it coming now... so fast huh? any problems? want to share?
just drop a few words here okay...
Tuesday, July 21, 2009
Saturday, June 27, 2009
Electicity & Magnetism
The most important thing about this topic is your ability to differentiate parallel circuit and seriel circuit. any prob?
Monday, April 13, 2009
April.....
Hello boys and girls... any problem so far? Want to share?...
Feel free to share any doubts you have regarding science form 1 up to
science form 3
Feel free to share any doubts you have regarding science form 1 up to
science form 3
Thursday, March 19, 2009
Objectives of the folio
The objectives of doing this folio are:
a) To investigate in detail the factors of infertility in humans
b) To study the technology advancement in overcoming infertility in humans
c) To cultivate creative and critical thinking skills among students
d) To expose students to using computer and internet to complete a given task
e) To instill nobel values when conducting investigation
(Guys, you'll can add more if you have any :D)
GOOd LucK!!!!!
a) To investigate in detail the factors of infertility in humans
b) To study the technology advancement in overcoming infertility in humans
c) To cultivate creative and critical thinking skills among students
d) To expose students to using computer and internet to complete a given task
e) To instill nobel values when conducting investigation
(Guys, you'll can add more if you have any :D)
GOOd LucK!!!!!
Tuesday, March 17, 2009
artificial insemination
Artificial insemination is the placement of sperm into a woman’s reproductive tract by other than natural means. The sperm is most often placed in the uterus (intrauterine insemination) or in the cervix (intracervical insemination).
Couples with fertility issues may benefit from artificial insemination. It may be recommended for numerous fertility problems, including low sperm count, impotence, poor interaction between sperm and cervical mucus, endometriosis and unexplained infertility. In these cases, the sperm can be collected and prepared in a way that allows it to be placed into the woman’s reproductive tract. The procedure is typically performed when the woman is ovulating. A number of methods may be used to determine the time of ovulation, including an ovulation test, basal body temperature chart and a cervical mucus examination.
For couples, the cause of infertility must be diagnosed before the procedure is performed. The male’s sperm is analyzed to determine if it is suitable for insemination. Blood tests and ultrasounds may be performed on the woman to determine if she is ovulating normally. For women with irregular ovulation patterns, drugs are frequently used to induce ovulation prior to artificial insemination.
In some cases, the male partner’s sperm cannot be used for insemination. In these situations, a donor’s sperm can be used. Donor sperm is saved and frozen and is available from sperm banks around the country. The donors are tested for infectious diseases and screened for certain genetic diseases. This option may also be recommended for women without a male partner who wish to become pregnant.
The American Society for Reproductive Medicine estimates that the success rate of artificial insemination may be as high as 15 percent each cycle. Although success rates are higher for other forms of fertility treatments, artificial insemination is often one of the first methods used. It is less invasive and less expensive then more complex procedures, such as in vitro fertilization.
For couples, the cause of infertility must be diagnosed before the procedure is performed. The male’s sperm is analyzed to determine if it is suitable for insemination. Blood tests and ultrasounds may be performed on the woman to determine if she is ovulating normally. For women with irregular ovulation patterns, drugs are frequently used to induce ovulation prior to artificial insemination.
In some cases, the male partner’s sperm cannot be used for insemination. In these situations, a donor’s sperm can be used. Donor sperm is saved and frozen and is available from sperm banks around the country. The donors are tested for infectious diseases and screened for certain genetic diseases. This option may also be recommended for women without a male partner who wish to become pregnant.
The American Society for Reproductive Medicine estimates that the success rate of artificial insemination may be as high as 15 percent each cycle. Although success rates are higher for other forms of fertility treatments, artificial insemination is often one of the first methods used. It is less invasive and less expensive then more complex procedures, such as in vitro fertilization.
Overcoming Infertility
Infertility is hard to pin down. A couple with no known reproductive problems might try for years to have a baby but fail simply because their timing was off. Are they infertile? Not physically, but they would be classified as such because infertility is usually defined as the inability to conceive after 1 year of unprotected sex.
