id string | dataset string | question string | options sequence | answer string | explanation string |
|---|---|---|---|---|---|
openbookqa_687 | openbookqa | <ctx>
amensalism is a non - symbiotic species interaction in which one organism negatively affects the other organism but is unaffected by that organism. this type of species interaction is common in nature, and an example in insect ecology is between goats and insects. the two individuals compete for the same food source, but goats will deprive the latter from feeding. the goat is completely unaffected by the interaction, but the insect is left hungry. commensalism commensalism is a different type of ecological interaction between species in which one species gains benefits while the other is neither harmed nor benefited. two examples of commensalism that can be seen in insect ecology are phoresy, an interaction in which one attaches itself to another for transportation, and inquilinism, the use of another organism for shelter. ticks and mites have adapted to latch onto beetles, flies, and bees ( as well as other organisms ) for transportation, an example of phoresy. in terms of inquilinism, insects commonly establish themselves in human garages or shelters of other animals for protection against predators and weather. parasitoid insects parasitoids are insects that live intimately with a host, feed off of the host like a parasite, but eventually kill the host. this specific type of species interaction is exclusive to insects and is employed most commonly by wasps. an example of this is when parasitoid wasps inject their eggs into aphids. the eggs will eventually hatch and produce wasp larvae that feed on and consume the organism. additionally, some parasitoids chemically affect the host to propagate the development of parasitic offspring. parasitoid wasps typically prey on a specific insect or spider species, and the host life - stage at which the wasp deposits its seed differs. in regard to humans, parasitoid insects are favored because they can be used as biological pest controls for farmers, preying on other insects that damage crops. references bibliography ( 1999 ). ecological entomology. 2nd edition ( illustrated ). john wiley and sons.,. limited preview on google books. accessed on 09 jan 2010, external links articles containing video clips
cannibalism in poultry is the act of one individual of a poultry species consuming all or part of another individual of the same species as food. it commonly occurs in flocks of domestic hens reared for egg production, although it can also occur in domestic turkeys, pheasants and other poultry species. poultry create a social order of dominance known as pecking order. when pressure occurs within the flock, pecking can increase in aggression and escalate to cannibalism. cannibalism can occur as a consequence of feather pecking which has caused denuded areas and bleeding on a bird's skin. cannibalism can cause large mortality rates within the flock and large decreases in production due to the stress it causes. vent pecking, sometimes called'cloacal cannibalism ', is considered to be a separate form of cannibalistic pecking as this occurs in well - feathered birds and only the cloaca is targeted. there are several causes that can lead to cannibalism such as : light and overheating, crowd size, nutrition, injury / death, genetics and learned behaviour. research has been conducted to attempt to understand why poultry engage in this behaviour, as it is not totally understood. there are known methods of control to reduce cannibalism such as crowd size control, beak trimming, light manipulation, perches, selective genetics and eyewear. motivational basis poultry species which exhibit cannibalism are omnivores. for example, hens in the wild often scratch at the soil to search for seeds, insects and even larger animals such as lizards or young mice, although they are mainly herbivorous in adulthood. feather pecking is often the initial cause of an injury which then attracts the cannibalistic pecking of other birds – perhaps as re - directed foraging or feeding behaviour. in the close confines of modern farming systems, the increased pecking attention is easily observed by multiple birds which join in the attack, and often the escape attempts of the cannibalised bird attract more pecking attention. causes light and overheating high intensity light with prolonged exposure can lead to cannibalism of poultry in captivity
to a zygote the parasite moves to the salivary glands where it can be passed on to a vertebrate species, for example humans. the mosquito acts as a vector for malaria. the parasite tends to reduce the mosquito's lifespan and inhibits the production of offspring. a second example of parasitism is brood parasitism. cuckoos regularly do this type of parasitism. cuckoos lay their eggs in the nest of another species of birds. the host, therefore, provides for the cuckoo chick as if it were as their own, unable to tell the difference. the cuckoo chicks eject the host's young from the nest meaning they get a greater level of care and resources from the parents. rearing for young is costly and can reduce the success of future offspring, thus the cuckoo attempts to avoid this cost through brood parasitism. in a similar way to predation, parasitism can lead to an evolutionary arms race. the host evolves to protect themselves from the parasite and the parasite evolves to overcome this restriction. neutralism neutralism is where species interact, but the interaction has no noticeable effects on either species involved. due to the interconnectedness of communities, true neutralism is rare. examples of neutralism in ecological systems are hard to prove, due to the indirect effects that species can have on each other. see also references further reading akin, wallace e. ( 1991 ). global patterns : climate, vegetation, and soils. university of oklahoma press.. barbour, burke, and pitts, 1987. terrestrial plant ecology, 2nd ed. cummings, menlo park, ca. morin, peter j. ( 1999 ). community ecology. wiley - blackwell press.. odum, e. p. ( 1959 ) fundamentals of ecology. w. b. saunders co., philadelphia and london. ricklefs, r. e. ( 2005 ) the economy of nature, 6th ed. wh freeman, usa. ricketts, taylor h., eric dinerstein, david m. olson, colby j. loucks et al. ( wwf ) ( 1999 ). terrestrial ecoregions of north america : a conservation assessment. island press
##lution of dasyscolia ciliata, a species of wasp, and ophrys speculum, a species of orchid. these two species have both evolved in such a way that the wasp is the only known pollinator of the plant. this relationship can be seen in other species of flowering plants and pollinating insects, but a more distinct example is the coevolution of ants and acacias. the acacia ant ( pseudomyrmex ferruginea ) is an insect that has been discovered to protect five different species of acacia trees. the ant provides protection to the plant while the acacias reciprocate by supplying food and shelter. over generations, these two species have adapted to accommodate each other, an example of coevolution. interspecific relationships due to their diverse functions, diets, and lifestyles, insects are integral components of terrestrial ecological communities. beyond functioning as decomposers, carnivores, and herbivores, insects often participate in other species interactions. these interactions can both positively and adversely affect plants, mammals, and other insects. more specifically, insects participate in mutualism, amensalism, commensalism, predation and parasitism. mutualism mutualism is a symbiotic relationship between two or more species in which each benefits. common mutualistic relationships include cleaning symbiosis, animal induced pollination, or protection from predators. one example of insect mutualism is the pollination of flowering plants by insects, a field of study known as anthecology. primarily, various bee species work as pollinators of flowering plants, feeding on their nectar and in turn picking up their pollen and spreading it to other flowers. another example of insect mutualism is the process by which ants shelter and feed aphids in their anthills and feed off of their honeydew in return. amensalism amensalism is a non - symbiotic species interaction in which one organism negatively affects the other organism but is unaffected by that organism. this type of species interaction is common in nature, and an example in insect ecology is between goats and insects. the two individuals compete for the same food
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The following are multiple choice questions (with answers) about STEM.
A bird eating a lizard is an example of what type of relationship?
A. symbiotic
B. producer
C. parasitic
D. predatory
Answer: | [
"symbiotic",
"producer",
"parasitic",
"predatory"
] | D | |
medmcqa_9451 | medmcqa | <ctx>
and socioeconomic factors. references for many of these environmental risk factors have been collected in an online database. there may be an association between non - celiac gluten sensitivity and schizophrenia in a small proportion of people, though large randomized controlled trials and epidemiological studies will be needed before such an association can be firmly established. withdrawal of gluten from the diet is an inexpensive measure which may improve the symptoms in a small ( ≤3 % ) number of people with schizophrenia. a meta - analysis found that high neuroticism increases the risk of psychosis and schizophrenia. several long - term studies found that individuals born with congenital visual impairment do not develop schizophrenia, suggesting a protective effect. the effects of estrogen in schizophrenia have been studied in view of the association between the onset of menopause in women who develop schizophrenia at this time. add - on estrogen therapies have been studied and evaluated for their effect on the symptoms experienced. raloxifene as an adjunctive agent has shown positive results. findings have supported the hypothesis that schizophrenia is associated with alterations of the tryptophane - kynurenine metabolic pathway due to activation of specific sections of the immune system. the relevance of some auto - antibodies that act against the nmdar and vgkc is being studied. current estimates suggest that between 1. 5 - 6. 5 % of patients have these antibodies in their sera. preliminary results have shown that these patients can be treated with immunotherapy such as ivig or plasma exchange and steroids, in addition to antipsychotic medication ( s ), which can lead to a reduction in symptoms. childhood antecedents in general, the antecedents of schizophrenia are subtle and those who will go on to develop schizophrenia do not form a readily identifiable subgroup – which would lead to identification of a specific cause. average group differences from the norm may be in the direction of superior as well as inferior performance. overall, birth cohort studies have indicated subtle nonspecific behavioral features, some evidence for psychotic - like experiences ( particularly hallucinations ), and various cognitive antecedents. there have been some inconsistencies in the particular domains of functioning identified and
##mia during anticipation and receipt of reward, although this finding is extremely inconsistent. these abnormalities may be related to circadian rhythm dysfunction in bipolar, including increased sleep latency, evening preference and poor sleep quality, as the neural systems responsible for both processes are functionally linked. a few lines of evidence suggest that elevated dopamine signaling, possibly due to reduced functionality in dat, underlie abnormalities in reward function. dopaminergic drugs such as l - dopa can precipitate mania, and drugs that attenuate dopaminergic signaling extracellularly ( antipsychotics ) and intracellularly ( lithium ) can be efficacious in treating mania. while a large body of translational evidence exists to support dat hypofunction, in vivo evidence is limited to one study reporting reduced dat binding in the caudate. neuroimaging structural in a review of structural neuroimaging in bipolar disorder, strakowski proposed dysfunction in an iterative emotional network called the " anterior limbic network ", composed of the thalamus, globus pallidus, striatum, ventrolateral prefrontal cortex, ventromedial prefrontal cortex, acc, amygdala, dorsolateral prefrontal cortex, and cerebellar vermis. structural imaging studies frequently find abnormalities in these regions which are putatively involved in emotional and cognitive functions that are disrupted in bipolar disorder. for example, while structural neuroimaging studies do not always find abnormal pfc volume in bipolar disorder, when they do, pfc volume is reduced. furthermore, reduced pfc volume is associated with response inhibition deficits and duration of illness. when the pfc at large is not examined and the focus is narrowed to the orbitofrontal cortex and medial prefrontal cortex, results more consistently observed reductions, although not in bipolar youth. the sgacc volume is observed to be reduced not only in bipolar disorder, but also in unipolar disorder, as well as people with a family history of affective disorders. enlargement of the striatum and globus pallidus are commonly found, and although some studies
. intranasal administration of oxytocin in patients with an significantly lowered food anticipation and eating concern. substance use disorder uncontrolled and continuous use of a substance, drugs or alcohol, is known as substance use disorder. substances can interfere with neuronal signaling and potentially disrupt the brain circuit. addiction to these substances impairs thinking, behavior, and other biological functions. intranasal delivery of insulin is associated with improvement in brain metabolic activities and alleviate impulsivity. opioid addiction is prevalent and associated with many substance abuse deaths. a study observed high biodistribution in the brain and reduction in opioid overdose in rats administered with naloxone - loaded lipid nanoparticles. post - traumatic stress disorder witnessing a devastating or terrifying situation can lead to post - traumatic stress disorder ( ptsd ). this mental health condition triggers anxiety, depression, and extreme fear with memories. intranasal administration of temperature - sensitive hydrogels loaded with ptsd medications showed enhanced brain targeting effects and tissue distribution. similarly, another study observed anti - ptsd effects with intranasal administration of loaded hydrogels. schizophrenia schizophrenia is a chronic mental health condition caused by changes in brain chemistry and structure. genetics and environment are hypothesized to play a key role in development of this disorder. research suggests impaired gene expression or chemical imbalance may impact this condition. anxiety can increase risk of schizophrenia and symptoms include hallucinations, disorganized speech, and abnormal behavior. davunetide ( nap ) is a segment of activity - dependent neuroprotective protein ( adnp ). adnp is reported be downregulated with schizophrenia. a study observed decreased hyperactivity in mice when treated with nap via the intranasal route. migraine migraine occurs with episodes of intense headache causing nausea and throbbing pain. stress and hormonal changes can be a trigger migraine. a nasal spray containing sumatriptan demonstrated a significant reduction of migraine pain. further clinical studies of intranasal administration of sumatriptan ( st ) can help evaluate efficacy and safety of such delivery systems. nanosystems for intranasal drug delivery nanoparticles are drug
2014 jun ; 71 ( 6 ) : 681 - 8. iacoviello bm, wu g, alvarez e, huryk k, collins ka, murrough jw, iosifescu dv, charney ds. cognitive - emotional training as an intervention for major depressive disorder. depress anxiety. 2014 aug ; 31 ( 8 ) : 699 - 706. feder a, fred - torres s, southwick sm, charney ds. the biology of human resilience : opportunities for enhancing resilience across the life span. biol psychiatry. 2019 sep 15 ; 86 ( 6 ) : 443 - 453. krystal jh, charney ds, duman rs. a new rapid - acting antidepressant. cell. 2020 apr 2 ; 181 ( 1 ) : 7. charney aw, katz c, southwick sm, charney ds. a call to protect the health care workers fighting covid - 19 in the united states. am j psychiatry. 2020 jul 31. feder a, costi s, rutter sb, collins ab, govindarajulu u, jha mk, horn sr, kautz m, corniquel m, collins ka, bevilacqua l, glasgow am, brallier j, pietrzak rh, murrough jw, charney ds. a randomized controlled trial of repeated ketamine administration for chronic posttraumatic stress disorder. am j psychiatry. 2021 feb 1 ; 178 ( 2 ). references external links mount sinai hospital homepage icahn school of medicine at mount sinai homepage dean's office, icahn school of medicine at mount sinai biological psychiatry : a journal of psychiatric neuroscience and therapeutics video : demons of mind : neuroscience and other weapons, library of congress video : coping with anxiety and depression in uncertain times, national library of medicine american medical academics american medical researchers american psychiatrists american textbook writers bipolar disorder researchers living people members of the national academy of medicine icahn school of medicine at mount sinai faculty penn state college of medicine alumni yale school of medicine alumni year of birth missing ( living people ) antidepressants
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The following are multiple choice questions (with answers) about STEM.
A pt. was treated with amitryptiline for depression developed urinary retention, constipation and blurring of vision, most likely cause is :
A. Anticholinergic side effects
B. Expressed symptoms of depression
C. Superadded prostatic enlargement
D. Any of the above
Answer: | [
"Anticholinergic side effects",
"Expressed symptoms of depression",
"Superadded prostatic enlargement",
"Any of the above"
] | A | Ans. is 'a' Anticholinergic side effects Tricyclic Antidepressants have prominent Anticholinergic side effects. Symptoms are -Dry mouthBad TasteBlurred vision (mydriasis)ConstipationUrinary retentionEpigastric distress |
arc_easy_269 | arc_easy | <ctx>
##ientific studies can seek to identify aspects of science that need improvement, and develop ways to improve them. if science is accepted as the fundamental engine of economic growth and social progress, this could raise " the question of what we – as a society – can do to accelerate science, and to direct science toward solving society's most important problems. " however, one of the authors clarified that a one - size - fits - all approach is not thought to be right answer – for example, in funding, darpa models, curiosity - driven methods, allowing " a single reviewer to champion a project even if his or her peers do not agree ", and various other approaches all have their uses. nevertheless, evaluation of them can help build knowledge of what works or works best. reforms meta - research identifying flaws in scientific practice has inspired reforms in science. these reforms seek to address and fix problems in scientific practice which lead to low - quality or inefficient research. a 2015 study lists " fragmented " efforts in meta - research. pre - registration the practice of registering a scientific study before it is conducted is called pre - registration. it arose as a means to address the replication crisis. pregistration requires the submission of a registered report, which is then accepted for publication or rejected by a journal based on theoretical justification, experimental design, and the proposed statistical analysis. pre - registration of studies serves to prevent publication bias ( e. g. not publishing negative results ), reduce data dredging, and increase replicability. reporting standards studies showing poor consistency and quality of reporting have demonstrated the need for reporting standards and guidelines in science, which has led to the rise of organisations that produce such standards, such as consort ( consolidated standards of reporting trials ) and the equator network. the equator ( enhancing the quality and transparency of health research ) network is an international initiative aimed at promoting transparent and accurate reporting of health research studies to enhance the value and reliability of medical research literature. the equator network was established with the goals of raising awareness of the importance of good reporting of research, assisting in the development, dissemination and implementation of reporting guidelines for different types of study designs, monitoring the status of the quality of reporting of research studies in the health sciences literature,
##ently, 1 ) percent of the time. a significant result is widely seen as an important indicator that the correlation is not random. while correlations track the relationship between truly independent measurements, such as smoking and cancer, they are much less effective when variables cannot be isolated, a common circumstance in biological systems. for example, statistics found a high correlation between lower back pain and abnormalities in spinal discs, although it was later discovered that serious abnormalities were present in two - thirds of pain - free patients. minimum threshold publishers journals such as plos one use a “ minimal - threshold ” standard, seeking to publish as much science as possible, rather than to pick out the best work. their peer reviewers assess only whether a paper is methodologically sound. almost half of their submissions are still rejected on that basis. unpublished research only 22 % of the clinical trials financed by the national institutes of health ( nih ) released summary results within one year of completion, even though the nih requires it. fewer than half published within 30 months ; a third remained unpublished after 51 months. when other scientists rely on invalid research, they may waste time on lines of research that are themselves invalid. the failure to report failures means that researchers waste money and effort exploring blind alleys already investigated by other scientists. fraud in 21 surveys of academics ( mostly in the biomedical sciences but also in civil engineering, chemistry and economics ) carried out between 1987 and 2008, 2 % admitted fabricating data, but 28 % claimed to know of colleagues who engaged in questionable research practices. lack of access to data and software clinical trials are generally too costly to rerun. access to trial data is the only practical approach to reassessment. a campaign to persuade pharmaceutical firms to make all trial data available won its first convert in february 2013 when glaxosmithkline became the first to agree. software used in a trial is generally considered to be proprietary intellectual property and is not available to replicators, further complicating matters. journals that insist on data - sharing tend not to do the same for software. even well - written papers may not include sufficient detail and / or tacit knowledge ( subtle skills and extemporisations not considered notable ) for the replication to
##t suggestions from the world at large. this approach helped ensure that the technical aspects of the novel the martian were as accurate as possible. technical communication collaboration in technical communication ( also commonly referred to as technical writing ) has become increasingly important in the creation and dissemination of technical documents in multiple technical and occupational fields, including : computer hardware and software, medicine, engineering, robotics, aeronautics, biotechnology, information technology, and finance. collaboration in technical communication allows for greater flexibility, productivity and innovation for technical writers and the companies they work for, resulting in technical documents that are more comprehensive and accurate than documents produced by individuals. technical communication collaboration typically occurs on shared document work - spaces ( such as google docs ), through social media sites, videoconferencing, sms and im, and on cloud - based authoring platforms. science scientific collaboration rapidly advanced throughout the twentieth century as measured by the increasing numbers of coauthors on published papers. wagner and leydesdorff found international collaborations to have doubled from 1990 to 2005. while collaborative authorships within nations has also risen, this has done so at a slower rate and is not cited as frequently. notable examples of scientific collaboration include cern, the international space station, the iter nuclear fusion experiment, and the european union's human brain project. medicine collaboration in health care is defined as health care professionals assuming complementary roles and cooperatively working together, sharing responsibility for problem - solving and making decisions to formulate and carry out plans for patient care. collaboration between physicians, nurses, and other health care professionals increases team members ’ awareness of each other's type of knowledge and skills, leading to continued improvement in decision making. a collaborative plan is filed with each state board of medicine where the pa works. this plan formally delineates the scope of practice approved by the physician. collaboration between stakeholders in health and social care welfare services, including healthcare systems, have become more specialised over time and are provided by an increasing number of departments and organisations. one disadvantage from this development is fragmented supply of health and social services, which hampers integration of services resulting in suboptimal care, higher cost due to overlaps and poor quality of care. the current system, in which care is fragmented and delivered
requested that the institute of medicine ( iom ) establish a committee to recommend ways to strengthen omics - based test development and evaluation. the iom's recommendations released in march 2012 spoke to the many parties responsible for discovery and development of omics - based tests, including investigators, their institutions, sponsors of research, the fda, and journals. the report identified best practices to enhance development, evaluation, and translation of omics - based tests while simultaneously reinforcing steps to ensure that these tests are appropriately assessed for scientific validity before they are used to guide patient treatment in clinical trials. the iom's recommendations aimed to ensure that progress in omics test development is grounded in sound scientific practice and is reproducible, resulting not only in improved health care but also in continued public trust. the iom report further added that " failure by many parties [ at duke ] to detect or act on problems with key data and computational methods … led to the inappropriate enrollment of patients in clinical trials, premature launch of companies and retraction of dozens of research papers. " the report specifically called for scientific investigators to make the data, computer codes and computational procedures used to develop their clinical tests " publicly accessible for independent review " and to ensure that their data and research steps are presented comprehensibly. the report also found that so - called " omics " tests – such as genomics and proteomics, which are diagnostic tools based on molecular patterns – are in general highly prone to errors. iom committee chair gilbert omenn, a computational biologist at the university of michigan, said the problems could have been avoided. but he noted, as well, that those kinds of problems were not unique to duke. " there are a lot of lessons here that surely apply to other places, " omenn said. continuing controversy one question that neither duke nor people involved in the research have been able to explicitly answer thus far is how data corruption or manipulation that would require thorough knowledge of microarray data warehouse ( large specialised databases ) as well as bioinformatics occurred. robert califf's comments about tmqf only addresses data provenance, adequate quantitative collaboration, accountability and open dialogue about issues beyond the individual lab
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The following are multiple choice questions (with answers) about STEM.
