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Vermifilter-Vermifilter-Vermifiltration is a low-cost aerobic wastewater treatment option. Because energy is not required for aeration, vermifilters can be considered "passive treatment" systems (pumps may be required if gravity flow is not possible). Another advantage is the high treatment efficiency given the low spa... | milkshake721/2.1M-wiki-STEM |
Vermifilter-Terminology-Alternative terms used to describe the vermifiltration process include aerobic biodigester, biological filter with earthworms, or wet vermicomposting. The treatment system may be described using terms such as vermi-digester and vermi-trickling filter.
When this kind of sanitation system is used ... | milkshake721/2.1M-wiki-STEM |
Vermifilter-Overview-Vermifiltration was first advocated by researchers at the University of Chile in 1992 as a low-cost sustainable technology suitable for decentralised sewage treatment in rural areas. Vermifilters offer treatment performance similar to conventional decentralised wastewater treatment systems, but wit... | milkshake721/2.1M-wiki-STEM |
Vermifilter-Overview-Microorganisms present are heterotrophic and autotrophic. Heterotrophic microorganisms are important in oxidising carbon (decomposition), whereas autotrophic microorganisms are important in nitrification. | milkshake721/2.1M-wiki-STEM |
Vermifilter-Overview-As a result of oxidation reactions, biodegradation and microbial stimulation by enzymatic action, organic matter decomposition and pathogen destruction occurs in the vermifilter. In a study where municipal wastewater was treated in a vermifilter, removal ratios for biochemical oxygen demand (BOD5) ... | milkshake721/2.1M-wiki-STEM |
Vermifilter-Process types-Vermifilters can be used for primary, secondary and tertiary treatment of blackwater and greywater. | milkshake721/2.1M-wiki-STEM |
Vermifilter-Process types-Primary treatment of blackwater Vermifilters can be used for aerobic primary treatment of domestic blackwater. Untreated blackwater enters a ventilated enclosure above a bed of filter medium. Solids accumulate on the surface of the filter bed while liquid drains through the filter medium and i... | milkshake721/2.1M-wiki-STEM |
Vermifilter-Process types-Primary treatment vermifilter reactors are designed to digest solid material, such as contained in raw sewage. Twin-chamber parallel reactors offer the advantage of being able to allow one to rest, while the other is active, in order to facilitate hygienic removal of humus with reduced pathoge... | milkshake721/2.1M-wiki-STEM |
Vermifilter-Process types-Worms actively digest the solid organic material. Over time, an equilibrium is reached in which the volume digested by a stable population of worms is equal to the input volume of solid waste. Seasonal and environmental factors (such as temperature) and variable influent volumes can cause buil... | milkshake721/2.1M-wiki-STEM |
Vermifilter-Process types-Primary treatment of wet mixed blackwater can also include greywater containing food solids, grease and other biodegradable waste. Solid material is reduced to stable humus (worm castings), with volume reductions of up to tenfold.The process produces primary treated blackwater, with much of th... | milkshake721/2.1M-wiki-STEM |
Vermifilter-Process types-Secondary treatment Secondary and tertiary treatment vermifilters can be underneath the primary vermifilter in a single tower, but are typically single reactors, where several reactors can be chained in series as sequential vermifilters. Drainage within the reactor is provided by filter media ... | milkshake721/2.1M-wiki-STEM |
Vermifilter-Process types-Sprinklers or drippers can be used in secondary and tertiary treatment vermifilter reactors (see image).
