Search This Blog

Friday, March 20, 2020

New feminism

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

New feminism is a form of Christian feminism that not only emphasizes the integral complementarity of women and men, rather than the superiority of men over women or women over men, but also advocates for respecting persons from conception to natural death.

New feminism, as a form of difference feminism, supports the idea that men and women have different strengths, perspectives, and roles, while advocating for the equal worth and dignity of both sexes. Among its basic concepts are that biological differences are significant and do not compromise sexual equality. New Feminism holds that women should be valued in their role as child bearers, that women are individuals with equal worth as men; and that in social, economic and legal senses they should be equal, while accepting the natural differences between the sexes.

History

The term was originally used in Britain in the 1920s to distinguish new feminists from traditional mainstream suffragist feminism. These women, also referred to as welfare feminists, were particularly concerned with motherhood, like their opposite numbers in Germany at the time, Helene Stöcker and her Bund für Mutterschutz. New feminists campaigned strongly in favour of such measures as family allowances paid directly to mothers. They were also largely supportive of protective legislation in industry. A major proponent of this was Eleanor Rathbone of the suffragist-successor society, the National Union of Societies for Equal Citizenship.

New feminists were opposed mainly by young women, especially those in the Six Point Group, particularly Winifred Holtby, Vera Brittain, and Dorothy Evans, who saw this as a retrograde step towards the separate spheres ideology of the 19th century. They were particularly opposed to protective legislation, which they saw as being in practice restrictive legislation, which kept women out of better-paid jobs on the pretext of health and welfare considerations.

Recent use

In recent years, the term has been revived by feminists responding to Pope John Paul II's call for a "'new feminism' which rejects the temptation of imitating models of 'male domination' in order to acknowledge and affirm the true genius of women in every aspect of the life of society and overcome all discrimination, violence and exploitation . . . 'Reconcile people with life'". John Paul II links the new feminism of pro-life, pro-person advocacy to the feminine genius identified in his 1988 apostolic letter Mulieris Dignitatem, or, On the Dignity and Vocation of Women. In section 30 of this letter, John Paul II identified women as having a "genius that belongs" to them and called on them to use it to restore "sensitivity for human beings in every circumstance. Women are mothers and caregivers as well as participants in every realm of human endeavor. He describes the 'feminine genius' as including empathy, interpersonal relations, emotive capacity, subjectivity, communication, intuition and personalization. In the controversial section 24 of this letter, John Paul II defends the equality of women and argues that husbands and wives are to be mutually submissive to each other. 

John Paul II had begun his theologically-based affirmation of integral gender complementarity in his Wednesday audiences between 1979 and 1984, in what is now compiled as the Theology of the Body. In this work, he describes his belief that men and women are formed as complementary human beings for the sake of loving and being loved. 

John Paul II continued his call for women to become advocates of humanity in his Apostolic Letter to Women prior to the 1995 Beijing Women's conference.

Since then, women interested in advocating for the person--along with their male collaborators--have been developing personalist feminism. "Personalist feminism" was a term first coined by Prudence Allen to describe the feminism called for by John Paul II. Women have also been developing new feminism as a philosophical theory about sexual complementarity. They agree that being the equal to men in their professional and social capacities does not require denying their physical differences as women nor the importance of being a mother whether physically or spiritually.

Theory

Integral sex complementarity

While the Greeks acknowledged the possibility of sex complementarity, systematic developments into this philosophy of the person did not begin until Augustine of Hippo, who recognized the implications of the Christian doctrine of the resurrection. The first western philosopher to articulate a complete theory of sex complementarity was Hildegard of Bingen, a 12th-century Benedictine nun. Her advances were soon buried by the 13th century Aristotelian Revolution, and the lack of higher education for women in the following centuries.

Philosophical developments in the concept of integral gender complementarity were popularized in the early 20th century by two students of Edmund Husserl: Dietrich von Hildebrand and Edith Stein. Von Hildebrand argued against the "terrible anti-personalism" of his age, stating that it is the "general dissimilarity in the nature of both which enables... a real complementary relationship". Stein revived the metaphysics of Thomas Aquinas to argue that a difference in bodies constitutes a difference in spirit, that the soul is not unisex. Stein's argument has been criticized for not realizing that the immateriality of the human soul transcends the limitations of the body as Aquinas argues. New feminist theories were also influenced by the Personalist and Phenomenology movements of the early 20th century. 

Integral complementarity differs from fractional complementarity, in that it argues that men and women are each whole persons in and of themselves, and, together, equal more than the sum of their parts. The concept of fractional complementarity argues that a man and woman each make up a part of a person. By this theory, when they are joined together, they then comprise one, composite being.