If a scientist wants the medical community to revise old information and use new research findings in the treatment of a disease, it would be best to present the information
A. at a school science fair.
B. in a newspaper article.
C. at a physicians' conference.
D. in a television commercial.
Answer: | [
"at a school science fair.",
"in a newspaper article.",
"at a physicians' conference.",
"in a television commercial."
] | C | |
qasc_7208 | qasc | <ctx>
the most common causes of bridge accidents. as rust displaces a much higher volume than the originating mass of iron, its build - up can also cause failure by forcing apart adjacent components. it was the cause of the collapse of the mianus river bridge in 1983, when support bearings rusted internally and pushed one corner of the road slab off its support. three drivers on the roadway at the time died as the slab fell into the river below. the following ntsb investigation showed that a drain in the road had been blocked for road re - surfacing, and had not been unblocked ; as a result, runoff water penetrated the support hangers. rust was also an important factor in the silver bridge disaster of 1967 in west virginia, when a steel suspension bridge collapsed within a minute, killing 46 drivers and passengers who were on the bridge at the time. similarly, corrosion of concrete - covered steel and iron can cause the concrete to spall, creating severe structural problems. it is one of the most common failure modes of reinforced concrete bridges. measuring instruments based on the half - cell potential can detect the potential corrosion spots before total failure of the concrete structure is reached. until 20 – 30 years ago, galvanized steel pipe was used extensively in the potable water systems for single and multi - family residents as well as commercial and public construction. today, these systems have long ago consumed the protective zinc and are corroding internally, resulting in poor water quality and pipe failures. the economic impact on homeowners, condo dwellers, and the public infrastructure is estimated at 22 billion dollars as the insurance industry braces for a wave of claims due to pipe failures. corrosion in nonmetals most ceramic materials are almost entirely immune to corrosion. the strong chemical bonds that hold them together leave very little free chemical energy in the structure ; they can be thought of as already corroded. when corrosion does occur, it is almost always a simple dissolution of the material or chemical reaction, rather than an electrochemical process. a common example of corrosion protection in ceramics is the lime added to soda - lime glass to reduce its solubility in water ; though it is not nearly as soluble as pure sodium silicate, normal glass does form
for free at openstax. org perhaps the most familiar example of corrosion is the formation of rust on iron. iron will rust when it is exposed to oxygen and water. rust formation involves the creation of a galvanic cell at an iron surface, as illustrated in figure 17. 15. the relevant redox reactions are described by the following equations : further reaction of the iron ( ii ) product in humid air results in the production of an iron ( iii ) oxide hydrate known as rust : the stoichiometry of the hydrate varies, as indicated by the use of x in the compound formula. unlike the patina on copper, the formation of rust does not create a protective layer and so corrosion of the iron continues as the rust flakes off and exposes fresh iron to the atmosphere. figure 17. 15 ( a ) the statue of liberty is covered with a copper skin, and was originally brown, as shown in this painting. ( b ) exposure to the elements has resulted in the formation of the blue - green patina seen today.
17. 6 corrosion learning objectives by the end of this section, you will be able to : • define corrosion • list some of the methods used to prevent or slow corrosion corrosion is usually defined as the degradation of metals by a naturally occurring electrochemical process. the formation of rust on iron, tarnish on silver, and the blue - green patina that develops on copper are all examples of corrosion. the total cost of corrosion remediation in the united states is significant, with estimates in excess of half a trillion dollars a year. chemistry in everyday life statue of liberty : changing colors the statue of liberty is a landmark every american recognizes. the statue of liberty is easily identified by its height, stance, and unique blue - green color ( figure 17. 15 ). when this statue was first delivered from france, its appearance was not green. it was brown, the color of its copper “ skin. ” so how did the statue of liberty change colors? the change in appearance was a direct result of corrosion. the copper that is the primary component of the statue slowly underwent oxidation from the air. the oxidation - reduction reactions of copper metal in the environment occur in several steps. copper metal is oxidized to copper ( i ) oxide ( cu2o ), which is red, and then to copper ( ii ) oxide, which is black coal, which was often high in sulfur, was burned extensively in the early part of the last century. as a result, atmospheric sulfur trioxide, carbon dioxide, and water all reacted with the cuo these three compounds are responsible for the characteristic blue - green patina seen on the statue of liberty ( and other outdoor copper structures ). fortunately, formation of patina creates a protective layer on the copper surface, preventing further corrosion of the underlying copper. the formation of the protective layer is called passivation, a phenomenon discussed further in another chapter of this text. 840 17 • electrochemistry access for free at openstax. org perhaps the most familiar example of corrosion is the formation of rust on iron. iron will rust when it is exposed to oxygen and water. rust formation involves the creation of a galvanic cell at an iron surface, as illustrated in figure 17. 15. the
##dehyde or a ketone, a carboxylic acid, and then a peroxide. corrosion and rusting the term corrosion refers to the electrochemical oxidation of metals in reaction with an oxidant such as oxygen. rusting, the formation of iron oxides, is a well - known example of electrochemical corrosion ; it forms as a result of the oxidation of iron metal. common rust often refers to iron ( iii ) oxide, formed in the following chemical reaction : the oxidation of iron ( ii ) to iron ( iii ) by hydrogen peroxide in the presence of an acid : here the overall equation involves adding the reduction equation to twice the oxidation equation, so that the electrons cancel : disproportionation a disproportionation reaction is one in which a single substance is both oxidized and reduced. for example, thiosulfate ion with sulfur in oxidation state + 2 can react in the presence of acid to form elemental sulfur ( oxidation state 0 ) and sulfur dioxide ( oxidation state + 4 ). thus one sulfur atom is reduced from + 2 to 0, while the other is oxidized from + 2 to + 4. redox reactions in industry cathodic protection is a technique used to control the corrosion of a metal surface by making it the cathode of an electrochemical cell. a simple method of protection connects protected metal to a more easily corroded " sacrificial anode " to act as the anode. the sacrificial metal instead of the protected metal, then, corrodes. a common application of cathodic protection is in galvanized steel, in which a sacrificial coating of zinc on steel parts protects them from rust. oxidation is used in a wide variety of industries such as in the production of cleaning products and oxidizing ammonia to produce nitric acid. redox reactions are the foundation of electrochemical cells, which can generate electrical energy or support electrosynthesis. metal ores often contain metals in oxidized states such as oxides or sulfides, from which the pure metals are extracted by smelting at high temperature in the presence of a reducing agent. the process of electropl
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The following are multiple choice questions (with answers) about STEM.
What event has an effect on corrosion?
A. global warming
B. heating liquids
C. Greenhouse gasses
D. flow of electrons
Answer: | [
"global warming",
"heating liquids",
"Greenhouse gasses",
"flow of electrons"
] | A | |
aquarat_31877 | aquarat | <ctx>
average it lands heads up 50 % of the time ) and an experiment where you toss the coin 5 times. a possible result of the experiment that we consider here is 5 heads. let outcomes be considered unlikely with respect to an assumed distribution if their probability is lower than a significance threshold of 0. 05. a potential null hypothesis implying a one - tailed test is " this coin is not biased toward heads ". beware that, in this context, the term " one - tailed " does not refer to the outcome of a single coin toss ( i. e., whether or not the coin comes up " tails " instead of " heads " ) ; the term " one - tailed " refers to a specific way of testing the null hypothesis in which the critical region ( also known as " region of rejection " ) ends up in on only one side of the probability distribution. indeed, with a fair coin the probability of this experiment outcome is 1 / 25 = 0. 031, which would be even lower if the coin were biased in favour of tails. therefore, the observations are not likely enough for the null hypothesis to hold, and the test refutes it. since the coin is ostensibly neither fair nor biased toward tails, the conclusion of the experiment is that the coin is biased towards heads. alternatively, a null hypothesis implying a two - tailed test is " this coin is fair ". this one null hypothesis could be examined by looking out for either too many tails or too many heads in the experiments. the outcomes that would tend to refute this null hypothesis are those with a large number of heads or a large number of tails, and our experiment with 5 heads would seem to belong to this class. however, the probability of 5 tosses of the same kind, irrespective of whether these are head or tails, is twice as much as that of the 5 - head occurrence singly considered. hence, under this two - tailed null hypothesis, the observation receives a probability value of 0. 063. hence again, with the same significance threshold used for the one - tailed test ( 0. 05 ), the same outcome is not statistically significant. therefore, the two - tailed null hypothesis will be preserved in this case
, h, and tails, t. the symbols h and t represent more generalised variables expressing the numbers of heads and tails respectively that might have been observed in the experiment. thus n = h + t = h + t. next, let r be the actual probability of obtaining heads in a single toss of the coin. this is the property of the coin which is being investigated. using bayes'theorem, the posterior probability density of r conditional on h and t is expressed as follows : where g ( r ) represents the prior probability density distribution of r, which lies in the range 0 to 1. the prior probability density distribution summarizes what is known about the distribution of r in the absence of any observation. we will assume that the prior distribution of r is uniform over the interval [ 0, 1 ]. that is, g ( r ) = 1. ( in practice, it would be more appropriate to assume a prior distribution which is much more heavily weighted in the region around 0. 5, to reflect our experience with real coins. ) the probability of obtaining h heads in n tosses of a coin with a probability of heads equal to r is given by the binomial distribution : substituting this into the previous formula : this is in fact a beta distribution ( the conjugate prior for the binomial distribution ), whose denominator can be expressed in terms of the beta function : as a uniform prior distribution has been assumed, and because h and t are integers, this can also be written in terms of factorials : example for example, let n = 10, h = 7, i. e. the coin is tossed 10 times and 7 heads are obtained : the graph on the right shows the probability density function of r given that 7 heads were obtained in 10 tosses. ( note : r is the probability of obtaining heads when tossing the same coin once. ) the probability for an unbiased coin ( defined for this purpose as one whose probability of coming down heads is somewhere between 45 % and 55 % ) is small when compared with the alternative hypothesis ( a biased coin ). however, it is not small enough to cause us to believe that the coin has a significant bias. this probability is
in the square, in such a way that each point in the square is equally likely to be hit. since the square has area 1, the probability that the dart will hit any particular subregion of the square is equal to the area of that subregion. for example, the probability that the dart will hit the right half of the square is 0. 5, since the right half has area 0. 5. next, consider the event that the dart hits exactly a point in the diagonals of the unit square. since the area of the diagonals of the square is 0, the probability that the dart will land exactly on a diagonal is 0. that is, the dart will almost never land on a diagonal ( equivalently, it will almost surely not land on a diagonal ), even though the set of points on the diagonals is not empty, and a point on a diagonal is no less possible than any other point. tossing a coin repeatedly consider the case where a ( possibly biased ) coin is tossed, corresponding to the probability space, where the event occurs if a head is flipped, and if a tail is flipped. for this particular coin, it is assumed that the probability of flipping a head is, from which it follows that the complement event, that of flipping a tail, has probability. now, suppose an experiment were conducted where the coin is tossed repeatedly, with outcomes and the assumption that each flip's outcome is independent of all the others ( i. e., they are independent and identically distributed ; i. i. d ). define the sequence of random variables on the coin toss space, where. i. e. each records the outcome of the th flip. in this case, any infinite sequence of heads and tails is a possible outcome of the experiment. however, any particular infinite sequence of heads and tails has probability 0 of being the exact outcome of the ( infinite ) experiment. this is because the i. i. d. assumption implies that the probability of flipping all heads over flips is simply. letting yields 0, since by assumption. the result is the same no matter how much we bias the coin towards heads, so long as we constrain to be strictly between 0 and 1. in
in statistics, the question of checking whether a coin is fair is one whose importance lies, firstly, in providing a simple problem on which to illustrate basic ideas of statistical inference and, secondly, in providing a simple problem that can be used to compare various competing methods of statistical inference, including decision theory. the practical problem of checking whether a coin is fair might be considered as easily solved by performing a sufficiently large number of trials, but statistics and probability theory can provide guidance on two types of question ; specifically those of how many trials to undertake and of the accuracy of an estimate of the probability of turning up heads, derived from a given sample of trials. a fair coin is an idealized randomizing device with two states ( usually named " heads " and " tails " ) which are equally likely to occur. it is based on the coin flip used widely in sports and other situations where it is required to give two parties the same chance of winning. either a specially designed chip or more usually a simple currency coin is used, although the latter might be slightly " unfair " due to an asymmetrical weight distribution, which might cause one state to occur more frequently than the other, giving one party an unfair advantage. so it might be necessary to test experimentally whether the coin is in fact " fair " – that is, whether the probability of the coin's falling on either side when it is tossed is exactly 50 %. it is of course impossible to rule out arbitrarily small deviations from fairness such as might be expected to affect only one flip in a lifetime of flipping ; also it is always possible for an unfair ( or " biased " ) coin to happen to turn up exactly 10 heads in 20 flips. therefore, any fairness test must only establish a certain degree of confidence in a certain degree of fairness ( a certain maximum bias ). in more rigorous terminology, the problem is of determining the parameters of a bernoulli process, given only a limited sample of bernoulli trials. preamble this article describes experimental procedures for determining whether a coin is fair or unfair. there are many statistical methods for analyzing such an experimental procedure. this article illustrates two of them. both methods prescribe an experiment ( or trial )
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The following are multiple choice questions (with answers) about STEM.
Two unbiased coin are tossed .what is the probability of getting atmost one head?
