bluuebunny/crossref_metadata_2025 huggingface dataset:
Unplanned splenectomy—harbinger of complications
Authors: Spencer CDR David D. , Ragland CAPT Jerry J. , Limjoco CAPT Uriel R. , Rubio LCDR Carlos E.
Published: October 2018

Splenectomy alone or in combination with other major operative procedures has been implicated as the cause of excessive morbidity and mortality. We retrospectively studied 151 consecutive patients with splenectomy performed between 1985 and 1992. Subsets of patients according to indication for splenectomy were compared with a cohort of patients having elective open cholecystectomy. Morbidity with elective splenectomy (11.5%) was not significantly increased over that with elective open cholecystectomy (6.8%). Morbidity with nonelective splenectomy (40.4%) was increased when compared with that of elective splenectomy (11.5%) or with elective open cholecystectomy (6.8%). Mortality was significantly worse for nonelective (10.6%) than for elective splenectomy (1%). Nonelective splenectomy should be recognized as one event in a cascade of events leading to excessive morbidity and mortality. Splenectomy should not be implicated as the sole or primary cause of such excesses.
Acute myocarditis presenting as acute myocardial infarction
Authors: Silverman Alan J. , Kapadia Nafisa , Borin Andrew J.
Published: October 2018

Myocarditis, often caused by an infectious agent, may have a presentation mimicking that of acute myocardial infarction. The authors describe a young man who, when first seen in the emergency department, appeared to have an acute myocardial infarction with normal coronary arteries. At autopsy, the histologic findings were diagnostic of active myocarditis, mixed-cell type. Neutrophilic infiltration with microabscess suggested an infectious cause, although the etiology was uncertain. The patient's clinical course, pathologic' findings, and several treatment modalities are discussed The differentiation between acute myocardial infarction and acute myocarditis can be difficult. Electrocardiographic changes and enzyme elevations are common in both. Therefore, clinicians should consider myocarditis in all patients-particularly young patients with normal coronary arteries and suspected myocardial infarction.
Effects of different intermittent mandatory ventilation rates on oxygen consumption in premature infants recovering from respiratory distress syndrome
Authors: Greenspan Jay , Locke Robert G.
Published: October 2018

Oxygen consumption at intermittent mandatory ventilation (IMV) rates of 10 and 20 breaths per minute was evaluated to determine whether a higher IMV rate in mechanically ventilated premature infants with apnea and respiratory insufficiency would reduce metabolic expenditure. Ten studies were performed in seven infants, with three infants studied twice after a trial of failed elective extubation. The mean birth weight was 952 ± 183 kg (SD), and the mean postnatal age was 12 ± 8 days (SD). Mean oxygen consumption per kilogram of body weight was not significantly related to pulmonary resistance, dynamic lung compliance, or resistive work of breathing. Mean oxygen consumption was not altered at the different IMV rates. The oxygen consumption difference at the two IMV rates was not significantly related to dynamic lung compliance, resistance, or work of breathing. These results demonstrate that mechanically dependent premature infants without bronchopulmonary dysplasia do not have significant alteration in oxygen consumption with changes in IMV. This finding suggests that there is no potential metabolic energy balance benefit in use of moderately higher IMV rates to achieve improved growth rates in this population of infants.
Performance of osteopathic medical school graduates on the American Osteopathic Board of Internal Medicine certifying examinations 1985 to 1994
Authors: Slick Gary L. , Dolan Sandra , Draba Robert E.
Published: October 2018

This study examined the trends in the medical knowledge of osteopathic internal medicine residents in American Osteopathic Association-approved residency programs during a recent 10-year period and compared these trends with the declining medical knowledge observed for internal medicine residents graduated from allopathic medical schools and trained in allopathic residency programs. These results demonstrate a similar pattern of declining medical knowledge that appears to have leveled off during the past few years of the study. These trends occurred among candidates from both large and smaller training institutions. Various factors may have contributed to these observations.
Obstructive sleep apnea: A multisystemic disorder
Authors: D’Alonzo Gilbert E. , Kaluza Charles L. , Krachman Samuel L.
Published: October 2018

