadership Award
2022 SXSW Innovation Awards Finalist in the Smart Cities, Transportation & Delivery category
See also
Ambient IoT
References
External links
Wiliot: Mr. Beacon podcast
2017 establishments in Israel
Cloud applications
Internet of things companies
Israeli companies established in 2017
Supply chain software companies
Wireless sensor network
Companies based in Caesarea
Software companies of Israel | Wiliot | [
"Technology"
] | 762 | [
"Wireless networking",
"Wireless sensor network"
] |
71,242,696 | https://en.wikipedia.org/wiki/S4716 | S4716 is an S star located at the center of the Milky Way galaxy orbiting the supermassive blackhole Sgr A* at the speed of 8,000 kilometres per second in closest approach of 100 AU. As of July 2022, the orbital period of S4716 was the shortest known of any star in the Milky Way galaxy. It orbits the Sgr A* in 4.0 years, on an elliptical orbit with an eccentricity of 0.75. Its closest approach to Sgr A* is 15 billion kilometers (about the distance to the space probe Voyager 2 in 2022, or three times the distance of Neptune from the Sun), while its farthest approach is 100 billion kilometers. The star can be detected by NIRC2 (Keck), OSIRIS (Keck), SINFONI (VLT), NACO (VLT) and GRAVITY (VLT).
The star's radius is 2.45 solar radii.
References
Galactic Center
B-type main-sequence stars
Sagittarius (constellation) | S4716 | [
"Astronomy"
] | 220 | [
"Sagittarius (constellation)",
"Constellations"
] |
71,243,460 | https://en.wikipedia.org/wiki/Architectural%20education%20in%20India | <noinclude>Architectural education in India includes educational activities involved in the education and training of architects in the country. A typical outline of the architectural education pathway is presented below.
Overview
The architectural education in India includes educational activities involved in the education and training of architects in India. It is regulated by the Council of Architecture.
Pathway
The following provides typical outline of architectural education in India:
Diploma in Architecture or Architectural Assistantship is a 3-year long diploma (ISCED level 4) programme. Candidates are required to have completed the second year of Upper Secondary Education (Class 10). Graduates are eligible for admission to undergraduate programmes.
Bachelor of Architecture (B.Arch) is a 5-year long undergraduate professional (ISCED level 6) programme. Candidates are required to have completed the 12th grade of school (ISCED level 3) or diploma (ISCED level 4) with mathematics as core course. Additionally, candidates are required to pass the admission test National Aptitude Test in Architecture (NATA). Graduates are eligible to register as an architect and for admission to postgraduate programmes. Additionally, graduates with ten years experience in teaching, research and professional practice are eligible for admission to doctoral programmes in architecture.
Master of Architecture (M.Arch) is a 2-year long postgraduate (ISCED level 7) programme. Candidates are required to have completed Bachelor of Architecture (B.Arch) or equivalent recognised by the Council of Architecture. Additionally, candidates are required to pass the admission test Postgraduate Entrance Test in Architecture (PGETA). Graduates are eligible for admission to doctoral programmes in architecture.
Doctor of Philosophy (PhD) in Architecture is a terminal degree (ISCED level 8) programme. Candidates are required to have completed Master of Architecture (M.Arch) or postgraduate degree in allied fields. Additionally, Bachelor of Architecture (B.Arch) graduates with ten years experience in teaching, research and professional practice are eligible for admission.
Regulatory body
The Council of Architecture is a statutory body constituted by the Indian Ministry of Education under the Architects Act of 1972. It is responsible for regulation of architectural education and practice of architecture throughout India. It approves higher education institutions in India to provide a 5-year long Bachelor of Architecture (B.Arch) and a 2-year long Master of Architecture (M.Arch) degrees.
Bachelor of Architecture
The Bachelor of Architecture (B.Arch) is an undergraduate degree classified as ISCED level 6. It is also a professional degree that fulfils the academic requirements for registration as an architect with the Council of Architecture. The Council of Architecture maintains a list of approved architecture schools that offer this degree.
Structure
The B.Arch programme lasts 5 years and is divided into 10 semesters, each consisting of 90 working days. During their 8th or 9th semester, students undergo 80 days of practical training. In the 10th semester, students complete an Architectural Thesis, where they demonstrate their ability to conceive an architectural design of built environment.
See also
Architecture of India
References
Architectural education
Architectural education in India
Architecture in India
Architectural education by country | Architectural education in India | [
"Engineering"
] | 615 | [
"Architectural education",
"Architecture"
] |
71,245,442 | https://en.wikipedia.org/wiki/Peziza%20oliviae | Peziza oliviae is a species of fungus in the family Peziza. It is an olive-brown stalked cup fungus discovered growing underwater in streams in the U.S. State of Oregon.
Description
Peziza oliviae has small olive to golden-brown stalked cups 0.7–2.5 cm in height with a diameter of 0.8–4 cm.
Habitat and distribution
Found in small streams in the Cascade Range of North Central Oregon at elevations between 800 and 1500 metres. P. oliviae was found growing on dead wooden debris on the bottom of streams or on saturated wood at the surface or bank of the stream. Documented June through October.
Discovery
P. oliviae was discovered in 2014 by Jonathan L. Frank of Southern Oregon University.
References
Pezizaceae
Fungi described in 2014
Fungi of the United States
Fungus species | Peziza oliviae | [
"Biology"
] | 171 | [
"Fungi",
"Fungus species"
] |
71,247,549 | https://en.wikipedia.org/wiki/HU%20Tauri | HU Tauri is a tight binary star system in the equatorial constellation of Taurus. It is an eclipsing binary, which means that the member stars periodically eclipse each other every 2.056 days. They have a combined apparent visual magnitude of 5.85, which is bright enough to be dimly visible to the naked eye. During the primary eclipse, the magnitude drops to 6.68, while the secondary eclipse decreases the magnitude to 5.91. The distance to this system, based on parallax measurements, is approximately 414 light years.
The variable nature of this system was reported by W. Strohmeier and R. Knigge in 1960. In 1963, Strohmeier found a period of 2.056297 days, and A. Mammano and associates derived orbital elements for a single-lined spectroscopic binary in 1967. A light curve for the system was assembled by O. Tümer and M. Kurutaç in 1979. M. Parthasarathy and M. B. K. Sarma in 1980 noted asymmetries in the light curve near the primary eclipse, which suggested gas streams are partially obscuring the light from the primary component.
This is a semidetached binary system with an orbital period of 2.0563056 days in an essentially circular orbit. The primary component is presently a B-type main-sequence star with a stellar classification of B8V. It has 4.4 times the mass and 2.6 times the radius of the Sun. The primary eclipse is an occultation in which the secondary completely covers the primary. The cooler and larger secondary star is over-luminous for its mass, indicating that it has evolved away from the main sequence, and is filling its Roche lobe. The spectrum of the system suggests that the secondary is undergoing mass loss, with a gas stream transferring matter to the primary.
References
Further reading
B-type main-sequence stars
G-type subgiants
Algol variables
Spectroscopic binaries
Taurus (constellation)
1471
BD+20 785
029365
021604
Tauri, HU | HU Tauri | [
"Astronomy"
] | 440 | [
"Taurus (constellation)",
"Constellations"
] |
71,247,696 | https://en.wikipedia.org/wiki/Praseodymium%28III%29%20perchlorate | Praseodymium(III) perchlorate is the perchlorate salt of praseodymium, with the chemical formula of Pr(ClO4)3.
Preparation
Praseodymium(III) perchlorate can be prepared from praseodymium(III,IV) oxide. Dissolving praseodymium(III,IV) oxide in a slight excess of hydrochloric acid and adding a small amount of hydrogen peroxide can prepare praseodymium perchlorate.
Chemical properties
Praseodymium perchlorate can form two complexes with crown ether 18-crown-6 in stoichiometric ratios of 1:1 and 1:2., and can form complexes with L-proline, glutamic acid, mandelic acid, penicillamine. It can also form complexes with imidazole and alanine.
References
Praseodymium(III) compounds
Perchlorates | Praseodymium(III) perchlorate | [
"Chemistry"
] | 202 | [
"Perchlorates",
"Salts"
] |
69,647,244 | https://en.wikipedia.org/wiki/Pohlia%20nutans | Pohlia nutans, the nodding thread-moss, is a species of moss in the family Mniaceae. It has a cosmopolitan distribution, found on all seven continents; Europe, Iceland, Siberia, Japan, North America, Greenland, the Andes of South America, South Africa, Tasmania and nearby mainland Australia, New Zealand, and the Antarctic Peninsula and Mount Rittmann in Antarctica. An extremophile, it is resistant to cold, drought, salt, acid, heavy metals, and intense UV radiation.
Pohlia nutans is subject to fungal infections which cause fairy rings to appear. Some causative agents have been identified, including species of Cladosporium, Mortierella gamsii and Mortierella fimbricystis.
Subtaxa
The following subtaxa are accepted:
References
Mniaceae
Cosmopolitan species
Plants described in 1879 | Pohlia nutans | [
"Biology"
] | 176 | [
"Cosmopolitan species",
"Organisms by location"
] |
69,652,211 | https://en.wikipedia.org/wiki/Filippo%20Frontera | Filippo Frontera (Savelli, 16 November 1941) is an Italian astrophysicist and professor, who deals with astronomical investigations on celestial gamma-rays.