A. A)3/6
B. B)2/3
C. C)3/4
D. D)1/4
Answer: | [
"A)3/6",
"B)2/3",
"C)3/4",
"D)1/4"
] | C | Here S={HH,HT,TH,TT}
Let Ee=event of getting one head
E={TT,HT,TH}
P(E)=n(E)/n(S)=3/4
Option C |
medmcqa_5187 | medmcqa | <ctx>
branchial arch or gill arch of fish ), is the first of six pharyngeal arches that develops during the fourth week of development. it is located between the stomodeum and the first pharyngeal groove. processes this arch divides into a maxillary process and a mandibular process, giving rise to structures including the bones of the lower two - thirds of the face and the jaw. the maxillary process becomes the maxilla ( or upper jaw, although there are large differences among animals ), and palate while the mandibular process becomes the mandible or lower jaw. this arch also gives rise to the muscles of mastication. meckel's cartilage meckel's cartilage forms in the mesoderm of the mandibular process and eventually regresses to form the incus and malleus of the middle ear, the anterior ligament of the malleus and the sphenomandibular ligament. the mandible or lower jaw forms by perichondral ossification using meckel's cartilage as a'template ', but the maxillary does not arise from direct ossification of meckel's cartilage. derivatives the skeletal elements and muscles are derived from mesoderm of the pharyngeal arches. skeletal malleus and incus of the middle ear maxilla and mandible spine of sphenoid bone sphenomandibular ligament palatine bone squamous part of temporal bone anterior ligament of malleus muscles muscles of mastication ( chewing ) masseter medial and lateral pterygoid muscles temporalis mylohyoid muscle digastric muscle, anterior belly tensor veli palatini muscle tensor tympani muscle other mucous membrane and glands of the anterior two thirds of the tongue are derived from ectoderm and endoderm of the arch. nerve supply the mandibular and maxillary branches of the trigeminal nerve ( cn v ) innervate the structures derived from the corresponding processes of the first arch. in some lower animals, each arch is supplied by two cranial nerves. the nerve of the arch itself runs along the cranial side of the
##fies to form the lesser cornu and upper part of the body of the hyoid bone. caudal to what will eventually become the stapes, reichert's cartilage also forms the styloid process of the temporal bone. the cartilage between the hyoid bone and styloid process will not remain as development continues, but its perichondrium will eventually form the stylohyoid ligament. derivatives skeletal from the cartilage of the second arch arises stapes, temporal styloid process, stylohyoid ligament, and lesser cornu of the hyoid bone. muscles facial muscles occipitofrontalis muscle platysma stylohyoid muscle posterior belly of digastric muscle stapedius muscle auricular muscles nerve supply facial nerve ( cn vii ) blood supply the artery of the second arch is the second aortic arch, which gives origin to the stapedial artery in some mammals but atrophies in most humans. muscles derived from the pharyngeal arches pharyngeal muscles or branchial muscles are striated muscles of the head and neck. unlike skeletal muscles that developmentally come from somites, pharyngeal muscles are developmentally formed from the pharyngeal arches. most of the skeletal musculature supplied by the cranial nerves ( special visceral efferent ) is pharyngeal. exceptions include, but are not limited to, the extraocular muscles and some of the muscles of the tongue. these exceptions receive general somatic efferent innervation. first arch all of the pharyngeal muscles that come from the first pharyngeal arch are innervated by the mandibular divisions of the trigeminal nerve. these muscles include all the muscles of mastication, the anterior belly of the digastric, the mylohyoid, tensor tympani, and tensor veli palatini. second arch all of the pharyngeal muscles of the second pharyngeal arch are innervated by the facial nerve. these muscles include the muscles of facial expression, the posterior belly of the dig
the vagal and glossopharyngeal nerves. relations it is situated anterolaterally to the levator veli palatini muscle. from its origin to its insertion, the muscle passes vertically between the medial pterygoid plate and the medial pterygoid muscle. actions / movements bilateral contraction of the two tensor veli palatini muscles makes the soft palate ( especially its anterior portion ) taut, as well as flattening the arch of the soft palate and thereby depressing it. unilateral contraction draws the soft palate ipsilaterally. function the tensor veli palatini tenses the soft palate and by doing so, assists the levator veli palatini in elevating the palate to occlude and prevent entry of food into the nasopharynx during swallowing. the tensed palate consequently provides a stable platform for elevation of the pharynx during swallowing by the pharyngeal muscles. since it is also attached to the lateral cartilaginous lamina of the pharyngotympanic tube ( auditory tube or eustachian tube ), it assists in its opening during swallowing or yawning to allow air pressure to equalize between the tympanic cavity and the outside air. equalization of air pressure in the tympanic cavity is essential for preventing damage to the tympanic membrane and a resulting loss of hearing acuity. additional images see also levator veli palatini references external links muscles of the head and neck pharynx
a bone is a rigid organ that constitutes part of the skeleton in most vertebrate animals. bones protect the various other organs of the body, produce red and white blood cells, store minerals, provide structure and support for the body, and enable mobility. bones come in a variety of shapes and sizes and have complex internal and external structures. they are lightweight yet strong and hard and serve multiple functions. bone tissue ( osseous tissue ), which is also called bone in the uncountable sense of that word, is hard tissue, a type of specialised connective tissue. it has a honeycomb - like matrix internally, which helps to give the bone rigidity. bone tissue is made up of different types of bone cells. osteoblasts and osteocytes are involved in the formation and mineralisation of bone ; osteoclasts are involved in the resorption of bone tissue. modified ( flattened ) osteoblasts become the lining cells that form a protective layer on the bone surface. the mineralised matrix of bone tissue has an organic component of mainly collagen called ossein and an inorganic component of bone mineral made up of various salts. bone tissue is mineralized tissue of two types, cortical bone and cancellous bone. other types of tissue found in bones include bone marrow, endosteum, periosteum, nerves, blood vessels and cartilage. in the human body at birth, there are approximately 300 bones present ; many of these fuse together during development, leaving a total of 206 separate bones in the adult, not counting numerous small sesamoid bones. the largest bone in the body is the femur or thigh - bone, and the smallest is the stapes in the middle ear. the greek word for bone is οστεον ( " osteon " ), hence the many terms that use it as a prefix — such as osteopathy. in anatomical terminology, including the terminologia anatomica international standard, the word for a bone is os ( for example, os breve, os longum, os sesamoideum ). structure bone is not uniformly solid, but consists of a flexible matrix
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The following are multiple choice questions (with answers) about STEM.
In an adult, the hyoid bone is seen at which of the following level of the cervical veebrae?
A. C2
B. C3
C. C4
D. C5
Answer: | [
"C2",
"C3",
"C4",
"C5"
] | B | The hyoid bone is found at the level of third cervical veebrae in adults. It is situated above the thyroid cailage in the anterior wall of the hypopharynx in relation to the base of the tongue. It is made up of a body, bilateral greater cornua and bilateral lesser cornua. It is a sesamoid bone and is suspended in between the supra hyoid and infra hyoid musculature and is therefore responsible for the concavity between the chin and the anterior neck. The body is convex from side to side. At either end of the body on its upper surface is a small tubercle called lesser cornu. It is the point of attachment of medial end of middle constrictor muscle and stylohyoid ligament. |
aquarat_36969 | aquarat | <ctx>
4. 2 classifying chemical reactions 12. use the following equations to answer the next four questions : i. ii. iii. iv. v. ( a ) which equation describes a physical change? ( b ) which equation identifies the reactants and products of a combustion reaction? ( c ) which equation is not balanced? ( d ) which is a net ionic equation? 4 • exercises 201 13. indicate what type, or types, of reaction each of the following represents : ( a ) ( b ) ( c ) 14. indicate what type, or types, of reaction each of the following represents : ( a ) ( b ) ( c ) ( d ) 15. silver can be separated from gold because silver dissolves in nitric acid while gold does not. is the dissolution of silver in nitric acid an acid - base reaction or an oxidation - reduction reaction? explain your answer. 16. determine the oxidation states of the elements in the following compounds : ( a ) nai ( b ) gdcl3 ( c ) lino3 ( d ) h2se ( e ) mg2si ( f ) rbo2, rubidium superoxide ( g ) hf 17. determine the oxidation states of the elements in the compounds listed. none of the oxygen - containing compounds are peroxides or superoxides. ( a ) h3po4 ( b ) al ( oh ) 3 ( c ) seo2 ( d ) kno2 ( e ) in2s3 ( f ) p4o6 18. determine the oxidation states of the elements in the compounds listed. none of the oxygen - containing compounds are peroxides or superoxides. ( a ) h2so4 ( b ) ca ( oh ) 2 ( c ) broh ( d ) clno2 ( e ) ticl4 ( f ) nah 19. classify the following as acid - base reactions or oxidation - reduction reactions : ( a ) ( b ) ( c ) ( d ) ( e ) ( f ) 20. identify the atoms that are oxidized and reduced, the change in oxidation state for each, and the oxidizing and reducing agents in each of the following equations : ( a ) (
law, difference law, constant multiple law, and identity law, last, applying the quotient law : 4. 11 find
we analyze the case where there are distinct roots and the case where there is a repeated root : if the roots are distinct, the general solution is where the exponentials may be complex. if the roots are equal, the general solution is in both cases, the solution may be found by setting. hence, in the first case, and in the second case, example given we substitute the simple solution : for to be a solution, either, which gives the trivial solution, or the coefficient of is zero. solving the quadratic equation, we get. the general solution is therefore difference equation analogue there is a difference equation analogue to the cauchy – euler equation. for a fixed, define the sequence as applying the difference operator to, we find that if we do this times, we find that where the superscript denotes applying the difference operator times. comparing this to the fact that the - th derivative of equals suggests that we can solve the n - th order difference equation in a similar manner to the differential equation case. indeed, substituting the trial solution brings us to the same situation as the differential equation case, one may now proceed as in the differential equation case, since the general solution of an - th order linear difference equation is also the linear combination of linearly independent solutions. applying reduction of order in case of a multiple root will yield expressions involving a discrete version of, ( compare with : ) in cases where fractions become involved, one may use instead ( or simply use it in all cases ), which coincides with the definition before for integer. see also hypergeometric differential equation cauchy – euler operator references bibliography ordinary differential equations
4. 1 writing and balancing chemical equations 1. what does it mean to say an equation is balanced? why is it important for an equation to be balanced? 2. consider molecular, complete ionic, and net ionic equations. ( a ) what is the difference between these types of equations? ( b ) in what circumstance would the complete and net ionic equations for a reaction be identical? 3. balance the following equations : ( a ) ( b ) ( c ) ( d ) ( e ) ( f ) ( g ) ( h ) 4. balance the following equations : ( a ) ( b ) ( c ) ( d ) ( e ) ( f ) ( g ) ( h ) 5. write a balanced molecular equation describing each of the following chemical reactions. ( a ) solid calcium carbonate is heated and decomposes to solid calcium oxide and carbon dioxide gas. ( b ) gaseous butane, c4h10, reacts with diatomic oxygen gas to yield gaseous carbon dioxide and water vapor. ( c ) aqueous solutions of magnesium chloride and sodium hydroxide react to produce solid magnesium hydroxide and aqueous sodium chloride. ( d ) water vapor reacts with sodium metal to produce solid sodium hydroxide and hydrogen gas. 6. write a balanced equation describing each of the following chemical reactions. ( a ) solid potassium chlorate, kclo3, decomposes to form solid potassium chloride and diatomic oxygen gas. ( b ) solid aluminum metal reacts with solid diatomic iodine to form solid al2i6. ( c ) when solid sodium chloride is added to aqueous sulfuric acid, hydrogen chloride gas and aqueous sodium sulfate are produced. ( d ) aqueous solutions of phosphoric acid and potassium hydroxide react to produce aqueous potassium dihydrogen phosphate and liquid water. 200 4 • exercises access for free at openstax. org 7. colorful fireworks often involve the decomposition of barium nitrate and potassium chlorate and the reaction of the metals magnesium, aluminum, and iron with oxygen. ( a ) write the formulas of barium nitrate and potassium chlorate. ( b ) the decomposition of solid potassium chlorate
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The following are multiple choice questions (with answers) about STEM.
Four of the following five parts numbered (a), (b), (c), (d) and (e) in the following equation are exactly equal. Which of the parts is not equal to the other four? The number of that part is the answer.
A. A)xy2 – x2y + 2x2y2
B. B)xy2(1 – 2x) + x2y(2y – 1)
C. C)xy2(1 + x) – x2y(1 – y)
D. D)xy[y(1 + x) – x(1 – y)]
Answer: | [
"A)xy2 – x2y + 2x2y2",
"B)xy2(1 – 2x) + x2y(2y – 1)",
"C)xy2(1 + x) – x2y(1 – y)",
"D)xy[y(1 + x) – x(1 – y)]"
] | B | The other parts are equal to xy2 – x2y + 2x2y2.
Answer B |
medmcqa_5843 | medmcqa | <ctx>
on the right has melted ), although both have been in the sunlight for the same time. the thermal conductivities of the pavements are the same. gray objects have a uniform ability to absorb all parts of the electromagnetic spectrum. colored objects behave in similar but more complex ways, which gives them a particular color in the visible range and may make them special in other ranges of the nonvisible spectrum. take, for example, the strong absorption of infrared radiation by the skin, which allows us to be very sensitive to it.
, of each photon is multiplied by the number of states available at that frequency, and the probability that each of those states will be occupied. integrating the above equation over the power output given by the stefan – boltzmann law is obtained, as : where the constant of proportionality is the stefan – boltzmann constant and is the radiating surface area. the wavelength, for which the emission intensity is highest, is given by wien's displacement law as : for surfaces which are not black bodies, one has to consider the ( generally frequency dependent ) emissivity factor. this factor has to be multiplied with the radiation spectrum formula before integration. if it is taken as a constant, the resulting formula for the power output can be written in a way that contains as a factor : this type of theoretical model, with frequency - independent emissivity lower than that of a perfect black body, is often known as a grey body. for frequency - dependent emissivity, the solution for the integrated power depends on the functional form of the dependence, though in general there is no simple expression for it. practically speaking, if the emissivity of the body is roughly constant around the peak emission wavelength, the gray body model tends to work fairly well since the weight of the curve around the peak emission tends to dominate the integral. constants definitions of constants used in the above equations : variables definitions of variables, with example values : radiative heat transfer the net radiative heat transfer from one surface to another is the radiation leaving the first surface for the other minus that arriving from the second surface. formulas for radiative heat transfer can be derived for more particular or more elaborate physical arrangements, such as between parallel plates, concentric spheres and the internal surfaces of a cylinder. see also incandescence infrared photography interior radiation control coating heat transfer planck radiation radiant cooling sakuma – hattori equation thermal dose unit view factor references further reading e. m. sparrow and r. d. cess. radiation heat transfer. hemisphere publishing corporation, 1978. kuenzer, c. and s. dech ( 2013 ) : thermal infrared remote sensing : sensors, methods, applications ( = remote sensing and digital image processing 17 ). do
0. 0103 nm? 30. ( a ) what is the ratio of power outputs by two microwave ovens having frequencies of 950 and 2560 mhz, if they emit the same number of photons per second? ( b ) what is the ratio of photons per second if they have the same power output? 31. how many photons per second are emitted by the antenna of a microwave oven, if its power output is 1. 00 kw at a frequency of 2560 mhz? 32. some satellites use nuclear power. ( a ) if such a satellite emits a 1. 00 - w flux of rays having an average energy of 0. 500 mev, how many are emitted per second? ( b ) these rays affect other satellites. how far away must another satellite be to only receive one ray per second per square meter? 33. ( a ) if the power output of a 650 - khz radio station is 50. 0 kw, how many photons per second are produced? ( b ) if the radio waves are broadcast uniformly in all directions, find the number of photons per second per square meter at a distance of 100 km. assume no reflection from the ground or absorption by the air. 34. how many x - ray photons per second are created by an x - ray tube that produces a flux of x rays having a power of 1. 00 w? assume the average energy per photon is 75. 0 kev. 35. ( a ) how far away must you be from a 650 - khz radio station with power 50. 0 kw for there to be only one photon per second per square meter? assume no reflections or absorption, as if you were in deep outer space. ( b ) discuss the implications for detecting intelligent life in other solar systems by detecting their radio broadcasts. 36. assuming that 10. 0 % of a 100 - w light bulb ’ s energy output is in the visible range ( typical for incandescent bulbs ) with an average wavelength of 580 nm, and that the photons spread out uniformly and are not absorbed by the atmosphere, how far away would you be if 500 photons per second enter the 3. 00 - mm diameter pupil of your eye? ( this
— roughly 3000 k, or 10 times room temperature — radiates 10, 000 times as much energy per unit area. the total radiative intensity of a black body rises as the fourth power of the absolute temperature, as expressed by the stefan – boltzmann law. in the plot, the area under each curve grows rapidly as the temperature increases. the rate of electromagnetic radiation emitted at a given frequency is proportional to the amount of absorption that it would experience by the source, a property known as reciprocity. thus, a surface that absorbs more red light thermally radiates more red light. this principle applies to all properties of the wave, including wavelength ( color ), direction, polarization, and even coherence, so that it is quite possible to have thermal radiation which is polarized, coherent, and directional, though polarized and coherent forms are fairly rare in nature far from sources ( in terms of wavelength ). see section below for more on this qualification. as for photon statistics thermal light obeys super - poissonian statistics. near - field and far - field the general properties of thermal radiation as described by planck's law apply if the linear dimension of all parts considered, as well as radii of curvature of all surfaces are large compared with the wavelength of the ray considered'( typically from 8 - 25 micrometres for the emitter at 300 k ). indeed, thermal radiation as discussed above takes only radiating waves ( far - field, or electromagnetic radiation ) into account. a more sophisticated framework involving electromagnetic theory must be used for smaller distances from the thermal source or surface ( near - field radiative heat transfer ). for example, although far - field thermal radiation at distances from surfaces of more than one wavelength is generally not coherent to any extent, near - field thermal radiation ( i. e., radiation at distances of a fraction of various radiation wavelengths ) may exhibit a degree of both temporal and spatial coherence. planck's law of thermal radiation has been challenged in recent decades by predictions and successful demonstrations of the radiative heat transfer between objects separated by nanoscale gaps that deviate significantly from the law predictions. this deviation is especially strong ( up to
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The following are multiple choice questions (with answers) about STEM.