Hydraulic factors (hydraulic retention time, hydraulic loading rate and organic loading rate) and biological factors (earthworm numbers, levels of biofilm) can influence treatment efficienc... | milkshake721/2.1M-wiki-STEM |
Vermifilter-Design-Vermifilters are enclosed reactors made from durable materials that eliminate the entry of vermin, usually plastic or concrete. Ventilation must be sufficient to ensure an aerobic environment for the worms and microorganisms, while also inhibiting entry of unwanted flies. Temperature within the react... | milkshake721/2.1M-wiki-STEM |
Vermifilter-Design-Influent entry Influent entry is from above the filter media. Full-flush toilets can have the entry point into the side of the reactor, whereas micro-flush toilets, because these do not provide sufficient water to convey solids through sewer pipes, are generally installed directly above the reactor. ... | milkshake721/2.1M-wiki-STEM |
Vermifilter-Design-Filter substrate Drainage within the vermifilter reactor is provided by the filter media. The filter media has the dual purpose of retaining the solid organic material, while also providing a habitat suitable for sustaining a population of composting worms. This population requires adequate moisture ... | milkshake721/2.1M-wiki-STEM |
Vermifilter-Design-Vermifilter reactors may comprise a single section packed only with organic media, or up to three filter sections comprising an organic top layer that provides habitat for the earthworms, an inorganic upper layer of sand and lower layer of gravel. The filter sits on top of a sump or drainage layer of... | milkshake721/2.1M-wiki-STEM |
Vermifilter-Design-Common filter packing materials include sawdust, wood chips, coir, bark, peat, and straw for the organic layer. Gravel, quartz sand, round stones, pumice, mud balls, glass balls, ceramsite and charcoal are commonly used for the inorganic layer. The surface area and porosity of these filter materials ... | milkshake721/2.1M-wiki-STEM |
Vermifilter-Sizing-Vermifilters can be constructed as single tower systems, or separate staged reactors (either gravity or pump operated) for the treatment of wastewater according to design requirements (primary, secondary, tertiary treatment). More stages can increase the degree of treatment because multiple stage sys... | milkshake721/2.1M-wiki-STEM |
Vermifilter-Sizing-The design parameters of vermifilters include stocking density of earthworms (although over time earthworm population tends to be self-moderating), filter media composition, hydraulic loading rate, hydraulic retention time and organic loading rate. Hydraulic retention time and hydraulic loading rate ... | milkshake721/2.1M-wiki-STEM |
Vermifilter-Sizing-In principle, provided the environment is aerobic, the longer the wastewater remains inside the filter, the greater the BOD5 and COD removal efficiency will be, but at the expense of hydraulic loading. Wastewater requires sufficient contact time with the biofilm to allow for the adsorption, transform... | milkshake721/2.1M-wiki-STEM |
Vermifilter-Operation and maintenance-A vermifilter has low mechanical and manual maintenance requirements, and, where gravity operated, requires no energy input. Recirculation, if required for improved effluent quality, would require a pump. Occasional topping up of organic materials may be required as these decompos... | milkshake721/2.1M-wiki-STEM |
Vermifilter-Operation and maintenance-Solids accumulate on the surface of the organic filter media (or filter packing). The liquid fraction drains through the medium into the sump or equaliser and is either discharged from the reactor or recirculated to the top for further treatment. Wastewater is discharged to the sur... | milkshake721/2.1M-wiki-STEM |
Vermifilter-Examples-Construction of primary and secondary domestic vermifilters from readily available materials A household pour-flush toilet, with combined primary vermifiltration and direct effluent infiltration into the soil below, is called the "Tiger Toilet" and has been tested by Bear Valley Ventures and Primov... | milkshake721/2.1M-wiki-STEM |
Vermifilter-Examples-"Tiger worm toilets" are also being promoted by Oxfam as a sanitation solution in refugee camps, slums and peri-urban areas in Africa, for example in Liberia.