Obstructive sleep apnea is a multisystemic disorder with pathologic sequelae that become apparent after a number of years. Patients with obstructive sleep apnea generally present with hypersomnolence, and diagnosis is eventually established through observation of the patient during sleep. Patients with obstructive sleep apnea snore loudly and experience nocturnal oxygen de saturation and repetitive disruptions from sleep that eventually lead to daytime hypersomnolence. Numerous complex interactive pathophysiologic events occur during each obstructive episode, and it is important for the clinician to be aware of the cardiopulmonary, neurologic, and anatomic abnormalities associated with this condition. The anatomic configuration of the pharynx and the physiologic response to occlusion of the upper airway have a major role in the pathogenesis of this disorder. Alveolar ventilation during an apneic episode is immediately reduced to zero, and the metabolic demands for oxygen must be met by oxygen stores within the body. With repetitive episodes of obstruction, the oxygen stores within the lungs are diminished and the rate of arterial oxyhemoglobin desaturation increases. During apneic episodes, the systemic blood pressure increases while heart rate and cardiac output decrease. Bradydysrhythmias have been noted with the obstructive apneic episodes, and ventricular dysrhythmias are associated with episodes of severe oxyhemoglobin de saturation. Coexisting cardiopulmonary or neuromuscular disease in patients with obstructive sleep apnea contributes to the development of hypoventilation, serious gas exchange derangement, and general cardiovascular instability
The application of antitrust laws to the healthcare industry
Authors: Kiss Lois E. , Ross-Lee Barbara , Weiser Michael A.
Published: October 2018

The move toward managed care initiatives and multi provider networks has intensified in recent years in response to escalating healthcare costs and increasing market dominance by the insurance industry. As a consequence, the antitrust laws have played a significant role in defining the limits of physician cooperation. An understanding of the application of antitrust laws to evolving healthcare delivery systems and a knowledge of the specific areas where providers must exercise caution are essential to physicians' strategic planning. This article looks at the major areas of innovation emerging in the healthcare delivery market and details some of the most important guidelines for safeguarding physician collaborations. The authors compare the ability of physicians and insurers to organize integrated care systems and question the continued protection of the insurance industry under the McCarran-Ferguson Act.
Pneumoscrotum: An unusual complication of pulmonary resection
Authors: Raudat Charles W. , Katris Francis , Woodhall Dennis
Published: October 2018

Pneumoscrotum occurred in a 53-year-old man as a complication after pulmonary resection for carcinoma. Recognition of this entity and its conservative management are crucial to a positive outcome and prevention of unnecessary interventions based on the differential diagnosis. A review of the literature is included with this description of an unusual complication.
Spontaneous hemoperitoneum
Authors: Lucha LCDR Paul A.
Published: October 2018

Massive hemoperitoneum seen without an obvious precipitating event is rare. A 21-year-old man was seen with diffuse abdominal pain of 48 hours' duration. He had no fever, nausea, or vomiting, and most laboratory values were normal. Exploration of the abdomen revealed free intraperitoneal blood with clotting but failed to reveal a source. The patient could recall no trauma or other inciting event. The only abnormalities found during laparotomy were multiple adhesions of the omentum to the lateral abdominal wall and localization of most of the clot within the greater omentum. The author cautions that a high index of suspicion followed by laparotomy are the management tools for controlling spontaneous hemoperitoneum. Conservative management produces a high mortality rate.
Osteopathic manipulative treatment applications for the emergency department patient
Authors: Paul Frank A. , Buser Boyd R.
Published: October 2018