One gray of radiation is equal to:
A. 1 rad
B. 10 rad
C. 100 rad
D. 1000 rad
Answer: | [
"1 rad",
"10 rad",
"100 rad",
"1000 rad"
] | C | Ans. 100 rad |
mmlu_aux_4454 | mmlu_auxiliary | <ctx>
conduction, convection, or radiation – is approximately proportional to the temperature difference δt. frozen food will warm up faster in a warm room than in a cold room. note that the rate of cooling experienced on a cold day can be increased by the added convection effect of the wind. this is referred to as wind chill. for example, a wind chill of - 20 °c means that heat is being lost at the same rate as if the temperature were - 20 °c without wind. applicable situations this law describes many situations in which an object has a large thermal capacity and large conductivity, and is suddenly immersed in a uniform bath which conducts heat relatively poorly. it is an example of a thermal circuit with one resistive and one capacitative element. for the law to be correct, the temperatures at all points inside the body must be approximately the same at each time point, including the temperature at its surface. thus, the temperature difference between the body and surroundings does not depend on which part of the body is chosen, since all parts of the body have effectively the same temperature. in these situations, the material of the body does not act to " insulate " other parts of the body from heat flow, and all of the significant insulation ( or " thermal resistance " ) controlling the rate of heat flow in the situation resides in the area of contact between the body and its surroundings. across this boundary, the temperature - value jumps in a discontinuous fashion. in such situations, heat can be transferred from the exterior to the interior of a body, across the insulating boundary, by convection, conduction, or diffusion, so long as the boundary serves as a relatively poor conductor with regard to the object's interior. the presence of a physical insulator is not required, so long as the process which serves to pass heat across the boundary is " slow " in comparison to the conductive transfer of heat inside the body ( or inside the region of interest — the " lump " described above ). in such a situation, the object acts as the " capacitative " circuit element, and the resistance of the thermal contact at the boundary acts as the ( single ) thermal resistor. in electrical circuits, such a combination would charge
this by using the equation for the rate of radiative heat transfer. solution insert the temperatures values and, so that discussion this value is a significant rate of heat transfer to the environment ( note the minus sign ), considering that a person at rest may produce energy at the rate of 125 w and that conduction and convection will also be transferring energy to the environment. indeed, we would probably expect this person to feel cold. clothing significantly reduces heat transfer to the environment by many methods, because clothing slows down both conduction and convection, and has a lower emissivity ( especially if it is white ) than skin. the earth receives almost all its energy from radiation of the sun and reflects some of it back into outer space. because the sun is hotter than the earth, the net energy flux is from the sun to the earth. however, the rate of 14. 44 take - home experiment : temperature in the sun place a thermometer out in the sunshine and shield it from direct sunlight using an aluminum foil. what is the reading? now remove the shield, and note what the thermometer reads. take a handkerchief soaked in nail polish remover, wrap it around the thermometer and place it in the sunshine. what does the thermometer read? 14. 45 14. 46 14. 47
longer turnover times are unhealthy, because a minimum amount of fresh air is necessary to supply oxygen for breathing and to dilute household pollutants. the term used for the process by which outside air leaks into the house from cracks around windows, doors, and the foundation is called “ air infiltration. ” a cold wind is much more chilling than still cold air, because convection combines with conduction in the body to increase the rate at which energy is transferred away from the body. the table below gives approximate wind - chill factors, which are the temperatures of still air that produce the same rate of cooling as air of a given temperature and speed. wind - chill factors are a dramatic reminder of convection ’ s ability to transfer heat faster than conduction. for example, a 15. 0 m / s wind at has the chilling equivalent of still air at about. take - home experiment : convection rolls in a heated pan take two small pots of water and use an eye dropper to place a drop of food coloring near the bottom of each. leave one on a bench top and heat the other over a stovetop. watch how the color spreads and how long it takes the color to reach the top. watch how convective loops form. 14. 37 14. 38
. 3 ). other properties used to measure temperature include electrical resistance and color, as shown in figure 13. 4, and the emission of infrared radiation, as shown in figure 13. 5. misconception alert : human perception vs. reality on a cold winter morning, the wood on a porch feels warmer than the metal of your bike. the wood and bicycle are in thermal equilibrium with the outside air, and are thus the same temperature. they feel different because of the difference in the way that they conduct heat away from your skin. the metal conducts heat away from your body faster than the wood does ( see more about conductivity in conduction ). this is just one example demonstrating that the human sense of hot and cold is not determined by temperature alone. another factor that affects our perception of temperature is humidity. most people feel much hotter on hot, humid days than on hot, dry days. this is because on humid days, sweat does not evaporate from the skin as efficiently as it does on dry days. it is the evaporation of sweat ( or water from a sprinkler or pool ) that cools us off. 530 13 • temperature, kinetic theory, and the gas laws access for free at openstax. org figure 13. 3 the curvature of a bimetallic strip depends on temperature. ( a ) the strip is straight at the starting temperature, where its two components have the same length. ( b ) at a higher temperature, this strip bends to the right, because the metal on the left has expanded more than the metal on the right. figure 13. 4 each of the six squares on this plastic ( liquid crystal ) thermometer contains a film of a different heat - sensitive liquid crystal material. below, all six squares are black. when the plastic thermometer is exposed to temperature that increases to, the first liquid crystal square changes color. when the temperature increases above the second liquid crystal square also changes color, and so forth. ( credit : arkrishna, wikimedia commons ) figure 13. 5 fireman jason ormand uses a pyrometer to check the temperature of an aircraft carrier ’ s ventilation system. infrared radiation ( whose emission varies with
</ctx>
The following are multiple choice questions (with answers) about STEM.
Have you ever walked outside thinking it was one temperature but quickly discovered it felt colder? That is because of the "wind chill" effect. Wind chill is how cold people and animals feel when they are outside, not the actual temperature on the thermometer . It is based on how quickly your body loses heat when it is exposed to wind and cold. When the wind is strong, your body quickly loses heat, making the temperature of your skin drop. When scientists first started calculating wind chill, they used research conducted in 1945 by explorers to Antarctica who measured how quickly water froze outside. But water freezes faster than exposed skin, so the wind chill index based on that data wasn't accurate. In 2001, the US government began to measure wind chill more precisely by testing how quickly people's skin froze. Twelve volunteers were placed in a chilled wind tunnel. Equipment was stuck to their faces to measure the heat flow from their cheeks, forehead, nose and chin while they walked three miles per hour on a treadmill . The experiment revealed how quickly exposed skin can be damaged, particularly unprotected areas like your fingers, toes, the tip of your nose and your ear lobes. In fact, 40 percent of your body heat can be lost through your head! Signs you might have frostbite are when the skin turns white or pale and you lose feeling in that area. The information collected from the volunteers helped scientists work out the math to compute wind chill. It involves wind speed and air temperature. If, for example, the temperature outside is zero degrees Fahrenheit and the wind is blowing at 15 miles per hour, the wind chill is calculated at 19 degrees below zero. At that wind chill temperature, exposed skin can freeze in 30 minutes. You can find a calculation table at www.nws.noaa.gov/om/windchill/index.shtml. Experts advise in cold weather that you wear loose-fitting, lightweight, warm clothing, worn on top of each other. Air caught between the clothes will keep you warm. The best cold-weather coats have head coverings made of woven material that keep out water. So next time the temperature drops and you want to play outside, listen to your parents when they tell you to wrap up warm! According to the text, wind chill _ .
A. means how fast exposed skin freezes
B. doesn't affect your head as much as other body parts
C. changes according to the temperature on the thermometer
D. changes from person to person depending on their health
Answer: | [
"means how fast exposed skin freezes",
"doesn't affect your head as much as other body parts",
"changes according to the temperature on the thermometer",
"changes from person to person depending on their health"
] | A | null |
arc_easy_1632 | arc_easy | <ctx>
on average, agriculture contributes 4 % of national gdps. global agricultural production is responsible for between 14 and 28 % of global greenhouse gas emissions, making it one of the largest contributors to global warming, in large part due to conventional agricultural practices, including nitrogen fertilizers and poor land management. agronomy is the science and technology of producing and using plants for food, fuel, fibre, and land reclamation. agronomy encompasses work in the areas of plant genetics, plant physiology, meteorology, and soil science. agronomy is the application of a combination of sciences. agronomists today are involved with many issues including producing food, creating healthier food, managing the environmental impact of agriculture, and extracting energy from plants. food processing food processing includes the methods and techniques used to transform raw ingredients into food for human consumption. food processing takes clean, harvested or slaughtered and butchered components and uses them to produce marketable food products. there are several different ways in which food can be produced. one - off production : this method is used when customers make an order for something to be made to their own specifications, for example, a wedding cake. the making of one - off products could take days depending on how intricate the design is. batch production : this method is used when the size of the market for a product is not clear, and where there is a range within a product line. a certain number of the same goods will be produced to make up a batch or run, for example a bakery may bake a limited number of cupcakes. this method involves estimating consumer demand. mass production : this method is used when there is a mass market for a large number of identical products, for example chocolate bars, ready meals and canned food. the product passes from one stage of production to another along a production line. just - in - time ( jit ) ( production ) : this method of production is mainly used in restaurants. all components of the product are available in - house and the customer chooses what they want in the product. it is then prepared in a kitchen, or in front of the buyer as in sandwich delicatessens, pizzerias, and sushi bars. industry influence
smallholders " an important method for climate change mitigation. issues productivity according to conventional theory, economies of scale allow agricultural productivity, in terms of inputs versus outputs, to rise as the size of the farm rises. specialization has also been a major factor in increasing agricultural productivity, for example as commodity processing began to move off the farm in the 19th century, farmers could spend more effort on primary food production. although numerous studies show that larger farms are more productive than smaller ones, some writers state that whilst conventional farming creates a high output per worker, some small - scale, sustainable, polyculture farmers can produce more food per acre of land. small farms have some economic advantages. farmers support the local economy of their communities. an american study showed that small farms with incomes of $ 100, 000 or less spend almost 95 percent of their farm - related expenses within their local communities. the same study took into comparison the fact that farms with incomes greater than $ 900, 000 spend less than 20 percent of their farm - related expenses in the local economy. small - scale agriculture often sells products directly to consumers. disintermediation gives the farmer the profit that would otherwise go to the wholesaler, the distributor, and the supermarket. about two - thirds of the revenue is expended on product marketing. if farmers sell their products directly to consumers, they receive a higher percentage of the retail price, although they will spend more time selling the same amounts of product, which is an opportunity cost. food security because smallholding farms frequently require less industrial inputs and can be an important way to improve food security in less - developed contexts, addressing the productivity and financial sustainability of small holders is an international development priority and measured by indicator 2. 3 of sustainable development goal 2. the international fund for agricultural development has an ongoing program for adaptation for smallholder agriculture. during the global covid - 19 pandemic, and the attendant disruptions of food systems, their role has become more important. environmental and climate adaptation while the historical focus on smallholders has been increasing global food supply under climate change and the role played by smallholder communities, climate adaptation efforts are still hindered by lack of information on how smallholder farmers are experiencing and responding to climate change
which loss can occur, and given that food is grown for projected need as opposed to a global marketplace demand. nevertheless, on - farm losses in storage in developing countries, particularly in african countries, can be high although the exact nature of such losses is much debated. in the food industry of the united states, the food supply of which is the most diverse and abundant of any country in the world, loss occurs from the beginning of food production chain. from planting, crops can be subjected to pest infestations and severe weather, which cause losses before harvest. since natural forces ( e. g. temperature and precipitation ) remain the primary drivers of crop growth, losses from these can be experienced by all forms of outdoor agriculture. on average, farms in the united states lose up to six billion pounds of crops every year because of these unpredictable conditions. according to the ipcc sixth assessment report, encouraging the development of technologies that address issues in food harvesting and post - harvesting could have a significant impact on decreasing food waste in the supply chain early - on. the use of machinery in harvesting can cause loss, as harvesters may be unable to discern between ripe and immature crops, or collect only part of a crop. economic factors, such as regulations and standards for quality and appearance, also cause food waste ; farmers often harvest selectively, preferring to leave crops not to standard in the field ( where they can be used as fertilizer or animal feed ), since they would otherwise be discarded later. this method of removing undesirable produce from harvest collection, distribution sites and grocery stores is called culling. however, usually when culling occurs at the production, food processing, retail and consumption stages, it is to remove or dispose of produce with a strange or imperfect appearance rather than produce that is spoiled or unsafe to eat. in urban areas, fruit and nut trees often go unharvested because people either do not realize that the fruit is edible or they fear that it is contaminated, despite research which shows that urban fruit is safe to consume. food processing food loss continues in the post - harvest stage, but the amounts of post - harvest loss involved are relatively unknown and difficult to estimate. regardless, the variety of factors that contribute to
used to optimize processes and to improve the quality and safety of food products. smart farming : smart farming involves the use of sensors and data analytics to optimize crop yields and reduce waste. this technology can help farmers to make more informed decisions about when to plant, water, and harvest crops, which can improve the efficiency and sustainability of agriculture. marketing as consumers grow increasingly removed from food production, the role of product creation, advertising, and publicity become the primary vehicles for information about food. with processed food as the dominant category, marketers have almost infinite possibilities in product creation. of the food advertised to children on television, 73 % is fast or convenience foods. one of the main challenges in food industry marketing is the high level of competition in the market. companies must differentiate themselves from their competitors by offering unique products or using innovative marketing techniques. for example, many food companies are now using social media platforms to promote their products and engage with customers. another important aspect of food industry marketing is understanding consumer behavior and preferences. this includes factors such as age, gender, income, and cultural background. companies must also be aware of changing consumer trends and adapt their marketing strategies accordingly. labor and education until the last 100 years, agriculture was labor - intensive. farming was a common occupation and millions of people were involved in food production. farmers, largely trained from generation to generation, carried on the family business. that situation has changed dramatically today. in america in 1870, 70 – 80 % of the us population was employed in agriculture., less than 2 % of the population is directly employed in agriculture, and about 83 % of the population lives in cities. see also agroindustry agricultural expansion dietary supplement factory farming food fortification, also called nutrification geography of food local food ultra - processed food references works cited further reading nelson, scott reynolds. oceans of grain : how american wheat remade the world ( 2022 ) excerpt 534 pages. 448 pages. 836 pages. 301 pages. food fight : the inside story of the food industry external links agriculture mass production industries ( economics )
</ctx>
The following are multiple choice questions (with answers) about STEM.
When can producers make the most food?
A. summer, because there is more sunlight
B. summer, because there is more heat
C. spring, because there is more rain
D. spring, because there are more leaves
Answer: | [
"summer, because there is more sunlight",
"summer, because there is more heat",
"spring, because there is more rain",
"spring, because there are more leaves"
] | A | |
aquarat_11153 | aquarat | <ctx>
and those that go into the unchosen bin. this can be generalized to any number of bins with the constraint that every item must go to exactly one bin. the number of ways to put objects into bins is given by the multinomial coefficient where n is the number of items, m is the number of bins, and is the number of items that go into bin i. one way to see why this equation holds is to first number the objects arbitrarily from 1 to n and put the objects with numbers into the first bin in order, the objects with numbers into the second bin in order, and so on. there are distinct numberings, but many of them are equivalent, because only the set of items in a bin matters, not their order in it. every combined permutation of each bins'contents produces an equivalent way of putting items into bins. as a result, every equivalence class consists of distinct numberings, and the number of equivalence classes is. the binomial coefficient is the special case where k items go into the chosen bin and the remaining items go into the unchosen bin : see also binomial coefficient combinatorics block design kneser graph list of permutation topics multiset pascal's triangle permutation probability subset notes references erwin kreyszig, advanced engineering mathematics, john wiley & sons, inc, 1999. external links topcoder tutorial on combinatorics c code to generate all combinations of n elements chosen as k many common types of permutation and combination math problems, with detailed solutions the unknown formula for combinations when choices can be repeated and order does not matter combinations with repetitions ( by : akshatha ag and smitha b ) the dice roll with a given sum problem an application of the combinations with repetition to rolling multiple dice combinatorics
mr. jones has two children. the older child is a girl. what is the probability that both children are girls? under the aforementioned assumptions, in this problem, a random family is selected. in this sample space, there are four equally probable events : only two of these possible events meet the criteria specified in the question ( i. e., gg, gb ). since both of the two possibilities in the new sample space { gg, gb } are equally likely, and only one of the two, gg, includes two girls, the probability that the younger child is also a girl is. second question mr. smith has two children. at least one of them is a boy. what is the probability that both children are boys? this question is identical to question one, except that instead of specifying that the older child is a boy, it is specified that at least one of them is a boy. in response to reader criticism of the question posed in 1959, gardner said that no answer is possible without information that was not provided. specifically, that two different procedures for determining that " at least one is a boy " could lead to the exact same wording of the problem. but they lead to different correct answers : from all families with two children, at least one of whom is a boy, a family is chosen at random. this would yield the answer of. from all families with two children, one child is selected at random, and the sex of that child is specified to be a boy. this would yield an answer of. grinstead and snell argue that the question is ambiguous in much the same way gardner did. they leave it to the reader to decide whether the procedure, that yields 1 / 3 as the answer, is reasonable for the problem as stated above. the formulation of the question they were considering specifically is the following : consider a family with two children. given that one of the children is a boy, what is the probability that both children are boys? in this formulation the ambiguity is most obviously present, because it is not clear whether we are allowed to assume that a specific child is a boy, leaving the other child uncertain, or whether it should be interpreted in the same way as " at
all the 3 - multisubsets of the set s = { 1, 2, 3, 4 }. this is displayed in the following table. the second column lists the donuts you actually chose, the third column shows the nonnegative integer solutions of the equation and the last column gives the stars and bars representation of the solutions. number of k - combinations for all k the number of k - combinations for all k is the number of subsets of a set of n elements. there are several ways to see that this number is 2n. in terms of combinations,, which is the sum of the nth row ( counting from 0 ) of the binomial coefficients in pascal's triangle. these combinations ( subsets ) are enumerated by the 1 digits of the set of base 2 numbers counting from 0 to 2n − 1, where each digit position is an item from the set of n. given 3 cards numbered 1 to 3, there are 8 distinct combinations ( subsets ), including the empty set : representing these subsets ( in the same order ) as base 2 numerals : 0 – 000 1 – 001 2 – 010 3 – 011 4 – 100 5 – 101 6 – 110 7 – 111 probability : sampling a random combination there are various algorithms to pick out a random combination from a given set or list. rejection sampling is extremely slow for large sample sizes. one way to select a k - combination efficiently from a population of size n is to iterate across each element of the population, and at each step pick that element with a dynamically changing probability of ( see reservoir sampling ). another is to pick a random non - negative integer less than and convert it into a combination using the combinatorial number system. number of ways to put objects into bins a combination can also be thought of as a selection of two sets of items : those that go into the chosen bin and those that go into the unchosen bin. this can be generalized to any number of bins with the constraint that every item must go to exactly one bin. the number of ways to put objects into bins is given by the multinomial coefficient where n is the number of items
other coin is also gold, is. the flaw is in the last step. while those two cases were originally equally likely, the fact that you are certain to find a gold coin if you had chosen the gg box, but are only 50 % sure of finding a gold coin if you had chosen the gs box, means they are no longer equally likely given that you have found a gold coin. specifically : the probability that gg would produce a gold coin is 1. the probability that ss would produce a gold coin is 0. the probability that gs would produce a gold coin is. initially gg, ss and gs are equally likely. therefore, by bayes'rule the conditional probability that the chosen box is gg, given we have observed a gold coin, is : the correct answer of can also be obtained as follows : originally, all six coins were equally likely to be chosen. the chosen coin cannot be from drawer s of box gs, or from either drawer of box ss. so it must come from the g drawer of box gs, or either drawer of box gg. the three remaining possibilities are equally likely, so the probability that the drawer is from box gg is. alternatively, one can simply note that the chosen box has two coins of the same type of the time. so, regardless of what kind of coin is in the chosen drawer, the box has two coins of that type of the time. in other words, the problem is equivalent to asking the question " what is the probability that i will pick a box with two coins of the same color? ". bertrand's point in constructing this example was to show that merely counting cases is not always proper. instead, one should sum the probabilities that the cases would produce the observed result ; and the two methods are equivalent only if this probability is either 1 or 0 in every case. this condition is correctly applied in the second solution method, but not in the first. the paradox as stated by bertrand it can be easier to understand why is incorrect, if you consider the paradox bertrand used. after a box has been chosen, but before a drawer is opened, there is a probability that the box has two of the same kind of coin. so
</ctx>
The following are multiple choice questions (with answers) about STEM.
A child want to buy 5 new toys. If there are 15 toys that satisfy the child's criteria,in how many different ways can the child select the 5 new toys if the order of selection doesn't matter.
