5 elements

Rhenium

Rhenium was discovered by the German chemists Ida Tacke-Noddack, Walter Noddack and Otto Carl Berg in 1925. Rhenium was discovered in Germany.Rhenium is used in flash lamps for photography and for filaments in mass spectrographs and ion gages, but is most frequently used as an alloying agent in tungsten and molybdenum and as a catalyst for performing certain reactions to a type of hydrocarbon known as an olefin.
Interesting facts:

• Symbol based on the coat of arms of the Rhine League which regulated trade in the Middle Ages in that area.
• A metal with a very high melting point, second only to tungsten. It is usually available as a grey powder and is among the rarest metals on Earth. Rhenium is used in filaments and for catalysts in the chemicals industry.
• Melting point: 3185 ^oC, 5765 ^oF, 3458.15 K
• Rhenium has no known biological role
• Rhenium does not occur uncombined in nature or as a compound in a mineral species

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Osmium

Osmium was discovered by a  British chemist named Smithson Tennant in 1803. It was discovered in United Kingdom. Osmium tetroxide smells bad and is very poisonous. Because of these problems, osmium is primarily used to make very hard alloys for fountain pen tips, instrument pivots, needles and electrical contacts.
Interesting facts:

• Osmium metal is found only in a limited number of locations in the world
• Osmium is found in the mineral iridosmine (Os, Ir) and in platinum bearing river sands of the Urals, and North and South America
• the metal is a lustrous, bluish white, color and also, is extremely hardremains brittle even at high temperatures that begin to approach the melting point
• member of the six element "platinum group", and among those elements, it has the highest melting point yet the lowest vapor pressure
• Osmium tetroxide is highly toxic and can cause lung congestion, skin damage, or eye damage

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Iridium

A British chemist named Smithson Tennant discovered iridium in 1803 in the United Kingdom. Pure iridium is very brittle and is nearly impossible to machine. It is primarily used as a hardening agent for platinum. Platinum-iridium alloys are used to make crucibles and other high temperature equipment. Iridium is also alloyed with osmium to make the tips of fountain pens and compass bearings.
Interesting facts:

• Iridium is considered to be of low toxicity.
• Iridium in powder form is a known irritant and is a fire hazard
• Iridium is a rare, hard, lustrous, brittle, very dense platinum-like metal.

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Tungsten

Tungsten was discovered by Juan José and Fausto Elhuyar, Spanish chemists and brothers, in 1783 in samples of the mineral wolframite. Tungsten was discovered in Spain. Tungsten has the highest melting point of all metallic elements and is used to make filaments for incandescent light bulbs, fluorescent light bulbs and television tubes.
Interesting facts:

•  has an excellent corrosion resistance and is not attacked easily by most mineral acids, so it is used a lot for glass-to-metal seals.
• Tungsten carbide is very important to the metal-working, mining, and petroleum industries

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Tantalum

Tantalum was discovered by Anders Gustaf Ekenberg, a Swedish chemist, in 1802 in minerals obtained from Ytterby, Sweden. Tantalum is used to make components for chemical plants, nuclear power plants, airplanes and missiles. It can be drawn into a fine wire that is used to evaporate metals, such as aluminum. It has a high melting point and is frequently used as a substitute for platinum, which is more expensive.
interesting facts:

• It is highly corrosion-resistant
• It is easily fabricated and a good conductor of heat and electricity

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Technology and Reproduction

 

Assisted Reproductive Technologies in Canada

 

Assisted reproductive technologies are infertility treatments that involve fertility drugs and the management of eggs, sperm, and/or embryos outside of the human body. This typically includes IVF and IVF- related procedures such as intracytoplasmic sperm injection. Some definitions also include intrauterine insemination.⁵

 

Conventional IVF treatment involves the stimulation of the ovaries using hormonal medications, the retrieval of eggs from the ovaries, the fertilization of the eggs outside the body, and the transfer of the resulting embryo into the uterus

 

http://www.cadth.ca/products/environmental-scanning/health-technology-update/issue-10-september-2008/assisted-reproductive

 



In Vitro Fertilization (IVF)

 

Sperm Donation
The first regulation of reproductive technologies in Canada was for the donation of semen samples for use in artificial insemination or in vitro fertilization. In 1996, the Semen Regulations (The Processing and Distribution of Semen for Assisted Conception Regulations) of the Food and Drugs Act were issued, and were updated in March 2000.

Semen donors are usually anonymous and undergo rigorous screening for medical and genetic diseases and for all sexually transmitted and other infectious diseases, including AIDS and hepatitis. All donations must be quarantined for six months and the donor re-tested at this time to ensure samples are negative for the viruses that lead to those diseases. The Semen Regulations also stipulate that if a donated sample has a high white blood cell count, it must be destroyed, as this is often indicative of a viral or bacterial infection.

http://www.parl.gc.ca/Content/LOP/researchpublications/prb0035-e.htm


Egg Donation
Egg donation is a product of in vitro fertilization (IVF) technology. In IVF, multiple eggs are stimulated to grow via hormone therapy (controlled ovarian hyperstimulation) and are then harvested from the woman. Retrieval of the eggs requires sedation as they are removed vaginally with the use of a needle. The mature eggs are subsequently fertilized outside of the body and allowed to grow for a few days. The resulting embryos are then inserted into the uterus (a maximum of three, usually) and will be followed by implantation and pregnancy if the procedure is successful.

