Search This Blog

Friday, September 6, 2024

Mother

From Wikipedia, the free encyclopedia
https://en.wikipedia.org/wiki/Mother
Portrait of a woman holding her young child, c. 1900 – c. 1920
Statue of a mother with children at the Monumental Cemetery of Staglieno in Genoa

A mother is the female parent of a child. A woman may be considered a mother by virtue of having given birth, by raising a child who may or may not be her biological offspring, or by supplying her ovum for fertilisation in the case of gestational surrogacy.

A biological mother is the female genetic contributor to the creation of the infant, through sexual intercourse or egg donation. A biological mother may have legal obligations to a child not raised by her, such as an obligation of monetary support. An adoptive mother is a female who has become the child's parent through the legal process of adoption. A putative mother is a female whose biological relationship to a child is alleged but has not been established. A stepmother is a non-biological female parent married to a child's preexisting parent, and may form a family unit but generally does not have the legal rights and responsibilities of a parent in relation to the child.

A father is the male counterpart of a mother. Women who are pregnant may be referred to as expectant mothers or mothers-to-be. The process of becoming a mother has been referred to as "matrescence".

The adjective "maternal" refers to a mother and comparatively to "paternal" for a father. The verb "to mother" means to procreate or to sire a child, or to provide care for a child, from which also derives the noun "mothering". Related terms of endearment are mom (mama, mommy), mum (mummy), mumsy, mamacita (ma, mam) and mammy. A female role model that children can look up to is sometimes referred to as a mother-figure.

Types of motherhood

Map of countries by crude birth rate
Map of countries by fertility rate
Mother and child. Gandola Monastery, Lahaul, India.

Biological mother

Biological motherhood for humans, as in other mammals, occurs when a pregnant female gestates a fertilized ovum (the "egg"). A female can become pregnant through sexual intercourse after she has begun to ovulate. In well-nourished girls, menarche (the first menstrual period) usually takes place around the age of 12 or 13.

Typically, a fetus develops from the viable zygote, resulting in an embryo. Gestation occurs in the woman's uterus until the fetus (assuming it is carried to term) is sufficiently developed to be born. In humans, gestation is often around 9 months in duration, after which the woman experiences labor and gives birth. This is not always the case, however, as some babies are born prematurely, late, or in the case of stillbirth, do not survive gestation. Usually, once the baby is born, the mother produces milk via the lactation process. The mother's breast milk is the source of antibodies for the infant's immune system, and commonly the sole source of nutrition for newborns before they are able to eat and digest other foods; older infants and toddlers may continue to be breastfed, in combination with other foods, which should be introduced from approximately six months of age.

Childlessness is the state of not having children. Childlessness may have personal, social or political significance. Childlessness may be voluntary childlessness, which occurs by choice, or may be involuntary due to health problems or social circumstances. Motherhood is usually voluntary, but may also be the result of forced pregnancy, such as pregnancy from rape. Unwanted motherhood occurs especially in cultures which practice forced marriage and child marriage.

Non-biological mother

Mother can often apply to a woman other than the biological parent, especially if she fulfills the main social role in raising the child. This is commonly either an adoptive mother or a stepmother (the biologically unrelated partner of a child's father). The term "othermother" or "other mother" is also used in some contexts for women who provide care for a child not biologically their own in addition to the child's primary mother.

Adoption, in various forms, has been practiced throughout history, even predating human civilization. Modern systems of adoption, arising in the 20th century, tend to be governed by comprehensive statutes and regulations. In recent decades, international adoptions have become more and more common.

Adoption in the United States is common and relatively easy from a legal point of view (compared to other Western countries). In 2001, with over 127,000 adoptions, the US accounted for nearly half of the total number of adoptions worldwide.

Surrogate mother

Main article: Surrogacy

A surrogate mother is a woman who bears a child that came from another woman's fertilized ovum on behalf of a couple unable to give birth to children. Thus the surrogate mother carries and gives birth to a child that she is not the biological mother of. Surrogate motherhood became possible with advances in reproductive technologies, such as in vitro fertilization.

Not all women who become pregnant via in vitro fertilization are surrogate mothers. Surrogacy involves both a genetic mother, who provides the ovum, and a gestational (or surrogate) mother, who carries the child to term.

Lesbian and bisexual motherhood

The possibility for lesbian and bisexual women in same-sex relationships to become mothers has increased over the past few decades due to technological developments. Modern lesbian parenting originated with women who were in heterosexual relationships who later identified as lesbian or bisexual, as changing attitudes provided more acceptance for non-heterosexual relationships. Other ways for such women to become mothers is through adopting, foster parenting or in vitro fertilization.

Transgender motherhood

This section is about transgender women who are parents. For pregnancy in transgender men and nonbinary people, see Transgender pregnancy.

Transgender women may have biological children with a partner by utilizing their sperm to fertilize an egg and form an embryo. For transgender women, there is currently no accessible way to carry a child. However, research is being done on uterus transplants, which could potentially allow transgender women to carry and give birth to children through Caesarean section. Other types of motherhood include adoption or foster parenting. However, adoption agencies often refuse to work with transgender parents or are reluctant to do so.

Social role

See also: Sociology of the family § Sociology of motherhood
Sikkimese mother with child
Percentage of births to unmarried women, selected countries, 1980 and 2007
Mother and children (Mahabalipuram, India)

The social roles associated with motherhood are variable across time, culture, and social class. Historically, the role of women was confined to some extent to being a mother and wife, with women being expected to dedicate most of their energy to these roles, and to spend most of their time taking care of the home. In many cultures, women received significant help in performing these tasks from older female relatives, such as mothers in law or their own mothers.

Olga Pearson Engdahl was American Mother of the Year in 1963.

Regarding women in the workforce, mothers are said to often follow a "mommy track" rather than being entirely "career women". Mothers may be stay at home mothers or working mothers. In recent decades there has been an increase in stay at home fathers too. Social views on these arrangements vary significantly by culture: in Europe for instance, in German-speaking countries there is a strong tradition of mothers exiting the workforce and being homemakers. Mothers have historically fulfilled the primary role in raising children, but since the late 20th century, the role of the father in child care has been given greater prominence and social acceptance in some Western countries. The 20th century also saw more and more women entering paid work. Mothers' rights within the workforce include maternity leave and parental leave.