A. A)210
B. B)1365
C. C)3003
D. D)5005
Answer: | [
"A)210",
"B)1365",
"C)3003",
"D)5005"
] | C | The number of ways of choosing 5 toys out of 15 are counted by = 15C5 ways = 3003
Answer: Option C |
openbookqa_2064 | openbookqa | <ctx>
in particular newspaper ) have lower energy savings than the previous materials, with recycled products costing 45 % and 21 % less energy, respectively. recycled paper has a large market in china. however, work still needs to be done to facilitate mixed paper recycling instead of newspaper. utilizing these recycling methods would permit spending less energy and resources on extracting new resources to use in manufacturing. despite significant progress in recycling over the last decades, the paper sector is a substantial contributor to global greenhouse gas emissions. the pulp and paper industries produce 50 % of their energy from biomass, which still requires vast energy. policy public policies help to discuss and provide a market incentive for more efficient use of materials. severe impediments to material efficiency improvement include hesitation to invest, a lack of available and accessible information, and economic disincentives. however, a wide range of policy strategies and innovations have been created in some countries to achieve the mentioned goals. these include regulation and guidelines ; economic incentives ; voluntary agreements and actions ; information, education, and training ; and funding for research, development, and demonstration. in 2022, the united states released the " the critical material innovation, efficiency, and alternatives " program. it will be to study, develop, demonstrate, and trade with the primary goal of creating new alternatives to critical material, promoting efficient manufacturing and use. in addition, the u. s. department of energy released a new " energy efficiency materials pilot program for nonprofits " program to provide nonprofit organizations with funding to upgrade building materials to improve energy efficiency, lower utility costs, and reduce carbon emissions. see also circular economy conservation ethic conservation movement ecological deficit energy conservation environmental protection renewable energy sustainable architecture references material flow sustainable building building engineering
recycling is the process of converting waste materials into new materials and objects. this concept often includes the recovery of energy from waste materials. the recyclability of a material depends on its ability to reacquire the properties it had in its original state. it is an alternative to " conventional " waste disposal that can save material and help lower greenhouse gas emissions. it can also prevent the waste of potentially useful materials and reduce the consumption of fresh raw materials, reducing energy use, air pollution ( from incineration ) and water pollution ( from landfilling ). recycling is a key component of modern waste reduction and is the third component of the " reduce, reuse, and recycle " waste hierarchy. it promotes environmental sustainability by removing raw material input and redirecting waste output in the economic system. there are some iso standards related to recycling, such as iso 15270 : 2008 for plastics waste and iso 14001 : 2015 for environmental management control of recycling practice. recyclable materials include many kinds of glass, paper, cardboard, metal, plastic, tires, textiles, batteries, and electronics. the composting and other reuse of biodegradable waste — such as food and garden waste — is also a form of recycling. materials for recycling are either delivered to a household recycling center or picked up from curbside bins, then sorted, cleaned, and reprocessed into new materials for manufacturing new products. in ideal implementations, recycling a material produces a fresh supply of the same material — for example, used office paper would be converted into new office paper, and used polystyrene foam into new polystyrene. some types of materials, such as metal cans, can be remanufactured repeatedly without losing their purity. with other materials, this is often difficult or too expensive ( compared with producing the same product from raw materials or other sources ), so " recycling " of many products and materials involves their reuse in producing different materials ( for example, paperboard ). another form of recycling is the salvage of constituent materials from complex products, due to either their intrinsic value ( such as lead from car batteries and gold from printed circuit boards ), or their hazardous nature ( e
pollution with the release of nitrogen dioxide ( no2 ), sulfur dioxide ( so2 ), and carbon dioxide ( co2 ). waste water discharged from pulp and paper mills outside of north america may contain solids, nutrients, and dissolved organic matter that are classified as pollutants. nutrients such as nitrogen and phosphorus can cause or exacerbate eutrophication of fresh water bodies. printing inks and toners are very expensive and use environment - damaging volatile organic compounds, heavy metals and non - renewable oils, although standards for the amount of heavy metals in ink have been set by some regulatory bodies. deinking recycled paper pulp results in a waste slurry, sometimes weighing 22 % of the weight of the recycled wastepaper, which may go to landfills. environmental impact of electronics a paperless work environment requires an infrastructure of electronic components to enable the production, transmission, and storage of information. the industry that produces these components is one of the least sustainable and most environmentally damaging sectors in the world. the process of manufacturing electronic hardware involves the extraction of precious metals and the production of plastic on an industrial scale. the transmission and storage of digital data is facilitated by data centers, which consume significant amounts of the electricity supply of a host country. eliminating paper via automation and electronic forms automation the need for paper is eliminated by using online systems, such as replacing index cards and rolodexes with databases, typed letters and faxes with email, and reference books with the internet. another way to eliminate paper is to automate paper - based processes that rely on forms, applications and surveys to capture and share data. this method is referred to as " electronic forms " or e - forms and is typically accomplished by using existing print - perfect documents in electronic format to allow for prefilling of existing data, capturing data manually entered online by end - users, providing secure methods to submit form data to processing systems, and digitally signing the electronic documents without printing. the technologies that may be used with electronic forms automation include – portable document format ( pdf ) – to create, display and interact with electronic documents and forms e - form ( electronic form ) management software – to create, integrate and route forms and form data with processing systems databases –
, and print double - sided. also, look for paper that has been made with recycled materials. when shopping, buy in bulk in order to reduce the amount of packaging required to package the goods. look for products made with recycled materials. bring reusable bags in which to carry purchased goods in order to reduce the number of disposed paper / plastic bags. use water sparingly by installing water - efficient shower heads and faucets, and install energy - efficient appliances. make sure that sinks and hoses are not dripping. do not excessively water plants. use transportation efficiently, and utilize mass transportation when possible. recycling used motor oil is also a way to eliminate the disposal of a hazardous material. eating locally produced foods reduces the amount of fuel required for the food's transportation. additional examples of p2 include using energy efficient machinery, developing clean - burning fuel, reducing the amount of chemicals released into water sources, creating a production process that results in a reduced amount of waste, and utilizing water conservation techniques. see also atmospheric dispersion modeling, mathematical simulations of how air pollutants disperse in the ambient atmosphere car - free movement cleaner production environmentalism energy conservation green chemistry industrial ecology pollutant release and transfer register polluter pays principle pollution control recycling waste management extended producer responsibility clean water act of 1972 waste minimization zero emission references external links united states national pollution prevention information center united states pollution prevention regional information center national pollution prevention roundtable finds p2 programs effective ( article ) pollution prevention directory : turi - toxics use reduction institute the southwest network for zero waste - center for environmental excellence pollution prevention regional information center ( p2ric ) - epa region 7 ( iowa, kansas, missouri, nebraska ) the environmental sustainability resource center ( esrc ) - p2 resources, news and information pollution industrial ecology prevention
</ctx>
The following are multiple choice questions (with answers) about STEM.
Recycling products such as papers can help the environment to
A. demolish
B. heal
C. fall apart
D. be destroyed
Answer: | [
"demolish",
"heal",
"fall apart",
"be destroyed"
] | B | |
aquarat_30847 | aquarat | <ctx>
10−1 ( 0. 1 ; one tenth ) iso : deci - ( d ) legal history : 10 % was widespread as the tax raised for income or produce in the ancient and medieval period ; see tithe. mathematics – poker : the odds of being dealt only one pair in poker are about 5 to 2 against ( 2. 37 to 1 ), for a probability of 0. 42 ( 42 % ). mathematics – poker : the odds of being dealt no pair in poker are nearly 1 to 2, for a probability of about 0. 5 ( 50 % ). 100 ( 1 ; one ) demography : the population of monowi, an incorporated village in nebraska, united states, was one in 2010. religion : one is the number of gods in judaism, christianity, and islam ( monotheistic religions ). computing – unicode : one character is assigned to the lisu supplement unicode block, the fewest of any public - use unicode block as of unicode 15. 0 ( 2022 ). mathematics : ≈, the ratio of the diagonal of a square to its side length. mathematics : φ ≈, the golden ratio. mathematics : ≈, the ratio of the diagonal of a unit cube. mathematics : the number system understood by most computers, the binary system, uses 2 digits : 0 and 1. mathematics : ≈ 2. 236 067 9775, the correspondent to the diagonal of a rectangle whose side lengths are 1 and 2. mathematics : + 1 ≈, the silver ratio ; the ratio of the smaller of the two quantities to the larger quantity is the same as the ratio of the larger quantity to the sum of the smaller quantity and twice the larger quantity. mathematics : e ≈, the base of the natural logarithm. mathematics : the number system understood by ternary computers, the ternary system, uses 3 digits : 0, 1, and 2. religion : three manifestations of god in the christian trinity. mathematics : π ≈, the ratio of a circle's circumference to its diameter. religion : the four noble truths in buddhism. biology : 7 ± 2, in cognitive science, george a. miller's estimate of the number of objects that can be simultaneously held
regular numbers are numbers that evenly divide powers of 60 ( or, equivalently, powers of 30 ). equivalently, they are the numbers whose only prime divisors are 2, 3, and 5. as an example, 602 = 3600 = 48 × 75, so as divisors of a power of 60 both 48 and 75 are regular. these numbers arise in several areas of mathematics and its applications, and have different names coming from their different areas of study. in number theory, these numbers are called 5 - smooth, because they can be characterized as having only 2, 3, or 5 as their prime factors. this is a specific case of the more general - smooth numbers, the numbers that have no prime factor greater in the study of babylonian mathematics, the divisors of powers of 60 are called regular numbers or regular sexagesimal numbers, and are of great importance in this area because of the sexagesimal ( base 60 ) number system that the babylonians used for writing their numbers, and that was central to babylonian mathematics. in music theory, regular numbers occur in the ratios of tones in five - limit just intonation. in connection with music theory and related theories of architecture, these numbers have been called the harmonic whole numbers. in computer science, regular numbers are often called hamming numbers, after richard hamming, who proposed the problem of finding computer algorithms for generating these numbers in ascending order. this problem has been used as a test case for functional programming. number theory formally, a regular number is an integer of the form, for nonnegative integers,, and. such a number is a divisor of. the regular numbers are also called 5 - smooth, indicating that their greatest prime factor is at most 5. more generally, a - smooth number is a number whose greatest prime factor is at the first few regular numbers are several other sequences at the on - line encyclopedia of integer sequences have definitions involving 5 - smooth numbers. although the regular numbers appear dense within the range from 1 to 60, they are quite sparse among the larger integers. a regular number is less than or equal to some threshold if and only if the point belongs to the tetrahedron bounded by the coordinate planes
( block ) into subcells. 2, 333, 606, 816 = 2, 357, 947, 691 = 13313 = 119 2, 373, 046, 875 = 755 2, 494, 357, 888 = 227 2, 535, 525, 376 = 765 2, 562, 890, 625 = 506252 = 2254 = 158 2, 565, 726, 409 = 506532 = 13693 = 376 2, 695, 730, 992 = number of ( unordered, unlabeled ) rooted trimmed trees with 29 nodes 2, 706, 784, 157 = 775 2, 873, 403, 980 = number of uniform rooted trees with 27 nodes 2, 834, 510, 744 = number of nonequivalent dissections of an 22 - gon into 19 polygons by nonintersecting diagonals up to rotation 2, 887, 174, 368 = 785 2, 971, 215, 073 = 11th fibonacci prime ( 47th fibonacci number ) and a markov prime. 3, 000, 000, 000 to 3, 999, 999, 999 3, 010, 936, 384 = 548722 = 14443 = 386 3, 077, 056, 399 = 795 3, 166, 815, 962 = 26th pell number. 3, 192, 727, 797 = 24th motzkin number. 3, 276, 800, 000 = 805 3, 323, 236, 238 = 31st wedderburn – etherington number. 3, 333, 333, 333 = repdigit 3, 404, 825, 447 = 237 3, 405, 691, 582 = hexadecimal cafebabe ; used as a placeholder in programming. 3, 405, 697, 037 = hexadecimal cafed00d ; used as a placeholder in programming. 3, 461, 824, 644 = number of secondary structures of rna molecules with 28
m - th even number ( ). this may be expressed mathematically as follows : a positive value is mapped to ( ), and a negative value is mapped to ( ). such a code may be used for simplicity, even if suboptimal. truly optimal codes for two - sided geometric distributions include multiple variants of the golomb code, depending on the distribution parameters, including this one. simple algorithm below is the rice – golomb encoding, where the remainder code uses simple truncated binary encoding, also named " rice coding " ( other varying - length binary encodings, like arithmetic or huffman encodings, are possible for the remainder codes, if the statistic distribution of remainder codes is not flat, and notably when not all possible remainders after the division are used ). in this algorithm, if the m parameter is a power of 2, it becomes equivalent to the simpler rice encoding : fix the parameter m to an integer value. for n, the number to be encoded, find quotient = q = floor ( n / m ) remainder = r = n modulo m generate codeword the code format : < quotient code > < remainder code >, where quotient code ( in unary coding ) write a q - length string of 1 bits ( alternatively, of 0 bits ) write a 0 bit ( respectively, a 1 bit ) remainder code ( in truncated binary encoding ) let if code r in binary representation using b bits. if code the number in binary representation using b + 1 bits. decoding : decode the unary representation of q ( count the number of 1 in the beginning of the code ) skip the 0 delimiter let interpret next b bits as a binary number r'' '. if holds, then the reminder otherwise interpret b + 1 bits as a binary number r ', the reminder is given by compute example set. thus. the cutoff is. for example, with a rice – golomb encoding using parameter, the decimal number 42 would first be split into = 4 and = 2, and would be encoded as qcode ( ), rcode ( ) = qcode ( 4 ), rcode ( 2 ) = 11110, 010
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The following are multiple choice questions (with answers) about STEM.
1/2,16,4,15,3,56,_ ?
A. A)28/3
B. B)27/3
C. C)26/3
D. D)25/3
Answer: | [
"A)28/3",
"B)27/3",
"C)26/3",
"D)25/3"
] | A | take alternative no. 1/2, 4,3
16/4=4
15/5 = 3
56/6 =28/3
hence ans is 28/3
ANSWER:A |
medmcqa_4122 | medmcqa | <ctx>
preservation, 5th ed., s. s. block ( ed. ), lippincott, williams & wilkins, philadelphia,. welter g. 1976, cleaning and preservation of coins and medals, s. j. durst, new york,. white c. 2010, projectile dynamics in sport : principles and applications, routledge, london,. wiberg n. 2001, inorganic chemistry, academic press, san diego,. wijayawardena m. a. a., megharaj m. & naidu r. 2016, " exposure, toxicity, health impacts and bioavailability of heavy metal mixtures ", in d. l. sparks, advances in agronomy, vol. 138, pp. 175 – 234, academic press, london,. wingerson l. 1986, " america cleans up liberty ", new scientist, 25 december / 1 january 1987, pp. 31 – 35, accessed 1 october 2016. wong m. y., hedley g. j., xie g., kolln l. s, samuel i. d. w., pertegas a., bolink h. j., mosman - colman, e., " light - emitting electrochemical cells and solution - processed organic light - emitting diodes using small molecule organic thermally activated delayed fluorescence emitters ", chemistry of materials, vol. 27, no. 19, pp. 6535 – 6542,. wulfsberg g. 1987, principles of descriptive inorganic chemistry, brooks / cole publishing company, monterey, california,. wulfsberg g. 2000, inorganic chemistry, university science books, sausalito, california,. yadav j. s., antony a., subba reddy, b. v. 2012, " bismuth ( iii ) salts as synthetic tools in organic transformations ", in t. ollevier ( ed. ), bismuth - mediated organic reactions, topics in current chemistry 311, springer, heidelberg,. yang d. j., jolly w. l. & o'keefe a. 1977, " conversion of hydrous germanium ( ii ) oxide to ge
not indicated because of excessive occlusal wear in the 1980s and early 1990s. modern bonding techniques and the increasing unpopularity of amalgam filling material have made composites more attractive for class ii restorations. opinions vary, but composite is regarded as having adequate longevity and wear characteristics to be used for permanent class ii restorations. whether composite materials last as long or have similar leakage and sensitivity properties when compared to class ii amalgam restorations was described as a matter of debate in 2008. composition as with other composite materials, a dental composite typically consists of a resin - based oligomer matrix, such as a bisphenol a - glycidyl methacrylate ( bisgma ), urethane dimethacrylate ( udma ) or semi - crystalline polyceram ( pex ), and an inorganic filler such as silicon dioxide ( silica ). without a filler the resin wears easily, exhibits high shrinkage and is exothermic. compositions vary widely, with proprietary mixes of resins forming the matrix, as well as engineered filler glasses and glass ceramics. the filler gives the composite greater strength, wear resistance, decreased polymerisation shrinkage, improved translucency, fluorescence and colour, and a reduced exothermic reaction on polymerisation. it also however causes the resin composite to become more brittle with an increased elastic modulus. glass fillers are found in multiple different compositions allowing an improvement on the optical and mechanical properties of the material. ceramic fillers include zirconia - silica and zirconium oxide. matrices such as bishppp and bbp, contained in the universal adhesive bisgma, have been demonstrated to increase the cariogenicity of bacteria leading to the occurrence of secondary caries at the composite - dentin interface. bishppp and bbp cause an increase of glycosyltransferase in s. mutans bacteria, which results in increased production of sticky glucans that allow s. mutans'adherence to the tooth. this results in a cariogenic biofilms at the interface of composite and tooth. the cariogenic activity
, concern of its toxicity has existed since the invention of amalgam as a dental material. it is banned or restricted in norway, sweden and finland. see dental amalgam controversy. direct gold direct gold fillings were practiced during the times of the civil war in america. although rarely used today, due to expense and specialized training requirements, gold foil can be used for direct dental restorations. composite resin dental composites, commonly described to patients as " white fillings ", are a group of restorative materials used in dentistry. they can be used in direct restorations to fill in the cavities created by dental caries and trauma, minor buildup for restoring tooth wear ( non - carious tooth surface loss ) and filling in small gaps between teeth ( labial veneer ). dental composites are also used as indirect restoration to make crowns and inlays in the laboratory. these materials are similar to those used in direct fillings and are tooth - colored. their strength and durability is not as high as porcelain or metal restorations and they are more prone to wear and discolouration. as with other composite materials, a dental composite typically consists of a resin - based matrix, which contains a modified methacrylate or acrylate. two examples of such commonly used monomers include bisphenol a - glycidyl methacrylate ( bisma ) and urethane dimethacrylate ( udma ), together with tri - ethylene glycol dimethacrylate ( tegma ). tegma is a comonomer which can be used to control viscosity, as bis gma is a large molecule with high viscosity, for easier clinical handling. inorganic filler such as silica, quartz or various glasses, are added to reduce polymerization shrinkage by occupying volume and to confirm radio - opacity of products due to translucency in property, which can be helpful in diagnosis of dental caries around dental restorations. the filler particles give the composites wear resistance as well. compositions vary widely, with proprietary mixes of resins forming the matrix, as well as engineered filler
##cosyltransferase in s. mutans bacteria, which results in increased production of sticky glucans that allow s. mutans'adherence to the tooth. this results in a cariogenic biofilms at the interface of composite and tooth. the cariogenic activity of bacteria increases with concentration of the matrix materials. bishppp has furthermore been shown to regulate bacterial genes, making bacteria more cariogenic, thus compromising the longevity of composite restorations. researchers are highlighting the need for new composite materials to be developed which eliminate the cariogenic products contained in composite resin and universal adhesives. a coupling agent such as silane is used to enhance the bond between these two components. an initiator package ( such as : camphorquinone ( cq ), phenylpropanedione ( ppd ) or lucirin ( tpo ) ) begins the polymerization reaction of the resins when blue light is applied. various additives can control the rate of reaction. filler types and particle size resin filler can be made of glasses or ceramics. glass fillers are usually made of crystalline silica, silicone dioxide, lithium / barium - aluminium glass, and borosilicate glass containing zinc / strontium / lithium. ceramic fillers are made of zirconia - silica, or zirconium oxide. fillers can be further subdivided based on their particle size and shapes such as : macrofilled filler macrofilled fillers have a particle size ranging from 5 - 10 µm. they have good mechanical strength but poor wear resistance. final restoration is difficult to polish adequately leaving rough surfaces, and therefore this type of resin is plaque retentive. microfilled filler microfilled fillers are made of colloidal silica with a particle size of 0. 4 µm. resin with this type of filler is easier to polish compared to macrofilled. however, its mechanical properties are compromised as filler load is lower than in conventional ( only 40 - 45 % by weight ). therefore, it is contraindicated for load - bearing situations, and has poor wear resistance. hybrid fill
</ctx>
The following are multiple choice questions (with answers) about STEM.