Types of Infertility
Hypofertile couples have trouble conceiving quickly. Their fertility may be less than ideal or they may be having problems with timing, but they can eventually conceive without special treatment. For example, the man might have a low sperm count, or the woman might have endometriosis—roadblocks, but not brick walls. Sterile couples won't be able to conceive without medical or surgical treatment. For example, the man might not create enough sperm to fertilize an egg, or the woman might have blocked fallopian tubes.
Infertility's Many Causes
A poorly functioning male reproductive system is the problem for 30 to 40 percent of couples seeking help for infertility. The man may have a low sperm count, sperm that move too slowly through the female reproductive system (low motility), semen that is too thick, or not enough of it.
Another 30 to 40 percent of fertility problems are caused by a malfunction in the female system. The most common, accounting for between 10 and 15 percent of all infertility, is the inability to release a healthy egg into the fallopian tube. Other problems include endometriosis, infection, or blocked tubes. In a significant percentage of couples (10 to 15 percent), sperm are unable to penetrate the mucus that lines the cervical canal leading to the uterus. About 10 percent of couples who seek help for infertility never learn the cause of their problem. Most turn out to be hypofertile and eventually do have children.
One important factor responsible for infertility in women is simply aging. Women tend to be most fertile in their early 20s. From then on, fertility declines rather slowly until about age 35, after which it becomes harder and harder to become pregnant. One in 7 couples is infertile if the woman is 30 to 34 years old; 1 in 5 is infertile if she is 35 to 40; and 1 in 4 can't conceive if she's 40 to 44.
Methods of Overcoming Infertility
Since the possible causes of female infertility are so varied and numerous, treatment may sometimes be difficult, and it may involve a great number of different measures from hormone replacement to surgery. In any case, in recent decades an increasing number of formerly hopeless fertility problems have been overcome thanks to remarkable medical advances. They are known under the collective terms "artificial insemination" and "assisted reproductive technology".
Types of Infertility
Hypofertile couples have trouble conceiving quickly. Their fertility may be less than ideal or they may be having problems with timing, but they can eventually conceive without special treatment. For example, the man might have a low sperm count, or the woman might have endometriosis—roadblocks, but not brick walls. Sterile couples won't be able to conceive without medical or surgical treatment. For example, the man might not create enough sperm to fertilize an egg, or the woman might have blocked fallopian tubes.
Infertility's Many Causes
A poorly functioning male reproductive system is the problem for 30 to 40 percent of couples seeking help for infertility. The man may have a low sperm count, sperm that move too slowly through the female reproductive system (low motility), semen that is too thick, or not enough of it.
Another 30 to 40 percent of fertility problems are caused by a malfunction in the female system. The most common, accounting for between 10 and 15 percent of all infertility, is the inability to release a healthy egg into the fallopian tube. Other problems include endometriosis, infection, or blocked tubes. In a significant percentage of couples (10 to 15 percent), sperm are unable to penetrate the mucus that lines the cervical canal leading to the uterus. About 10 percent of couples who seek help for infertility never learn the cause of their problem. Most turn out to be hypofertile and eventually do have children.
One important factor responsible for infertility in women is simply aging. Women tend to be most fertile in their early 20s. From then on, fertility declines rather slowly until about age 35, after which it becomes harder and harder to become pregnant. One in 7 couples is infertile if the woman is 30 to 34 years old; 1 in 5 is infertile if she is 35 to 40; and 1 in 4 can't conceive if she's 40 to 44.
Methods of Overcoming Infertility
Since the possible causes of female infertility are so varied and numerous, treatment may sometimes be difficult, and it may involve a great number of different measures from hormone replacement to surgery. In any case, in recent decades an increasing number of formerly hopeless fertility problems have been overcome thanks to remarkable medical advances. They are known under the collective terms "artificial insemination" and "assisted reproductive technology".