The social role and experience of motherhood varies greatly depending upon location. Mothers are more likely than fathers to encourage assimilative and communion-enhancing patterns in their children. Mothers are more likely than fathers to acknowledge their children's contributions in conversation. The way mothers speak to their children ("motherese") is better suited to support very young children in their efforts to understand speech (in context of the reference English) than fathers.

Since the 1970s, in vitro fertilization has made pregnancy possible at ages well beyond "natural" limits, generating ethical controversy and forcing significant changes in the social meaning of motherhood. This is, however, a position highly biased by Western world locality: outside the Western world, in-vitro fertilization has far less prominence, importance or currency compared to primary, basic healthcare, women's basic health, reducing infant mortality and the prevention of life-threatening diseases such as polio, typhus and malaria.

Traditionally, and still in most parts of the world today, a mother was expected to be a married woman, with birth outside of marriage carrying a strong social stigma. Historically, this stigma not only applied to the mother, but also to her child. This continues to be the case in many parts of the developing world today, but in many Western countries the situation has changed radically, with single motherhood being much more socially acceptable now. For more details on these subjects, see Legitimacy (family law) and single parent.

The total fertility rate (TFR), that is, the number of children born per woman, differs greatly from country to country. The TFR in 2013 was estimated to be highest in Niger (7.03 children born per woman) and lowest in Singapore (0.79 children/woman).

In the United States, the TFR was estimated for 2013 at 2.06 births per woman. In 2011, the average age at first birth was 25.6 and 40.7% of births were to unmarried women.

Health

Main article: Maternal mortality
Maternal mortality map, given as the annual number of female deaths per 100,000 live births in 2012
Infant mortality rates under age 1, per 1,000 live births in 2013

A maternal death is defined by WHO as "the death of a woman while pregnant or within 42 days of termination of pregnancy, irrespective of the duration and site of the pregnancy, from any cause related to or aggravated by the pregnancy or its management but not from accidental or incidental causes".

About 56% of maternal deaths occur in Sub-Saharan Africa and another 29% in South Asia.

In 2006, the organization Save the Children has ranked the countries of the world, and found that Scandinavian countries are the safest places to give birth, whereas countries in sub-Saharan Africa are the least safe to give birth. This study argues a mother in the bottom ten ranked countries is over 750 times more likely to die in pregnancy or childbirth, compared to a mother in the top ten ranked countries, and a mother in the bottom ten ranked countries is 28 times more likely to see her child die before reaching their first birthday.

The most recent data suggests that Italy, Sweden and Luxembourg are the safest countries in terms of maternal death and Afghanistan, Central African Republic and Malawi are the most dangerous.

Childbirth can be a dangerous process in the absence of effective measures to reduce death. When none of these measure are taken, the maternal death rate has been estimated as being within the order of magnitude of 1,500 deaths per 100,000 births. Modern medicine has greatly alleviated the risk of childbirth. In modern Western countries the current maternal mortality rate is around 10 deaths per 100,000 births.

Religious

The Hindu mother goddess Parvati feeding her son, the elephant-headed wisdom god Ganesha

Nearly all world religions define tasks or roles for mothers through either religious law or through the glorification of mothers who served in substantial religious events. There are many examples of religious law relating to mothers and women.

Major world religions which have specific religious law or religious texts that comment on mothers include: Christianity, Judaism, and Islam. Some examples of honoring motherhood include the veneration of the Blessed Virgin Mary as Mother of God and the multiple positive references to active womanhood as a mother in the Book of Proverbs.

Hindu's Mother Goddess and Demeter of ancient Greek pre-Christian belief are also mothers.

Mother-offspring violence

Main articles: Matricide and Filicide
Orestes Pursued by the Furies by William-Adolphe Bouguereau, 1862. Clytemnestra was murdered by Orestes and the Furies torment him for his crime.

History records many conflicts between mothers and their children. Some even resulted in murder, such as the conflict between Cleopatra III of Egypt and her son Ptolemy X.

In modern cultures, matricide (the killing of one's mother) and filicide (the killing of one's son or daughter) have been studied but remain poorly understood. Psychosis and schizophrenia are common causes of both, and young, indigent mothers with a history of domestic abuse are slightly more likely to commit filicide. Mothers are more likely to commit filicide than fathers when the child is 8 years old or younger. Matricide is most frequently committed by adult sons.

In the United States in 2012, there were 130 matricides (0.4 per million people) and 383 filicides (1.2 per million), or 1.4 incidents per day.

In art

Charity, by French painter William-Adolphe Bouguereau, 1878
Lemminkäinen's Mother, an 1897 painting by Akseli Gallen-Kallela: She is shown having just gathered her son's Lemminkäinen's broken body from the dark river.
This Congolese figure was used to protect women who had lost successive children to miscarriages or infant death and is considered one of the great masterpieces of African Art. Brooklyn Museum

Throughout history, mothers have been depicted in a variety of art works, including paintings, sculptures and written texts, that have helped define the cultural meaning of 'mother', as well as ideals and taboos of motherhood.

Fourth century grave reliefs on the island of Rhodes depicted mothers with children.

Paintings of mothers with their children have a long tradition in France. In the 18th century, these works embodied the Enlightenment's preoccupation with strong family bonds and the relation between mothers and children.

At the end of the nineteenth century, Mary Cassatt was a painter well known for her portraits of mothers.

American poet, essayist and feminist Adrienne Rich has noted "the disjuncture between motherhood as patriarchal institution and motherhood as complexly and variously lived experience". The vast majority of works depicting motherhood in western art history have been created by artists who are men, with very few having been created by women or mothers themselves, and these often focus on the "institution of motherhood" rather than diverse lived experiences. At the same time, art concerning motherhood has been historically marginalized within the feminist art movement, though this is changing with an increasing number of feminist publications addressing this topic.