Bismuth compounds are incorporated in root canal sealer materials because they are:
A. Radio-opaque
B. Germicidal
C. Radiolucent
D. Adhesive
Answer: | [
"Radio-opaque",
"Germicidal",
"Radiolucent",
"Adhesive"
] | A | Root canal sealers should be radiopaque, so that it can be visualized in the radiograph.
Radiopacity is provided by salts of heavy metals such as silver, barium and bismuth. |
medmcqa_2971 | medmcqa | <ctx>
the overt response is successfully inhibited, showing that the " point of no return " occurs after the lrp. based on the work of osman and colleagues we also know that in the go / no - go paradigm, feature discriminability ( e. g., discriminate between v and 5, easy ) or between l and 1 ( lowercase l and the number 1, difficult ) affects onset of the lrp difference between the " go " and " no - go " ( response execution ), but not lrp onset ( response preparation ). in contrast, they've shown that stimulus - response compatibility affects lrp onset ( response preparation ) but does not affect the onset of the difference waves ( response execution ). more generally, the distinction between response preparation and execution can refer to the time before and after the onset of the lrp such that the time between seeing the stimulus and the onset of the stimulus - locked lrp reflects response preparation processes and the time between onset of the stimulus - locked lrp and the behavioral response reflects response execution processes. overall, studies have shown that stimulus quality and stimulus compatibility affect response preparation processes, whereas factors related to response complexity tend to delay response execution processes. later studies on event preparation examining the foreperiod of the contingent negative variation ( cnv ), which orients the subject to respond to warned stimuli, and the foreperiod of the lrp were used to study the exact mechanism of event preparation. in their paper on inferences from cnv and lrp they cited experiments done by ulrich, moore, & osman ( 1993 ) in which three hypotheses could be derived. the abstract motor preparation hypothesis states that only the response hand that has been selected is prepared but nothing else. the muscle - unspecific preparation hypothesis suggests that muscles are cued at the same time when the limb side is not specified. the muscle - specific preparation hypothesis states that the muscle and limb are prepared when direction and limb side are specified. the muscle - specific preparation hypothesis gained the most support with follow up studies ( ulrich, leuthold, & sommer, 1998 ). leuthold et al. suggest that the motor processes be divided up into early
the best route of escape, based on prior experience. this means rapid integration of incoming information with prior knowledge, and then coordination of motor movements deemed necessary. complex escape responses generally require a more robust neural network. researchers will often evoke an escape response to test the potency of hormones and / or medication and their relationship to stress. as such, the escape response is fundamental to anatomical and pharmacological research. role of learning habituation a series of initially threatening encounters that do not lead to any true adverse outcomes for the animal can drive the development of habituation. habituation is an adaptation strategy that refers to the diminishing response of an animal to a stimulus following repetitive exposures of the animal to that same stimulus. in other words, the animal learns to distinguish between innately threatening situations and may choose to not go through with their escape response. this is a highly variable phenomenon, where the stimulus itself is highly specific, and the experience is highly context dependent. this suggests that there is no one mechanism by which a species will develop habituation to a stimulus, instead habituation may arise from the integration of experiences. a number of cognitive processes may operate during one single threatening experience, but the levels at which these processes are integrated will determine how the individual animal will potentially respond next. caenorhabditis elegans, commonly identified as nematodes, have been used as a model species for studies observing their characteristic " tap - withdrawal response ". the tapping on serves as the fear - provoking, mechanical stimulus which c. elegans worms will move away from. if the tapping stimulus continues without any direct effects on the worms, they will gradually stop responding to the stimulus. this response is modulated by a series of mechanosensory neurons ( avm, alm, pvd, and plm ) which synapse with interneurons ( avd, ava, avb, and pvc ) transmitting the signal to motor neurons that cause the back - and - forth movements. habituation to the tapping reduces activity of the initial mechanosensory neurons, seen as decrease in calcium channel activity and neurotransmitter release. the primary force driving escape habituation is
current pulses. this was an important finding because it showed that pir is an intrinsic property of the postsynaptic neuron, related to the membrane potential change associated with inhibition but independent of transmitter receptors or presynaptic properties. the latter conclusion has stood the test of time, marking pir as a robust property of cns neurons in a wide variety of contexts. " this cellular property can most easily be seen in the lamprey neural circuit. the swimming movement is produced by alternating neural activity between the left and right side of the body, causing it to bend back and forth while creating oscillating movements. while the lamprey is bent to the left, there is reciprocal inhibition on the right side causing it to relax due to hyperpolarization. immediately after this hyperopolarizing stimulus, the interneurons use post - inhibitory rebound to initiate activity in the right side. depolarization of the membrane causes it to contract while reciprocal inhibition is now applied to the left side. functions in invertebrates cpgs play a similarly critical role in coordinating behaviors in invertebrates, and studying invertebrate cpgs with fewer numbers of neurons has helped establish general principles of cpgs and their organization in the nervous system. one model circuit for studying cpgs is the stomatogastric ganglion in crabs and lobsters, a ~ 30 neuron circuit containing two cpgs that generate rhythmic motor output for chewing and digesting food. dissection of these circuits has revealed neural mechanisms of cpgs. for example, the pyloric cpg - which controls the contraction and dilation of the pylorus - contains a set of conditional oscillatory neurons and one pacemaker neuron that fires rhythmically when dissected out of the circuit. coordinated rhythmic behaviors like walking, flight and grooming are also controlled by cpgs in some invertebrates. continued research into how cpgs control these behaviors has revealed a nested cpg architecture to control rhythmic behaviors across various timescales. other examples of cpgs in invertebrate animals include a cpg modulating reflexive withdrawal, escape swimming and crawling in the mollusc tritonia, and to control the heartbeat of leeches. central pattern
perturbation. when the input current,, is large enough, the membrane potential ( ) surpasses its firing threshold and rises rapidly ( indeed, it reaches arbitrarily large values in finite time ) ; this represents the peak of the action potential. to simulate the recovery after the action potential, the membrane voltage is then reset to a lower value. to avoid dealing with arbitrarily large values in simulation, researchers will often set an upper limit on the membrane potential, above which the membrane potential will be reset ; for example latham et al. ( 2000 ) reset the voltage from + 20 mv to −80 mv. this voltage reset constitutes an action potential. the theta model is very similar to the qif model since the theta model differs from the qif model by means of a simple coordinate transform. by scaling the voltage appropriately and letting be the change in current from the minimum current required to elicit a spike, the qif model can be rewritten in the form similarly, the theta model can be rewritten as the following proof will show that the qif model becomes the theta model given an appropriate choice for the coordinate transform. define. recall that, so taking the derivative yields an additional substitution and rearranging in terms of yields using the trigonometric identities, and as defined above, we have that therefore, there exists a change of coordinates, namely, which transforms the qif model into the theta model. the reverse transformation also exists, and is attained by taking the inverse of the first transformation. applications neuroscience lobster stomatogastric ganglion though the theta model was originally used to model slow cytoplasmic oscillations that modulate fast membrane oscillations in a single cell, ermentrout and kopell found that the theta model could be applied just as easily to systems of two electrically coupled cells such that the slow oscillations of one cell modulates the bursts of the other. such cells serve as the central pattern generator ( cpg ) of the pyloric system in the lobster stomatograstic ganglion. in such a system, a slow oscillator, called the anterior burster ( ab ) cell, modulates the bursting
</ctx>
The following are multiple choice questions (with answers) about STEM.
The major initiating response for peristalsis is
A. Hormonal
B. Local stretching of gut
C. Neural
D. Gastric acid
Answer: | [
"Hormonal",
"Local stretching of gut",
"Neural",
"Gastric acid"
] | B | The major initiating response for peristalsis is local stretching of the gut. Peristalsis is a reflex that is initiated when the gut wall is stretched by the contents of the lumen. It occurs in all pas of the gastrointestinal tract from the esophagus to the rectum. The stretch initiates a circular contraction behind the stimulus and an area of relaxation in front of it. The wave of contraction then moves in an oral-to-caudal direction. This propels the contents of the lumen forward at rates that vary from 2 to 25 cm/s Ref: Ganong&;s Review of Medical Physiology 26th edition Pgno: 485 |
aquarat_267 | aquarat | <ctx>
triangles each have an angle of at the centre of the circle ), each with an area of ( derived from the expression for the area of a triangle : ). note that due to small angle approximation. through summing the areas of the triangles, the expression for the area of the circle can therefore be found : semicircle proof note that the area of a semicircle of radius r can be computed by the integral. by trigonometric substitution, we substitute, hence the last step follows since the trigonometric identity implies that and have equal integrals over the interval, using integration by substitution. but on the other hand, since, the sum of the two integrals is the length of that interval, which is. consequently, the integral of is equal to half the length of that interval, which is. therefore, the area of a circle of radius r, which is twice the area of the semi - circle, is equal to. this particular proof may appear to beg the question, if the sine and cosine functions involved in the trigonometric substitution are regarded as being defined in relation to circles. however, as noted earlier, it is possible to define sine, cosine, and in a way that is totally independent of trigonometry, in which case the proof is valid by the change of variables formula and fubini's theorem, assuming the basic properties of sine and cosine ( which can also be proved without assuming anything about their relation to circles ). isoperimetric inequality the circle is the closed curve of least perimeter that encloses the maximum area. this is known as the isoperimetric inequality, which states that if a rectifiable jordan curve in the euclidean plane has perimeter c and encloses an area a ( by the jordan curve theorem ) then moreover, equality holds in this inequality if and only if the curve is a circle, in which case and. fast approximation the calculations archimedes used to approximate the area numerically were laborious, and he stopped with a polygon of 96 sides. a faster method uses ideas of willebrord snell ( cyclometricus, 1621 ), further developed by christiaan
dimensional figures. the mathematician archimedes used the tools of euclidean geometry to show that the area inside a circle is equal to that of a right triangle whose base has the length of the circle's circumference and whose height equals the circle's radius, in his book measurement of a circle. ( the circumference is 2r, and the area of a triangle is half the base times the height, yielding the area r2 for the disk. ) archimedes approximated the value of π ( and hence the area of a unit - radius circle ) with his doubling method, in which he inscribed a regular triangle in a circle and noted its area, then doubled the number of sides to give a regular hexagon, then repeatedly doubled the number of sides as the polygon's area got closer and closer to that of the circle ( and did the same with circumscribed polygons ). triangle area quadrilateral area in the 7th century ce, brahmagupta developed a formula, now known as brahmagupta's formula, for the area of a cyclic quadrilateral ( a quadrilateral inscribed in a circle ) in terms of its sides. in 1842, the german mathematicians carl anton bretschneider and karl georg christian von staudt independently found a formula, known as bretschneider's formula, for the area of any quadrilateral. general polygon area the development of cartesian coordinates by rene descartes in the 17th century allowed the development of the surveyor's formula for the area of any polygon with known vertex locations by gauss in the 19th century. areas determined using calculus the development of integral calculus in the late 17th century provided tools that could subsequently be used for computing more complicated areas, such as the area of an ellipse and the surface areas of various curved three - dimensional objects. area formulas polygon formulas for a non - self - intersecting ( simple ) polygon, the cartesian coordinates ( i = 0, 1,..., n - 1 ) of whose n vertices are known, the area is given by the surveyor's formula : where when i = n
number in the domain of r. therefore, ∞ ∞ ∞
in geometry, the area enclosed by a circle of radius is. here the greek letter represents the constant ratio of the circumference of any circle to its diameter, approximately equal to 3. 14159. one method of deriving this formula, which originated with archimedes, involves viewing the circle as the limit of a sequence of regular polygons with an increasing number of sides. the area of a regular polygon is half its perimeter multiplied by the distance from its center to its sides, and because the sequence tends to a circle, the corresponding formula – that the area is half the circumference times the radius – namely,, holds for a circle. terminology although often referred to as the area of a circle in informal contexts, strictly speaking the term disk refers to the interior region of the circle, while circle is reserved for the boundary only, which is a curve and covers no area itself. therefore, the area of a disk is the more precise phrase for the area enclosed by a circle. history modern mathematics can obtain the area using the methods of integral calculus or its more sophisticated offspring, real analysis. however, the area of a disk was studied by the ancient greeks. eudoxus of cnidus in the fifth century b. c. had found that the area of a disk is proportional to its radius squared. archimedes used the tools of euclidean geometry to show that the area inside a circle is equal to that of a right triangle whose base has the length of the circle's circumference and whose height equals the circle's radius in his book measurement of a circle. the circumference is 2r, and the area of a triangle is half the base times the height, yielding the area r2 for the disk. prior to archimedes, hippocrates of chios was the first to show that the area of a disk is proportional to the square of its diameter, as part of his quadrature of the lune of hippocrates, but did not identify the constant of proportionality. historical arguments a variety of arguments have been advanced historically to establish the equation to varying degrees of mathematical rigor. the most famous of these is archimedes
</ctx>
The following are multiple choice questions (with answers) about STEM.
Consider a quarter of a circle of radius 20. Let r be the radius of the circle inscribed in this quarter of a circle. Find r.
A. A)20*(sqr2 -1)
B. B)8*(sqr3 -1)
C. C)4*(sqr7 - 1)
D. D)12* (sqr7 -1)
Answer: | [
"A)20*(sqr2 -1)",
"B)8*(sqr3 -1)",
"C)4*(sqr7 - 1)",
"D)12* (sqr7 -1)"
] | A | I got 20/(sqr2 +1) and just forgot to multiply by (sqr2 -1).
Answer A |
qasc_1955 | qasc | <ctx>
to the nuclear matrix. protein - coding genes regions of the genome with protein - coding genes include several elements : enhancer regions ( normally up to a few thousand basepairs upstream of transcription ). promoter regions ( normally less than a couple of hundred basepairs upstream of transcription ) include elements such as the tata and caat boxes, gc elements, and an initiator. exons are the part of the transcript that will eventually be transported to the cytoplasm for translation. when discussing gene with alternate splicing, an exon is a portion of the transcript that could be translated, given the correct splicing conditions. the exons can be divided into three parts the coding region is the portion of the mrna that will eventually be translated. upstream untranslated region ( 5'utr ) can serve several functions, including mrna transport, and initiation of translation ( including, portions of the kozak sequence ). they are never translated into the protein ( excepting various mutations ). the 3'region downstream from the stop codon is separated into two parts : 3'utr is never translated, but serves to add mrna stability. it is also the attachment site for the poly - a tail. the poly - a tail is used in the initiation of translation and also seems to have an effect on the long - term stability ( aging ) of the mrna. an unnamed region after the poly - a tail, but before the actual site for transcription termination, is spliced off during transcription, and so does not become part of the 3'utr. its function, if any, is unknown. introns are intervening sequences between the exons that are never translated. some sequences inside introns function as mirna, and there are even some cases of small genes residing completely within the intron of a large gene. for some genes ( such as the antibody genes ), internal control regions are found inside introns. these situations, however, are treated as exceptions. genes that are used as rna many regions of the dna are transcribed with rna as the functional form : rrna : ribosomal rna are used in the ribosome. trna : transfer rna are used in the translation process by
the genome may be expressed, so the term " junk dna " may be a misnomer. structure and function structure the structure of a protein - coding gene consists of many elements of which the actual protein coding sequence is often only a small part. these include introns and untranslated regions of the mature mrna. noncoding genes can also contain introns that are removed during processing to produce the mature functional rna. all genes are associated with regulatory sequences that are required for their expression. first, genes require a promoter sequence. the promoter is recognized and bound by transcription factors that recruit and help rna polymerase bind to the region to initiate transcription. the recognition typically occurs as a consensus sequence like the tata box. a gene can have more than one promoter, resulting in messenger rnas ( mrna ) that differ in how far they extend in the 5'end. highly transcribed genes have " strong " promoter sequences that form strong associations with transcription factors, thereby initiating transcription at a high rate. others genes have " weak " promoters that form weak associations with transcription factors and initiate transcription less frequently. eukaryotic promoter regions are much more complex and difficult to identify than prokaryotic promoters. additionally, genes can have regulatory regions many kilobases upstream or downstream of the gene that alter expression. these act by binding to transcription factors which then cause the dna to loop so that the regulatory sequence ( and bound transcription factor ) become close to the rna polymerase binding site. for example, enhancers increase transcription by binding an activator protein which then helps to recruit the rna polymerase to the promoter ; conversely silencers bind repressor proteins and make the dna less available for rna polymerase. the mature messenger rna produced from protein - coding genes contains untranslated regions at both ends which contain binding sites for ribosomes, rna - binding proteins, mirna, as well as terminator, and start and stop codons. in addition, most eukaryotic open reading frames contain untranslated introns, which are removed and exons, which are connected together in a process known as rna splicing. finally, the ends of gene transcripts are defined by cleavage and polyadenylation
codons. in addition, most eukaryotic open reading frames contain untranslated introns, which are removed and exons, which are connected together in a process known as rna splicing. finally, the ends of gene transcripts are defined by cleavage and polyadenylation ( cpa ) sites, where newly produced pre - mrna gets cleaved and a string of ~ 200 adenosine monophosphates is added at the 3'end. the poly ( a ) tail protects mature mrna from degradation and has other functions, affecting translation, localization, and transport of the transcript from the nucleus. splicing, followed by cpa, generate the final mature mrna, which encodes the protein or rna product. although the general mechanisms defining locations of human genes are known, identification of the exact factors regulating these cellular processes is an area of active research. for example, known sequence features in the 3'- utr can only explain half of all human gene ends. many noncoding genes in eukaryotes have different transcription termination mechanisms and they do not have pol ( a ) tails. many prokaryotic genes are organized into operons, with multiple protein - coding sequences that are transcribed as a unit. the genes in an operon are transcribed as a continuous messenger rna, referred to as a polycistronic mrna. the term cistron in this context is equivalent to gene. the transcription of an operon's mrna is often controlled by a repressor that can occur in an active or inactive state depending on the presence of specific metabolites. when active, the repressor binds to a dna sequence at the beginning of the operon, called the operator region, and represses transcription of the operon ; when the repressor is inactive transcription of the operon can occur ( see e. g. lac operon ). the products of operon genes typically have related functions and are involved in the same regulatory network. complexity though many genes have simple structures, as with much of biology, others can be quite complex or represent unusual edge - cases. eukaryotic genes often have introns are often much larger than their exons,
##ns, which aid in the removal of introns, the vast majority of introns are devoid of any functions. the theory does not exclude rare sequences within introns that could be used by the genome and the cell, especially because introns are so long. thus, the theory's predictions are precisely corroborated by the major elements in modern eukaryotic genomes. comparative analysis of the modern genome data from several living organisms found that the characteristics of split genes trace back to the earliest organisms. these organisms could have contained the split genes and complex proteins that occur in today's living organisms. studies employing maximum likelihood analysis found that the earliest eukaryotic organisms contained the same genes as modern organisms with yet a higher intron density. comparative genomics of many organisms including basal eukaryotes ( considered to be primitive eukaryotic organisms such as amoeboflagellata, diplomonadida, and parabasalia ) showed that intron - rich split genes accompanied and spliceosome from modern organisms were present in their earliest forebears, and that the earliest organisms came with all the eukaryotic cellular components. selected publications references gene expression genetics experiments genomics
</ctx>
The following are multiple choice questions (with answers) about STEM.