Low-flush vermifilter toilet systems with direct subsoil soakage are being marketed in Ghana and other African countries by the Ghana Sustai... | milkshake721/2.1M-wiki-STEM |
Paraboloid-Paraboloid-In geometry, a paraboloid is a quadric surface that has exactly one axis of symmetry and no center of symmetry. The term "paraboloid" is derived from parabola, which refers to a conic section that has a similar property of symmetry. | milkshake721/2.1M-wiki-STEM |
Paraboloid-Paraboloid-Every plane section of a paraboloid by a plane parallel to the axis of symmetry is a parabola. The paraboloid is hyperbolic if every other plane section is either a hyperbola, or two crossing lines (in the case of a section by a tangent plane). The paraboloid is elliptic if every other nonempty pl... | milkshake721/2.1M-wiki-STEM |
Paraboloid-Paraboloid-Equivalently, a paraboloid may be defined as a quadric surface that is not a cylinder, and has an implicit equation whose part of degree two may be factored over the complex numbers into two different linear factors. The paraboloid is hyperbolic if the factors are real; elliptic if the factors are... | milkshake721/2.1M-wiki-STEM |
Paraboloid-Properties and applications-Elliptic paraboloid In a suitable Cartesian coordinate system, an elliptic paraboloid has the equation z=x2a2+y2b2.
If a = b, an elliptic paraboloid is a circular paraboloid or paraboloid of revolution. It is a surface of revolution obtained by revolving a parabola around its axis... | milkshake721/2.1M-wiki-STEM |
Paraboloid-Properties and applications-Parabolic reflector On the axis of a circular paraboloid, there is a point called the focus (or focal point), such that, if the paraboloid is a mirror, light (or other waves) from a point source at the focus is reflected into a parallel beam, parallel to the axis of the paraboloid... | milkshake721/2.1M-wiki-STEM |
Paraboloid-Properties and applications-Therefore, the shape of a circular paraboloid is widely used in astronomy for parabolic reflectors and parabolic antennas.
The surface of a rotating liquid is also a circular paraboloid. This is used in liquid-mirror telescopes and in making solid telescope mirrors (see rotating f... | milkshake721/2.1M-wiki-STEM |
Paraboloid-Properties and applications-This property makes it simple to manufacture a hyperbolic paraboloid from a variety of materials and for a variety of purposes, from concrete roofs to snack foods. In particular, Pringles fried snacks resemble a truncated hyperbolic paraboloid.A hyperbolic paraboloid is a saddle s... | milkshake721/2.1M-wiki-STEM |
Paraboloid-Properties and applications-From the point of view of projective geometry, a hyperbolic paraboloid is one-sheet hyperboloid that is tangent to the plane at infinity.
A hyperbolic paraboloid of equation z=axy or z=a2(x2−y2) (this is the same up to a rotation of axes) may be called a rectangular hyperbolic p... | milkshake721/2.1M-wiki-STEM |
Paraboloid-Properties and applications-Plane sectionsA plane section of a hyperbolic paraboloid with equation z=x2a2−y2b2 can be a line, if the plane is parallel to the z-axis, and has an equation of the form bx±ay+b=0 a parabola, if the plane is parallel to the z-axis, and the section is not a line, a pair of inters... | milkshake721/2.1M-wiki-STEM |
Paraboloid-Properties and applications-Examples in architecture Saddle roofs are often hyperbolic paraboloids as they are easily constructed from straight sections of material. Some examples: Philips Pavilion Expo '58, Brussels (1958) IIT Delhi - Dogra Hall Roof St. Mary's Cathedral, Tokyo, Japan (1964) Cathedral of Sa... | milkshake721/2.1M-wiki-STEM |
Paraboloid-Cylinder between pencils of elliptic and hyperbolic paraboloids-The pencil of elliptic paraboloids z=x2+y2b2,b>0, and the pencil of hyperbolic paraboloids z=x2−y2b2,b>0, approach the same surface z=x2 for b→∞ which is a parabolic cylinder (see image). | milkshake721/2.1M-wiki-STEM |