The institution of motherhood in western art is often depicted through "the myth of the all-loving, all-forgiving and all-sacrificing mother" and related ideals. Examples include works featuring the Virgin Mary, an archetypal mother and a key historical basis for depictions of mothers in western art from the European Renaissance onwards. Mothers depicted in dominant art works are also primarily white, heterosexual, middle class and young or attractive.

These ideals of motherhood have been challenged by artists with lived experience as mothers. An example in western contemporary art is Mary Kelly's Post-Partum Document. Bypassing typical themes of tenderness or nostalgia, this work documents in extensive detail the challenges, complexities and day-to-day realities of the mother-child relationship. Other artists have addressed similar aspects of motherhood that fall outside dominant ideals, including maternal ambivalence, desire, and the pursuit of self-fulfillment.  While the ideal of maternal self-sacrifice and the 'good mother' forms an important part of many works of art relating to the Holocaust, other women's Holocaust and post-Holocaust art has engaged more deeply with mothers' trauma, taboos, and the experiences of second and third-generation Holocaust survivors. For example, works by first-generation survivors of the Holocaust such as Ella Liebermann-Shiber and Shoshana Neuman have depicted mothers abandoning and suffocating their children in an effort to stay alive themselves.

Increasingly diverse representations of motherhood can be found in contemporary works of art. Catherine Opie's self-portrait photographs, including of herself nursing, reference the existing Virgin Mary archetype while subverting its norms around sexuality by centering her identity as a lesbian. Rather than attempting to make her experience of motherhood fit into existing norms, Opie's photographs are "non-traditional and non-apologetic representations".

In her 2020 photography collection, Solana Cain explored the meaning of joy for Black mothers to challenge the lack of images in mainstream media that represent Black motherhood. Renee Cox's Yo Mama series of nude self-portraits challenge historical representations of both the black female body and of maternity and slavery in the US, the latter of which is often characterized by the "extreme passivity and devalued love" typically associated with motherhood.

Synonyms and translations

Mother with child in Peru
Mothers with children in liberated Guinea-Bissau, 1974
Main article: Mama and papa

The proverbial "first word" of an infant often sounds like "ma" or "mama". This strong association of that sound with "mother" has persisted in nearly every language on earth, countering the natural localization of language.

Familiar or colloquial terms for mother in English are:

In many other languages, similar pronunciations apply:

Etymology

Statue of Mother Armenia, aerial view in Yerevan

The modern English word is from Middle English moder, from Old English mōdor, from Proto-Germanic *mōdēr (cf. East Frisian muur, Dutch moeder, German Mutter), from Proto-Indo-European *méh₂tēr (cf. Irish máthair, Tocharian A mācar, B mācer, Lithuanian mótė). Other cognates include Latin māter, Greek μήτηρ, Common Slavic *mati (thence Russian мать (mat')), Persian مادر (madar), and Sanskrit मातृ (mātṛ).

Notable mothers in mythology

Zoology

In zoology, particularly in mammals, a mother fills many similar biological functions as a human mother.

Mammals

Many other mammal mothers also have numerous commonalities with humans.

Primates

The behavior and role of mothers in non-human species is most similar in species most closely related to humans. This means great apes are most similar, then the broader superfamily of all apes, then all primates.

at

Gestational age

From Wikipedia, the free encyclopedia
https://en.wikipedia.org/wiki/Gestational_age

In obstetrics, gestational age is a measure of the age of a pregnancy taken from the beginning of the woman's last menstrual period (LMP), or the corresponding age of the gestation as estimated by a more accurate method, if available. Such methods include adding 14 days to a known duration since fertilization (as is possible in in vitro fertilization), or by obstetric ultrasonography. The popularity of using this measure of pregnancy is largely due to convenience: menstruation is usually noticed, while there is generally no convenient way to discern when fertilization or implantation occurred.

Gestational age is contrasted with fertilization age which takes the date of fertilization as the start date of gestation. There are different approaches to defining the start of a pregnancy. This definition is unusual for saying that women become "pregnant" two weeks before having sex. The definition of pregnancy and the calculation of gestational age are also relevant in the context of the abortion debate and the beginning of human personhood.

Methods

According to American College of Obstetricians and Gynecologists, the main methods to calculate gestational age are:

  • Directly calculating the days since the beginning of the last menstrual period
  • Early obstetric ultrasound, comparing the size of an embryo or fetus to that of a reference group of pregnancies of known gestational age (such as calculated from last menstrual periods) and using the mean gestational age of other embryos or fetuses of the same size. If the gestational age as calculated from an early ultrasound is contradictory to the one calculated directly from the last menstrual period, it is still the one from the early ultrasound that is used for the rest of the pregnancy.
  • In case of in vitro fertilization, calculating days since oocyte retrieval or co-incubation and adding 14 days.

Gestational age can also be estimated by calculating days from ovulation if it was estimated from related signs or ovulation tests, and adding 14 days by convention.

A more complete listing of methods is given in following table:

Method of estimating gestational age Variability (2 standard deviations)
Days from oocyte retrieval or co-incubation in in vitro fertilisation + 14 days ±1 day
Days from estimated ovulation in ovulation induction + 14 days ±3 days
Days from artificial insemination + 14 days ±3 days
Days from known single sexual intercourse + 14 days ±3 days
Days from estimated ovulation by basal body temperature record + 14 days ±4 days
First-trimester physical examination ±2 weeks
Second-trimester physical examination ±4 weeks
Third-trimester physical examination ±6 weeks
First-trimester obstetric ultrasonography (crown-rump length) ±8% of the estimate
Second-trimester obstetric ultrasonography (head circumference, femur length) ±8% of the estimate
Third-trimester obstetric ultrasonography (head circumference, femur length) ±8% of the estimate

As a general rule, the official gestational age should be based on the actual beginning of the last menstrual period, unless any of the above methods gives an estimated date that differs more than the variability for the method, in which case the difference cannot probably be explained by that variability alone. For example, if there is a gestational age based on the beginning of the last menstrual period of 9.0 weeks, and a first-trimester obstetric ultrasonography gives an estimated gestational age of 10.0 weeks (with a 2 SD variability of ±8% of the estimate, thereby giving a variability of ±0.8 weeks), the difference of 1.0 weeks between the tests is larger than the 2 SD variability of the ultrasonography estimate, indicating that the gestational age estimated by ultrasonography should be used as the official gestational age.

