Parents of newborns know that they will not get much sleep, especially during
the first three or four months after birth. But now, University of Haifa
researchers claim that there is another period of sleeplessness – when the baby
starts to crawl – that lasts for about another three months.
Cohen of the university’s human development department, supervised by Prof. Anat
Sher, studied the sleeping habits of 28 healthy babies with normal development,
aged from four to 11 months. They were monitored by a device called Actigraph
that is able to give objective data on sleep habits. The parents also filled out
questionnaires and were interviewed. Video cameras were used to follow the
babies’ crawling activity, which began – on average – when they were seven
Before the babies began to crawl, they woke up an average of
1.55 times a night, but when they got about on their hands and knees, they
awakened 1.98 times per night. This change occurred more among babies who
learned to crawl earlier than other babies their age and among those who learned
later than usual, compared to babies with normal development. But the good news
for parents is that the irregular sleeping caused by crawling ability will end
three months later.
The researchers have a number of possible
explanations for this phenomenon.
“It may be that crawling, which is
connected to many changes involved in development and renewed psychological
organization, raises the level of wakefulness and causes a period of instability
that presents itself as waking up from sleep,” said Cohen. Another explanation
is that crawling may cause anxiety in the child, who is exposed to new
surroundings and can be physically separated from its mother at a time when its
psychological resilience has not yet developed. “This anxiety can be expressed
in irregular sleep patterns at night,” said Cohen.
Is homosexuality genetic? It’s a long-running debate. Now
researchers at the University of Tennessee at Knoxville say they’ve found a clue
that may unlock the mystery. It lies in epigenetics – how gene expression is
regulated by temporary switches.
The researchers used mathematical
modeling that found transmission of sex-specific “epi-marks” may signal
homosexuality. Epi-marks constitute an extra layer of information attached to
our genes’ “backbones,” that regulates their expression.
While genes hold
the instructions, epi-marks direct how those instructions are carried out. They
are usually produced anew each generation, but recent evidence demonstrates that
they sometimes carry over between generations.
According to the study,
published recently in The Quarterly Review of Biology, sex-specific epi-marks,
which are “erased” and thus normally do not pass between generations, can lead
to homosexuality when they “escape erasure” and are transmitted from father to
daughter or mother to son.
“Previous studies have shown that
homosexuality runs in families, leading most researchers to presume a genetic
underpinning of sexual preference,” said Prof.
Sergey Gavrilets, a
co-author of the paper. “However, no major gene for homosexuality has been found
despite numerous studies searching for a genetic connection.”
that epi-marks may be the trigger they’ve been searching
Sex-specific epi-marks produced in early fetal development protect
each sex from the substantial natural variation in testosterone that occurs
during later fetal development.
Different epi-marks protect different
sex-specific traits from being masculinized or feminized.
found homosexuality can occur in opposite-sex offspring when the sex-specific
epimarks are carried on to another generation.
“We discovered [that] when
these epi-marks are transmitted across generations from fathers to daughters or
mothers to sons, they may cause reversed effects, such as the feminization of
some traits in sons, such as sexual preference and, similarly a partial
masculinization of daughters,” said Gavrilets. “The study solves the
evolutionary riddle of homosexuality, finding that ‘sexually antagonistic’
epi-marks, which normally protect parents from natural variation in sex hormone
levels during fetal development, sometimes carry over across generations and
cause homosexuality in opposite- sex offspring,” he explained.
mathematical modeling demonstrates that gene coding for these epi-marks can
easily spread in the population because they always increase the fitness of the
parent but only rarely escape erasure and reduce fitness in offspring.
“Transmission of sexually antagonistic epimarks between generations is the most
plausible evolutionary mechanism of the phenomenon of human homosexuality,” said
About 70 new immigrant physicians are joining
the heath system – a help given the current serious shortage of MDs. The
Immigrant Absorption Ministry has been working on a special project to encourage
the immigration of Jewish physicians from the Diaspora. The doctors are given
help in obtaining their medical licenses, learning regular and professional
Hebrew and finding an employer. Once they are hired, the ministry pays the
doctors’ first monthly paycheck.
ASPARAGUS FOR HANGOVER?
You should never
drink too much alcohol, but if you do, asparagus extract may help with the
According to a study published in the Journal of Food Science,
the amino acids and minerals found in the vegetable may alleviate alcohol
hangovers and protect liver cells against toxins.
analyzed the components of young asparagus shoots and leaves to compare their
biochemical effects on human and rat liver cells.
“The amino acid and
mineral contents were found to be much higher in the leaves than the shoots,”
says lead researcher B.Y. Kim.
Chronic alcohol use causes oxidative
stress on the liver as well as the unpleasant physical effects associated with
“Cellular toxicities were significantly alleviated in response
to treatment with the extracts of asparagus leaves and shoots,” said Kim. “These
results provide evidence of how the biological functions of asparagus can help
alleviate alcohol hangover and protect liver cells.”
Asparagus has long
been used as an herbal medicine due to its claimed anti-cancer effects; it also
is believed to have antifungal, anti-inflammatory and diuretic properties.
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