Biography
Education and career
"Laurea" degree in physics with laude in 1966 at the Università di Bologna. Full professor of Experimental Physics of the University of Ferrara, Engineering Faculty, Ferrara, Italy, retired in 2012, for eight years Filippo Frontera was coordinator of the PhD course in Physics of this university. Previously, from 1969 to 1985, he was a scientist of the IASF-CNR institute (now OAS-INAF) in Bologna. As "Distinguished Scientist" of the University of Ferrara, he is continuing his research activity at the Physics and Earth Sciences Department, and is lecturer of "Measurements and Observations of celestial X-rays and gamma-rays" for the Master course in Physics. He is also associated scientist of the National Institute of Astrophysics (INAF) in Bologna. He is also adjunct professor of the International Center of Relativistic Astrophysics Network (ICRANET) and is a Faculty member of the international IRAP-PhD doctorate.
Scientific contributions
Since his "Laurea", he carried out his scientific activity in the field of the hard X-ray astronomy. He was Principal Investigator (PI) of many successful balloon experiments, launched from Italy, France, US and Australia. Among the most relevant results obtained, the first evidence of Quasi Periodic Oscillations from a black hole candidate, discovery that was confirmed about 20 years later with the CGRO NASA satellite mission. He was also PI of two experiments on board the BeppoSAX satellite launched on 30 April 1996 from Cape Canaveral, Florida (USA): the high energy telescope (15-300 keV) PDS (Phoswich Detection System) and the "Gamma-Ray Burst Monitor" (GRBM), with many relevant results from both of them. Concerning the GRBM, it had a fundamental role, along with the Wide Field Cameras also on board of BeppoSAX, for the discovery, occurred in 1997, of the extragalactic origin of Gamma Ray Bursts (GRBs), a mystery about 30 years old. This discovery was classified by the American journal Science among the top ten most important discoveries of the 1997 in all science fields. During the life time of BeppoSAX (30 April 1996 – 30 April 2002), the GRBM detected more than thousand GRBs, and allowed many other discoveries, among them, the so-called "Amati relation" from the name of the first author, of great importance for GRB physics and the first association of a GRB (980425) with a supernova explosion (SN1998bw). Thanks to the BeppoSAX discovery of their extragalactic origin, GRBs are now recognized to be an ideal laboratory for settling several still open issues in cosmology and fundamental physics.
Frontera was also co-investigator of the JEM-X experiment on board the INTEGRAL satellite with the realization of the field collimator and the ground calibration of the experiment at the X-ray facility LARIX designed and developed under the Frontera responsibility. LARIX, now extended and upgraded, is a trans-national facility of the European program AHEAD.
Frontera collaborated to the design and, at LARIX facility, to the calibration of the high energy X-ray experiment (HE) aboard the Chinese satellite Insight-HXMT developed at the Institute of High Energy Physics (IHEP) (PI Shuang-Nan Zhang), successfully launched on 15 June 2017 from the Chinese launch base of Jiuquan in the Gobi Desert. The collaboration with IHEP is continuing with the scientific exploitation of this satellite observations.
Technological innovations
In collaboration with INFN section of Ferrara and IASF-INAF (now OAS-INAF) of Bologna, Frontera led the development of the first Laue lens prototype to focus high energy X-rays. The mounting technique of such lens is the subject of an Italian Space Agency (ASI)-University of Ferrara patent. The development of Laue lenses for astrophysical applications is continuing and a new concept of Laue lens is the key instrument of a mission concept, ASTENA, proposed for the ESA long-term program “Voyage 2050".
Publications
He is author of more than 360 papers published in international refereed journals, among which Nature and Science and about 200 publications in Proceedings of international symposia, with more than 850 titles in the NASA ADS (Astrophysics Data System) archive, inclusive of Circulars, and Telegrams.
For the high citation rate (currently more than 22,000), in 2007 he was included among the "Highly cited researchers" by ISI-Thomson from Philadelphia (USA).
Memberships
Frontera is an emeritus member of the American Astronomical Society, member of the Italian Physical Society (SIF), of the Italian Society of General Relativity and Gravitation (SIGRAV) and of the Ferrara Academy of Sciences.
He is also member of the "Gruppo 2003 for the Scientific Research", an Association made of only Italian highly cited scientists.
Awards
In 1998, along with the research team of the Beppo-SAX satellite, Frontera was awarded the Bruno Rossi prize of the American Astronomical Society "for the prompt discovery and accurate localization of the X-ray counterpart of Gamma Ray Bursts, thus making possible their extragalactic origin".
For the same discovery, in 2002, along with the research group represented by the astrophysicist Ed van den Heuvel, he was awarded the Descartes prize for "solving the gamma ray burst riddle".
In 2010, Frontera along with Enrico Costa, one of his two deputy PIs for the BeppoSAX/PDS and GRBM experiments, was awarded the SIF Enrico Fermi prize, of the Italian Physical Society, for “the discovery of the afterglow, i.e., of the X-ray luminescence, from Gamma Ray Bursts”.
In 2012, Frontera received the Marcel Grossmann Award "for guiding the Gamma-ray Burst Monitor project on board the Beppo-SAX satellite which led to the discovery of the GRB X-ray afterglows, and to their optical identification".
In 2024, Frontera received the Insight-HXMT International collaboration Award, “in recognition of Outstanding Contributions to the Insight-HXMT Mission”.
In 2024, in honor of Frontera, the asteroid of the main belt, 2002 AP12, was named 126177 Filippofrontera.
Honours
Commander of the Order of Merit of the Italian Republic
"Initiative of President of Italy" — Rome, 13 February 2014
See also
University of Ferrara
Beppo-SAX
Bruno Rossi Prize
Enrico Fermi Prize (SIF)
Marcel Grossmann Award
ICRANet
INAF
References
External links
(IT) Curriculum vitae di Filippo Frontera, su fe.infn.it.
Publications by Filippo Frontera, from The SAO/NASA Astrophysics Data System
X-ray astronomy
Commanders of the Order of Merit of the Italian Republic
Academic staff of the University of Ferrara
University of Bologna alumni
Living people
1941 births
Italian astrophysicists | Filippo Frontera | [
"Astronomy"
] | 1,495 | [
"Astronomical sub-disciplines",
"X-ray astronomy"
] |
69,657,443 | https://en.wikipedia.org/wiki/Evelyne%20Pease%20Tyner | Dr Evelyn Pease Tyner née Pease (1924–2015) was a biochemist and environmentalist.
Family
Background
Tyner was born in Evansville, Indiana. Tyner won the first Westinghouse Science Talent Search essay assignment was “How Science Can Help Win the War” in 1942, Tyner suggested to solve the rubber shortage
with “Rubber from Weeds”, and submitted three rubbery substances she had prepared, including one from the common milkweed. This enabled Tyner to work as a lab assistant during the summers in the research department of Mead Johnson & Co while attending Evansville College before transferring to the University of Michigan. Tyner went on to study a Ph.D. in Biological Chemistry on “The anti-lipotropic activity of cysteine”, graduating in 1950 and then marrying David A. Tyner, a chemistry student who had worked on the Manhattan Project. Tyner then moved to the University of Wisconsin at Madison to research the synthesis of DNA, RNA and proteins (before the structure of DNA was determined) and published a paper on the relationship between the A-T and G-C bases. In 1954 Tyner established the extracurricular Science Seminar at Niles West High School in Skokie.
Conservation work
In 1963, Tyner campaigned to help save an area of virgin prairie in Glenview, which raised its profile as a valuable habitat and led to the University of Illinois at Chicago purchasing the land, which is now known as the James B. Woodworth Prairie Preserve. Tyner then campaigned to save The Grove and then a 32-acre plot at Kent Fuller Air Station Prairie in Glenview; this led to her being known as one of the “Frog and Fern Ladies”. The Evelyn Pease Tyner Interpretive Center was built in 2006, and in 2007 the project was awarded the Platinum certification for Leadership in Energy and Environmental Design (LEED) due to the center's vegetated roof which combined native and ornamental plants.
References
1924 births
2015 deaths
Date of birth missing
Date of death missing
20th-century American people
Scientists from Indiana
20th-century women scientists
20th-century American women
University of Michigan alumni
Women biochemists | Evelyne Pease Tyner | [
"Chemistry"
] | 441 | [
"Biochemists",
"Women biochemists"
] |
68,357,817 | https://en.wikipedia.org/wiki/Cyanobacterial%20morphology | Cyanobacterial morphology refers to the form or shape of cyanobacteria. Cyanobacteria are a large and diverse phylum of bacteria defined by their unique combination of pigments and their ability to perform oxygenic photosynthesis.
Cyanobacteria often live in colonial aggregates that can take a multitude of forms. Of particular interest among the many species of cyanobacteria are those that live colonially in elongate hair-like structures, known as trichomes. These filamentous species can contain hundreds to thousands of cells. They often dominate the upper layers of microbial mats found in extreme environments such as hot springs, hypersaline water, deserts and polar regions, as well as being widely distributed in more mundane environments.
Many filamentous species are also motile, gliding along their long axis, and displaying photomovement by which a trichome modulates its gliding according to the incident light. The latter has been found to play an important role in guiding the trichomes to optimal lighting conditions, which can either inhibit the cells if the incident light is too weak, or damage the cells if too strong.