Once the estimated due date (EDD) is established, it should rarely be changed, as the determination of gestational age is most accurate earlier in the pregnancy.

Assessment of gestational age can be made based on selected head and trunk parameters. Following are diagrams for estimating gestational age from obstetric ultrasound, by various target parameters:

Comparison to fertilization age

The fertilization or conceptional age (also called embryonic age and later fetal age) is the time from the fertilization. It usually occurs within a day of ovulation, which, in turn, occurs on average 14.6 days after the beginning of the preceding menstruation (LMP). There is also considerable variability in this interval, with a 95% prediction interval of the ovulation of 9 to 20 days after menstruation even for an average woman who has a mean LMP-to-ovulation time of 14.6. In a reference group representing all women, the 95% prediction interval of the LMP-to-ovulation is 8.2 to 20.5 days. The actual variability between gestational age as estimated from the beginning of the last menstrual period (without the use of any additional method mentioned in previous section) is substantially larger because of uncertainty which menstrual cycle gave rise to the pregnancy. For example, the menstruation may be scarce enough to give the false appearance that an earlier menstruation gave rise to the pregnancy, potentially giving an estimated gestational age that is approximately one month too large. Also, vaginal bleeding occurs during 15–25% of first trimester pregnancies, and may be mistaken as menstruation, potentially giving an estimated gestational age that is too low.

Uses

Gestational age is used for example for:

Timeline of pregnancy by gestational age

Estimation of due date

Distribution of gestational age at childbirth among singleton live births, given both when gestational age is estimated by first trimester ultrasound and directly by last menstrual period
Main article: Estimated date of delivery

The mean pregnancy length has been estimated to be 283.4 days of gestational age as timed from the first day of the last menstrual period and 280.6 days when retrospectively estimated by obstetric ultrasound measurement of the fetal biparietal diameter (BPD) in the second trimester. Other algorithms take into account other variables, such as whether this is the first or subsequent child, the mother's race, age, length of menstrual cycle, and menstrual regularity. In order to have a standard reference point, the normal pregnancy duration is assumed by medical professionals to be 280 days (or 40 weeks) of gestational age. Furthermore, actual childbirth has only a certain probability of occurring within the limits of the estimated due date. A study of singleton live births determined that childbirth has a standard deviation of 14 days when gestational age is estimated by first-trimester ultrasound and 16 days when estimated directly by last menstrual period.

The most common system used among healthcare professionals is Naegele's rule, which estimates the expected date of delivery (EDD) by adding a year, subtracting three months, and adding seven days to the first day of a woman's last menstrual period (LMP) or corresponding date as estimated from other means.

Medical fetal viability

There is no sharp limit of development, gestational age, or weight at which a human fetus automatically becomes viable. According to studies between 2003 and 2005, 20 to 35 percent of babies born at 23 weeks of gestation survive, while 50 to 70 percent of babies born at 24 to 25 weeks, and more than 90 percent born at 26 to 27 weeks, survive. It is rare for a baby weighing less than 500 g (17.6 ounces) to survive. A baby's chances for survival increases 3–4% per day between 23 and 24 weeks of gestation and about 2–3% per day between 24 and 26 weeks of gestation. After 26 weeks the rate of survival increases at a much slower rate because survival is high already. Prognosis depends also on medical protocols on whether to resuscitate and aggressively treat a very premature newborn, or whether to provide only palliative care, in view of the high risk of severe disability of very preterm babies.

Stages in prenatal development, showing viability and point of 50% chance of survival (limit of viability) at bottom. Weeks and months numbered by gestation.
Completed weeks of gestation at birth 21 and less 22 23 24 25 26 27 30 34
Chance of survival <1% 0–10% 10–35% 40–70% 50–80% 80–90% >90% >95% >98%

Birth classification

Using gestational age, births can be classified into broad categories:

Gestational Age in Weeks Classification
< 37 0/7 Preterm
34 0/7 - 36 6/7 Late preterm
37 0/7 - 38 6/7 Early Term
39 0/7 - 40 6/7 Full Term
41 0/7 - 41 6/7 Late Term
> 42 0/7 Postterm

Using the LMP (last menstrual period) method, a full-term human pregnancy is considered to be 40 weeks (280 days), though pregnancy lengths between 38 and 42 weeks are considered normal. A fetus born prior to the 37th week of gestation is considered to be preterm. A preterm baby is likely to be premature and consequently faces increased risk of morbidity and mortality. An estimated due date is given by Naegele's rule.

According to the WHO, a preterm birth is defined as "babies born alive before 37 weeks of pregnancy are completed." According to this classification, there are three sub-categories of preterm birth, based on gestational age: extremely preterm (fewer than 28 weeks), very preterm (28 to 32 weeks), moderate to late preterm (32 to 37 weeks). Various jurisdictions may use different classifications.

In classifying perinatal deaths, stillbirths and infant deaths

For most of the 20th century, official definitions of a live birth and infant death in the Soviet Union and Russia differed from common international standards, such as those established by the World Health Organization in the latter part of the century. Babies who were fewer than 28 weeks of gestational age, or weighed fewer than 1000 grams, or fewer than 35 cm in length – even if they showed some sign of life (breathing, heartbeat, voluntary muscle movement) – were classified as "live fetuses" rather than "live births." Only if such newborns survived seven days (168 hours) were they then classified as live births. If, however, they died within that interval, they were classified as stillbirths. If they survived that interval but died within the first 365 days they were classified as infant deaths.

More recently, thresholds for "fetal death" continue to vary widely internationally, sometimes incorporating weight as well as gestational age. The gestational age for statistical recording of fetal deaths ranges from 16 weeks in Norway, to 20 weeks in the US and Australia, 24 weeks in the UK, and 26 weeks in Italy and Spain.