PEKA Folio
Both women and men have hormonal cycles which determine both when a woman can achieve pregnancy and when a man is most virile. The female cycle is approximately twenty-eight days long, but the male cycle is variable. Men can ejaculate and produce sperm at any time of the month, but their sperm quality dips occasionally, which scientists guess is in relation to their internal cycle.
Furthermore, age also plays a role, especially for women.
[edit] Menstrual cycle
Main article: Menstrual cycle
Although women can become pregnant at any time during their menstrual cycle, peak fertility occurs during just a few days of the cycle: usually two days before and two days after the ovulation date[3]. This fertile window, varies between from woman to woman, just like the ovulation date often varies from cycle to cycle for the same woman[4]. The ovule is usually fertilisable for up to 48 hours after it is released from the ovary. However, sperm can survive inside the uterus between 48 to 72 hours on average, with the maximum being 120 hours (5 days).
[edit] Female fertility
The average age of menarche in the United States is about 12.5 years.[5] In postmenarchal girls, about 80% of the cycles were anovulatory in the first year after menarche, 50% in the third and 10% in the sixth year.[6][7] Women's fertility peaks around the age of 19-24, and often declines after 30.[citation needed] With a rise in women postponing pregnancy,[8] this can create an infertility problem. Of women trying to get pregnant, without using fertility drugs or in vitro fertilization:
At age 30, 75% will get pregnant within one year, and 91% within four years.
At age 35, 66% will get pregnant within one year, and 84% within four years.
At age 40, 44% will get pregnant within one year, and 64% within four years.[9]
The above figures are for pregnancies ending in a live birth and take into account the increasing rates of miscarriage in the aging population. According to the March of Dimes, "about 9 percent of recognised pregnancies for women aged 20 to 24 ended in miscarriage. The risk rose to about 20 percent at age 35 to 39, and more than 50 percent by age 42".[10]
Birth defects, especially those involving chromosome number and arrangement, also increase with the age of the mother. According to the March of Dimes, "At age 25, a woman has about a 1-in-1,250 chance of having a baby with Down syndrome; at age 30, a 1-in-1,000 chance; at age 35, a 1-in-400 chance; at age 40, a 1-in-100 chance; and at 45, a 1-in-30 chance."[11]
The use of fertility drugs and/or invitro fertilization can increase the chances of becoming pregnant at a later age. Successful pregnancies facilitated by fertility treatment have been documented in women as old as 67.[12]
Doctors recommend that women over 30 who have been unsuccessful in trying to conceive for more than 6 months undergo some kind of fertility testing.[13]
[edit] Male fertility and age
Erectile dysfunction increases with age,[14] but fertility does not decline in men as sharply as it does in women. There have been examples of males being fertile at 94 years old.[14] However, evidence suggests that increased male age is associated with a decline in semen volume, sperm motility, and sperm morphology.[15] In studies that controlled for female age, comparisons between men under 30 and men over 50 found relative decreases in pregnancy rates between 23% and 38%.[15]
[edit] Cause of decline
Sperm count declines with age, with men aged 50-80 years producing sperm at an average rate of 75% compared with men aged 20-50 years. However, an even larger difference is seen in how many of the seminiferous tubules in the testes contain mature sperm;
In males 20-39 years old, 90% of the seminiferous tubules contain mature sperm.
In males 40-69 years old, 50% of the seminiferous tubules contain mature sperm.
In males 80 years old and older, 10% of the seminiferous tubules contain mature sperm.[14]
Recent research has suggested increased risks for health problems for children of older fathers. A large scale Israeli study found that the children of men 40 or older were 5.75 times more likely than children of men under 30 to have an autism spectrum disorder, controlling for year of birth, socioeconomic status, and maternal age.[16] Increased paternal age has also been correlated to schizophrenia in numerous studies.[17][18] [19]
The American Fertility Society recommends an age limit for sperm donors of 50 years or less,[20] and many fertility clinics in the United Kingdom will not accept donations from men over 40 or 45 years of age. [21] In part because of this fact, more women are now using a take-home baby rate calculator to estimate their chances of success following invitro fertilization. [22]
Furthermore, age also plays a role, especially for women.