Overview
Cellular functions require a well-organized and coordinated internal structure to operate effectively. Cells need to build, sustain, and sometimes modify their shape, which allows them to rapidly change their behaviour in response to external factors. During different life cycle stages, such as cell growth, cell division or cell differentiation, internal structures must dynamically adapt to the current requirements. In eukaryotes, these manifold tasks are fulfilled by the cytoskeleton: proteinaceous polymers that assemble into stable or dynamic filaments or tubules in vivo and in vitro. The eukaryotic cytoskeleton is historically divided into three classes: the actin filaments (consisting of actin monomers), the microtubules (consisting of tubulin subunits) and the intermediate filaments (IFs), although other cytoskeletal classes have been identified in recent years. Only the collaborative work of all three cytoskeletal systems enables proper cell mechanics.
The long-lasting dogma that prokaryotes, based on their simple cell shapes, do not require cytoskeletal elements was finally abolished by the discovery of FtsZ, a prokaryotic tubulin homolog, and MreB, a bacterial actin homolog. These discoveries started an intense search for other cytoskeletal proteins in bacteria and archaea which finally led to the identification of bacterial IF-like proteins such as Crescentin from Caulobacter crescentus and even bacterial-specific cytoskeletal protein classes, including bactofilins. Constant influx of new findings finally established that numerous prokaryotic cellular functions, including cell division, cell elongation or bacterial microcompartment segregation are governed by the prokaryotic cytoskeleton.
Cyanobacteria are today's only known prokaryotes capable of performing oxygenic photosynthesis. Based on the presence of an outer membrane, cyanobacteria are generally considered Gram-negative bacteria. However, unlike other Gram-negative bacteria, cyanobacteria contain an unusually thick peptidoglycan (PG) layer between the inner and outer membrane, thus containing features of both Gram phenotypes. Additionally, the degree of PG crosslinking is much higher in cyanobacteria than in other Gram-negative bacteria, although teichoic acids, typically present in Gram-positive bacteria, are absent.
While Cyanobacteria are monophyletic, their cellular morphologies are extremely diverse and range from unicellular species to complex cell-differentiating, multicellular species. Based on this observation, cyanobacteria have been classically divided into five subsections. Subsection I cyanobacteria (Chroococcales) are unicellular and divide by binary fission or budding, whereas subsection II cyanobacteria (Pleurocapsales) are also unicellular but can undergo multiple fission events, giving rise to many small daughter cells termed baeocytes. Subsection III comprises multicellular, non-cell differentiating cyanobacteria (Oscillatoriales) and subsection IV and V cyanobacteria (Nostocales and Stigonematales) are multicellular, cell differentiating cyanobacteria that form specialized cell types in the absence of combined nitrogen (heterocysts), during unfavorable conditions (akinetes) or to spread and initiate symbiosis (hormogonia). Whereas subsections III and IV form linear cell filaments (termed trichomes) that are surrounded by a common sheath, subsection V can produce lateral branches and/or divide in multiple planes, establishing multiseriate trichomes. Considering this complex morphology, it was postulated that certain subsection V-specific (cytoskeletal) proteins could be responsible for this phenotype. However, no specific gene was identified whose distribution was specifically correlated with the cell morphology among different cyanobacterial subsections. Therefore, it seems more likely that differential expression of cell growth and division genes rather than the presence or absence of a single gene is responsible for the cyanobacterial morphological diversity.
Morphogenesis
Morphogenesis is the biological process that causes an organism to develop its shape. Cyanobacteria show a high degree of morphological diversity and can undergo a variety of cellular differentiation processes in order to adapt to certain environmental conditions. This helps them thrive in almost every habitat on Earth, ranging from freshwater to marine and terrestrial habitats, including even symbiotic interactions.
One factor which can drive morphological changes in cyanobacteria is light. As cyanobacteria are bacteria that use light to fuel their energy-producing photosynthetic machinery they depend on perceiving light in order to optimize their response and to avoid harmful light that could result in the formation of reactive oxygen species and subsequently in their death. Optimal light conditions may be defined by quantity (irradiance), duration (day–night cycle) and wavelength (color of light). The photosynthetically usable light range of the solar spectrum is generally referred to as PAR (photosynthetically active radiation), but some cyanobacteria may expand on PAR by not only absorbing in the visible spectrum, but also the near-infrared light spectrum. This employs a variety of chlorophylls and allows phototrophic growth up to a wavelength of 750 nm. To sense the light across this range of wavelengths, cyanobacteria possess various photoreceptors of the phytochrome superfamily.
Morphological plasticity, or the ability of one cell to alternate between different shapes, is a common strategy of many bacteria in response to environmental changes or as part of their normal life cycle. Bacteria may alter their shape by simpler transitions from rod to coccoid (and vice versa) as in Escherichia coli, by more complex transitions while establishing multicellularity or by the development of specialized cells, structures or appendages where the population presents a pleomorphic lifestyle. The precise molecular circuits that govern those morphological changes are yet to be identified, however, a so-far constant factor is that the cell shape is determined by the rigid PG sacculus which consists of glycan strands crosslinked by peptides. To grow, cells must synthesize new PG while breaking down the existent polymer to insert the newly synthesized material. How cells grow and elongate has been extensively reviewed in model organisms of both, rod-shaped and coccoid bacteria. The molecular basis for morphological plasticity and pleomorphism in more complex bacteria, however, is slowly being elucidated as well.
Despite their morphological complexity, cyanobacteria contain all conserved and so far known bacterial morphogens. Understanding cyanobacterial morphogenesis is challenging, as there are numerous morphotypes among cyanobacterial taxa, which can also vary within a given strain during its life cycle. Changes in cellular or even trichome morphologies are tasks that would require active cell wall remodelling and thus far no genes attributed to the different morphotypes have been identified in cyanobacteria. Therefore, the most likely scenario is that genes or their products are differentially regulated during these cell morphology transitions, as it has been hypothesized for most bacteria. In multicellular cyanobacteria, division of labor between cells within a trichome is achieved by different cell programing strategies. Thus, gene regulation occurs differentially in these specific cell types [30,97,98].
Diversity of forms
Cyanobacteria present remarkable variability in terms of morphology: from unicellular and colonial to multicellular filamentous forms. Their cell size varies from less than 1 μm in diameter (picocyanobacteria) up to 100 μm (some tropical forms in the genus Oscillatoria)
Filamentous forms exhibit functional cell differentiation such as heterocysts (for nitrogen fixation), akinetes (resting stage cells), and hormogonia (reproductive, motile filaments). These, together with the intercellular connections they possess, are considered the first signs of multicellularity.
Many cyanobacteria form motile filaments of cells, called hormogonia, that travel away from the main biomass to bud and form new colonies elsewhere. The cells in a hormogonium are often thinner than in the vegetative state, and the cells on either end of the motile chain may be tapered. To break away from the parent colony, a hormogonium often must tear apart a weaker cell in a filament, called a necridium.
Colonial and unicellular
In aquatic habitats, unicellular cyanobacteria are considered as an important group regarding abundance, diversity, and ecological character. Unicellular cyanobacteria have spherical, ovoid, or cylindrical cells that may aggregate into irregular or regular colonies bound together by the mucous matrix (mucilage) secreted during the growth of the colony. Based on the species, the number of cells in each colony may vary from two to several thousand.
Each individual cell (each single cyanobacterium) typically has a thick, gelatinous cell wall. They lack flagella, but hormogonia of some species can move about by gliding along surfaces.
Filamentous and multicellular
Some filamentous species can differentiate into several different cell types:
vegetative cells – the normal, photosynthetic cells that are formed under favorable growing conditions
akinetes – climate-resistant spores that may form when environmental conditions become harsh
thick-walled heterocysts – which contain the enzyme nitrogenase vital for nitrogen fixation in an anaerobic environment due to its sensitivity to oxygen.
Many of the multicellular filamentous forms of Oscillatoria are capable of a waving motion; the filament oscillates back and forth. In water columns, some cyanobacteria float by forming gas vesicles, as in archaea. These vesicles are not organelles as such. They are not bounded by lipid membranes but by a protein sheath.
Branched
Heterocysts
Heterocysts are specialized nitrogen-fixing cells formed during nitrogen starvation by some filamentous cyanobacteria, such as Nostoc punctiforme, Cylindrospermum stagnale, and Anabaena sphaerica. They fix nitrogen from atmospheric N2 using the enzyme nitrogenase, in order to provide the cells in the filament with nitrogen for biosynthesis.
Movement
Cyanobacteria are ubiquitous, finding habitats in most water bodies and in extreme environments such as the polar regions, deserts, brine lakes and hot springs. They have also evolved surprisingly complex collective behaviours that lie at the boundary between single-celled and multicellular life. For example, filamentous cyanobacteria live in long chains of cells that bundle together into larger structures including biofilms, biomats and stromatolites. These large colonies provide a rigid, stable and long-term environment for their communities of bacteria. In addition, cyanobacteria-based biofilms can be used as bioreactors to produce a wide range of chemicals, including biofuels like biodiesel and ethanol. However, despite their importance to the history of life on Earth, and their commercial and environmental potentials, there remain basic questions of how filamentous cyanobacteria move, respond to their environment and self-organize into collective patterns and structures.