The WHO defines the perinatal period as "The perinatal period commences at 22 completed weeks (154 days) of gestation and ends seven completed days after birth." Perinatal mortality is the death of fetuses or neonates during the perinatal period. A 2013 study found that "While only a small proportion of births occur before 24 completed weeks of gestation (about 1 per 1000), survival is rare and most of them are either fetal deaths or live births followed by a neonatal death."

Postnatal use

Gestational age (as well as fertilization age) is sometimes used postnatally (after birth) to estimate various risk factors. For example, it is a better predictor than postnatal age for risk of intraventricular hemorrhage in premature babies treated with extracorporeal membrane oxygenation.

Factors affecting pregnancy length

Child's gestational age at birth (pregnancy length) is associated with various likely causal maternal non-genetic factors: stress during pregnancy, age, parity, smoking, infection and inflammation, BMI. Also, preexisting maternal medical conditions with genetic component, e.g., diabetes mellitus type 1, systemic lupus erythematosus, anaemia. Parental ancestral background (race) also plays a role in pregnancy duration. Gestational age at birth is on average shortened by various pregnancy aspects: twin pregnancy, prelabor rupture of (fetal) membranes, pre-eclampsia, eclampsia, intrauterine growth restriction. The ratio between fetal growth rate and uterine size (reflecting uterine distension) is suspected to partially determine the pregnancy length.

Heritability of pregnancy length

Family-based studies showed that gestational age at birth is partially (25–40%) determined by genetic factors.
at

People skills

From Wikipedia, the free encyclopedia

People skills are patterns of behavior and behavioral interactions. Among people, it is an umbrella term for skills under three related set of abilities: personal effectiveness, interaction skills, and intercession skills. This is an area of exploration about how a person behaves and how they are perceived irrespective of their thinking and feeling. It is further elaborated as dynamics between personal ecology (cognitive, affective, physical and spiritual dimensions) and its function with other people's personality styles in numerous environments (life events, institutions, life challenges, etc.). British dictionary definition is "the ability to communicate effectively with people in a friendly way, especially in business" or personal effectiveness skills. In business it is a connection among people in a humane level to achieve productivity.

Portland Business Journal describes people skills as:

History

Human-relations studies emerged in the 1920s when companies became more interested in "soft skills" and interpersonal skills of employees. In organizations, improving people skills became a specialized role of the corporate trainer. By the mid-1930s, Dale Carnegie popularized people skills in How to Win Friends and Influence People and How to Stop Worrying and Start Living worldwide.

In the 1960s, US schools introduced people-skills topics and methods—often as a way to promote better self-esteem, communication and social interaction. These encompassed psychologist Thomas Gordon's "Effectiveness Training" variations as well as many other training programs. (By the 1980s, "traditional education" and a "back-to-basics" three-Rs emphasis largely pushed these programs aside, with notable exceptions.)

The first documented use of the phrase "people skills" was around 1970.

Business impact

The SCANS report states that business, labor and government authorities agree that having a wide range of people skills are necessary for 20th-century work success. Skills like customer service, building effective relationships, and teamwork are among the abilities most requested by employers in job postings. Lack of these skills is considered a serious psychological handicap. Constructive leadership based companies engage in helping individuals to grow, and through that growth employees take more responsibility and discharge it effectively. This in-turn will enhance the basic attitude of the individual; and that will reflect the general level of performance in the workplace. Studies indicate that many people who have difficulty in obtaining or holding a job possess the needed technical competence but lack interpersonal competence.

Lawrence A. Appley of American Management Association, reflected on these trainings as a responsibility to "increase the knowledge, sharpen and add to the skills, improve the habits, and change the attitudes of many of those for whose development we are responsible." Lack of people skills among upper echelons (top management) can result in bullying and/or harassment, which is not uncommon in the modern workplace due to changing values. The causes that are most identified with the situation are lack of necessary motivation, communication, influencing skills and empathy gap among upper echelons (Gilbert and Thompson, 2002). Training company staff in people skills and interpersonal skills increases the morale and dignity at work (Best, 2010). Employers that do not take steps to prevent harassment can face major costs in decreased productivity, low morale, increased absenteeism and health care costs, and potential legal expenses.

Educational importance

The Collaborative for Academic Social and Emotional Learning (CASEL) has identified 22 programs in the US that are especially comprehensive in social-emotional learning coverage and effective in documented impacts. UNESCO research found that young people who develop speaking/listening skills and who get to know others without WIIFM attitude have improved self-awareness, social-emotional adjustment and classroom behavior; in addition, self-destructive and violent behavior also decreased. People skills are also important for teachers in effective classroom management. Educators have found that more is needed than a degree in the field they are teaching. Knowing how to communicate and teach people instead of simply teaching their subject will help make a difference in the classroom. It is identified that 50 percent of classroom success lies in effective interpersonal relationships while the other 50 percent lies within academic skills. Requirement of people skills education is greatly emphasized within higher education and recruiters stress the required focus on this skill for securing entry-level jobs right off from campus placements. Oral communication and teamwork were ranked number 1 and 2 respectively among 15 job skills that executives and hiring managers identified as very important for new employees in a large US 2018 survey. But employers have trouble finding new employees with good oral communication because schools are not teaching the skills.
at

Neurogenetics

From Wikipedia, the free encyclopedia
Human karyogram

Neurogenetics studies the role of genetics in the development and function of the nervous system. It considers neural characteristics as phenotypes (i.e. manifestations, measurable or not, of the genetic make-up of an individual), and is mainly based on the observation that the nervous systems of individuals, even of those belonging to the same species, may not be identical. As the name implies, it draws aspects from both the studies of neuroscience and genetics, focusing in particular how the genetic code an organism carries affects its expressed traits. Mutations in this genetic sequence can have a wide range of effects on the quality of life of the individual. Neurological diseases, behavior and personality are all studied in the context of neurogenetics. The field of neurogenetics emerged in the mid to late 20th century with advances closely following advancements made in available technology. Currently, neurogenetics is the center of much research utilizing cutting edge techniques.