Introns are areas that
A. it keeps an organism warm
B. Plant reproduction
C. the wearing away of rock
D. do not code for protein
Answer: | [
"it keeps an organism warm",
"Plant reproduction",
"the wearing away of rock",
"do not code for protein"
] | D | |
arc_easy_1937 | arc_easy | <ctx>
the physiological condition of the birds ( especially males ) is indicated by the quality of their feathers, and this is used ( by the females ) in mate choice. additionally, when comparing different ornithomimus edmontonicus specimens, older individuals were found to have a pennibrachium ( a wing - like structure consisting of elongate feathers ), while younger ones did not. this suggests that the pennibrachium was a secondary sex characteristic and likely had a sexual function. molecular evolution several genes have been found to determine feather development. they will be key to understand the evolution of feathers. for instance, some genes convert scales into feathers or feather - like structures when expressed or induced in bird feet, such as the scale - feather converters sox2, zic1, grem1, spry2, and sox18. feathers and scales are made up of two distinct forms of keratin, and it was long thought that each type of keratin was exclusive to each skin structure ( feathers and scales ). however, feather keratin is also present in the early stages of development of american alligator scales. this type of keratin, previously thought to be specific to feathers, is suppressed during embryological development of the alligator and so is not present in the scales of mature alligators. the presence of this homologous keratin in both birds and crocodilians indicates that it was inherited from a common ancestor. this may suggest that crocodilian scales, bird and dinosaur feathers, and pterosaur pycnofibres are all developmental expressions of the same primitive archosaur skin structures ; suggesting that feathers and pycnofibers could be homologous. molecular dating methods in 2011 show that the subfamily of feather β - keratins found in extant birds started to diverge 143 million years ago, suggesting the pennaceous feathers of anchiornis were not made of the feather β - keratins present in extant birds. however, a study of fossil feathers from the dinosaur sinosauropteryx and other fossils revealed traces of beta - sheet proteins, using infrared spectroscopy and sulfur - x - ray spectroscopy. the presence of abundant alpha -
##feathers " in a tyrannosauroid. similarly to down feathers of modern birds, the " protofeathers " found in dilong were branched but not pennaceous, and may have been used for insulation. the discovery and description of the feathered tyrannosauroid yutyrannus in 2012 indicates the possibility large tyrannosaurids were also feathered as adults. based on the principle of phylogenetic bracketing, it was predicted that tyrannosaurids might also possess such feathering. however, a study in 2017 published by a team of researchers in biology letters described tyrannosaurid skin impressions collected in alberta, montana, and mongolia, which came from five genera ( tyrannosaurus, albertosaurus, gorgosaurus, daspletosaurus and tarbosaurus ). although the skin impressions are small, they are widely dispersed across the post - cranium, being collectively located on the abdomen, thoracic region, ilium, pelvis, tail, and neck. they show a tight pattern of fine, non - overlapping pebbly scales ( which co - author scott persons compared to those seen on the flanks of a crocodile ) and preserve no hints of feathering. the basic texture is composed of tiny " basement scales " approximately 1 to 2 mm in diameter, with some impressions showing 7 mm " feature scales " interspersed between them. additional scales can be seen in tyrannosaurid footprints. studies find that the facial integument of tyrannosaurids had scales on the dentary and maxilla, cornified epidermis and armor - like skin on the subordinate regions. bell et al. performed an ancestral character reconstruction based on what is known about integument distribution in tyrannosauroids. despite an 89 % probability that tyrannosauroids started out with feathers, they determined that scaly tyrannosaurids have a 97 % probability of being true. the data " provides compelling evidence of an entirely squamous covering in tyrannosaurus, " the team wrote, although they conceded that plumage may have still been present on the dorsal region where skin impressions haven't been found yet. bell et al. hyp
##otheca of the toucan beak has a much lower abundance of sulfur, and therefore the amino acid, cystine, compared to other keratin structures like hair. this indicates less disulfide crosslinking. inner beak the inner beak is a collagen foam, with a high glycine content and subsequent hardness as in most bones. the fibrous network of collagen trabeculae varies from 70 to 200 micrometers in thickness and are often hollow with an edge connectivity of 3 or above. these, along with even thinner ( 2 to 25 micrometer ) membranes characterize a closed cell foam network which provides the optimal strength at low density for flight consideration. the membranes and trabeculae have higher calcium mineralization content than the dense outer beak. micro - and nano - indentation testing supports the notion that the inner collagen trabeculae are stronger pound for pound than the outer shell. mechanical and material properties research has been conducted in order to determine mechanical and material properties of the toucan beak. the apparent density of the overall beak is estimated to be between 0. 1 and 0. 25 grams per cubic centimeter. outer beak properties the exterior shell of the beak, the rhamphotheca, has a tensile strength of around 50 mpa and a young's modulus of 6. 7 gpa. from testing the keratin - layer of the beak, it was found the mean value of the yield strength is 30 mpa. further, the yield strength of the beak is sensitive to the strain rate and is associated with the viscoelasticity of the inter - scale glue for the keratin scales. when the yield stress of the beak nears or exceeds the ultimate tensile strength, the fracture of the keratin scales is preferred for the beak over the viscoelastic deformation of the inter - scale glue. in regard to the young's modulus and yield strength of the keratin in the beak, these values do not change along the longitudinal and transverse direction. the keratin shell can therefore be considered transversely isotropic. the fracture modes of the keratin shell demonstrate a dependence on the strain
, astrop, t. i. a., mcnamara, m. e., webb, s., ito, s., wakamatsu, k., 2019. synchrotron - x - ray absorption spectroscopy of melanosomes in vertebrates and cephalopods : implications for the affinity of tullimonstrum. proceedings b 286, 20191649. doi : https : / / doi. org / 10. 1098 / rspb. 2019. 1649. slater, t. s., mcnamara, m. e., orr, p. j., foley, t. b., ito, s., wakamatsu, k., 2019. taphonomic experiments reveal controls on preservation of melanosomes and keratinous tissues in feathers. palaeontology 63, 103 - 115. doi : https : / / doi. org / 10. 1111 / pala. 12445. rossi, v., mcnamara, m. e., webb, s., ito, s., wakamatsu, k., 2019. tissue - specific geometry and chemistry of modern and fossilized melanosomes reveal internal anatomy of extinct vertebrates. pnas 116, 17880 - 17889. doi : https : / / doi. org / 10. 1073 / pnas. 1820285116. benton, m. j., dhouailly, d., jiang, b., mcnamara, m., 2019. the early origin of feathers. trends in ecology and evolution 34, 856 - 869. doi : https : / / doi. org / 10. 1016 / j. tree. 2019. 04. 018. yang, z. x., jiang, b. y., mcnamara, m. e., kearns, s. l., pittman, m., kaye, t. g., orr, p. j., xu, x., * benton, m. j., 2019. pterosaur integumentary structures with complex feather - like branching. nature ecology and evolution 3, 24 - 30. doi
</ctx>
The following are multiple choice questions (with answers) about STEM.
Which of these BEST describes the way a feather feels?
A. Colorful
B. Soft
C. Low
D. Bright
Answer: | [
"Colorful",
"Soft",
"Low",
"Bright"
] | B | |
aquarat_34556 | aquarat | <ctx>
standing there. they congratulated and asked kiri which roadie would he choose. he chose the weaker contender of the two, palak and so raghu got angry. kiri said that he can beat anyone, and so raghu said that if he can beat anyone, why doesn't he choose the stronger contender defeat him and win with respect? he had proved himself and reached the top so he should be confident enough to beat anyone in finale. but rajiv was giving him a different option. he was saying he should easily win by choosing the weaker of two. finally kiri decided to win the respect & chose nauman as his opponent for the grand finale & axed palak's rope. kiri could have won had he decided to go with palak. but raghu forced him to go with nauman and subsequently he lost. the final task took place near a lake. all the roadies were there. it was going to finally end. the winner was going to be declared. ranvijay encouraged them and gave an emotional speech. then, both nauman and kiri got bound by chains on their hands, legs and neck. they were tied to a chain which was connected to a pan carrying heavy weights. to win, they had to pull the rope connected to the pan and use their strength and speed to walk 20 steps and pull out the roadies flag. the race started. they both ran at first but were suddenly stopped by the force of the weight and nearly fell down. all the roadies ( except sufi, tamanna, devarshi and varisha ) were cheering for kiri. kiri was in lead. nauman was far behind. he even fell two times and his feet started bleeding very badly. but then he got up and used all his strength, went on and eventually won. nauman became the ultimate roadie. kiri and nauman were called back and both got a hero honda karizma bike. nauman, being the winner of the season, also won the prize money - rs. 3, 52, 000 voting history gang om blues gang brats indicates the contestant was immune that week. indicates the contestant was eliminated that week. indicates the
jacque, haga and edwards. during this lap, biaggi closes the small gap to gibernau and starts to put pressure on the spaniard. on lap ten - the halfway point of the race - and gibernau is still leading the race. his gap back to biaggi is + 0. 895 seconds at the start / finish straight but closes again significantly in sector one. by now, the top two start encounter some backmarkers, most notably aoki and garry mccoy. mccoy lets gibernau through with relative ease, but blocks biaggi significantly in the middle of the geert timmer bocht, causing him to lose valuable time and touch with the spaniard. lap eleven and biaggi now has it all to do to fix the small gap created by backmarker mccoy. this has opened up a + 0. 912 second gap back to biaggi for gibernau. mcwilliams has crashed out of the race and is ignoring the marshalls who are more concerned with removing his bike from the gravel. on lap twelve, gibernau sets another fastest lap and extends the gap he has to biaggi. third place rossi is also trying to pass some backmarkers but is forced to go onto the slippery exit chicane at the geert timmer bocht while trying to pass makoto tamada. lap thirteen and aoki has also gone down, the marshalls pushing his bike away from the circuit. he lost the front at de bult and almost hits barros as he rolls onto the circuit, who can narrowly avoid him and slow down. on lap fourteen, gibernau now has to overtake the other kawasaki backmarker in the form of andrew pitt, whom he overtakes without any problems. checa is now rapidly closing in on jacque exiting the ramshoek and makes his move at the entrance of the geert timmer bocht, passing jacque for fifth position on the inside of him. lap fifteen and the gap gibernau has to biaggi is now + 6. 743 seconds. by now, a small dry line is starting to
defiance, he went into the pits and urged everyone to do likewise, following him to switch bikes on grounds of safety reasons. mechanics quickly change the tyres on the bikes to put on the full wets, delaying the start. as all the riders and mechanics were still preparing, the new race start was pushed back to 15 : 50 with the pit lane reopening at 15 : 40 for a total of five minutes. the officials declared that the race distance still remains 19 laps, which is the original race distance. during the opening of the pit lane, some take off and do a sighting lap. officials declared that they are allowed to do one sighting lap, followed by a grid formation and one warm - up before the start. during the sighting lap, one of the riders - nobuatsu aoki - got stuck in the gravel and couldn't get out. after a relative period of waiting, all the riders line up on a now rain soaked grid and begin the warm - up lap. because of the reshuffle and delayed start, capirossi will start in pole position as usual. aoki however does have to start from the pits because he could not make the start in time. the same thing happened to aoki's teammate jeremy mcwilliams, meaning that both will have to start from the back of the grid. all riders slowly slot into their respective grid positions and as the lights go out, it is rossi who has the best start and moves up into the lead at the s - bocht ( turn 1 ), followed by biaggi in second and gibernau in third, moving up from seventh and taking multiple positions by going on the right side of the circuit. barros makes up multiple positions from the second row and moves up into fourth, also benefiting from capirossi's appalling start which dropped him way back into the field after he failed to get away properly. jacque, who initially looked to have a bad start, managed to get away well and overtakes multiple people before going up the inside of teammate barros at the haarbocht ( turn 2 ) for fourth position. also at the haarbocht, gibernau
. 901 seconds. on lap four, rossi sets the fastest lap, only for barros to snatch it away. fourth place barros is still right behind capirossi at the gardner straight but is unable to make a move entering doohan corner. rossi is slowly closing the gap and barros tries to go down the inside of capirossi at mg but is once again unable to get past. lap five and barros is right behind capirossi at the gardner straight but cannot get by capirossi due to the ducati's superior top speed. barros sets the fastest lap as well. gibernau's gap back to rossi was + 0. 703 seconds at the start / finish straight but that has already been reduced to + 0. 487 seconds in sector one. barros has now also broken the circuit record with a time of 1 : 31. 309, beating rossi's 2003 record of 1 : 31. 421 with + 0. 112 seconds. on lap six, the top six is as follows : gibernau, rossi, capirossi, barros, biaggi and bayliss. exiting stoner corner, sparks can be seen at the bottom of rossi's bike as he pushes at the max to close the gap to gibernau. barros is once again very close coming into honda corner but still cannot get past capirossi. replacement rider garry mccoy has come into the pits to retire with technical issues. at mg, barros is still right behind but cannot get side by side with the italian. lap seven and capirossi sets the fastest lap of the race. rossi has almost caught up to gibernau with capirossi closing the gap to him also. barros tries to pass capirossi around the outside but gets blocked and has to stay behind still. on lap eight, rossi has fully caught gibernau by now. barros is still right behind capirossi but caouldn't get past. lap nine and bayliss manages to get side by side with biaggi on the gardner straight, going past entering doohan corner for fifth spot. biaggi tries to hang on and re
</ctx>
The following are multiple choice questions (with answers) about STEM.
Anup start a bike at 6am. and rides it at 60kmph. Raghu started at 7pm with his car at 100kmph. When will Raghu overtake Anup?