All known cyanobacteria lack flagella; however, many filamentous species move on surfaces by gliding, a form of locomotion where no physical appendages are seen to aid movement. The actual mechanism behind gliding is not fully understood, although over a century has elapsed since its discovery. One theory suggests that gliding motion in cyanobacteria is mediated by the continuous secretion of polysaccharides through pores on individual cells. Another theory suggests that gliding motion involves the use of type IV pili, polymeric assemblies of the protein pilin, as the driving engines of motion. However, it is not clear how the action of these pili would lead to motion, with some suggesting they retract, while others suggest they push, to generate forces. Other scholars have suggested surface waves generated by the contraction of a fibril layer as the mechanism behind gliding motion in Oscillatoria. Recent work also suggests that shape fluctuations and capillary forces could be involved in gliding motion.
Through collective interaction, filamentous cyanobacteria self-organize into colonies or biofilms, symbiotic communities found in a wide variety of ecological niches. Their larger-scale collective structures are characterized by diverse shapes including bundles, vortices and reticulate patterns. Similar patterns have been observed in fossil records. For filamentous cyanobacteria, the mechanics of the filaments is known to contribute to self-organization, for example in determining how one filament will bend when in contact with other filaments or obstacles. Further, biofilms and biomats show some remarkably conserved macro-mechanical properties, typically behaving as viscoelastic materials with a relaxation time of about 20 min.
Cyanobacteria have strict light requirements. Too little light can result in insufficient energy production, and in some species may cause the cells to resort to heterotrophic respiration. Too much light can inhibit the cells, decrease photosynthesis efficiency and cause damage by bleaching. UV radiation is especially deadly for cyanobacteria, with normal solar levels being significantly detrimental for these microorganisms in some cases.
Filamentous cyanobacteria that live in microbial mats often migrate vertically and horizontally within the mat in order to find an optimal niche that balances their light requirements for photosynthesis against their sensitivity to photodamage. For example, the filamentous cyanobacteria Oscillatoria sp. and Spirulina subsalsa found in the hypersaline benthic mats of Guerrero Negro, Mexico migrate downwards into the lower layers during the day in order to escape the intense sunlight and then rise to the surface at dusk. In contrast, the population of Microcoleus chthonoplastes found in hypersaline mats at Salin-de-Giraud, Camargue, France migrate to the upper layer of the mat during the day and are spread homogenously through the mat at night. An in vitro experiment using P. uncinatum also demonstrated this species' tendency to migrate in order to avoid damaging radiation. These migrations are usually the result of some sort of photomovement, although other forms of taxis can also play a role.
Many species of cyanobacteria are capable of gliding. Gliding is a form of cell movement that differs from crawling or swimming in that it does not rely on any obvious external organ or change in cell shape and it occurs only in the presence of a substrate. Gliding in filamentous cyanobacteria appears to be powered by a "slime jet" mechanism, in which the cells extrude a gel that expands quickly as it hydrates providing a propulsion force, although some unicellular cyanobacteria use type IV pili for gliding. Individual cells in a trichome have two sets of pores for extruding slime. Each set is organized in a ring at the cell septae and extrudes slime at an acute angle. The sets extrude slime in opposite directions and so only one set is likely to be activated during gliding. An alternative hypothesis is that the cells use contractive elements that produce undulations running over the surface inside the slime tube like an earthworm. The trichomes rotate in a spiral fashion, the angle of which corresponds with the
pitch angle of Castenholz's contractile trichomes.
The cells appear to coordinate their gliding direction by an electrical potential that establishes polarity in the trichomes, and thus establishes a "head" and the "tail". Trichomes usually reverse their polarity randomly with an average period on the order of minutes to hours. Many species also form a semi-rigid sheath that is left behind as a hollow tube as the trichome moves forward. When the trichome reverses direction, it can move back into the sheath or break out.
Oscillatoria is a genus of filamentous cyanobacterium named after the oscillation in its movement. Filaments in colonies slide back and forth against each other until the whole mass is reoriented to its light source. Oscillatoria is mainly blue-green or brown-green and is commonly found in watering-troughs. It reproduces by fragmentation forming long filaments of cells which can break into fragments called hormogonia. The hormogonia can then grow into new, longer filaments.
Häder's cyanograph experiment
In 1987, Häder demonstrated that trichomes can position themselves quite precisely within their environment through photomovement. In Häder's cyanograph experiment a photographic negative is projected onto a Petri dish containing a culture of Phormidium uncinatum. After a few hours, the trichomes move away from the darker areas onto the lighter areas, forming a photographic positive on the culture. The experiment demonstrates that photomovement is effective not just for discrete light traps, but for minutely patterned, continuously differentiated light fields as well.
See also
Bacterial cellular morphologies
Colonial morphology
References
Cyanobacteria | Cyanobacterial morphology | [
"Biology"
] | 3,968 | [
"Algae",
"Cyanobacteria"
] |
68,357,890 | https://en.wikipedia.org/wiki/WASP-90 | WASP-90 is a faint 11th magnitude star located in the northern constellation Equuleus. With an apparent magnitude of 11.63, it is too faint to be detected with the naked eye, but can be seen with a telescope, and is located from the Solar System.
Properties
WASP-69 has a classification of F6. The paper states that the stars are slightly evolved, with radius up to twice that of the Sun. WASP-69 is 55% more massive than the Sun, and almost twice as large. It radiates at 4.3 times the Sun's luminosity from its photosphere at an effective temperature of 6,430 K. Despite it being a similar age, the star has a high metallicity that is 28% greater than that of the Sun.
Planetary system
In 2016, a bloated "hot Jupiter" was discovered orbiting the star. Due to the hosts state, the planet is irradiated.
References
F-type subgiants
F-type main-sequence stars
Planetary systems with one confirmed planet
Equuleus | WASP-90 | [
"Astronomy"
] | 219 | [
"Equuleus",
"Constellations"
] |
68,358,639 | https://en.wikipedia.org/wiki/Jaime%20Chamorro%20Cardenal | Jaime Chamorro Cardenal (October 23, 1934 – July 29, 2021) was a Nicaraguan newspaper editor and publisher. A civil engineer by training, journalism was the family business, as his father owned the newspaper La Prensa. Chamorro joined La Prensa in 1974, where he worked for 47 years and served as publisher for 28, from 1993 until his death in 2021.
Early life
Chamorro was born in Granada, Nicaragua, on October 23, 1934, to Margarita Cardenal Argüello and Pedro Joaquín Chamorro Zelaya, who had become sole owner of La Prensa in 1932. He had four siblings: Pedro Joaquín, Anita, Ligia and Xavier Chamorro Cardenal. He grew up first in the San Sebastián neighborhood of Managua, then from 1941 on El Triunfo street next to La Prensa, in a house built with the inheritance from his maternal grandfather’s death in 1936.
When he was 10, harassment from dictator Anastasio Somoza García forced the newspaper to close and his parents went into exile in New York. Pedro Joaquín, Anita and Ligia also left the country to pursue their studies, while Jaime and Xavier went to Granada, staying with their grandmother Isabel Argüello de Cardenal. Two years later, the paper reopened and his father returned, but by then Jaime was in school at Colegio Centro América in Granada, where he remained, making periodic trips to see his family in Managua. His father died in December 1952 and his brother Pedro Joaquín Chamorro Cardenal took over the paper.
Chamorro studied civil engineering at the University of Notre Dame in South Bend, Indiana, U.S.
Career
In June 1959, following his brother Pedro Joaquín, Chamorro was part of the Olama y Mollejones movement, a group of guerrillas that sought to overthrow the dictatorship of Luis Somoza Debayle. He was jailed for eight months as a consequence.
After college he married and, feeling the family did not need another journalist, embarked on a career in his chosen field of civil engineering. In the 1960s he focused on his construction company, Chamorro & Cuadra Contractors SA, formed with Pedro and José Cuadra, but the company faltered after an unsuccessful highway project, prior to the 1972 Nicaragua earthquake. Pedro Joaquín advised liquidating the company and in 1974 he asked Jaime to take over direction of La Prensa's finances.
In 1978, Pedro Joaquín, then La Prensa’s editor and an outspoken Somoza critic, was assassinated, turning the tide of public sympathy toward the Sandinista National Liberation Front’s (FSLN) efforts to overthrow Somoza. However Jaime Chamorro later became a critic of the FSLN, particularly for the censorship of non-state media in the 1980s. The FSLN shut down La Prensa in 1986, accusing it of sympathizing with the US-backed Contras, and Chamorro, then the newspaper’s senior editor, left the country until the paper reopened the following year, under a new peace accord.
In the late 1980s he was also a leader in the Conservative Party. In 1987 he published Frente a dos dictaduras : la lucha por la libertad de expresión (trans. Facing Two Dictatorships: The Struggle for Freedom of Expression), comparing the Somoza regime to FSLN rule in the 1980s particularly as regarded suppression of speech. Discussing the book in 2021, he argued the Somoza dictatorship had been more liberal in this regard because they had not captured all the institutions the FSLN had, like the judiciary.
In 1990, his sister-in-law (the widow of Pedro Joaquín) Violeta Barrios de Chamorro was elected president and left her role at the paper, and in 1993 Jaime Chamorro became publisher of the paper.