Paraboloid-Curvature-The elliptic paraboloid, parametrized simply as σ→(u,v)=(u,v,u2a2+v2b2) has Gaussian curvature K(u,v)=4a2b2(1+4u2a4+4v2b4)2 and mean curvature H(u,v)=a2+b2+4u2a2+4v2b2a2b2(1+4u2a4+4v2b4)3 which are both always positive, have their maximum at the origin, become smaller as a point on the surface move... | milkshake721/2.1M-wiki-STEM |
Paraboloid-Geometric representation of multiplication table-If the hyperbolic paraboloid z=x2a2−y2b2 is rotated by an angle of π/4 in the +z direction (according to the right hand rule), the result is the surface z=(x2+y22)(1a2−1b2)+xy(1a2+1b2) and if a = b then this simplifies to z=2xya2 .Finally, letting a = √2, we s... | milkshake721/2.1M-wiki-STEM |
Paraboloid-Dimensions of a paraboloidal dish-The dimensions of a symmetrical paraboloidal dish are related by the equation 4FD=R2, where F is the focal length, D is the depth of the dish (measured along the axis of symmetry from the vertex to the plane of the rim), and R is the radius of the rim. They must all be in th... | milkshake721/2.1M-wiki-STEM |
Paraboloid-Dimensions of a paraboloidal dish-A more complex calculation is needed to find the diameter of the dish measured along its surface. This is sometimes called the "linear diameter", and equals the diameter of a flat, circular sheet of material, usually metal, which is the right size to be cut and bent to make ... | milkshake721/2.1M-wiki-STEM |
Paraboloid-Dimensions of a paraboloidal dish-The volume of the dish, the amount of liquid it could hold if the rim were horizontal and the vertex at the bottom (e.g. the capacity of a paraboloidal wok), is given by π2R2D, where the symbols are defined as above. This can be compared with the formulae for the volumes of ... | milkshake721/2.1M-wiki-STEM |
Gravity spreading-Gravity spreading-Gravity spreading is a phenomenon in which a geological body laterally extends and vertically contracts to reduce its gravitational potential energy. It has been observed on many different scales, and at numerous locations on Earth, from rhyolite lava flows to passive margins. Additi... | milkshake721/2.1M-wiki-STEM |
Gravity spreading-Distinction from Gravity Gliding-Historically, geologists have used the terms "gravity spreading" and "gravity gliding" interchangeably, or with little distinction. This article follows the convention of "Excursus on gravity gliding and gravity spreading" by D.D. Schultz-Ela, which defines gravity spr... | milkshake721/2.1M-wiki-STEM |
Gravity spreading-Mechanism-For gravity spreading to occur, a rock mass must be driven to deformation by gravity. As long as the center of gravity of the system descends, portions of the system may rise. Of course, a material normally resists such deformation. For gravity spreading to occur, the differential stress mus... | milkshake721/2.1M-wiki-STEM |
Gravity spreading-Examples-Earth Mountains Heart Mountain in Wyoming, United States, has been extensively studied, because Ordovician age carbonates (Madison Limestone), sit on top of a much younger (~50Ma) sedimentary formation (Willwood Formation). It is now largely accepted that this juxtaposition of old rocks on to... | milkshake721/2.1M-wiki-STEM |
Gravity spreading-Examples-Passive Margins Gravity spreading in passive margins occurs when gravitational forces are strong enough to overcome the overburdens resistance to motion along its basal surface, and the internal strength. The gravitational forces are a function of the dip of the slope and the dip of the décol... | milkshake721/2.1M-wiki-STEM |
Gravity spreading-Examples-Mars Satellite images of Mars have shown that the Thaumasia Plateau has large amounts of thrust faults, normal faults, and ridges. This rifting has resulted in canyons, and compression at the front of the "mega-slide" has caused the ridges and thrust faults observed at low end of the region. ... | milkshake721/2.1M-wiki-STEM |
Gravity spreading-Examples-Tharsis, a volcanic plateau, was emplaced. This increased both the heat flux of the area, as well as the topographic slope. Volcanism associated with Tharsis also deposited ash and lava flows.