The emergency department (ED) setting offers osteopathic physicians multiple opportunities to provide osteopathic manipulative treatment (OMT) as either the primary therapy or as an adjunct to the intervention. In doing so, osteopathic physicians can decrease or eliminate the morbidity and symptoms associated with protracted dysfunction. Low back pain, chest pain, torticollis, asthma, and sinusitis are some of the illnesses in which OMT should be implemented as part of the management plan, note the authors. They provide a guide to the general usage of OMT when the aforementioned illnesses present themselves in ED patients, but also emphasize the importance of first ruling out any underlying illnesses that could be manifested by musculoskeletal symptoms.
The power of words: Communicating effectively with young patients
Authors: Marino, Ronald V. , Kohen Daniel P.
Published: October 2018

Communication skills are the cornerstone of the doctor-patient relationship. This article provides clinically helpful hints to practitioners working with children and families. Specific examples of clinical phrases are presented along with alternative phrases that may enhance the clinical process.
Effects of thyroid hormone treatment on 31P-NMR spectroscopy of muscle and on nerve conduction studies in a patient with long-standing severe hypothyroidism
Authors: Reeves, Roy
Published: October 2018

Hypothyroidism exerts a significant effect on several body systems, including the functioning of muscle and nerve. Described here is the case of a severely hypothyroid patient with weakness and numbness of the legs who showed marked clinical improvement with thyroid hormone treatment. Concurrently obtained phosphorus 31-nuclear magnetic resonance (NRM) spectra and nerve conduction studies showed changes in muscle phosphorus metabolism with increases in conduction velocities. Phosphorus 31-NMR spectroscopy is useful for evaluating metabolism in muscle in hypothyroid patients.
Acute appendicitis secondary to non-0 group I Vibrio cholerae
Authors: Cook Michael A. , Nedunchezian Deeptha , Manfredi Orlando L.
Published: October 2018

Acute appendicitis is the most common abdominal surgical condition and is usually associated with colonic flora. The patient described had acute appendicitis associated with an uncommon microorganism. This report underscores the importance of obtaining an adequate occupational, travel, and dietary history.
Influence of mutation bias and hydrophobicity on the substitution rates and sequence entropies of protein evolution
Authors: Jiménez-Santos María José , Arenas Miguel , Bastolla Ugo
Published: October 2018

The number of amino acids that occupy a given protein site during evolution reflects the selective constraints operating on the site. This evolutionary variability is strongly influenced by the structural properties of the site in the native structure, and it is quantified either through sequence entropy or through substitution rates. However, while the sequence entropy only depends on the equilibrium frequencies of the amino acids, the substitution rate also depends on the exchangeability matrix that describes mutations in the mathematical model of the substitution process. Here we apply two variants of a mathematical model of protein evolution with selection for protein stability, both against unfolding and against misfolding. Exploiting the approximation of independent sites, these models allow computing site-specific substitution processes that satisfy global constraints on folding stability. We find that site-specific substitution rates do not depend only on the selective constraints acting on the site, quantified through its sequence entropy. In fact, polar sites evolve faster than hydrophobic sites even for equal sequence entropy, as a consequence of the fact that polar amino acids are characterized by higher mutational exchangeability than hydrophobic ones. Accordingly, the model predicts that more polar proteins tend to evolve faster. Nevertheless, these results change if we compare proteins that evolve under different mutation biases, such as orthologous proteins in different bacterial genomes. In this case, the substitution rates are faster in genomes that evolve under mutational bias that favor hydrophobic amino acids by preferentially incorporating the nucleotide Thymine that is more frequent in hydrophobic codons. This appearingly contradictory result arises because buried sites occupied by hydrophobic amino acids are characterized by larger selective factors that largely amplify the substitution rate between hydrophobic amino acids, while the selective factors of exposed sites have a weaker effect. Thus, changes in the mutational bias produce deep effects on the biophysical properties of the protein (hydrophobicity) and on its evolutionary properties (sequence entropy and substitution rate) at the same time. The program Prot_evol that implements the two site-specific substitution processes is freely available athttps://ub.cbm.uam.es/prot_fold_evol/prot_fold_evol_soft_main.php#Prot_Evol.
МОРФОСТРУКТУРНЫЙ АНАЛИЗ ПРИ РЕШЕНИИ ГЕОЛОГИЧЕСКИХ ПРОБЛЕМ ВОСТОКА АЗИИ, "Геоморфология"
Authors: Изосов Л.А. , Чупрынин В. И. , МЕЛЬНИЧЕНКО Ю.И. , Ли Н.С.
Published: October 2018