Meaning of the body

New feminists promote an understanding of the human person as one who is made in the image and likeness of God (imago Dei) for the purpose of union and communion. They see distinct differences in the ways in which men and women make a sincere gift of themselves through the 'nuptial meaning of the body', and see these gifts as shedding light on the mysteries of God and their own vocation, mission and dignity.

Other ideas promoted by new feminists include:
  • that the different bodily structures of men and women lead both to different lived experiences.
  • that the different ways in which men and women give life physically are linked to emotional, spiritual, and intellectual dispositions.
  • that fulfillment as a woman means exercising maternal care, whether physically or spiritually. New feminists believe that whether or not they do it well, women are physically structured to be mothers, to develop life with their wombs. They purport the idea that the physical capacity for motherhood connects with the psychological, spiritual and emotional characteristics that women would need to be mothers.
  • that regardless of whether or not a woman ever gives birth, she has the capacity for maternal love in spiritual motherhood.

The feminine genius

The phrase "the feminine genius" is used to describe the genius that John Paul II identified as belonging to women, "which can ensure sensitivity for human beings in every circumstance. He argues that this sensitivity is linked to maternity. Work on unpacking the nature of this link can be found in various anthologies, such as Women in Christ: Toward a New Feminism (2004) and Woman as Prophet in the Home and the World (2016). The characteristics of these feminine genius-maternity links raise many open questions. For example:
Emphasis on the person
Because they can receive and develop life within their wombs, women can have a special openness to the new person - their child. This includes the capacity to unify all of humankind because people were all once united with their mothers in their wombs. The open questions here include the degree to which it takes a decision to consider every human person as some one's child and the ways in which such a decision has implications for social policy, the arts, and human culture.
 
Empathy
Because of the need to care for their developing children, within their wombs and as infants, caring mothers tend to become more empathetic. The open questions on this characteristic include whether the development of empathy is physiological or the result of the choice to be caring. They also include evaluating Edith Stein's argument that women have "a profound need to share [their lives] with another and, consequently, a capacity for unselfish love, for commitment, a capacity to transcend the self...".
 
Receptivity
Only women are created with a physical empty space inside of themselves capable of receiving another person and conceiving new life. Through pregnancy, women give a gift of self - their own bodies - so that others, their children, can receive the gift of life. The open questions here include the correlation between sexual receptivity and other kinds of receptivity, e.g. emotional, psychological, spiritual, intellectual and so forth.
 
Protection of life
Because of the new human life within their wombs, women have a special vocation to care for their own children and a special sensitivity to the needs of all those who cannot care for themselves - the weak, the poor, the outcast - all those whose life is not valued. New feminists believe it to be a particular injustice when women support abortion, infanticide, embryonic stem cell research, or in-vitro fertilization. The open questions here concern the best ways to meet the needs of women and offer the support necessary to end these injustices and build a more humane society. Personalist feminists argue that the collaboration of men is so necessary for these tasks that they too need to be feminists.
 
Sanctity and modesty
Women have a sense of modesty to guard against the exploitation or objectification of that holy mystery. Only total love - unconditional commitment and mutual self-giving in marriage - "has the capacity to absorb the shame of human nature." The key to this absorption is valuing sexuality as the embodiment of a person whom is dearly loved. New feminists are typically against what Russell D. Moore termed "the Concubine Culture" of couples living together and having sex outside of marriage.
 
Supportive of men
By enabling men to become fathers, women give men a great gift. While he shares in parenthood, man always remains outside the process of pregnancy and birth. In many ways, women facilitate a man's fatherhood and parenting skills. For New feminists, the fulfillment of masculinity means being a father, whether physically or spiritually. In order to become a physical father, a man must give away his semen, in order to create new life. All spiritual fathers, according to New Feminists, have a responsibility to protect the mutual self-giving of man and woman. This sense of protection of their wives and families is also built into a man's physical capacities in the greater physical strength of men, generally speaking, as well as their psychological need to feel competent and capable. There are many unresolved questions here include the ways in which women facilitate fatherhood, substantiating the claim that fatherhood is key to male fulfillment, and the ways in which fatherhood is imaged in the Trinity and by Christ.
 
There is controversy as not all new feminists accept John Paul II's argument in sections 23-24 of Mulieris Dignitatem that due to Genesis 1:27 and Ephesians 5:21, husband and wives are to be mutually submissive. For example, in Eastern Orthodoxy, spiritual fatherhood means spiritual priesthood – the offering of a man's body and blood for the sanctification of the world. It was because Jesus gave his body and blood away both as a sacrifice for his Church and as a gift to the Church in the form of the Eucharist that new spiritual life could be conceived. "A man is 'head' of his wife not to stroke his own ego, but in order to give up his body for her" and thus create new life. As keepers of the Eucharist, men are entrusted with the body and blood of Christ. All men, whether single or married, are entrusted with woman – the body of the Church. "She is their Eucharist."

