62 research outputs found
Dental Microwear and Diet of the Plio-Pleistocene Hominin Paranthropus boisei
The Plio-Pleistocene hominin Paranthropus boisei had enormous, flat, thickly enameled cheek teeth, a robust cranium and mandible, and inferred massive, powerful chewing muscles. This specialized morphology, which earned P. boisei the nickname “Nutcracker Man”, suggests that this hominin could have consumed very mechanically challenging foods. It has been recently argued, however, that specialized hominin morphology may indicate adaptations for the consumption of occasional fallback foods rather than preferred resources. Dental microwear offers a potential means by which to test this hypothesis in that it reflects actual use rather than genetic adaptation. High microwear surface texture complexity and anisotropy in extant primates can be associated with the consumption of exceptionally hard and tough foods respectively. Here we present the first quantitative analysis of dental microwear for P. boisei. Seven specimens examined preserved unobscured antemortem molar microwear. These all show relatively low complexity and anisotropy values. This suggests that none of the individuals consumed especially hard or tough foods in the days before they died. The apparent discrepancy between microwear and functional anatomy is consistent with the idea that P. boisei presents a hominin example of Liem's Paradox, wherein a highly derived morphology need not reflect a specialized diet
High rate of unintended pregnancy among pregnant women in a maternity hospital in Córdoba, Argentina: a pilot study
<p>Abstract</p> <p>Background</p> <p>Although Argentina has a new law on Reproductive Health, many barriers continue to exist regarding provision of contraceptive methods at public healthcare facilities.</p> <p>Methods</p> <p>We asked 212 pregnant women selected at random at the Maternity and Neonatal Hospital, Córdoba, Argentina, to participate in our descriptive study. Women were asked to complete a structured questionnaire. The objectives were to determine the rate of unintended pregnancies, reasons for not using contraception, past history of contraceptive use, and intended future use.</p> <p>Results</p> <p>Two hundred women responded to the questionnaire. Forty percent of the women stated that they had never used contraception and pregnancy was declared unintended by 65%. In the unintended pregnancy group, almost 50% of women said that they had not been using a contraceptive method because they were "unaware about contraception", and 25% stated that their contraceptive method had failed. Almost 85% of women stated that they intended to use contraception after delivery.</p> <p>Conclusion</p> <p>Approximately two-thirds of all pregnancies in this sample were unintended. Although the data is limited by the small sample size, our findings suggest that our government needs to invest in counseling and in improving the availability and access to contraceptive methods.</p
Behavioral, Ecological, and Evolutionary Aspects of Meat-Eating by Sumatran Orangutans (Pongo abelii)
Meat-eating is an important aspect of human evolution, but how meat became a substantial component of the human diet is still poorly understood. Meat-eating in our closest relatives, the great apes, may provide insight into the emergence of this trait, but most existing data are for chimpanzees. We report 3 rare cases of meat-eating of slow lorises, Nycticebus coucang, by 1 Sumatran orangutan mother–infant dyad in Ketambe, Indonesia, to examine how orangutans find slow lorises and share meat. We combine these 3 cases with 2 previous ones to test the hypothesis that slow loris captures by orangutans are seasonal and dependent on fruit availability. We also provide the first (to our knowledge) quantitative data and high-definition video recordings of meat chewing rates by great apes, which we use to estimate the minimum time necessary for a female Australopithecus africanus to reach its daily energy requirements when feeding partially on raw meat. Captures seemed to be opportunistic but orangutans may have used olfactory cues to detect the prey. The mother often rejected meat sharing requests and only the infant initiated meat sharing. Slow loris captures occurred only during low ripe fruit availability, suggesting that meat may represent a filler fallback food for orangutans. Orangutans ate meat more than twice as slowly as chimpanzees (Pan troglodytes), suggesting that group living may function as a meat intake accelerator in hominoids. Using orangutan data as a model, time spent chewing per day would not require an excessive amount of time for our social ancestors (australopithecines and hominids), as long as meat represented no more than a quarter of their diet
Women's attitudes towards mechanisms of action of family planning methods: survey in primary health centres in Pamplona, Spain
Irala J de, Lopez del Burgo C, Lopez de Fez CM, Arredondo J, Mikolajczyk RT, Stanford JB. Women's attitudes towards mechanisms of action of family planning methods: survey in primary health centres in Pamplona, Spain. BMC Women's Health. 2007;7(1): 10.Background: Informed consent in family planning includes knowledge of mechanism of action. Some methods of family planning occasionally work after fertilization. Knowing about postfertilization effects may be important to some women before choosing a certain family planning method. The objective of this survey is to explore women's attitudes towards postfertilization effects of family planning methods, and beliefs and characteristics possibly associated with those attitudes. Methods: Cross-sectional survey in a sample of 755 potentially fertile women, aged 18–49, from Primary Care Health Centres in Pamplona, Spain. Participants were given a 30-item, self-administered, anonymous questionnaire about family planning methods and medical and surgical abortion. Logistic regression was used to identify variables associated with women's attitudes towards postfertilization effects. Results: The response rate was 80%. The majority of women were married, held an academic degree and had no children. Forty percent of women would not consider using a method that may work after fertilization but before implantation and 57% would not consider using one that may work after implantation. While 35.3% of the sample would stop using a method if they learned that it sometimes works after fertilization, this percentage increased to 56.3% when referring to a method that sometimes works after implantation. Women who believe that human life begins at fertilization and those who consider it is important to distinguish between natural and induced embryo loss were less likely to consider the use of a method with postfertilization effects. Conclusion: Information about potential postfertilization effects of family planning methods may influence women's acceptance and choice of a particular family planning method. Additional studies in other populations are necessary to evaluate whether these beliefs are important to those populations
Nordic Seas polynyas and their role in preconditioning marine productivity during the Last Glacial Maximum.
Arctic and Antarctic polynyas are crucial sites for deep-water formation, which helps sustain global ocean circulation. During glacial times, the occurrence of polynyas proximal to expansive ice sheets in both hemispheres has been proposed to explain limited ocean ventilation and a habitat requirement for marine and higher-trophic terrestrial fauna. Nonetheless, their existence remains equivocal, not least due to the hitherto paucity of sufficiently characteristic proxy data. Here we demonstrate polynya formation in front of the NW Eurasian ice sheets during the Last Glacial Maximum (LGM), which resulted from katabatic winds blowing seaward of the ice shelves and upwelling of warm, sub-surface Atlantic water. These polynyas sustained ice-sheet build-up, ocean ventilation, and marine productivity in an otherwise glacial Arctic desert. Following the catastrophic meltwater discharge from the collapsing ice sheets at ~17.5 ka BP, polynya formation ceased, marine productivity declined dramatically, and sea ice expanded rapidly to cover the entire Nordic Seas
Author Correction: Identification of multiple risk loci and regulatory mechanisms influencing susceptibility to multiple myeloma
Correction to: Nature Communications; https://doi.org/10.1038/s41467-018-04989-w, published online 13 September 2018
Field study of the fate of labelled fertilizer nitrate applied to barley and maize in sandy soils
A diverse mammal-dominated, footprint assemblage from wetland deposits in the Lower Cretaceous of Maryland
Caractère inapproprié de l’urgence perçue des alarmes sonores utilisées dans les salles d’opération d’hôpitaux
Assessment of methods for studying the dissolution of phosphate fertilizers of differing solubility in soil
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