In the 21st century he became at odds with the FSLN again, with the government blocking the import of paper, ink and other supplies for La Prensa in 2018 and 2019 before relenting. This followed on the protests that began in April 2018 in Nicaragua and the criminalization of independent journalists covering the unrest. However, Chamorro remained optimistic about the paper’s ability to adapt especially with internet-based work, telling vice-president Rosario Murillo that the paper, founded in 1926, would survive to celebrate its 100th birthday.
Personal life
Chamorro married Hilda Argeñal (born c. 1939) in 1961 and together they had five children.
Chamorro’s mother Margarita Cardenal Argüello died in 1998.
Following a brief illness, Chamorro died on July 29, 2021, at age 86. At the time of his death, three of his nieces and nephews were imprisoned (presidential pre-candidates Cristiana Chamorro Barrios, Pedro Joaquín Chamorro Barrios, and Juan Sebastián Chamorro) and a fourth, journalist Carlos Fernando Chamorro Barrios, was exiled, in a crackdown by the FSLN government on opposition leaders a few months before the 2021 Nicaraguan general election.
He was buried the next day (July 30, 2021) in Managua, in a private service observing precautions for the COVID-19 pandemic.
Works
References
2021 deaths
1934 births
Nicaraguan journalists
Civil engineers
20th-century newspaper publishers (people)
People from Granada, Nicaragua
Notre Dame College of Engineering alumni
People from Managua
Nicaraguan engineers | Jaime Chamorro Cardenal | [
"Engineering"
] | 1,131 | [
"Civil engineering",
"Civil engineers"
] |
68,360,178 | https://en.wikipedia.org/wiki/Ecological%20overshoot | Ecological overshoot is the phenomenon which occurs when the demands made on a natural ecosystem exceed its regenerative capacity. Global ecological overshoot occurs when the demands made by humanity exceed what the biosphere of Earth can provide through its capacity for renewal. Scientific use of the term in the context of the global ecological impact of humanity is attributed to a 1980 book by William R. Catton, Jr. titled Overshoot: The Ecological Basis of Revolutionary Change.
Record of global ecological overshoot
To determine whether ecological overshoot is happening requires the collection of global and nation-specific data regarding the availability of natural resources, the capability of the ecosystems to renew any natural resources that were consumed, and the rate at which the resources are being consumed, usually assessed for each calendar year.
This data collection, and analysis is typically done by scientific and conservation organisations, such as the Global Footprint Network, which aggregates data to assess the ecological footprint of each country and the global community.
These ecological resource accounts reveal that the global community has been exceeding the regenerative capacity of the Earth since 1970, which was the year when the consumption capacity of humanity first exceeded the biocapacity the Earth. Each year since 1970 humanity has witnessed global ecological overshoot.
Earth Overshoot Day
This problem is highlighted each year on Earth Overshoot Day, an illustrative calendar date obtained through calculation, on which day humanity's resource consumption for the year is considered to have exceeded the Earth’s capacity to regenerate those resources for that year.
Global ecological debt
This ecological debt is often referred to as our global 'ecological overshoot'. The data from the Global Footprint Network has been used to create the graph below, it shows that since the 1970s the global population is increasingly compromising the Earth's ecosystem. The red section of the graph indicates that the global population have been accruing a global ecological overshoot since 1970. This means that the rate at which we are using natural resources exceeds the time required by the ecosystems to regenerate the resources and absorb the waste products that are involved.
The continued over-exploitation of natural resources results in ever more severe damage to global ecosystems over time, this has destabilised many micro ecosystems causing increasing extinction rates and the macro ecosystems are coming under increasing pressure. In this way humans are currently exceeding the carrying capacity of Earth as we increase the ecological overshoot each year. The IPAT equation attempts to quantify the environmental impact ("I") of the human population ("P"), their affluence ("A") and technology ("T"). Furthermore the Jevons paradox warns us that increasing our efficiency using technology will usually result in increased ecological damage.
Causes
The majority of the world currently follow an economic paradigm that seeks to grow all three of the IPAT parameters: population size, affluence and use of technology. These behaviour patterns are causing escalating environmental damage and there is evidence for growing risk of ecological collapse.
The outcomes from various possible human behaviour scenarios have been explored in a demographic model developed by Prof Chris Bystroff. According to the Bystroff predictions, continuing with the growth economic paradigm will result in a rapid decrease in population numbers halving global population by 2040. The Bystroff predictions are echoed in further research by Dr William E. Rees, who originally developed the concept of Ecological Footprint. This research states that to reduce ecological overshoot it is necessary to reduce economic consumption drastically to stop growing the economy and to repay the accrued ecological debt by restoration and rewilding back to the one planet level or less. A recent review of the World 3 demographic model by KPMG also concludes that humans need to rethink their pursuit of economic growth or anticipate collapse by 2040. For countries that have already achieved social affluence, although their social performance and resource utilization levels are high, the ecological overshoot brought about by these developments is still maintaining a continuously increasing trend. On the other hand, many low-income countries tried increasing their per capita wealth through economic activities to improve their social shortfalls. However, their social development is slower than the resulting increase in ecological overshoot. In this case, the ecological environment will be more overwhelmed.
It is important to bear in mind that the data collected by the Global Footprint Network (GFN) makes the assumption that the whole biocapacity of the Earth is entirely at the disposal of humanity. However it is evident that we need biodiversity in order to survive, therefore unless we reserve some of the global biocapacity for other species we cannot survive. Several organisations argue that to reinstate biodiversity to levels comparable to those preceding the high extinction rates associated with the ongoing Holocene extinction event, at least 50% of the Earths biocapacity would need to be protected as nature reserve areas which are kept free from human intervention. This suggestion was presented in the book titled Half Earth. Global Footprint Network data shows that for over 50 years humanity has been stressing the ecosystems on the planet beyond their ability to recover.
A crisis of human behaviour (the Human Behavioural Crisis) has been highlighted as the driver of anthropogenic ecological overshoot in a peer-reviewed World Scientists' Warning paper led by Joseph J. Merz and co-authored by William E. Rees, Phoebe Barnard et al.
Effects
The most well known symptom of ecological overshoot is the rising extinction rate. Pandemics of zoonotic diseases, like COVID-19 also become increasingly likely with overpopulation and global travel because we encroach on wildlife habitats and accelerate the spread. Biocapacity is measured by calculating the amount of biologically productive land and sea area available to provide the resources a population consumes and to absorb its wastes, given the prevailing technology and management practices. Countries differ in the productivity of their ecosystems, and this is reflected in the National Footprint and Biocapacity Accounts kept by York University, FoDaFo and Global Footprint Network. A country has an ecological reserve if its Ecological footprint is smaller than its biocapacity; otherwise it is operating with an ecological overshoot. The former are often referred to as ecological creditors, and the latter as ecological debtors. Today, most countries, and the world as a whole, are in ecological overshoot. Over 85% of the world population lives in countries operating with an ecological overshoot.
Risk of societal collapse
In 2024, fourteen academics well known for their publications and efforts to warn humanity about the dangers of ongoing climate change published a "Special Report" in the journal BioScience where they attributed the "risk of societal collapse" to the underlying cause of "overshoot."The climate emergency is not an isolated issue. Global heating, although it is catastrophic, is merely one aspect of a profound polycrisis that includes environmental degradation, rising economic inequality, and biodiversity loss. Climate change is a glaring symptom of a deeper systemic issue: ecological overshoot, where human consumption outpaces the Earth's ability to regenerate. Overshoot is an inherently unstable state that cannot persist indefinitely.
Solving the problem of Ecological Overshoot
The pursuit of growth economics relies on continual increase in our numbers and our consumption. Several economists have been challenging the wisdom of this prevailing discipline for many years. Those suggesting a new economic paradigm can be considered collectively as advocates for degrowth.
See also
References
Further reading
The Population Bomb, by Paul R. Ehrlich
Overshoot: The Ecological Basis of Evolutionary Change, by William R. Catton Jr.
External links
EarthOvershoot.org
Ecosystems
Ecology
Sustainability | Ecological overshoot | [
"Biology"
] | 1,550 | [
"Ecology",
"Symbiosis",
"Ecosystems"
] |
68,360,872 | https://en.wikipedia.org/wiki/Time%20in%20South%20Sudan | Time in South Sudan is given by a single time zone, officially denoted as Central Africa Time (CAT; UTC+02:00). South Sudan has observed CAT since 1 February 2021. The country does not have an associated daylight saving time.
History
Upon the independence of South Sudan from Sudan on 9 July 2011, it observed East Africa Time (EAT; UTC+03:00). On 1 February 2021, South Sudan moved its time back one hour to the UTC offset +02:00, adopting Central Africa Time.
IANA time zone database
In the IANA time zone database, South Sudan is given one zone in the file zone.tab – Africa/Juba. "SS" refers to the country's ISO 3166-1 alpha-2 country code. Data for South Sudan directly from zone.tab of the IANA time zone database; columns marked with * are the columns from zone.tab itself:
See also
Time in Sudan
List of time zones by country
List of UTC time offsets
References
External links
Current time in South Sudan at Time.is
Time in South Sudan at TimeAndDate.com
Time by country
Geography of South Sudan
Time in Africa | Time in South Sudan | [
"Physics"
] | 237 | [
"Spacetime",
"Physical quantities",
"Time",
"Time by country"
] |
68,360,968 | https://en.wikipedia.org/wiki/Bryoria%20pseudofuscescens | Bryoria pseudofuscescens is a species of lichen of the family Parmeliaceae.