The egg harvesting technique developed for IVF has subsequently been used for the donation of eggs, in the same way as sperm has been used for donation purposes for decades. Donated eggs, from either known or anonymous donors, can be used to overcome infertility in women who: lack ovaries; have diminished ovarian function; or have a genetic disease or a history of genetic disease.
http://www.parl.gc.ca/Content/LOP/researchpublications/prb0035-e.htm

Gamete Intrafallopian Transfer (GIFT)
GIFT is similar to IVF. The woman's ovaries are stimulated to produce more eggs than usual, the eggs are collected, and the man needs to produce sperm (although donor sperm can be used). When egg collection has taken place, two eggs are mixed together with the sperm in a dish.

The main difference from IVF is that with GIFT the gametes (eggs and sperm) are immediately transferred to the woman's fallopian tubes, so fertilisation occurs inside, not outside, the woman's body. The embryo can begin its earliest development in natural surroundings rather than in an artificial environment.

Read more: http://www.babycenter.ca/preconception/fertilitytreatments/gift/#ixzz29ZRGAbe2


Zygote Intrafallopian Transfer (ZIFT)
ZIFT (Zygote Intrafallopian Transfer) is a similar procedure to GIFT, except that it is the newly fertilised egg (zygote) which is returned to the woman's fallopian tubes rather than the mixture of eggs and sperm.

This procedure shares the advantage of GIFT in that any resulting embryo will immediately be able to develop in the natural surroundings of your body. However, it's a much more invasive process than GIFT, involving two procedures instead of one: egg retrieval and then a separate laparoscopy to insert the embryo

Read more: http://www.babycenter.ca/preconception/fertilitytreatments/gift/#ixzz29ZSjDV8p


Tubal Embryo Transfer
Eggs are extracted from the woman in the same way as IVF, GIFT and other fertility procedures. They are placed in a Petri dish (culture dish used in a laboratory) along with sperm and allowed to fertilise. This usually takes a couple of days.

The next stage is the insertion of the embryos into the fallopian tubes. This is performed as a laparoscopy and involves making a small incision in the abdominal area before inserting a slim tube with a camera attached. This camera gives the specialist a clear view of the fallopian tubes.

http://www.medic8.com/healthguide/infertility/infertility-treatment/tubal-embryo-transfer.html

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Puberty around the world

How is puberty observed around the world?

Puberty

The period during which the secondary sex characteritics begin to develop and the capability of sexual reproduction is attained.

 

http://www.biology-online.org/dictionary/Puberty

 

First Nations

The manner in which she acted during her first menstrual blood flow was believed to bestow good or bad luck on the rest of her life and the lives of her relatives. To insure good luck certain rituals were observed. Proper conduct compelled young girls to remain in the same spot once their menarche started. If the girl was walking and detected her flow she could be obligated to wait in the cold until someone found her. With good reason young girls, around the age of puberty, would always dress appropriately for the weather in fear of unexpectedly beginning her menstrual flow. Once found, a close male relative of the father's moiety (opposite of the girl's societal clan) would build her a brush hut away from camp where she lived alone for several weeks, or if from a wealthy or distinguished family, she could remain there for upwards of a year or two. Women, such as her mother, aunts or cousins would visit to bring food, help with rituals and to ensure that procedures were being observed.

http://www.yukonmuseums.ca/treasures/km/01.html


Islam

Islam sets out no rites for puberty per se. But there is a series of actions beginning around age seven that lead children towards their gender-based, adult roles in Moslem society. Boys, for example, will begin to attend public prayers with the men and girls will start to focus their activities more on the home and the family. This division of roles is traditional, and in the modern era is undergoing transformation in different countries around the world.

http://uwacadweb.uwyo.edu/religionet/er/islam/islife.htm


Uaupes of Brazil

When a girl reaches puberty and her menstrual cycle starts it is her step forward into womanhood. In many countries it is celebrated over a period of days and often involves physical beatings. In the Uaupes people of Brazil the ritual of the menses includes house seclusion of the girl for one month with only bread and water. Once the seclusion is complete the girl is brought out naked and beat with sticks by family and friends until she is either dead or blacks out. Once the girl wakes up, if she does, the beating is repeated four times. After the fourth beating the sticks used to beat her with are dipped into pots of fat and given to the girl to lick for nourishment. She is now considered a woman and worthy of marriage.

http://akorra.com/2010/10/10/top-10-odd-puberty-rituals/


Jewish

When a Jewish girl reached the age of puberty, she was called, in Hebrew, betulah. This word defined her as an adolescent girl who had reached puberty but not yet given birth to her first child. It is sometimes translated as ‘virgin’, but in fact it related more to her age group than her physical state.

During her menstrual period, a Jewish woman was relieved of many of her normal duties. She was not required to draw and carry water from the well. She did not have to serve food to members of the family. She did not have to go to the marketplace. She did not have sexual intercourse. The days of her menstrual period were regarded as a time out, a time for herself. On these days, relieved of a number of her duties, she had time to think and rest.

http://www.womeninthebible.net/3.2.Major_Events.htm


Muslim

When the child reaches puberty, he becomes fully accountable for his deeds in front of Allah (SWT). It is first and foremost the responsibility of the parents to carry this message to the child.  The parents of the adolescent boy should inform him that the first time he ejaculates he becomes accountable for his actions in front of Allah (SWT), and he should perform the acts of worship in the same way that adult Muslims do.
When the girl is about nine years old, her parents should inform her that the first time she sees blood (menstruation), she becomes accountable for her acts and the worship acts prescribed on the Muslim women are also prescribed on her.

http://www.missionislam.com/family/puberty.htm




http://www.youtube.com/watch?v=GRe_-AhgfWU&feature=related