History

The field of neurogenetics emerged from advances made in molecular biology, genetics and a desire to understand the link between genes, behavior, the brain, and neurological disorders and diseases. The field started to expand in the 1960s through the research of Seymour Benzer, considered by some to be the father of neurogenetics.

Seymour Benzer in his office at Caltech in 1974 with a big model of Drosophila

His pioneering work with Drosophila helped to elucidate the link between circadian rhythms and genes, which led to further investigations into other behavior traits. He also started conducting research in neurodegeneration in fruit flies in an attempt to discover ways to suppress neurological diseases in humans. Many of the techniques he used and conclusions he drew would drive the field forward.

Early analysis relied on statistical interpretation through processes such as LOD (logarithm of odds) scores of pedigrees and other observational methods such as affected sib-pairs, which looks at phenotype and IBD (identity by descent) configuration. Many of the disorders studied early on including Alzheimer's, Huntington's and amyotrophic lateral sclerosis (ALS) are still at the center of much research to this day. By the late 1980s new advances in genetics such as recombinant DNA technology and reverse genetics allowed for the broader use of DNA polymorphisms to test for linkage between DNA and gene defects. This process is referred to sometimes as linkage analysis.  By the 1990s ever advancing technology had made genetic analysis more feasible and available. This decade saw a marked increase in identifying the specific role genes played in relation to neurological disorders. Advancements were made in but not limited to: Fragile X syndrome, Alzheimer's, Parkinson's, epilepsy and ALS.

Neurological disorders

While the genetic basis of simple diseases and disorders has been accurately pinpointed, the genetics behind more complex, neurological disorders is still a source of ongoing research. New developments such as the genome wide association studies (GWAS) have brought vast new resources within grasp. With this new information genetic variability within the human population and possibly linked diseases can be more readily discerned. Neurodegenerative diseases are a more common subset of neurological disorders, with examples being Alzheimer's disease and Parkinson's disease. Currently no viable treatments exist that actually reverse the progression of neurodegenerative diseases; however, neurogenetics is emerging as one field that might yield a causative connection. The discovery of linkages could then lead to therapeutic drugs, which could reverse brain degeneration.

Gene sequencing

One of the most noticeable results of further research into neurogenetics is a greater knowledge of gene loci that show linkage to neurological diseases. The table below represents a sampling of specific gene locations identified to play a role in selected neurological diseases based on prevalence in the United States.

Gene loci Neurological disease
APOE ε4, PICALM Alzheimer's disease
C9orf72, SOD1  amyotrophic lateral sclerosis
HTT Huntington's disease
DR15, DQ6 Multiple sclerosis
LRRK2, PARK2, PARK7 Parkinson's disease

Methods of research

Statistical analysis

Logarithm of odds (LOD) is a statistical technique used to estimate the probability of gene linkage between traits. LOD is often used in conjunction with pedigrees, maps of a family's genetic make-up, in order to yield more accurate estimations. A key benefit of this technique is its ability to give reliable results in both large and small sample sizes, which is a marked advantage in laboratory research.

Quantitative trait loci (QTL) mapping is another statistical method used to determine the chromosomal positions of a set of genes responsible for a given trait. By identifying specific genetic markers for the genes of interest in a recombinant inbred strain, the amount of interaction between these genes and their relation to the observed phenotype can be determined through complex statistical analysis. In a neurogenetics laboratory, the phenotype of a model organisms is observed by assessing the morphology of their brain through thin slices. QTL mapping can also be carried out in humans, though brain morphologies are examined using nuclear magnetic resonance imaging (MRI) rather than brain slices. Human beings pose a greater challenge for QTL analysis because the genetic population cannot be as carefully controlled as that of an inbred recombinant population, which can result in sources of statistical error.

Recombinant DNA

Recombinant DNA is an important method of research in many fields, including neurogenetics. It is used to make alterations to an organism's genome, usually causing it to over- or under-express a certain gene of interest, or express a mutated form of it. The results of these experiments can provide information on that gene's role in the organism's body, and it importance in survival and fitness. The hosts are then screened with the aid of a toxic drug that the selectable marker is resistant to. The use of recombinant DNA is an example of a reverse genetics, where researchers create a mutant genotype and analyze the resulting phenotype. In forward genetics, an organism with a particular phenotype is identified first, and its genotype is then analyzed.

Animal research

Drosophila
Zebrafish

Model organisms are an important tool in many areas of research, including the field of neurogenetics. By studying creatures with simpler nervous systems and with smaller genomes, scientists can better understand their biological processes and apply them to more complex organisms, such as humans. Due to their low-maintenance and highly mapped genomes, mice, Drosophila, and C. elegans are very common. Zebrafish and prairie voles have also become more common, especially in the social and behavioral scopes of neurogenetics.

In addition to examining how genetic mutations affect the actual structure of the brain, researchers in neurogenetics also examine how these mutations affect cognition and behavior. One method of examining this involves purposely engineering model organisms with mutations of certain genes of interest. These animals are then classically conditioned to perform certain types of tasks, such as pulling a lever in order to gain a reward. The speed of their learning, the retention of the learned behavior, and other factors are then compared to the results of healthy organisms to determine what kind of an effect – if any – the mutation has had on these higher processes. The results of this research can help identify genes that may be associated with conditions involving cognitive and learning deficiencies.

Human research

Many research facilities seek out volunteers with certain conditions or illnesses to participate in studies. Model organisms, while important, cannot completely model the complexity of the human body, making volunteers a key part to the progression of research. Along with gathering some basic information about medical history and the extent of their symptoms, samples are taken from the participants, including blood, cerebrospinal fluid, and/or muscle tissue. These tissue samples are then genetically sequenced, and the genomes are added to current database collections. The growth of these data bases will eventually allow researchers to better understand the genetic nuances of these conditions and bring therapy treatments closer to reality. Current areas of interest in this field have a wide range, spanning anywhere from the maintenance of circadian rhythms, the progression of neurodegenerative disorders, the persistence of periodic disorders, and the effects of mitochondrial decay on metabolism.