As of July 2021, its conservation status has not been estimated by the IUCN. In Iceland, it is found in only one location in Gálgahraun lava field in Álftanes and is locally classified as a critically endangered species (CR).
References
Lichen species
Lichens described in 1977
pseudofuscescens
Taxa named by Vilmos Kőfaragó-Gyelnik | Bryoria pseudofuscescens | [
"Biology"
] | 100 | [
"Fungus stubs",
"Fungi"
] |
68,362,170 | https://en.wikipedia.org/wiki/Spermospora%20avenae | Spermospora avenae or red leather leaf is a fungal plant pathogen of Avena sativa.
The slender colourless hyphae that colonise oat plants become broader in the leaf epidermis and develop a layer of swollen, irregular shaped cells from which conidiophores arise. These penetrate to the exterior and a single conidium forms, ready for dispersal. The colourless conidia are substantially longer than they are wide, crescent shaped and have two or three septa.
The disease symptoms on the plant leaves are initially small blue and reddish discolorations that then become larger and extend along the length of the leaf blade. The affected areas are irregular in shape. These eventually darken to red-brown and become leathery in appearance.
Wet weather is conducive to infections. The spores can survive on seeds and stubble. Foliar fungicide application has been found helpful, although is not sufficient by itself.
References
Pezizomycotina
Fungus species | Spermospora avenae | [
"Biology"
] | 201 | [
"Fungus stubs",
"Fungi",
"Fungus species"
] |
68,363,689 | https://en.wikipedia.org/wiki/Samsung%20Galaxy%20Z%20Fold%203 | The Samsung Galaxy Z Fold 3 (stylized as Samsung Galaxy Z Fold3, sold as Samsung Galaxy Fold 3 in certain territories) is a foldable smartphone that is part of the Samsung Galaxy Z series. It was revealed by Samsung Electronics on August 11, 2021 at the Samsung Unpacked event alongside the Z Flip 3. It is the successor to the Samsung Galaxy Z Fold 2.
In March 2022, Samsung rebranded the device as "Galaxy Fold 3" in certain Eastern European territories, potentially due to the Russian invasion of Ukraine and Russia's use of Z for military vehicles.
Specifications
Design
The Z Fold 3's outer display and back panel use Gorilla Glass Victus, whilst the foldable inner display is made of Samsung's proprietary "Ultra-Thin Glass" with two protective PET plastic layers covering it, the top of which is a replaceable screen protector.
The Z Fold 3 has an IPX8 ingress protection rating for water resistance up to and including full submersion for 30 minutes up to a maximum depth of 1.5 meters, with dust resistance not being rated. The outer frame is constructed from aluminum, marketed as 'Armor Frame' by Samsung, which is claimed to be 10% stronger than the Z Fold 2's aluminum frame.
Hardware
The Galaxy Z Fold 3 has two screens: its external cover screen which is a 6.23-inch 120 Hz display, and its foldable inner screen which is a 7.6-inch 120 Hz display featuring support for the S Pen Pro and the S Pen Fold Edition; both of which feature support for variable refresh rate to help maximize power efficiency.
While the inner display remained totally unchanged in its size and shape compared to the previous generation Z Fold 2, the external cover display was actually made ever so slightly wider by about +1 mm through a slight reduction in display bezel (making its aspect ratio ~24.5:9 vs the Fold 2's ~25:9), which as such also made it ever so slightly larger by about the same amount (~15.8 vs ~15.7 cm).
The device has 12 GB of RAM, and either 256 or 512 GB of UFS 3.1 flash storage, with no support for expanding the device's storage capacity via micro-SD cards.
The Z Fold 3 is powered by the Qualcomm Snapdragon 888, upgraded from the Z Fold 2's Qualcomm Snapdragon 865+.
The device's included battery is a 4400 mAh dual-cell that fast charges via a USB-C cable up to 25W, or via wireless charging up to 10W.
The Z Fold 3 features 3 rear cameras, including a 12MP wide-angle camera, 12MP ultra-wide camera, and a 12MP telephoto camera, and features two front facing cameras, a 10MP selfie camera on the outer display, and a 4MP under-screen camera on the foldable inner display.
Samsung used to disable camera-related functions if the user attempted to unlock the bootloader.
This behaviour was changed with newer updates.
References
External links
Samsung Galaxy
Foldable smartphones
Mobile phones introduced in 2021
Mobile phones with multiple rear cameras
Mobile phones with 4K video recording
Discontinued flagship smartphones
Discontinued Samsung Galaxy smartphones
Samsung smartphones | Samsung Galaxy Z Fold 3 | [
"Technology"
] | 675 | [
"Mobile computer stubs",
"Mobile technology stubs",
"Flagship smartphones",
"Crossover devices",
"Foldable smartphones",
"Discontinued flagship smartphones"
] |
68,366,070 | https://en.wikipedia.org/wiki/Cladonia%20atlantica | Cladonia atlantica, also known as the Atlantic cup lichen, is a species of lichen in the family Cladoniaceae. It is found among the Atlantic Coast of the US, ranging from South Carolina to the Northeastern United States.
Taxonomy
Name
The species name atlantica originates from the Atlantic Ocean, which is most likely due to the fact the species is found on the Atlantic Coast of the United States.
Subspecies
C. atlantica has 5 subspecies.
Cladonia atlantica f. atlantica
Cladonia atlantica f. microphylla A.Evans
Cladonia atlantica f. ramosa A.Evans
Cladonia atlantica f. ramosissima A.Evans
Cladonia atlantica f. subsimplex A.Evans
References
atlantica
Fungus species | Cladonia atlantica | [
"Biology"
] | 154 | [
"Fungus stubs",
"Fungi",
"Fungus species"
] |
68,366,509 | https://en.wikipedia.org/wiki/No.%20402%20Wing%20RAAF | No. 402 Wing was a Royal Australian Air Force wing. Formed in July 1996, it maintained and provided technical support for Tactical Fighter Group's aircraft. The wing was disbanded in October 1998, with most of its functions being transferred to No. 81 Wing.
History
No. 402 Wing was formed from No. 481 Wing on 1 July 1996. It was responsible for maintaining and providing technical support for the aircraft operated by the RAAF's Tactical Fighter Group. These mainly comprised the McDonnell Douglas F/A-18 Hornets operated by No. 81 Wing. The wing's establishment was the result of a review conducted to determine the best way of maintaining the Hornets. These tasks had previously been undertaken by No. 481 Wing, and No. 402 Wing replaced it.
The wing was made up of a headquarters, No. 481 Squadron, Weapons System Support Flight and Field Training Flight. No. 481 Squadron was established at the same time as No. 402 Wing was formed, and included the maintenance elements that hat previously been organised into two squadrons in No. 481 Wing. No. 402 Wing was mainly located at RAAF Base Williamtown.
No. 402 Wing as disbanded as a result of a decision by the Chief of Air Force that the RAAF's flying squadrons should undertake aircraft maintenance. The wing transferred most of its functions to No. 81 Wing and ceased operations on 31 July 1998. It and No. 481 Squadron were formally disbanded on 30 October 1998. Weapons System Support Flight and Field Training Flight were retained, with the former becoming part of the Tactical Fighter Group and the later reporting to No. 81 Wing's headquarters.
References
Citations
Works consulted
402 Wing
402 Wing
402 Wing
Aircraft maintenance
1996 establishments in Australia
1998 disestablishments in Australia | No. 402 Wing RAAF | [
"Engineering"
] | 356 | [
"Aircraft maintenance",
"Aerospace engineering"
] |
68,367,262 | https://en.wikipedia.org/wiki/Hurd%E2%80%93Mori%201%2C2%2C3-thiadiazole%20synthesis | The Hurd–Mori 1,2,3-thiadiazole synthesis is a name reaction in organic chemistry that allows for the generation of 1,2,3-thiadiazoles through the reaction of hydrazone derivatives with an N-acyl or N-tosyl group reacted with thionyl chloride. An analogous reaction gives 1,2,3-selenadiazoles by using selenium dioxide instead of thionyl chloride.
References
Carbon-heteroatom bond forming reactions
Name reactions | Hurd–Mori 1,2,3-thiadiazole synthesis | [
"Chemistry"
] | 109 | [
"Organic reactions",
"Name reactions",
"Carbon-heteroatom bond forming reactions",
"Chemical reaction stubs",
"Ring forming reactions"
] |
68,368,763 | https://en.wikipedia.org/wiki/Ricardo%20Vinuesa | Ricardo Vinuesa Motilva (born 4 February 1986 in Valencia, Spain) is a fluid dynamicist and machine-learning researcher. He is an associate professor at KTH Royal Institute of Technology in Stockholm (Sweden), as well as an Affiliated Researcher at the AI Sustainability Center. He is also vice director of the KTH Digitalization Platform. He is known for his work on turbulence (including computational fluid dynamics and machine-learning methods) and sustainability. Vinuesa led an influential study on the impact of AI on the 17 Sustainable Development Goals (SDGs) of the United Nations (UN).