The layers of salt and ice beneath the volcanics provided detachment points for the initiation of gr... | milkshake721/2.1M-wiki-STEM |
Relations (philosophy)-Relations (philosophy)-Relations are ways in which things, the relata, stand to each other. Relations are in many ways similar to properties in that both characterize the things they apply to. Properties are sometimes treated as a special case of relations involving only one relatum. In philosoph... | milkshake721/2.1M-wiki-STEM |
Relations (philosophy)-Overview-The concept of relation has a long and complicated history. One of the interests for the Greek philosophers lay in the number of ways in which a particular thing might be described, and the establishment of a relation between one thing and another was one of these. A second interest lay ... | milkshake721/2.1M-wiki-STEM |
Relations (philosophy)-Overview-An understanding of types of relation is important to an understanding of relations between many things including those between people, communities and the wider world. Most of these are complex relations but of the simpler, analytical relations out of which they are formed there are som... | milkshake721/2.1M-wiki-STEM |
Relations (philosophy)-Internal and external relations-An important distinction is between internal and external relations. A relation is internal if it is fully determined by the features of its relata. For example, an apple and a tomato stand in the internal relation of similarity to each other because they are both ... | milkshake721/2.1M-wiki-STEM |
Relations (philosophy)-History-Ancient Greek philosophy Traditionally the history of the concept of relation begins with Aristotle and his concept of relative terms. In Metaphysics he states: "Things are called relative as the double to the half... as that which can act to that which can be acted upon... and as the kno... | milkshake721/2.1M-wiki-STEM |
Relations (philosophy)-History-It was left to the Scottish philosopher David Hume to reduce these kinds of mental association to three: "To me there appears to be only three principles of connexion among ideas namely Resemblance, Contiguity in time or place, and Cause or Effect".The problem which troubled Hume of being... | milkshake721/2.1M-wiki-STEM |
Relations (philosophy)-History-Late modern and contemporary philosophy Late modern American philosopher C. S. Peirce recorded that his own categories of relation grew originally out of a study of Kant. He introduced three metaphysical categories which pervaded his philosophy, and these were ordered through a considerat... | milkshake721/2.1M-wiki-STEM |
Relations (philosophy)-History-Secondness: The idea of secondness "is predominant in the ideas of causation" coming into being as "an action and reaction" between ourselves and some other, or between ourselves and a stimulus.: 159–163 It is essentially dyadic in character and in some versions of symbolic logic is repr... | milkshake721/2.1M-wiki-STEM |
Relations (philosophy)-History-Thirdness: "Ideas in which thirdness predominates include the idea of a sign or representation... For example, a picture signifies by similarity". This type of relation is essentially triadic in nature and is represented in Peirce's logic as a brace or bracket.These categories of relation... | milkshake721/2.1M-wiki-STEM |
Infertility-Infertility-Infertility is the inability of a person, animal or plant to reproduce by natural means. It is usually not the natural state of a healthy adult, except notably among certain eusocial species (mostly haplodiploid insects). It is the normal state of a human child or other young offspring, because ... | milkshake721/2.1M-wiki-STEM |
Infertility-Infertility-In humans, infertility is the inability to become pregnant after one year of unprotected and regular sexual intercourse involving a male and female partner. There are many causes of infertility, including some that medical intervention can treat. Estimates from 1997 suggest that worldwide about ... | milkshake721/2.1M-wiki-STEM |
Infertility-Infertility-The main cause of infertility in humans is age, and an advanced maternal age can raise the probability of suffering a spontaneous abortion during pregnancy. | milkshake721/2.1M-wiki-STEM |
Infertility-Infertility-Male infertility is responsible for 20–30% of infertility cases, while 20–35% are due to female infertility, and 25–40% are due to combined problems in both parts. In 10–20% of cases, no cause is found. The most common cause of female infertility is age, which generally manifests in sparse or ab... | milkshake721/2.1M-wiki-STEM |
Infertility-Definition-"Demographers tend to define infertility as childlessness in a population of women of reproductive age," whereas the epidemiological definition refers to "trying for" or "time to" a pregnancy, generally in a population of women exposed to a probability of conception. Currently, female fertility n... | milkshake721/2.1M-wiki-STEM |