New feminist positions

Distinction, not discrimination
"Discrimination is an evil, but distinction is God's design." New feminists claim that men and women are different and that this difference affects the way they live their lives, what they care about, and their strengths and weaknesses. Women can fulfill their vocational calling by acting as spiritual mothers in whatever their occupation: as wife, mother, consecrated woman, working professional, or single woman. Differences between the sexes should never be used to unilaterally discriminate except in cases when a task is contingent upon a person being of a certain sex, e.g., women give birth and only men can be priests in Catholic and Eastern Orthodox Churches.
 
Marriage as communion
New feminists consider marriage to be a reciprocal self-giving of persons in free, total, faithful and fruitful communion. This means that marriage is more than a "partnership"; it is a communion of persons.
 
Celebration of the family and the home
New feminists argue that a true feminism is not just about women, it is about the Family – both individually and collectively in the Church and Humanity. The family is the foundational unit of society, yet many women do not have the choice to stay at home with their children because of social, economic or political pressures. Women's work as mothers and in the home must be valued as good in and of itself.
 
Love and service, not power, domination or bitterness
Dismayed by what they see as the bitterness, hatred, or retribution of many feminists against men or other women for current or past injustices, new feminists argue that men and women should cooperate with one another in interpersonal communion. This means giving of themselves in mutual service and love.
 
True freedom remembers purpose, including oughts as well as rights
In order for men and women to be truly free, new feminists assert that they must honor the Creator and love accordingly. Philosophy and Religion, then, are essential components in the search for how men and women should and ought to act for "a higher truth or good", not just how they want or can act. New feminists assert that people must gratefully remember God loves them as shown by creation; they must recognize that life, in some way, is a gift and not a mere thing which a person can claim as his or her exclusive property.
 
Fruitfulness, not just productivity
To be fruitful is to enable others to love and be loved. While productivity is valuable, helpful and necessary, it must be geared towards respect and love for the person – even though it takes longer, requires patience and the cooperation of others, and is appreciated not measured. Every act of service is a witness to the worth of the human person and thus promotes the progress of the whole human race.
 
Fertility, not sterility
Many new feminists assert that fertility is a natural, healthy biological process, not a disease that women need to take the Pill to be cured from. If women respect their fertility – their potential for physical and spiritual motherhood, they demand respect from others and deny that their sexuality is reducible to self-gratification. This devaluing of sexuality occurs with the use of contraceptives. Thus, the vast majority of new feminists discuss the spiritual, emotional, and physical benefits for men and women by following natural family planning instead of utilizing contraception.

Proponents

Contemporary proponents include Pia de Solenni, Janet E. Smith, Katrina Zeno, Elizabeth Fox-Genovese, R. Mary Lemmons, Colleen Carroll Campbell, Mary Beth Bonacci, Sister Prudence Allen, Alice von Hildebrand, Kimberly Hahn, Helen Alvare, Dorinda C. Bordlee, and Mary Ellen Bork. The work of earlier Catholic thinkers on masculinity and femininity, such as Hildegard of Bingen, Edith Stein and G. E. M. Anscombe, has also become recently influential in the development of new feminism. Though primarily originally in the thought of John Paul II, the movement also includes prominent non-Catholics, like Jewish author Wendy Shalit and Protestant activist Enola Aird.

Critiques

Critics of the movement argue that it was created by a patriarchal structure for its own maintenance. "It will always mean that men are defining women and telling women what it is like to be a woman," according to Sister of Mercy Mary Aquin O'Neill, director of the Mount Agnes Theological Center for Women in Baltimore. Until women are members of this higher authority, it can never make authoritative decisions about their perspectives because they are excluded from the vote.

Other critics maintain that no movement that opposes abortion and birth control in the form of artificial contraception can be positive for women. New feminism may also be a form of gender or biological determinism, which may be seen as old prejudices in a new guise.

This modern use of new feminism by the Catholic Church attempts to stray away from the traditional sentiments of the 1912 Catholic Encyclopedia that women and men do not belong together in the political, economic, and social spheres. It was never clarified though as to why these changes were made, and the Vatican still followed many premises that shared the same anthropological arguments of the 1912 Catholic Encyclopedia. Another critique of new feminism is that Pope John Paul II's positions can too easily be tied to more traditional Catholic teachings. This could cause the continuation of a worldview that negates the ability for men and women to successfully work together in a professional and/or social setting.
at

Thursday, March 19, 2020

Oldest Dryas

From Wikipedia, the free encyclopedia
 
Alpine valley, like Oldest Dryas

The Oldest Dryas is a biostratigraphic subdivision layer corresponding to an abrupt cooling event, or stadial, which occurred during the last glacial retreat. The time period to which the layer corresponds varies between regions, but it is generally dated as starting at 18.5-17 ka BP and ending 15-14 ka BP. As with the Younger and Older Dryas events, the stratigraphic layer is marked by abundance of the pollen and other remains of Dryas octopetala, an indicator species that colonizes arctic-alpine regions. In the Alps, the Oldest Dryas corresponds to the Gschnitz stadial of the Würm glaciation. The term was originally defined specifically for terrestrial records in the region of Scandinavia, but has come to be used both for ice core stratigraphy in areas across the world and to refer to the time period itself and its associated temporary reversal of the glacial retreat.