Most-cited Publications
Vinuesa R, Azizpour H, Leite I, Balaam M, Dignum V, Domisch S, Felländer A, Langhans SD, Tegmark M, Fuso Nerini F. The role of artificial intelligence in achieving the Sustainable Development Goals. Nature communications. 2020 Jan 13;11(1):1-0. (Cited 487 times, according to Google Scholar )
Srinivasan PA, Guastoni L, Azizpour H, Schlatter PH, Vinuesa R. Predictions of turbulent shear flows using deep neural networks. Physical Review Fluids. 2019 May 10;4(5):054603. (Cited 118 times, according to Google Scholar.)
R Vinuesa, A Noorani, A Lozano-Durán, GKE Khoury, P Schlatter, ...[et al.] Aspect ratio effects in turbulent duct flows studied through direct numerical simulation Journal of Turbulence 15 (10), 677-706 (Cited 115 times, according to Google Scholar.)
SM Hosseini, R Vinuesa, P Schlatter, A Hanifi, DS Henningson. Direct numerical simulation of the flow around a wing section at moderate Reynolds number International Journal of Heat and Fluid Flow 61, 117-128 (Cited108 times, according to Google Scholar.)
Vinuesa R, Negi PS, Atzori M, Hanifi A, Henningson DS, Schlatter P. Turbulent boundary layers around wing sections up to Rec= 1,000,000. International Journal of Heat and Fluid Flow. 2018 Aug 1;72:86-99. (Cited 99 times, according to Google Scholar.)
References
21st-century Spanish physicists
Academic staff of the KTH Royal Institute of Technology
21st-century Swedish physicists
Spanish emigrants to Sweden
Fluid dynamicists
1986 births
Living people | Ricardo Vinuesa | [
"Chemistry"
] | 520 | [
"Fluid dynamicists",
"Fluid dynamics"
] |
68,368,980 | https://en.wikipedia.org/wiki/NGC%207503 | NGC 7503 is an elliptical galaxy in the constellation Pisces. It was discovered by the astronomer Albert Marth on September 2, 1864. It is the brightest galaxy in its cluster (a BCG).
In 2001, SN 2001ic, a type Ia supernova, was detected within NGC 7503.
References
External links
Pisces (constellation)
Elliptical galaxies
Radio galaxies
7503
4C objects
70628 | NGC 7503 | [
"Astronomy"
] | 87 | [
"Pisces (constellation)",
"Constellations"
] |
68,369,974 | https://en.wikipedia.org/wiki/Rubidium%20sesquioxide | Rubidium sesquioxide is a chemical compound with the formula or more accurately . In terms of oxidation states, Rubidium in this compound has a nominal charge of +1, and the oxygen is a mixed peroxide () and superoxide () for a structural formula of . It has been studied theoretically as an example of a strongly correlated material.
The compound was predicted to be a rare example of a ferromagnetic compound that is magnetic due to a p-block element, and a half-metal that was conducting in the minority spin band. However, while the material does have exotic magnetic behavior, experimental results instead showed an electrically insulating magnetically frustrated system. also displays a Verwey transition where charge ordering appears at 290 K.
Rubidium sesquioxide can be prepared by reacting the peroxide and the superoxide :
It is initially discovered in 1907, and more thoroughly characterized in 1939. The compound crystallizes in a body-centered cubic form with the same crystal structure as and .
See also
Rubidium oxide
References
Rubidium compounds
Sesquioxides | Rubidium sesquioxide | [
"Chemistry"
] | 222 | [
"Inorganic compounds",
"Inorganic compound stubs"
] |
68,370,026 | https://en.wikipedia.org/wiki/Epoxy%20value | Epoxy value derives from the Epoxy equivalent weight (EEW) or Weight Per Epoxide (WPE) and is a measure of the epoxy content of an epoxy resin or epoxy reactive diluent, or glycidyl ether. This is an important parameter as it allows determination of the correct mix ratio of an epoxy system with a curing agent. The epoxide equivalent weight is usually measured first and done by titration. The standard test method is ASTM D1652 though this has been modified by certain states of the USA. The epoxy equivalent weight (EEW) maybe defined as: the number of grams of epoxy resin required to give 1 mole of epoxy groups. The epoxy value is defined as the number of moles of epoxy group per 100g resin.
Example calculations
Polyoxypropylene diglycidyl ether, a reactive diluent with the trade name of Diluent F, has an average molecular weight of 1000 and a functionality of 2 so the EEW is 1000/2 = 500. The epoxy value is defined as the number of moles of epoxy group per 100g resin. So as an example using an epoxy resin with molar mass of 382 and that has 2 moles of epoxy groups per mole of resin, the EEW = 382/2 = 191, and the epoxy value is calculated as follows: 100/191 = 0.53 (i.e. the epoxy value of the resin is 0.53).
Alternative techniques
There are methods using instruments that do not use traditional titration techniques to determine epoxide equivalent weights.
See also-related test methods
Acid value
Amine value
Hydroxyl value
Iodine value
Peroxide value
Saponification value
References
Further reading
Synthetic resins | Epoxy value | [
"Chemistry"
] | 392 | [
"Synthetic materials",
"Synthetic resins",
"Analytical chemistry stubs"
] |
78,503,672 | https://en.wikipedia.org/wiki/C/1968%20H1%20%28Tago%E2%80%93Honda%E2%80%93Yamamoto%29 | Comet Tago–Honda–Yamamoto, formally designated C/1968 H1, is a retrograde non-periodic comet discovered by Akihiko Tago, Minoru Honda, and Hirofumi Yamamoto on 1 May 1968. Although officially named after the three Japanese astronomers, it was actually first spotted by Kōichi Itagaki about five days earlier on 25 April 1968, however he could not report his sighting for another couple of weeks.
Discovery and observations
Japanese amateur astronomer Kōichi Itagaki, a resident of Yamagata City, was the first person to spot the comet on 25 April 1968, at the time a 7th-magnitude object located near the Andromeda Galaxy. It wasn't until Akihiko Tago, Minoru Honda and Hirofumi Yamamoto made independent observations of the comet on April 30 and later reported their findings to the Tokyo Astronomical Observatory the following day.
C/1968 H1 made its closest approach to Earth on 26 April 1968 at a distance of . The comet then rapidly declined in brightness as it begins its outbound flight back to the outer Solar System. Despite the bright moonlight conditions, M. J. Gainsford managed to observe the comet on May 12, noting that the comet had faded to magnitude 8.75. It was last seen on the evening of 5 June 1968.
See also
C/1969 T1 (Tago–Sato–Kosaka)
References
External links
Non-periodic comets
Near-Earth comets | C/1968 H1 (Tago–Honda–Yamamoto) | [
"Astronomy"
] | 296 | [
"Astronomy stubs",
"Comet stubs"
] |
78,507,933 | https://en.wikipedia.org/wiki/Umdat%20al-Talib | Umdat al-Talib fi Ansabi Ale Abi Talib (, ) is a genealogy book written by "Ahmad ibn Ali ibn Husayn al-Husayni", known as "Ibn Inabah" (died 828 AH1425 AD/CE), a famous Shiite scholar and noble genealogist of the 9th century AH15th century AD/CE.
This book deals with the genealogy of Abu Talib ibn Abd al-Muttalib (the leader of Banu Hashim, a clan of the Qurayshi tribe of Mecca in the Hejazi region of the Arabian Peninsula, he being the brother of Abdullah ibn Abd al-Muttalib, the father of the Islamic Prophet Muhammad) and the descendants of Ali ibn Abi Talib (the cousin and son-in-law of the Islamic prophet Muhammad, and the first Shia Imam) in details.
Synopsis
"Umdat al-Talib fi Ansabi Ale Abi Talib" (in , ), is the Ibn Inabah'''s most important work. This book is of great importance in the science of genealogy in the Islamic sources.
In this book, Ibn Inabah describes the biography of Abu Talib's ancestors and then his descendants. Finally, he describes in more detail the lineage of Ali ibn Abi Talib (the first Shia Imam) through his children in five chapters:
In the book "Umdat al-Talib fi Ansabi Ale Abi Talib", after a preface, the author lists in a detailed introduction the ancestors of Prophet Abraham (the common Hebrew patriarch of the Abrahamic religions, including Judaism, Christianity, and Islam) and then his children up to Abu Talib ibn Abd al-Muttalib (the leader of Banu Hashim, uncle of the Islamic Prophet Muhammad) known as "Abu Talib" or "Abi Talib". Then Ibn Inabah mentions the children of Abu Talib: Aqil ibn Abi Talib, Ja'far ibn Abi Talib, and Ali ibn Abi Talib (the first Shia Imam, the only successor whom the Prophet Muhammad introduced him clearly in the public, refer to Ghadir Khumm).
After going through these chapters, Ibn Inabah briefly mentions the children and grandchildren of the sons of Abu Talib in several another chapters. Finally, the author Ibn Inabah, describes in more detail the lineage of Ali ibn Abi Talib through his children in five chapters: Hasan ibn Ali (known as "Imam Hassan" in Shia doctrine, the second Shia Imam), Husayn ibn Ali (known as "Imam Hossein" in Shia doctrine, the third Shia Imam), Muhammad ibn al-Hanafiyya, Abbas ibn Ali (known as "Abu al-Fadl", in , son of Ali ibn Abi Talib, he fought until his last breath to save his elder brother, Husayn ibn Ali, when he was surrounded in Karbala to force him to swear allegiance, so "Abu al-Fadl" was killed on the day of Ashura), and Umar ibn Ali (in , son of Ali ibn Abi Talib who accompanied his brother, Husayn ibn Ali, to Karbala and was killed on the day of Ashura too).