Infertility-Definition-World Health Organization The World Health Organization defines infertility as follows: Infertility is "a disease of the reproductive system defined by the failure to achieve a clinical pregnancy after 12 months or more of regular unprotected sexual intercourse (and there is no other reason, such... | milkshake721/2.1M-wiki-STEM |
Infertility-Definition-a woman over 35 has not conceived after six months of contraceptive-free sexual intercourse.These time intervals would seem to be reversed; this is an area where public policy trumps science. The idea is that for women beyond age 35, every month counts and if made to wait another six months to pr... | milkshake721/2.1M-wiki-STEM |
Infertility-Definition-United Kingdom In the UK, previous NICE guidelines defined infertility as failure to conceive after regular unprotected sexual intercourse for two years in the absence of known reproductive pathology. Updated NICE guidelines do not include a specific definition, but recommend that "A woman of rep... | milkshake721/2.1M-wiki-STEM |
Infertility-Definition-Primary vs. secondary infertility Primary infertility is defined as the absence of a live birth for women who desire a child and have been in a union for at least 12 months, during which they have not used any contraceptives. The World Health Organisation also adds that 'women whose pregnancy spo... | milkshake721/2.1M-wiki-STEM |
Infertility-Effects-Psychological The consequences of infertility are manifold and can include societal repercussions and personal suffering. Advances in assisted reproductive technologies, such as IVF, can offer hope to many couples where treatment is available, although barriers exist in terms of medical coverage and... | milkshake721/2.1M-wiki-STEM |
Infertility-Effects-Partners may become more anxious to conceive, increasing sexual dysfunction. Marital discord often develops, especially when they are under pressure to make medical decisions. Women trying to conceive often have depression rates similar to women who have heart disease or cancer. Emotional stress and... | milkshake721/2.1M-wiki-STEM |
Infertility-Effects-In many cultures, inability to conceive bears a stigma. In closed social groups, a degree of rejection (or a sense of being rejected by the couple) may cause considerable anxiety and disappointment. Some respond by actively avoiding the issue altogether.In the United States some treatments for infer... | milkshake721/2.1M-wiki-STEM |
Infertility-Causes-Male infertility is responsible for 20–30% of infertility cases, while 20–35% are due to female infertility, and 25–40% are due to combined problems in both parts. In 10–20% of cases, no cause is found. The most common cause of female infertility are ovulation problems, usually manifested by scanty o... | milkshake721/2.1M-wiki-STEM |
Infertility-Causes-Iodine Deficiency Iodine deficiency may lead to infertility. | milkshake721/2.1M-wiki-STEM |
Infertility-Causes-Natural infertility Before puberty, humans are naturally infertile; their gonads have not yet developed the gametes required to reproduce: boys' testicles have not developed the sperm cells required to impregnate a female; girls have not begun the process of ovulation which activates the fertility of... | milkshake721/2.1M-wiki-STEM |
Infertility-Causes-The absence of fertility in children is considered a natural part of human growth and child development, as the hypothalamus in their brain is still underdeveloped and cannot release the hormones required to activate the gonads' gametes. Fertility in children before the ages of eight or nine is consi... | milkshake721/2.1M-wiki-STEM |
Infertility-Causes-Delayed puberty Delayed puberty, puberty absent past or occurring later than the average onset (between the ages of ten and fourteen), may be a cause of infertility. In the United States, girls are considered to have delayed puberty if they have not started menstruating by age 16 (alongside lacking b... | milkshake721/2.1M-wiki-STEM |
Infertility-Causes-Immune infertility Antisperm antibodies (ASA) have been considered as infertility cause in around 10–30% of infertile couples. In both men and women, ASA production are directed against surface antigens on sperm, which can interfere with sperm motility and transport through the female reproductive tr... | milkshake721/2.1M-wiki-STEM |
Infertility-Causes-Sexually transmitted infections Infections with the following sexually transmitted pathogens have a negative effect on fertility: Chlamydia trachomatis and Neisseria gonorrhoeae. There is a consistent association of Mycoplasma genitalium infection and female reproductive tract syndromes. M. genitaliu... | milkshake721/2.1M-wiki-STEM |
Infertility-Causes-Genetic Mutations to NR5A1 gene encoding steroidogenic factor 1 (SF-1) have been found in a small subset of men with non-obstructive male factor infertility where the cause is unknown. Results of one study investigating a cohort of 315 men revealed changes within the hinge region of SF-1 and no rare ... | milkshake721/2.1M-wiki-STEM |