Genome-wide association studies

Such databases are used in genome-wide association studies (GWAS). Examples of phenotypes investigated by notable neurogenetics GWAS include:

Behavioral neurogenetics

Main article: Behavioural genetics

Advances in molecular biology techniques and the species-wide genome project have made it possible to map out an individual's entire genome. Whether genetic or environmental factors are primarily responsible for an individual's personality has long been a topic of debate. Thanks to the advances being made in the field of neurogenetics, researchers have begun to tackle this question by beginning to map out genes and correlate them to different personality traits. There is little to no evidence to suggest that the presence of a single gene indicates that an individual will express one style of behavior over another; rather, having a specific gene could make one more predisposed to displaying this type of behavior. It is starting to become clear that most genetically influenced behaviors are due to the effects of many variants within many genes, in addition to other neurological regulating factors like neurotransmitter levels. Due to fact that many behavioral characteristics have been conserved across species for generations, researchers are able to use animal subjects such as mice and rats, but also fruit flies, worms, and zebrafish, to try to determine specific genes that correlate to behavior and attempt to match these with human genes.

Cross-species gene conservation

While it is true that variation between species can appear to be pronounced, at their most basic they share many similar behavior traits which are necessary for survival. Such traits include mating, aggression, foraging, social behavior and sleep patterns. This conservation of behavior across species has led biologists to hypothesize that these traits could possibly have similar, if not the same, genetic causes and pathways. Studies conducted on the genomes of a plethora of organisms have revealed that many organisms have homologous genes, meaning that some genetic material has been conserved between species. If these organisms shared a common evolutionary ancestor, then this might imply that aspects of behavior can be inherited from previous generations, lending support to the genetic causes – as opposed to the environmental causes – of behavior. Variations in personalities and behavioral traits seen amongst individuals of the same species could be explained by differing levels of expression of these genes and their corresponding proteins.

Aggression

See also: Genetics of aggression

There is also research being conducted on how an individual's genes can cause varying levels of aggression and aggression control.

Outward displays of aggression are seen in most animals

Throughout the animal kingdom, varying styles, types and levels of aggression can be observed leading scientists to believe that there might be a genetic contribution that has conserved this particular behavioral trait. For some species varying levels of aggression have indeed exhibited direct correlation to a higher level of Darwinian fitness.

Development

Shh and BMP gradient in the neural tube

A great deal of research has been done on the effects of genes and the formation of the brain and the central nervous system. The following wiki links may prove helpful:

There are many genes and proteins that contribute to the formation and development of the central nervous system, many of which can be found in the aforementioned links. Of particular importance are those that code for BMPs, BMP inhibitors and SHH. When expressed during early development, BMP's are responsible for the differentiation of epidermal cells from the ventral ectoderm. Inhibitors of BMPs, such as NOG and CHRD, promote differentiation of ectoderm cells into prospective neural tissue on the dorsal side. If any of these genes are improperly regulated, then proper formation and differentiation will not occur. BMP also plays a very important role in the patterning that occurs after the formation of the neural tube. Due to the graded response the cells of the neural tube have to BMP and Shh signaling, these pathways are in competition to determine the fate of preneural cells. BMP promotes dorsal differentiation of pre-neural cells into sensory neurons and Shh promotes ventral differentiation into motor neurons. There are many other genes that help to determine neural fate and proper development include, RELN, SOX9, WNT, Notch and Delta coding genes, HOX, and various cadherin coding genes like CDH1 and CDH2.

Some recent research has shown that the level of gene expression changes drastically in the brain at different periods throughout the life cycle. For example, during prenatal development the amount of mRNA in the brain (an indicator of gene expression) is exceptionally high, and drops to a significantly lower level not long after birth. The only other point of the life cycle during which expression is this high is during the mid- to late-life period, during 50–70 years of age. While the increased expression during the prenatal period can be explained by the rapid growth and formation of the brain tissue, the reason behind the surge of late-life expression remains a topic of ongoing research.

Current research

Neurogenetics is a field that is rapidly expanding and growing. The current areas of research are very diverse in their focuses. One area deals with molecular processes and the function of certain proteins, often in conjunction with cell signaling and neurotransmitter release, cell development and repair, or neuronal plasticity. Behavioral and cognitive areas of research continue to expand in an effort to pinpoint contributing genetic factors. As a result of the expanding neurogenetics field a better understanding of specific neurological disorders and phenotypes has arisen with direct correlation to genetic mutations. With severe disorders such as epilepsy, brain malformations, or mental retardation a single gene or causative condition has been identified 60% of the time; however, the milder the intellectual handicap the lower chance a specific genetic cause has been pinpointed. Autism for example is only linked to a specific, mutated gene about 15–20% of the time while the mildest forms of mental handicaps are only being accounted for genetically less than 5% of the time. Research in neurogenetics has yielded some promising results, though, in that mutations at specific gene loci have been linked to harmful phenotypes and their resulting disorders. For instance a frameshift mutation or a missense mutation at the DCX gene location causes a neuronal migration defect also known as lissencephaly. Another example is the ROBO3 gene where a mutation alters axon length negatively impacting neuronal connections. Horizontal gaze palsy with progressive scoliosis (HGPPS) accompanies a mutation here. These are just a few examples of what current research in the field of neurogenetics has achieved.
at

Gene–environment correlation

From Wikipedia, the free encyclopedia

Gene–environment correlation (or genotype–environment correlation) is said to occur when exposure to environmental conditions depends on an individual's genotype.

Definition

Gene–environment correlations (or rGE) is correlation of two traits, e.g. height and weight, which would mean that when one changes, so does the other. Gene–environment correlations can arise by both causal and non-causal mechanisms. Of principal interest are those causal mechanisms which indicate genetic control over environmental exposure. Genetic variants influence environmental exposure indirectly via behavior. Three causal mechanisms giving rise to gene–environment correlations have been described.