Dating

The edge of the ice in Greenland

The period was between 16,050-13,050 BC, from Roberts, 1998. A date from Kilkeel, Northern Ireland, extends the start of the period to as early as 17,050 BC. A strong sequence of carbon-14 dates derived from layered material in the Hauterive/Rouges-Terres excavations on the northwest shore of Lake Neuchâtel in Switzerland, 1992–1993, places the end of the Oldest Dryas at about 12,700 BC, calibrated. The same date from Antarctica and the south China sea is 14,600 and 14,700, respectively, and a Greenland ice core indicates 14,500. David Miles refers to the Oldest Dryas as the last Heinrich event (H1) and dates it to between 16,500 and 14,500 years ago.

The ultimate standard to which all these dates are to be compared is the graph of the oxygen isotope ratio cycles, which gives change in isotope concentration on the y-axis, with time on the x-axis. The graph plots many events that are sharply defined, but others are not. The selection of a terminal point is sometimes partially arbitrary.

The end of the Oldest Dryas is sharply defined. The beginning is a long, gently sloping band, probably no earlier than 17,050 BC, but the date might be set later by approximately 1000 years. Data derived from isotope variation of nitrogen and argon trapped in Greenland ice gives a high-resolution date for the end of the oldest Dryas at the sharp temperature rise of 14.67 ky BP.

Lake Neuchatel

The complete sequence of late Pleistocene climatic periods, defined for Northern Europe, are the Oldest Dryas (stadial), the Bölling (interstadial), the Older Dryas (stadial), the Allerød (interstadial), and the Younger Dryas (stadial). The Holocene begins immediately afterward. The last three are also Blytt-Sernander periods. 

Sometimes, the Older Dryas is missing, as in the Jura Mountains of France, or it is negligible in the evidence. In that case, the initial part of the sequence appears to be Oldest Dryas (cold), Bølling-Allerød (warm), Younger Dryas (cold). The Bølling-Allerød corresponds to the Windermere interstadial in Britain.

Often, however, the apparently-missing Older Dryas is a problem of resolution in the evidence. Some scientists have undertaken high-resolution studies, which combine a variety of climatological methods. They, like the ones conducted on Owens and Mono Lakes, in California, usually detect the Older Dryas. Even when it is detected, it appears to be no more than a few centuries of slightly-cooler weather on the oxygen isotope ratio graph.

Flora

During the Oldest Dryas, Europe was treeless and similar to the Arctic tundra, but much drier and grassier than the modern tundra. It contained shrubs and herbaceous plants such as the following:
  • Grassland (Inner Mongolia)
  • Artemisia vulgaris
  • Betula nana
  • Dryas octopetala

Fauna

Species were mainly Arctic but during the Glacial Maximum, the warmer weather species had withdrawn into refugia and began to repopulate Europe in the Oldest Dryas. 

The brown bear, Ursos arctos, was among the first to arrive in the north. Genetic studies indicate North European brown bears came from a refugium in the Carpathians of Moldavia. Other refugia were in Italy, Spain and Greece. 

The bears would not have returned north except in pursuit of food. The tundra must already have been well populated. It is likely that the species hunted by humans at Lake Neuchâtel in Switzerland by the end of the period were present during it. Here are other animals present:
  • Gavia arctica
  • Podiceps nigricollis
  • Cygnus cygnus
  • Aquila chrysaetos
The above birds are primarily maritime. They must have fed in the copious glacial waters of the north that were just beginning to be released.

  • Glacial stream
  • Lota lota
  • Salmo trutta
  • Salvelinus
The smaller mammals of the food chain inhabited the herbaceous blanket of the tundra:
  • Microtus oeconomus
  • Microtus arvalis
  • Lepus timidus
  • Marmota marmota
In addition to bears and birds were other predators of the following small animals:
  • Lynx (or Felis) lynx
  • Alopex lagopus
  • Canis lupus
  • Icelandic horse, perhaps like Equus ferus
Humans were interested in the large mammals, which included:
At some point, the larger mammals arrived: hyena, woolly rhinoceros, cave bear and mammoth.
  • Rangifer tarandus
  • Capra ibex
  • Woolly rhinoceros
  • Mammoth

Human prehistory

Jōmon pottery

Human cultures in Europe were Upper Palaeolithic and belonged to Cro-Magnon man. Neanderthals had long since disappeared by replacement or amalgamation with Homo sapiens. The Magdalenian culture of reindeer hunters prevailed in Western Europe. From the Carpathians eastward, the Epigravettian continued the prior Gravettian. In Japan, the Jōmon culture had already become sedentary and was producing some food, and possibly grew rice, but it was not at all urban. It was manufacturing the first known pottery.