This genealogical report by Ibn Inabah provides brief but useful information about how the Alawi clan spread across its lands and places of residence, which is a suitable guide for historians. Later historians and Hadith scholars such as "Kia Gilani" in the book "Seraj al-Ansab" (in ), Hurr Amili in the book "Amal ol-Aamel" (in ), and Mohammad-Baqer Majlesi known as "Allamah Majlesi" in the book "Bihar al-Anwar" (in ), have greatly benefited from the book "Umdat al-Talib fi Ansabi Ale Abi Talib" by Ibn Inabah.
About the author
"Sayyid Ahmad ibn Ali ibn Al-Hussein ibn Ali ibn Muhanna ibn Inabah" known as "Ibn Inabah" was born in 748 AH1347 AD/CE, probably in the city of Hillah in Iraq. Ibn Inabah died in the city of Kerman in Iran in the month of Safar 828 AHJanuary 1425 AD/CE at the age of 77.
According to Ibn Inabah autobiography, his lineage reaches back to Ali ibn Abi Talib (the first Shia Imam) through 20 intermediaries. He is considered a descendant of Abd Allah al-Mahd (an Islamic scholar, theologian and hadith narrator, grandson of both Hasan ibn Ali and Husayn ibn Ali), hence his lineage is "Hassani-Husseini". His relationship is to Hasan ibn Ali (the second Shia Imam) through his father and to Husayn ibn Ali (the third Shia Imam) through his mother.
"Ibn Inabah" was a Shiite historian and genealogist. He was one of the special students of "Ibn Mu'ayyah" (the prominent genealogist and historian). He lived at the same time as Muhammad ibn Makki (known as "Al-Shahid al-Awwal", , a prominent Shia scholar and author, and the first jurist who sacrificed his life and brutally murdered for defending his school, Shia).
From his early youth, "Ibn Inabah" studied genealogy under the supervision of "Abu Abdullah Muhammad ibn Qasim ibn Mu'ayyah Dibaji" (in , died 776 AH1374 AD/CE) known as "Ibn Mu'ayyah" (in ). Ibn Inabah became the beloved and the noble of his master "Ibn Mu'ayyah" among colleagues. During his education, Ibn Inabah benefited from numerous sources and teachers, but he undoubtedly gained the most scientific knowledge from the works of his bold master "Ibn Mu'ayyah". As can be seen from Ibn Inabah circumstances, after the death of his master "Ibn Mu'ayyah", he embarked on a journey of exploration and traveled to Isfahan, Herat, Samarkand, Mecca, and Mazaar (in the Mishan Plain), and benefited from the knowledge of many genealogists.
His most important work is "Umdat al-Talib fi Ansabi Ale Abi Talib" (in , ) which is written in Arabic language. In this book, Ibn Inabah describes the biography of Abu Talib ibn Abd al-Muttalib's ancestors and then his descendants. Finally, he describes the descendants of Ali ibn Abi Talib with more detail.
As can be seen from "Ibn Inabah's" writings, he was a trusted and reliable person in transmitting authentic documents and Hadiths (a form of Islamic oral tradition containing the sayings, actions, and approvals of the prophet Muhammad or his progeny, specially descendants of Ali, the twelve Imams in Twelver Shia) of Imams from the previous generation to the newer generation. This reputation has made his books very practical in the Shiite religion. His book "Umdat al-Talib fi Ansabi Ale Abi Talib" (, ) is one of the basic books on the Shiite Imams genealogy in Islamic scholarly circles. The authenticity and purity of Hadiths are determined by the people who transmit them. In narrating Hadiths and transmitting pure Islamic knowledge, "Ibn Inabah" took his method from his prominent master "Ibn Mu'ayyah" (has a strong reputation among colleagues and was a highly trusted Hadith narrator and transmitter of the time) and then in the root, a reliable source that scholars use to verify Hadiths, "Ibn Inabah" reached out to al-Allama al-Hilli (one of the few purest narrator and transmitters, one of the most influential Twelver Shi'i Muslim authors of all time).
"Ibn Inabah's" sect is not very clear in the historical reports and evidences, and there are disagreements among scholars over his school of thoughts. There is some evidence that he was either a Zaydi or a Twelver Shia. Some have doubted whether he is a Shiite. But this seems to be incorrect, although it is not certain that he was a Twelver Shia. However, most likely, "Ibn Inabah" was either a Zaydi or a Twelver Shiite.Ibn Inabah has written several another books too. Some of these works include "Al-Fosul al-Fakhriyah fi Usul al-Bariyah" (in , ), "Al-Tohfat al-Jalaaliate fi Ansabi al-Talibiyyah" (in , ), "Bahr al-Ansab fi Nasabi Bani Hashim" (in , ), "Risalah fi Usul Shajarat al-Sadah Ale Abi Alawi" (in , ) and “Ansabi Ale Abi Talib” (in , ).
Editions Ibn Inabah has written the book "Umdat al-Talib fi Ansabi Ale Abi Talib" (, ) three times in different volumes and editions as follows:
Shahab ud-Din Mar'ashi Najafi (an Iraqi Shia Grand Ayatollah and Marja') called the three editions as follows: The first edition as "Kubra" (), the second edition as "Wusta" () and the third edition as "Sughra" () respectively.
Structure
In the original manuscript of "Umdat al-Talib fi Ansabi Ale Abi Talib", the text of the book is rich and full of information, but it does not follow a specific order. In the book, the information is presented one after the other in a narrative manner. The divisions and chapters of the book "Umdat al-Talib fi Ansabi Ale Abi Talib" are not clear and informative, and in order to find a person or his\her lineage, one must search its contents sufficiently. For example, to finding the description of descendants and lineage of an Imam, the audience may have to examine a great deal of detail and needs to extensively search around them. Finding a specific lineage and progeny in this book takes a considerable amount of time. In the such valuable genealogical descriptions, the book subject may move from ancient classes to very distant generations and suddenly return to the original ancestors and the discussion becomes prolonged and from old generations goes back to far before that to their ancient ancestors. The classification of the original handwritten version of the book is traditional and abstruse. The author does not cite all of his sources, but in some cases he mentions the name of the narrator or the book from which he quoted a specific matter.
The fame of the book "Umdat al-Talib fi Ansabi Ale Abi Talib" is due to the rare information it provides on the subject of genealogical examination of the Fourteen Infallibles (The Fourteen Infallibles are the Islamic prophet Muhammad, his daughter Fatima, and the Twelve Imams).
Motivation for writing
Because Ibn Inabah traveled to different regions, he saw people claiming to be Alawi (the descendant of Ali the first Shia Imam called Alids or Alawis) and no one identified or denied it, because they were not aware of the lineage of the Alids; Therefore, he wrote the book "Umdat al-Talib fi Ansabi Ale Abi Talib" to explain the principles and branches of the sacred lineage of Alids. In the preface to the first two editions of "Umdat al-Talib" (in , ), Ibn Inabah'' says that he wrote this book because a group of people doubted the genealogy of the family of Abi Talib.
Time of publication
The first handwritten compilation was probably completed in 802 AH1399 AD/CE in Iraq by its author, Ibn Inabah. The first printed academic version was probably published in 1380 AH1960 AD/CE in Iran.
See also
Al-Majdi fi Ansab al-Talibiyyin
Alids
The Fourteen Infallibles
Family tree of Muhammad
Kashf al-Ghumma
Bihar al-Anwar
Sorure Ahle Iman
Du'a' Kumayl
Aban ibn Abi Ayyash
Abu Basir al-Asadi
Al-Urwah al-Wuthqa
Abu Basir al-Moradi
Ibn Khaldun
Al-Zubayr ibn Bakkar
Encyclopaedia of Shia
Encyclopedia of Imam Ali
Mirza Muhammad al-Akhbari
Tabaghat Aa'lam Al-Shia
Hisham ibn al-Hakam
References
External links
Umdat al-ṭālib fī nasab Āl Abī Ṭālib by Ibn ‘Inabah, Aḥmad ibn ‘Alī
'Umdat al-talib fi ansab Al 'Abi Talib
Arabic Books by Ibn Inabah, Ahmad ibn Ali
Umdat al-talib fi ansab Al 'Abi Talib
Family of Muhammad
Hashemite people
Muslim family trees
Family trees
1400s books
2000s books
Shia Islam
Family history
Medieval genealogies and succession lists
Genealogy publications
Kinship and descent
Descent from antiquity
Family trees of royalty
History of Shia Islam
Shia literature
Books about Islam
15th-century books
Medieval Arabic literature
15th-century Arabic-language books
Oral history books | Umdat al-Talib | [
"Biology"
] | 2,803 | [
"Behavior",
"Human behavior",
"Kinship and descent"
] |
78,509,160 | https://en.wikipedia.org/wiki/Silver%20hypoiodite | Silver hypoiodite is a chemical compound with the chemical formula . This is an ionic compound of silver and the polyatomic ion hypoiodite.
Synthesis
Adding iodine to a dilute neutral solution of silver nitrate:
References
Silver compounds
Hypoiodites | Silver hypoiodite | [
"Chemistry"
] | 58 | [
"Hypoiodites",
"Oxidizing agents"
] |
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