A. A)8:30am
B. B)9:40am
C. C)10:00am
D. D)12:00pm
Answer: | [
"A)8:30am",
"B)9:40am",
"C)10:00am",
"D)12:00pm"
] | A | Suppose bike is overtaken by car xhrs after 6am
Distance covered by the bike in x hrs = distance covered by the car in x-1 hr
60x = 100(x-1)
40x = 100
x = 2.5 hrs
Required time = 6+2.5 = 8:30am
Answer is A |
mmlu_aux_3598 | mmlu_auxiliary | <ctx>
plant disease resistance protects plants from pathogens in two ways : by pre - formed structures and chemicals, and by infection - induced responses of the immune system. relative to a susceptible plant, disease resistance is the reduction of pathogen growth on or in the plant ( and hence a reduction of disease ), while the term disease tolerance describes plants that exhibit little disease damage despite substantial pathogen levels. disease outcome is determined by the three - way interaction of the pathogen, the plant and the environmental conditions ( an interaction known as the disease triangle ). defense - activating compounds can move cell - to - cell and systematically through the plant's vascular system. however, plants do not have circulating immune cells, so most cell types exhibit a broad suite of antimicrobial defenses. although obvious qualitative differences in disease resistance can be observed when multiple specimens are compared ( allowing classification as “ resistant ” or “ susceptible ” after infection by the same pathogen strain at similar inoculum levels in similar environments ), a gradation of quantitative differences in disease resistance is more typically observed between plant strains or genotypes. plants consistently resist certain pathogens but succumb to others ; resistance is usually specific to certain pathogen species or pathogen strains. background plant disease resistance is crucial to the reliable production of food, and it provides significant reductions in agricultural use of land, water, fuel and other inputs. plants in both natural and cultivated populations carry inherent disease resistance, but this has not always protected them. the late blight great famine of ireland of the 1840s was caused by the oomycete phytophthora infestans. the world ’ s first mass - cultivated banana cultivar gros michel was lost in the 1920s to panama disease caused by the fungus fusarium oxysporum. the current wheat stem rust, leaf rust and yellow stripe rust epidemics spreading from east africa into the indian subcontinent are caused by rust fungi puccinia graminis and p. striiformis. other epidemics include chestnut blight, as well as recurrent severe plant diseases such as rice blast, soybean cyst nematode, citrus canker. plant pathogens can spread rapidly over great distances, vectored by water, wind
crops, for example, have been altered such that they are resistant to pests, can be grown in more extreme heat, cold, or drought, and produce longer, stronger fibers to be used in textile production. one of the biggest threats to rice, which is a staple food crop especially in india and other countries within asia, is blast disease, which is a fungal infection that causes lesions to form on all parts of the plant. a genetically engineered strain of rice has been developed so that it is resistant to blast, greatly improving the crop yield of farmers and allowing rice to be more accessible to everyone. some other crops have been modified such that they produce higher yields per plant or that they require less land for growing. the latter can be helpful in extreme climates with little arable land and also decreases deforestation, as fewer trees need to be cut down in order to make room for crop fields. others yet have been altered such that they do not require the use of insecticides or fungicides. this addresses various health concerns associated with such pesticides and can also work to improve biodiversity within the area in which these crops are grown. in a review of borlaug's 2000 publication entitled ending world hunger : the promise of biotechnology and the threat of antiscience zealotry, the authors argued that borlaug's warnings were still true in 2010, research conducted by the gmo risk assessment and communication of evidence ( grace ) program through the eu between 2007 and 2013 focused on many uses of gm crops and evaluated many facets of their effects on human, animal, and environmental health. the body of scientific evidence concluding that gm foods are safe to eat and do not pose environmental risks is wide. findings from the international council of scientists ( 2003 ) that analyzed a selection of approximately 50 science - based reviews concluded that " currently available genetically modified foods are safe to eat, " and " there is no evidence of any deleterious environmental effects having occurred from the trait / species combinations currently available. " the united nations food and agriculture organization ( fao ) supported the same consensus a year later in addition to recommending the extension of biotechnology to the developing world. similarly, the royal society ( 2003 ) and british medical association
##a, h. tefera, and r. j. nelson. 2004. biotechnology in the developing world : a case for increased investments in orphan crops. food policy 29 ( 1 ) : 15 – 44. r. j. nelson, r. l. naylor, m. m. jahn. 2004. the role of genomics research in improvement of " orphan " crops. crop science 44 : 1901 – 1904. trognitz, f. c., p. m. manosalva, d. o. nino - liu, ma. del r. herrera, m. ghislain, b. r. trognitz and r. j. nelson. 2002. plant defense genes associated with quantitative resistance to potato late blight in solanum phureja x s. tuberosum hybrids. mol. plant - microbe interactions 15 ( 6 ) : 587 – 597. thiele, g., r. nelson, o. ortiz, and s. sherwood. 2001. participatory research and training : ten lesson from the farmer field schools ( ffs ) in the andes. currents 27 : 4 – 11. nelson, r. j., orrego, r., ortiz, o., mundt, m., fredrix, m. and vien, n. v. 2001. working with resource - poor farmers to manage plant diseases. plant disease 85 : 684 – 695. perez, w. g., j. s. gamboa, y. v. falcon, m. coca, r. m. raymundo and r. j. nelson. 2001. genetic structure of peruvian populations of phytophthora infestans. phytopathology 91 : 956 – 965. garrett, k. a., r. j. nelson, c. c. mundt, g. chacon, r. e. jaramillo, and g. a. forbes. 2001. the effects of host diversity and other management components on epidemics of late blight in the humid highland tropics. phytopathology 91 : 993 – 1000. shanti, m. l
. the fungicides are applied at the end of the harvest and chlorothalonil has been shown in experiments to reduce purple spot by 99 % and increase yields by 36 %. this increase in yield as a result of purple spot control has been shown to translate into a net return of $ 200 – 400 per acre for asparagus growers. asparagus rust asparagus rust was first reported in the u. s. in 1896. it began on the asparagus crops of mostly northeastern states and began to move westward across the country - for each successive year the disease was discovered in new western areas until in 1902 it was reported in california for the first time. research to control the disease began with bordeaux mixture experiments around the start of the 20th century. copper and sulfur dust were tried as well but their success was very limited. sulfur was the only one to have much success at all. rust resistant strains of asparagus were cultivated but by the 1940s and 1950s these strains of asparagus were no longer providing adequate levels of resistance. in the 1950s zineb and mancozeb were developed as the primary means to control rust. zineb reduced infection by 85 % and mancozeb by 97 %. by 1989 ebdc fungicides had become the most common fungicidal means to control rust on asparagus. however, after the epa almost cancelled the use of ebdcs on asparagus many processors decided they would not accept ebdc - treated asparagus despite the epa allowing its use after review. this meant that many growers were left with no registered fungicide to use on asparagus. since 1990 the epa has granted exemptions for tebuconazole, myclobutanil, and triadimefon for use on asparagus. bananas hawaii is the primary state in the u. s. where bananas are grown. the average yield is 15, 000 pounds / acre. approximately 600 - 800 plants are grown per acre. planting occurs year - round. banana bunches are ready for harvest 12 to 15 months after initial planting. on a banana plantation, plants can be seen at all stages of vegetative growth and
</ctx>
The following are multiple choice questions (with answers) about STEM.
Bananas are one of the world' s most important food crops. They are also one of the most valuable exports. Bananas do not grow from seeds. Instead, they grow from existing plants. Bananas are threatened by disease because all the plants on a farm are copies of each other. They all share the same genetic weaknesses. For example, the Cavendish banana is most popular in North American and European markets. However,some kinds of fungus organisms easily infect the Cavendish. Black Sigatoka disease affects the leaves of Cavendish banana plants. The disease is controlled on large farms by putting chemicals on the plant' s leaves. Farmers put anti-fungal chemicals on their crops up to once a week. Another fungal disease is more serious. Panama disease attacks the roots of the banana plant. There is no chemical treatment for this disease. Infected plants must be destroyed. Panama disease has affected crops in Southeast Asia, Australia and South Africa. There is concern that it may spread to bananas grown in the Americas. This could threaten an important export product for Central and South America. The International Network for the Improvement of Banana and Plantain supports research on bananas. The group has headquarters in France and other offices in the major banana-growing areas of the world. The group says that more research must be done to develop improved kinds of bananas. The group says that fungal diseases mainly affect only one kind of banana. In fact, there are five hundred different kinds of bananas. Food and Agriculture Organization of the United Nations has said that the Cavendish banana represents only 10% of world production. The U.N. agency says farmers should grow different kinds of bananas. This protects against diseases that affect only one kind. Experts warn that disease may cause the Cavendish banana to disappear. This happened earlier to another popular banana because of its genetic weakness against disease. Bananas are threatened by disease because _ .
A. they grow from seeds
B. they are one of the most valuable exports
C. the only way to prevent it is to put chemicals on their leaves
D. they have genetic weaknesses against disease
Answer: | [
"they grow from seeds",
"they are one of the most valuable exports",
"the only way to prevent it is to put chemicals on their leaves",
"they have genetic weaknesses against disease"
] | D | null |
qasc_5618 | qasc | <ctx>
.............................. forest soils 390. 5 - 390. 7............................. forest meteorology. forest microclimatology 391 - 410. 9................................ sylviculture 411 - 428................................... conservation and protection. including forest influences, damage by elements, fires, forest reserves 430 - ( 559 )................................. exploitation and utilization. including timber trees, fuelwood, logging, transportation, valuation 561 - 669. 5................................ administration. policy sf - animal culture 41 - 55....................................... history 84 - 84. 64.................................. economic zoology 84. 82 - 85. 6............................... rangelands. range management. grazing 87............................................
prather, f. schmiegelow, t. d. sisk, and d. j. vosick. 2006. recommendations for integrating restoration ecology and conservation biology in ponderosa pine forests of the southwestern united states. restoration ecology 14 : 4 - 10. fule, p. z., j. e. crouse, a. e. cocke, m. m. moore, and w. w. covington. 2004. changes in canopy fuels and potential fire behavior 1880 - 2040 : grand canyon, arizona. ecological modelling 175 : 231 - 248. covington, w. w. 2003. restoring ecosystem health in frequent - fire forests of the american west. ecological restoration 21 : 1 : 7 - 11 covington, w. w., p. z. fule, s. c. hart, and r. p. weaver. 2001. modeling ecological restoration effects on ponderosa pine forest structure. restoration ecology 9 ( 4 ) : 421 - 431. covington, w. w. 2000. helping western forests heal : the prognosis is poor for us forest ecosystems. nature 408 ( 6809 ) : 135 - 136. references external links the association for fire ecology society for ecological restoration online healthy forests and rangelands us forest service national headquarters the use of fire in forest restoration - a collection of papers the aldo leopold foundation american foresters 1947 births northern arizona university faculty living people forestry academics forestry researchers yale school of forestry & environmental studies alumni university of north texas alumni
height of vegetation structure to have at the end of the grazing season. this allows managers to set the appropriate stocking rate to best attain a desired vegetation height. as a rule of thumb, the average vor reading for suitable grouse nesting habitat is 3. 5in ( 8. 89 cm ). lekking habitat can be managed by burning, mowing, clear cutting, and grazing across the entire range of the sharp - tailed grouse subspecies. ammann ( 1957 ) found that leks that contained woody vegetation did not exceed 30 % of the total lek area. similarly, moyles ( 1989 ) found a negative correlation with increased in aspen trees ( populus tremuloides ) on lekking sites and the number of displaying males present. trees may provide perches for avian predators but further work needs to be done on the effects of tree encroachment. status and conservation these birds are declining in numbers and range due to habitat loss, but overall they are not considered a threatened species references further reading berger, r. p., and r. k. baydack. 1992 effects of aspen succession on sharp - tailed grouse, tympanuchus phasianellus. in the interlake region of manitoba. canadian field naturalist 106 : 185 - 191 bergerud, a. t. 1988. mating systems in grouse. pages 439 - 470 in adaptive strategies and population ecology of northern grouse. ( bergerud, a. t. and m. w. gratson, eds. ) univ. of minnesota press, minneapolis. bergerud, a. t. and m. w. gratson 1988. population ecology of north american grouse. pages 578 - 685 in adaptive strategies and population ecology of northern grouse. ( bergerud, a. t. and m. w. gratson, eds. ) univ. of minnesota press, minneapolis clarke, julia a. ( 2004 ) : morphology, phylogenetic taxonomy, and systematics of ichthyornis and apatornis ( avialae : ornithurae ). bulletin of the american museum of natural history 286 : 1 - 179 pdf fulltext clawson, m.
. portland author marcy houle says that the park " captures the essence of what is natural and wild and beautiful about the northwest... from this forest sanctuary, panoramic views of the city of portland, the willamette and columbia rivers, and five major peaks of the cascade range... can be seen through the tall fir trees. from its inception..., forest park has been a refuge for both people and wildlife, and an integral part of the environment of portland. " ecology vegetation forest park lies in the coast range ecoregion designated by the u. s. environmental protection agency ( epa ). in its natural state, the forest consists mainly of three tree species, douglas - fir, western hemlock, and western red cedar, and smaller numbers of grand fir, black cottonwood, red alder, bigleaf maple, madrone, and western yew. much of the forest that existed here before 1850 was gone by 1940. the stage of re - growth in the forest depends on when it was last logged or burned. in the mid - 1990s, about one percent of the total vegetation in the park consisted of grasses, bracken, thistle, and fireweed in sections of the forest cleared two to five years earlier. another two percent had reached the shrub stage, between three and thirty years old, with small trees dominated by such plants as thimbleberry, salmonberry, and blackberry. forest areas 10 to 30 years old that contained tall alder and maple trees and smaller conifers accounted for about 20 percent of the park. larger areas were occupied by forests in which conifers had grown taller than the alders and maples. about 50 percent of forest park consists of these areas, which are between 30 and 80 years old and in which douglas - firs have begun to dominate. another 25 percent of the park contains forests dominated by middle - aged conifers, 80 to 250 years old. in these areas, red alders, which live for about 100 years, have begun to die, and the douglas - firs, which can live for 750 years, attain heights up to about. under the big trees are shade - tolerant trees such as western red cedar, western
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The following are multiple choice questions (with answers) about STEM.
What is required for the ideal habitat for new stands of cottonwood?
A. sunlight
B. nutrients
C. warmth
D. Sediment
Answer: | [
"sunlight",
"nutrients",
"warmth",
"Sediment"
] | D | |
medmcqa_7841 | medmcqa | <ctx>
tool ( frax ) estimates the probability of hip fracture and the probability of a major osteoporotic fracture ( mof ), which could occur in a bone other than the hip. in addition to bone density ( t - score ), calculation of the frax score involves age, body characteristics, health behaviors, and other medical history. as of 2014, the national osteoporosis foundation ( nof ) recommends pharmaceutical treatment for osteopenic postmenopausal women and men over 50 with frax hip fracture probability of > 3 % or frax mof probability > 20 %. as of 2016, the american association of clinical endocrinologists and the american college of endocrinology agree. in 2017, the american college of physicians recommended that clinicians use individual judgment and knowledge of patients'particular risk factors for fractures, as well as patient preferences, to decide whether to pursue pharmaceutical treatment for women with osteopenia over 65. pharmaceutical treatment for low bone density includes a range of medications. commonly used drugs include bisphosphonates ( alendronate, risedronate, and ibandronate ) — some studies show that decreased fracture risk and increased bone density after bisphosphonate treatment for osteopenia. other medications include selective estrogen receptor modulators ( serms ) ( e. g., raloxifene ), estrogens ( e. g., estradiol ), calcitonin, and parathyroid hormone - related protein analogues ( e. g., abaloparatide, teriparatide ). these drugs are not without risks. in this complex landscape, many argue that clinicians must consider a patient's individual risk of fracture, not simply treat those with osteopenia as equally at risk. a 2005 editorial in the annals of internal medicine states " the objective of using osteoporosis drugs is to prevent fractures. this can be accomplished only by treating patients who are likely to have a fracture, not by simply treating t - scores. " history osteopenia, from greek οστεον ( osteon ), " bone " and
, and often the thyroid gland ( depending on local referral patterns ). they also deal with diseases involving the skin, breast, soft tissue, trauma, peripheral artery disease and hernias and perform endoscopic procedures such as gastroscopy and colonoscopy. genetics – is a branch of biology concerned with the study of genes, genetic variation, and heredity in organisms. genitourinary system – the genitourinary system, or urogenital system, are the organs of the reproductive system and the urinary system. these are grouped together because of their proximity to each other, their common embryological origin and the use of common pathways, like the male urethra. also, because of their proximity, the systems are sometimes imaged together. geriatrics – or geriatric medicine, is a specialty that focuses on health care of elderly people. it aims to promote health by preventing and treating diseases and disabilities in older adults. there is no set age at which patients may be under the care of a geriatrician, or geriatric physician, a physician who specializes in the care of elderly people. rather, this decision is determined by the individual patient's needs, and the availability of a specialist. it is important to note the difference between geriatrics, the care of aged people, and gerontology, which is the study of the aging process itself. the term geriatrics comes from the greek γερων geron meaning " old man ", and ιατρος iatros meaning " healer ". however, geriatrics is sometimes called medical gerontology. gonad – a gonad, sex gland, or reproductive gland is a mixed gland that produces the gametes ( sex cells ) and sex hormones of an organism. in the female of the species the reproductive cells are the egg cells, and in the male the reproductive cells are the sperm. the male gonad, the testicle, produces sperm in the form of spermatozoa. the female gonad, the ovary, produces egg cells. both of these gametes are haploid cells. some hermaphroditic animals have a type of go
ovocyte and embryo quality. in order to optimise pregnancy rates, there is significant evidence that a morphological scoring system is the best strategy for the selection of embryos. since 2009 where the first time - lapse microscopy system for ivf was approved for clinical use, morphokinetic scoring systems has shown to improve to pregnancy rates further. however, when all different types of time - lapse embryo imaging devices, with or without morphokinetic scoring systems, are compared against conventional embryo assessment for ivf, there is insufficient evidence of a difference in live - birth, pregnancy, stillbirth or miscarriage to choose between them. active efforts to develop a more accurate embryo selection analysis based on artificial intelligence and deep learning are underway. embryo ranking intelligent classification assistant ( erica ), is a clear example. this deep learning software substitutes manual classifications with a ranking system based on an individual embryo's predicted genetic status in a non - invasive fashion. studies on this area are still pending and current feasibility studies support its potential. embryo transfer the number to be transferred depends on the number available, the age of the patient and other health and diagnostic factors. in countries such as canada, the uk, australia and new zealand, a maximum of two embryos are transferred except in unusual circumstances. in the uk and according to hfea regulations, a woman over 40 may have up to three embryos transferred, whereas in the us, there is no legal limit on the number of embryos which may be transferred, although medical associations have provided practice guidelines. most clinics and country regulatory bodies seek to minimise the risk of multiple pregnancy, as it is not uncommon for multiple embryos to implant if multiple embryos are transferred. embryos are transferred to the patient's uterus through a thin, plastic catheter, which goes through her vagina and cervix. several embryos may be passed into the uterus to improve chances of implantation and pregnancy. luteal support luteal support is the administration of medication, generally progesterone, progestins, hcg, or gnrh agonists, and often accompanied by estradiol, to increase the success rate
matrix are strong determinants of duct morphogenesis. biochemistry estrogen and growth hormone ( gh ) are essential for the ductal component of mammary gland development, and act synergistically to mediate it. neither estrogen nor gh are capable of inducing ductal development without the other. the role of gh in ductal development has been found to be mostly mediated by its induction of the secretion of insulin - like growth factor 1 ( igf - 1 ), which occurs both systemically ( mainly originating from the liver ) and locally in the mammary fat pad through activation of the growth hormone receptor ( ghr ). however, gh itself also acts independently of igf - 1 to stimulate ductal development by upregulating estrogen receptor ( er ) expression in mammary gland tissue, which is a downstream effect of mammary gland ghr activation. in any case, unlike igf - 1, gh itself is not essential for mammary gland development, and igf - 1 in conjunction with estrogen can induce normal mammary gland development without the presence of gh. in addition to igf - 1, other paracrine growth factors such as epidermal growth factor ( egf ), transforming growth factor beta ( tgf - β ), amphiregulin, fibroblast growth factor ( fgf ), and hepatocyte growth factor ( hgf ) are involved in breast development as mediators downstream to sex hormones and gh / igf - 1. during embryonic development, igf - 1 levels are low, and gradually increase from birth to puberty. at puberty, the levels of gh and igf - 1 reach their highest levels in life and estrogen begins to be secreted in high amounts in females, which is when ductal development mostly takes place. under the influence of estrogen, stromal and fat tissue surrounding the ductal system in the mammary glands also grows. after puberty, gh and igf - 1 levels progressively decrease, which limits further development until pregnancy, if it occurs. during pregnancy, progesterone and prolact
</ctx>
The following are multiple choice questions (with answers) about STEM.
Hormone replacement therapy (H) is indicated in:
A. women with breast cancer
B. Osteoporosis
C. women with uterine cancer
D. previous history of thromboembolic episode
Answer: | [
"women with breast cancer",
"Osteoporosis",
"women with uterine cancer",
"previous history of thromboembolic episode"
] | B | H Indications symptomatic women who suffer from oestrogen defeciency(therapeutic) high risk cases for menopausal complications like cardiovascular disease,osteoporosis,stroke,alzheimers disease,colonic cancer(prophylactic) premature menopause,spontaneous or following surgery(tubectomy,hysterectomy) gonadal dysgenesis in adolescents(therapeutic0 women demanding H as prophylaxis. SHAW'S TEXTBOOK OF GYNAECOLOGY,Pg no:70,16 th edition |
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