[edit] Menstrual cycle
Main article: Menstrual cycle
Although women can become pregnant at any time during their menstrual cycle, peak fertility occurs during just a few days of the cycle: usually two days before and two days after the ovulation date[3]. This fertile window, varies between from woman to woman, just like the ovulation date often varies from cycle to cycle for the same woman[4]. The ovule is usually fertilisable for up to 48 hours after it is released from the ovary. However, sperm can survive inside the uterus between 48 to 72 hours on average, with the maximum being 120 hours (5 days).
[edit] Female fertility
The average age of menarche in the United States is about 12.5 years.[5] In postmenarchal girls, about 80% of the cycles were anovulatory in the first year after menarche, 50% in the third and 10% in the sixth year.[6][7] Women's fertility peaks around the age of 19-24, and often declines after 30.[citation needed] With a rise in women postponing pregnancy,[8] this can create an infertility problem. Of women trying to get pregnant, without using fertility drugs or in vitro fertilization:
At age 30, 75% will get pregnant within one year, and 91% within four years.
At age 35, 66% will get pregnant within one year, and 84% within four years.
At age 40, 44% will get pregnant within one year, and 64% within four years.[9]
The above figures are for pregnancies ending in a live birth and take into account the increasing rates of miscarriage in the aging population. According to the March of Dimes, "about 9 percent of recognised pregnancies for women aged 20 to 24 ended in miscarriage. The risk rose to about 20 percent at age 35 to 39, and more than 50 percent by age 42".[10]
Birth defects, especially those involving chromosome number and arrangement, also increase with the age of the mother. According to the March of Dimes, "At age 25, a woman has about a 1-in-1,250 chance of having a baby with Down syndrome; at age 30, a 1-in-1,000 chance; at age 35, a 1-in-400 chance; at age 40, a 1-in-100 chance; and at 45, a 1-in-30 chance."[11]
The use of fertility drugs and/or invitro fertilization can increase the chances of becoming pregnant at a later age. Successful pregnancies facilitated by fertility treatment have been documented in women as old as 67.[12]
Doctors recommend that women over 30 who have been unsuccessful in trying to conceive for more than 6 months undergo some kind of fertility testing.[13]
[edit] Male fertility and age
Erectile dysfunction increases with age,[14] but fertility does not decline in men as sharply as it does in women. There have been examples of males being fertile at 94 years old.[14] However, evidence suggests that increased male age is associated with a decline in semen volume, sperm motility, and sperm morphology.[15] In studies that controlled for female age, comparisons between men under 30 and men over 50 found relative decreases in pregnancy rates between 23% and 38%.[15]
[edit] Cause of decline
Sperm count declines with age, with men aged 50-80 years producing sperm at an average rate of 75% compared with men aged 20-50 years. However, an even larger difference is seen in how many of the seminiferous tubules in the testes contain mature sperm;
In males 20-39 years old, 90% of the seminiferous tubules contain mature sperm.
In males 40-69 years old, 50% of the seminiferous tubules contain mature sperm.
In males 80 years old and older, 10% of the seminiferous tubules contain mature sperm.[14]
Recent research has suggested increased risks for health problems for children of older fathers. A large scale Israeli study found that the children of men 40 or older were 5.75 times more likely than children of men under 30 to have an autism spectrum disorder, controlling for year of birth, socioeconomic status, and maternal age.[16] Increased paternal age has also been correlated to schizophrenia in numerous studies.[17][18] [19]
The American Fertility Society recommends an age limit for sperm donors of 50 years or less,[20] and many fertility clinics in the United Kingdom will not accept donations from men over 40 or 45 years of age. [21] In part because of this fact, more women are now using a take-home baby rate calculator to estimate their chances of success following invitro fertilization. [22]
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