One of the most remarkable discoveries of the period was the domestic wolf, a distinct breed of Canis lupus, with smaller teeth. The domestic dog, Canis familiaris, also has been found. It is thought that the animals helped with the hunting, but they would, by the nature of the hunt, have gradually become adept at herding.
at

Older Dryas

From Wikipedia, the free encyclopedia
 
The Older Dryas was a stadial (cold) period between the Bølling and Allerød interstadials (warmer phases), about 14,000 years Before Present), towards the end of the Pleistocene. Its date is not well defined, with estimates varying by 400 years, but its duration is agreed to have been around 200 years.

The gradual warming since the Last Glacial Maximum (27,000 to 24,000 years BP) has been interrupted by two cold spells: the Older Dryas and the Younger Dryas (c. 12,900-11,650 BP). In northern Scotland, the glaciers were thicker and deeper during the Older Dryas than the succeeding Younger Dryas, and there is no evidence of human occupation of Britain. In Northwestern Europe was also an earlier Oldest Dryas (18.5-17 ka BP-15-14 ka BP). The Dryas are named after an indicator genus, the Arctic and Alpine plant Dryas, the remains of which are found in higher concentrations in deposits from colder periods.

The Older Dryas was a variable cold, dry Blytt-Sernander period, observed in climatological evidence in only some regions, depending on latitude. In regions in which it is not observed, the Bølling-Allerød is considered a single interstadial period. Evidence of the Older Dryas is strongest in northern Eurasia, particularly part of Northern Europe, roughly equivalent to Pollen zone Ic.

Dates

In the Greenland oxygen isotope record, the Older Dryas appears as a downward peak establishing a small, low-intensity gap between the Bølling and the Allerød. That configuration presents a difficulty in estimating its time, as it is more of a point than a segment. The segment is small enough to escape the resolution of most carbon-14 series, as the points are not close enough together to find the segment.

One approach to the problem assigns a point and then picks an arbitrary segment. The Older Dryas is sometimes considered to be "centered" near 14,100 BP or to be 100 to 150 years long "at" 14,250 BP.
A second approach finds carbon-14 or other dates as close to the end of the Bølling and the beginning of the Allerød as possible and then selects endpoints that based on them: for example, 14,000-13,700 BP.

The best approach attempts to include the Older Dryas in a sequence of points as close together as possible (high resolution) or within a known event.

For example, pollen from the island of Hokkaidō, Japan, records a Larix pollen peak and matching sphagnum decline at 14,600-13700 BP. In the White Sea, a cooling occurred at 14,700-13,400/13,000, which resulted in a re-advance of the glacier in the initial Allerød. In Canada, the Shulie Lake phase, a re-advance, is dated to 14,000-13,500 BP. On the other hand, varve chronology in southern Sweden indicates a range of 14,050-13,900 BP.

Capturing the Older Dryas by high resolution continues to be of interest to climatologists.

Description

Northern Europe offered an alternation of steppe and tundra environments depending on the permafrost line and the latitude. In moister regions, around lakes and streams, were thickets of dwarf birch, willow, sea buckthorn, and juniper. In the river valleys and uplands, to the south, were open birch forests.

The first trees, birch and pine, had spread into Northern Europe 500 years earlier. During the Older Dryas, the glacier re-advanced, and the trees retreated southward, to be replaced by a mixture of grassland and cool-weather alpine species. The biome has been called "Park Tundra," "Arctic tundra," "Arctic pioneer vegetation," or “birch woodlands." It is now in the transition between taiga and tundra in Siberia. Then, it stretched from Siberia to Great Britain, in a more-or-less unbroken expanse. 

To the northwest was the Baltic ice lake, which was truncated by the edge of the glacier. Species had access to Denmark and southern Sweden. Most of Finland and the Baltic countries were under the ice or the lake for most of the period. Northern Scandinavia was glaciated. Between Britain and the Continental Europe were rolling hills prolifically populated with animals. Thousands of specimens, hundreds of tons of bones, have been recovered from the bottom of the North Sea, called "Doggerland," and they continue to be recovered.

There are many more species found for the period than in this article. Most families were more diverse than they are today, and they were yet more so in the last interglacial. A great extinction, especially of mammals, continued throughout the end of the Pleistocene, and it may be continuing today.