Infertility-Causes-Other causes Factors that can cause male as well as female infertility are: DNA damage DNA damage reduces fertility in female ovocytes, as caused by smoking, other xenobiotic DNA damaging agents (such as radiation or chemotherapy) or accumulation of the oxidative DNA damage 8-hydroxy-deoxyguanosine D... | milkshake721/2.1M-wiki-STEM |
Infertility-Causes-General factors Diabetes mellitus, thyroid disorders, undiagnosed and untreated coeliac disease, adrenal disease Hypothalamic-pituitary factors Hyperprolactinemia Hypopituitarism The presence of anti-thyroid antibodies is associated with an increased risk of unexplained subfertility with an odds rati... | milkshake721/2.1M-wiki-STEM |
Infertility-Causes-Environmental factors Toxins such as glues, volatile organic solvents or silicones, physical agents, flame retardants, chemical dusts, polychlorinated biphenyls, and pesticides. Tobacco smokers are 60% more likely to be infertile than non-smokers.German scientists have reported that a virus called ad... | milkshake721/2.1M-wiki-STEM |
Infertility-Causes-Alimentary habitsObesity: Obesity can have a significant impact on male and female fertility. BMI (body mass index) may be a significant factor in fertility, as an increase in BMI in the male by as little as three units can be associated with infertility. Several studies have demonstrated that an inc... | milkshake721/2.1M-wiki-STEM |
Infertility-Causes-Low weight: Obesity is not the only way in which weight can impact fertility. Men who are underweight tend to have lower sperm concentrations than those who are at a normal BMI. For women, being underweight and having extremely low amounts of body fat are associated with ovarian dysfunction and infer... | milkshake721/2.1M-wiki-STEM |
Infertility-Causes-Females The following causes of infertility may only be found in females. | milkshake721/2.1M-wiki-STEM |
Infertility-Causes-For a woman to conceive, certain things have to happen: vaginal intercourse must take place around the time when an egg is released from her ovary; the system that produces eggs has to be working at optimum levels; and her hormones must be balanced.For women, problems with fertilization arise mainly ... | milkshake721/2.1M-wiki-STEM |
Infertility-Causes-Common causes of infertility of females include: ovulation problems (e.g. PCOS, the leading reason why women present to fertility clinics due to anovulatory infertility) tubal blockage pelvic inflammatory disease caused by infections like tuberculosis age-related factors uterine problems previous tub... | milkshake721/2.1M-wiki-STEM |
Infertility-Causes-Infertility associated with viable, but immotile sperm may be caused by primary ciliary dyskinesia. The sperm must provide the zygote with DNA, centrioles, and activation factor for the embryo to develop. A defect in any of these sperm structures may result in infertility that will not be detected by... | milkshake721/2.1M-wiki-STEM |
Infertility-Causes-Combined infertility In some cases, both the man and woman may be infertile or subfertile, and the couple's infertility arises from the combination of these conditions. In other cases, the cause is suspected to be immunological or genetic; it may be that each partner is independently fertile but the ... | milkshake721/2.1M-wiki-STEM |
Infertility-Causes-Unexplained infertility In the US, up to 20% of infertile couples have unexplained infertility. In these cases, abnormalities are likely to be present but not detected by current methods. Possible problems could be that the egg is not released at the optimum time for fertilization, that it may not en... | milkshake721/2.1M-wiki-STEM |
Infertility-Diagnosis-If both partners are young and healthy and have been trying to conceive for one year without success, a visit to a physician or women's health nurse practitioner (WHNP) could help to highlight potential medical problems earlier rather than later. The doctor or WHNP may also be able to suggest life... | milkshake721/2.1M-wiki-STEM |
Infertility-Treatment-Treatment depends on the cause of infertility, but may include counselling, fertility treatments, which include in vitro fertilization. According to ESHRE recommendations, couples with an estimated live birth rate of 40% or higher per year are encouraged to continue aiming for a spontaneous pregna... | milkshake721/2.1M-wiki-STEM |
Infertility-Treatment-Medical treatments Medical treatment of infertility generally involves the use of fertility medication, medical device, surgery, or a combination of the following. If the sperm is of good quality and the mechanics of the woman's reproductive structures are good (patent fallopian tubes, no adhesion... | milkshake721/2.1M-wiki-STEM |
Infertility-Treatment-In vitro fertilization IVF is the most commonly used ART. It has been proven useful in overcoming infertility conditions, such as blocked or damaged tubes, endometriosis, repeated IUI failure, unexplained infertility, poor ovarian reserve, poor or even nil sperm count.