(i) Passive gene–environment correlation refers to the association between the genotype a child inherits from their parents and the environment in which the child is raised. Parents create a home environment that is influenced by their own heritable characteristics. Biological parents also pass on genetic material to their children. When the children's genotype also influences their behavioral or cognitive outcomes, the result can be a spurious relationship between environment and outcome. For example, because parents who have histories of antisocial behavior (which is moderately heritable) are at elevated risk of abusing their children, a case can be made for saying that maltreatment may be a marker for genetic risk that parents transmit to children rather than a causal risk factor for children’s conduct problems.
(ii) Evocative (or reactive) gene–environment correlation happens when an individual's (heritable) behavior evokes an environmental response. For example, the association between marital conflict and depression may reflect the tensions that arise when engaging with a depressed spouse rather than a causal effect of marital conflict on risk for depression.
(iii) Active gene–environment correlation occurs when an individual possesses a heritable inclination to select environmental exposure. For example, individuals who are characteristically extroverted may seek out very different social environments than those who are shy and withdrawn.

Gene–environment correlation can also arise from non-causal mechanisms, including evolutionary processes and behavioral 'contamination' of the environmental measure. Evolutionary processes, such as genetic drift and natural selection, can cause allele frequencies to differ between populations. For example, exposure to malaria-bearing mosquitoes over many generations may have caused the higher allele frequency among certain ethnic groups for the sickle hemoglobin (HbS) allele, a recessive mutation that causes sickle-cell disease but confers resistance against malaria. In this way, HbS genotype has become associated with the malarial environment.

Evidence

Quantitative genetic studies

Twin and adoption studies have provided much of the evidence for gene–environment correlations by demonstrating that putative environmental measures are heritable. For example, studies of adult twins have shown that desirable and undesirable life events are moderately heritable as are specific life events and life circumstances, including divorce, the propensity to marry, marital quality and social support. Studies in which researchers have measured child-specific aspects of the environment have also shown that putative environmental factors, such as parental discipline or warmth, are moderately heritable. Television viewing, peer group orientations and social attitudes have all been shown to be moderately heritable. There is also a growing literature on the genetic factors influencing behaviors that constitute a risk to health, such as the consumption of alcohol, tobacco and illegal drugs, and risk-taking behaviors. Like parental discipline, these health related behaviors are genetically influenced, but are thought to have environmentally mediated effects on disease. To the extent that researchers have attempted to determine why genes and environments are correlated, most evidence has pointed to the intervening effects of personality and behavioral characteristics.

Environments are heritable because genotype influences the behaviours that evoke, select, and modify features of the environment. Thus, environments less amenable to behavioural modification tend to be less heritable. For example, negative life events that are beyond the control of the individual (e.g., the death of a loved one, losing one’s home in a natural disaster) have lower heritability than negative life events that may be dependent on an individual’s behaviour (e.g., getting a divorce, getting fired from a job). Similarly, personal life events (i.e., events that occur directly to an individual) are more highly heritable than network life events (i.e., events that occur to someone within an individual’s social network, thus affecting the individual indirectly).

Molecular genetic studies

Evidence for the existence of gene–environment correlations has recently started to accrue from molecular genetic investigations. The Collaborative Studies on Genetics of Alcoholism (COGA) group has reported that a single-nucleotide polymorphism in intron 7 of the gamma-aminobutyric acid A a2 receptor (rs279871; GABRA2) was associated with alcohol dependence and marital status. Individuals who had the high-risk GABRA2 variant (i.e., the variant associated with alcohol dependence) were less likely to be married, in part because they were at higher risk for antisocial personality disorder and were less likely to be motivated by a desire to please others. There is also molecular evidence for passive gene–environment correlation. A recent study found that children were almost 2.5 times more likely to be diagnosed with attention-deficit hyperactivity disorder (ADHD) if their mothers were divorced, separated, or never married. In this sample, however, mothers possessing the short allele of the dopamine receptor gene DRD2 were more likely to be divorced, separated, or never married. Moreover, their children were more likely to have ADHD. Therefore, part of the association between parental marital status and ADHD diagnosis among children in this sample is due to the confounding variable of maternal DRD2 genotype. Both of these studies also found evidence for gene–environment interaction.

A polygenic score (PGS; also called a polygenic risk score), which is a number assigned to individuals based on variation in multiple genetic loci and their associated regression weights from genome-wide association studies, can also be used to demonstrate gene–environment correlation. This effect, often referred to as "genetic nurture", is suggestive of passive gene–environment correlation when parental polygenic score independently predicts offspring outcome beyond the offspring's own PGS, and has been demonstrated for educational attainment in humans.

Significance

Doctors want to know whether exposure to environmental risk causes disease. The fact that environmental exposures are heritable means that the relationship between environmental exposure and disease may be confounded by genotype. That is, the relationship may be spurious (not causal), because the same genetic factors might be influencing both exposure to environmental risk and disease. In such cases, measures aimed at reducing environmental exposure will not reduce the risk for disease. On the other hand, heritability of exposure to environmental conditions itself does not mean environmental factors are not responsible for disease and so exposure reduction would benefit individuals with genetic predisposition to risk behavior.

For example, a study of children born to twin sisters investigated whether the relationship between parental divorce and offspring alcohol and emotional problems was causal or confounded by parental genotype. The study found that the offspring of twin sisters who were discordant for divorce had equally high levels of emotional problems, suggesting that genetic factors which made twin siblings divorce-prone also increased their children’s risk for depression and anxiety. This finding suggests that preventing the parents’ divorce would have had little impact on offspring risk for emotional problems (although the findings for alcohol problems in the children were consistent with a causal role for divorce).

at
Subscribe to: Posts (Atom)

Magnet school

From Wikipedia, the free encyclopedia https://en.wikipedia.org/wiki/Magnet_sc...

  • Islamic State and the Levant
    From Wikipedia, the free encyclopedia Islamic State of Iraq and the Levant الدولة الإسلامية في العراق والشام   ( ...
  • Heart Sutra
    From Wikipedia, the free encyclopedia A reproduction of the palm -leaf manuscript in Siddham script ...
  • Slum
    From Wikipedia, the free encyclopedia ...