Evidence

The Older Dryas is a period of cooling during the Bølling-Allerød warming, estimated to be from 13,900 to 13,600 years before present (BP), and the estimated ages can vary using different age dating methods. Numerous studies on chronology and palaeoclimate of last deglaciation show a cooling event within Bølling-Allerød warming that reflects the occurrence of Older Dryas. The determination of paleotemperatures varies from study to study depending on the sample collected. δ18O measurements are most common when analyzing Ice core samples whereas the changing abundance pattern of fauna and flora are most commonly used when examining lake sediments. Moraine belts are usually studied in places with palaeoglacier presented. As for ocean sediments, the variations of alkenone levels and faunal abundances were measured to model paleotemperatures in separate studies showed in the following sections.

Ice core δ18O evidence

The North Greenland Ice Core Project (GRIP) members drilled an undisturbed ice core from North Greenland (75.1 8N, 42.3 8W). The ice core record showed a cold oscillation between 14,025 to13,904 years BP, which is reflected in the increased δ18O during this period. This cold oscillation was also observed in earlier ice core records (GRIP[8][9] and GISP2) drilled in early 1990s by GRIP members.

Lake sediment evidence

A multi-proxy study on late glacial lake sediments of Moervaart palaeolake shows multiple pieces of evidence in various aspects to support Older Dryas.

The lake sediment had an erosional surface prior to Older Dryas suggesting a change to colder climate. Microstructure observation of the sediments shows that fossil soil wedges or frost cracks were observed in the top of Older Dryas deposits, which indicates mean annual air temperatures below -1 to 0 ℃ and cold winters. This conclusion is also supported by the presence of Juniperus, which indicates a protecting snow cover in winter. This change is also shown on the records at the Rieme sites on the Great SandRidge of Maldegem-Stekene at Snellegem in NW Belgium, and many other sites in north-western Europe.

δ18O measurements show a decreasing trend in δ18O at the transition to the Older Dryas, which corresponds to the ice core record of precipitation in the northern hemisphere.

Pollen analysis shows a temporary decrease in the pollen levels of trees and shrubs with a short-term increase of herbaceous pollen. The changed pollen pattern suggests an increased abundance of grass as well as a retreat of tree and shrubs. The change of vegetation distribution further indicates a colder and drier climate during this period. As for aquatic plant evidence, both aquatic and semi-aquatic botanical taxa show a sharp decrease, suggesting lower lake levels caused by drier climate. The drier climate is also reflected by increased salinity indicated by diatom analysis.

The change of Chironomids population also indicates a colder climate. Microtendipes is an indicator of intermediate temperature in Late glacial deposits in northern Europe (Brooks and Birks, 2001). The abundance of Microtendipes peaked in the early part of Older Dryas suggesting a cold oscillation. The mollusc data (Valvata piscinalis as a cold-water indicator) suggests a lower summer temperature comparing to previous Bølling period.

Ocean sediment evidence

Recent research on sea surface temperature (SST) for the past 15,000 years in southern Okinawa modelled the Paleoclimate of ocean sediment core (ODP 1202B) using an alkenone analysis. The results show a cooling stage at 14,300 to 13,700 years BP between Bølling and Allerød warm phases, corresponding to the Older Dryas event.

Another study on an ocean sediment core from Norwegian Trench also suggests a cooling between Bølling and Allerød warm phases. The glacial polar faunal study on ocean sediment core Troll 3.1 based on Neogloboquadrina pachyderma abundances suggests that there were two cooling events before Younger Dryas in which one of the events occurred within Bølling-Allerød interstadial and can be associated with Older Dryas.

Moraine evidence

The study on late-glacial climate change in White Mountains (New Hampshire, USA) refined the deglaciation history of White Mountain Moraine System (WMMS) by mapping moraine belts and related lake sequences. The result suggests that the Littleton-Bethlehem (L-B) readvance of ice sheet occurred between 14,000 and 13,800 years BP. The L-B readvance coincided with the Older Dryas events and provides the first well-documented and dated evidence of Older Dryas.

Another Glacial chronology and palaeoclimate study on moraine suggests a cold oscillation in the second late-glacial (LG2) following the first late-glacial readvance (LG1) at around 14,000±700 to 13,700±1200 years BP. The LG2 cold oscillation around 14,000 years BP can correspond to the cooling of Greenland Interstadial 1 (GI-1d-Older Dryas) that happened around the same time period, which is the first chronological evidence that supports the presence of Older Dryas in the Tatra Mountains.