Intracytoplasmic sperm injec... | milkshake721/2.1M-wiki-STEM |
Infertility-Treatment-Stem cell therapy Nowadays, there are several treatments (still in experimentation) related to stem cell therapy. It is a new opportunity, not only for partners with lack of gametes, but also for same-sex couples and single people who want to have offspring. Theoretically, with this therapy, we ca... | milkshake721/2.1M-wiki-STEM |
Infertility-Treatment-Spermatogonial stem cells transplant: it takes places in the seminiferous tubule. With this treatment, the patient experience spermatogenesis, and therefore, it has the chance to have offspring if he wants to. It is specially oriented for cancer patients, whose sperm is destroyed due to the gonado... | milkshake721/2.1M-wiki-STEM |
Infertility-Treatment-Ovarian stem cells: it is thought that women have a finite number of follicles from the very beginning. Nevertheless, scientists have found these stem cells, which may generate new oocytes in postnatal conditions. Apparently there are only 0.014% of them (this could be an explanation of why they w... | milkshake721/2.1M-wiki-STEM |
Infertility-Epidemiology-Prevalence of infertility varies depending on the definition, i.e. on the time span involved in the failure to conceive.
Infertility rates have increased by 4% since the 1980s, mostly from problems with fecundity due to an increase in age.
Fertility problems affect one in seven couples in the U... | milkshake721/2.1M-wiki-STEM |
Infertility-Epidemiology-Data on income-limited individuals, male infertility, and fertility within non-traditional families may be limited due to traditional social norms. Historical data on fertility and infertility is limited as any form of study or tracking only began in the early 20th century. Per one account, "Th... | milkshake721/2.1M-wiki-STEM |
Infertility-Society and culture-Perhaps except for infertility in science fiction, films and other fiction depicting emotional struggles of assisted reproductive technology have had an upswing first in the latter part of the 2000s decade, although the techniques have been available for decades. Yet, the number of peopl... | milkshake721/2.1M-wiki-STEM |
Infertility-Society and culture-High-cost treatments are out of financial reach for some couples.
Debate over whether health insurance companies (e.g. in the US) should be required to cover infertility treatment.
Allocation of medical resources that could be used elsewhere The legal status of embryos fertilized in vitr... | milkshake721/2.1M-wiki-STEM |
Infertility-Society and culture-One of the best known is the HFEA – The UK's regulator for fertility treatment and embryo research. This was set up on 1 August 1991 following a detailed commission of enquiry led by Mary Warnock in the 1980s A similar model to the HFEA has been adopted by the rest of the countries in th... | milkshake721/2.1M-wiki-STEM |
Allen Brain Atlas-Allen Brain Atlas-The Allen Mouse and Human Brain Atlases are projects within the Allen Institute for Brain Science which seek to combine genomics with neuroanatomy by creating gene expression maps for the mouse and human brain. They were initiated in September 2003 with a $100 million donation from P... | milkshake721/2.1M-wiki-STEM |
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