Flora

Older Dryas species are usually found in sediment below the bottom layer of the bog. Indicator species are the Alpine plants:
Grasslands species are the following:

Fauna

A well-stocked biozone prevailed on the Arctic plains and thickets of the Late Pleistocene. Plains mammals were most predominant:
  • Equus ferus, the wild horse. Many authors refer to it as Equus caballus, but the latter term is most correctly reserved for the domestic horse. Ferus is presumed to be one or more ancestral or related stocks to caballus and has been described as "caballine".
  • Coelodonta antiquitatis, woolly rhinoceros
So much meat on the hoof must have supported large numbers of Carnivora: Ursidae:
The sea also had its share of carnivores; their maritime location made them survive until modern times: Phocidae:
The top of the food chain was supported by larger numbers of smaller animals farther down, which lived in the herbaceous blanket covering the tundra or steppe and helped maintain it by carrying seeds, manuring and aerating it.

Humans

Eurasia was populated by Homo sapiens sapiens (Cro-Magnon man) during the late Upper Paleolithic. Bands of humans survived by hunting the mammals of the plains. In Northern Europe they preferred reindeer, in Ukraine the woolly mammoth. They sheltered in huts and manufactured tools around campfires. Ukrainian shelters were supported by mammoth tusks. Humans were already established across Siberia and in North America.

Two domestic dogs (Canis familiaris) have been found in late Pleistocene Ukraine and were a heavy breed, similar to a Great Dane, perhaps useful to run down Elephantidae. The large number of mammoth bones at campsites make it clear that even then, the Elephantidae in Europe were approaching the limit of their duration. Their bones were used for many purposes, one being the numerous objects of art, including an engraved star map.

Late Upper Palaeolithic culture was by no means uniform. Many local traditions have been defined. The Hamburgian culture had occupied the lowlands and Northern Germany before the Older Dryas. During the Older Dryas, contemporaneous with the Havelte Group of the late Hamburgian, the Federmesser culture appeared and occupied Denmark and southern Sweden, following the reindeer. South of the Hamburgian was the longstanding Magdalenian. In Ukraine was the Moldovan, which used tusks to build shelters.
at

Wax

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

Cetyl palmitate, a typical wax ester.
 
Commercial honeycomb foundation, made by pressing beeswax between patterned metal rollers.
 
Waxes are a diverse class of organic compounds that are lipophilic, malleable solids near ambient temperatures. They include higher alkanes and lipids, typically with melting points above about 40 °C (104 °F), melting to give low viscosity liquids. Waxes are insoluble in water but soluble in organic, nonpolar solvents. Natural waxes of different types are produced by plants and animals and occur in petroleum.

Chemistry

Ceroline brand wax for floors and furniture, first half of 20th century. From the Museo del Objeto del Objeto collection

Waxes are organic compounds that characteristically consist of long alkyl chains. Natural waxes may contain unsaturated bonds and include various functional groups such as fatty acids, primary and secondary alcohols, ketones, aldehydes and fatty acid esters, and aromatic compounds may also be present. Synthetic waxes often consist of homologous series of long-chain aliphatic hydrocarbons (alkanes or paraffins) that lack functional groups.

Plant and animal waxes

Waxes are synthesized by many plants and animals. Those of animal origin typically consist of wax esters derived from a variety of fatty acids and carboxylic alcohols. In waxes of plant origin, characteristic mixtures of unesterified hydrocarbons may predominate over esters. The composition depends not only on species, but also on geographic location of the organism.

Animal waxes

The best known animal wax is beeswax used in constructing the honeycombs of honeybees, but other insects secrete waxes. A major component of the beeswax is myricyl palmitate which is an ester of triacontanol and palmitic acid. Its melting point is 62-65 °C. Spermaceti occurs in large amounts in the head oil of the sperm whale. One of its main constituents is cetyl palmitate, another ester of a fatty acid and a fatty alcohol. Lanolin is a wax obtained from wool, consisting of esters of sterols.

Plant waxes

Plants secrete waxes into and on the surface of their cuticles as a way to control evaporation, wettability and hydration. The epicuticular waxes of plants are mixtures of substituted long-chain aliphatic hydrocarbons, containing alkanes, alkyl esters, fatty acids, primary and secondary alcohols, diols, ketones, aldehydes. From the commercial perspective, the most important plant wax is carnauba wax, a hard wax obtained from the Brazilian palm Copernicia prunifera. Containing the ester myricyl cerotate, it has many applications, such as confectionery and other food coatings, car and furniture polish, floss coating, and surfboard wax. Other more specialized vegetable waxes include jojoba oil, candelilla wax and ouricury wax.

Modified plant and animal waxes

Plant and animal based waxes or oils can undergo selective chemical modifications to produce waxes with more desirable properties than are available in the unmodified starting material. This approach has relied on green chemistry approaches including olefin metathesis and enzymatic reactions and can be used to produce waxes from inexpensive starting materials like vegetable oils.

Petroleum derived waxes

Although many natural waxes contain esters, paraffin waxes are hydrocarbons, mixtures of alkanes usually in a homologous series of chain lengths. These materials represent a significant fraction of petroleum. They are refined by vacuum distillation. Paraffin waxes are mixtures of saturated n- and iso- alkanes, naphthenes, and alkyl- and naphthene-substituted aromatic compounds. A typical alkane paraffin wax chemical composition comprises hydrocarbons with the general formula CnH2n+2, such as hentriacontane, C31H64. The degree of branching has an important influence on the properties. Microcrystalline wax is a lesser produced petroleum based wax that contains higher percentage of isoparaffinic (branched) hydrocarbons and naphthenic hydrocarbons.

Millions of tons of paraffin waxes are produced annually. They are used in foods (such as chewing gum and cheese wrapping), in candles and cosmetics, as non-stick and waterproofing coatings and in polishes.

Montan wax

Montan wax is a fossilized wax extracted from coal and lignite. It is very hard, reflecting the high concentration of saturated fatty acids and alcohols. Although dark brown and odorous, they can be purified and bleached to give commercially useful products.

Polyethylene and related derivatives

As of 1995, about 200 million kilograms/y were consumed.

Polyethylene waxes are manufactured by one of three methods: 1- direct polymerization of ethylene (may include co -monomers also); 2- thermal degradation of high molecular weight polyethylene resin; 3- recovery of low molecular weight fractions from high molecular weight resin production.

Each production technique generates products with slightly different properties. Key properties of low molecular weight polyethylene waxes are viscosity, density and melt point.

Polyethylene waxes produced by means of degradation or recovery from polyethylene resin streams contain very low molecular weight materials that must be removed to prevent volatilization and potential fire hazards during use. Polyethylene waxes manufactured by this method are usually stripped of low molecular weight fractions to yield a flash point > 500°F(> 260°C). Many polyethylene resin plants produce a low molecular weight stream often referred to as Low Polymer Wax (LPW). LPW is unrefined and contains volatile oligomers, corrosive catalyst and may contain other foreign material and water. Refining of LPW to produce a polyethylene wax involves removal of oligomers and hazardous catalyst. Proper refining of LPW to produce polyethylene wax is especially important when being used in applications requiring FDA or other regulatory certification.

Uses

Waxes are mainly consumed industrially as components of complex formulations, often for coatings. The main use of polyethylene and polypropylene waxes is in the formulation of colourants for plastics. Waxes confer matting effects and wear resistance to paints. Polyethylene waxes are incorporated into inks in the form of dispersions to decrease friction. They are employed as release agents, find use as slip agents in furniture, and confer corrosion resistance.

Candles

Wax candle.

Waxes such as paraffin wax or beeswax, and hard fats such as tallow are used to make candles, used for lighting and decoration.

Wax products

Waxes are used as finishes and coatings for wood products. Beeswax is frequently used as a lubricant on drawer slides where wood to wood contact occurs.

Other uses

A lava lamp is a novelty item that contains wax melted from below by a bulb. The wax rises and falls in decorative, molten blobs.

Sealing wax was used to close important documents in the Middle Ages. Wax tablets were used as writing surfaces. There were different types of wax in the Middle Ages, namely four kinds of wax (Ragusan, Montenegro, Byzantine, and Bulgarian), "ordinary" waxes from Spain, Poland, and Riga, unrefined waxes and colored waxes (red, white, and green). Waxes are used to make wax paper, impregnating and coating paper and card to waterproof it or make it resistant to staining, or to modify its surface properties. Waxes are also used in shoe polishes, wood polishes, and automotive polishes, as mold release agents in mold making, as a coating for many cheeses, and to waterproof leather and fabric. Wax has been used since antiquity as a temporary, removable model in lost-wax casting of gold, silver and other materials.

Wax with colorful pigments added has been used as a medium in encaustic painting, and is used today in the manufacture of crayons, china markers and colored pencils. Carbon paper, used for making duplicate typewritten documents was coated with carbon black suspended in wax, typically montan wax, but has largely been superseded by photocopiers and computer printers. In another context, lipstick and mascara are blends of various fats and waxes colored with pigments, and both beeswax and lanolin are used in other cosmetics. Ski wax is used in skiing and snowboarding. Also, the sports of surfing and skateboarding often use wax to enhance the performance.

Some waxes are considered food-safe and are used to coat wooden cutting boards and other items that come into contact with food. Beeswax or coloured synthetic wax is used to decorate Easter eggs in Romania, Ukraine, Poland, Lithuania and the Czech Republic. Paraffin wax is used in making chocolate covered sweets.

Wax is also used in wax bullets, which are used as simulation aids.

Specific examples

Animal waxes

Vegetable waxes

Mineral waxes

Petroleum waxes

at
Subscribe to: Posts (Atom)

Introduction to entropy

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

  • 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 ...