Окраинные моря Западно-Тихоокеанской зоны перехода континент-океан рассматриваются как вихревые структуры. В Япономорском регионе (ЯР) применение линеаментного анализа (комплекса геоморфологических, геологических и геофизических методов) позволило выявить в континентальной части Япономорского региона рудоконтролирующие зоны (эндогенного оруденения, месторождений алмазов и др.), скрытых разломов фундамента и магматических очаговых структур, а на дне Японского моря разломных структур. В регионе: 1) выявлены три литосферные вихревые морфоструктуры - Япономорская (ЯМ), Нижнеамурская (НА) и Сунляо (СЛ), 2) выделены два структурных этажа: мантийный и литосферный, включающие, соответственно, тектонический каркас и вихревые структуры, тесно связанные с подстилающей астеносферой. ЯМ морфоструктура отражает процесс раскрытия Японского моря - как результат взаимодействия Евроазиатской и Тихоокеанской плит; НА - соответствует межгорная впадина, с которой на западе сочленяется нефтегазоносная депрессия Сунляо вихревого типа. В ЯР развиты нефтегазоносные мезокайнозойские осадочные бассейны, представляющие литосферные вихри. Линеаментный анализ позволит по-новому прогнозировать характер миграции углеводородов в земной коре и выявлять предполагаемые места их скопления. Этот метод может быть использован в процессе подготовительного этапа при исследовании нефтегазоносности Западно-Тихоокеанских окраинных морей, а также Арктических бассейнов.
Deadenylation by the CCR4‐NOT complex contributes to the turnover of hairy‐related mRNAs in the zebrafish segmentation clock
Authors: Fujino Yuuri , Yamada Kazuya , Sugaya Chihiro , Ooka Yuko , Ovara Hiroki , Ban Hiroyuki , Akama Kagari , Otosaka Shiori , Kinoshita Hirofumi , Yamasu Kyo , Mishima Yuichiro , Kawamura Akinori
Published: October 2018

In the zebrafish segmentation clock, hairy/enhancer of split‐related genes her1, her7, and hes6 encodes components of core oscillators. Since the expression of cyclic genes proceeds rapidly in the presomitic mesoderm (PSM), these hairy‐related mRNAs are subject to strict post‐transcriptional regulation. In this study, we demonstrate that inhibition of the CCR4‐NOT deadenylase complex lengthens poly(A) tails of hairy‐related mRNAs and increases the amount of these mRNAs, which is accompanied by defective somite segmentation. In transgenic embryos, we show that EGFP mRNAs with 3′UTRs of hairy‐related genes exhibit turnover similar to endogenous mRNAs. Our results suggest that turnover rates of her1, her7, and hes6 mRNAs are differently regulated by the CCR4‐NOT deadenylase complex possibly through their 3′UTRs in the zebrafish PSM.
Vibration measurement and structural performance evaluation of a 17th century timber guest house in Japan
Authors: Toyoda Takahiro , Fujita Kaori , Takano Kiyoshi
Published: October 2018

To clarify the actual structural performance of an existing traditional timber structure in Japan, vibration measurements were carried out at a 17th century timber guest house (Gekkouden of Gokokuji temple). The results of the micro tremor measurement, earthquake monitoring, and analysis are discussed in this paper. For minute angles of less than 1/5000 rad, it was revealed through earthquake monitoring that each dominant frequency was strongly dependent on the vibration amplitude. It was also confirmed that the dominant frequencies of the lower vibration modes in 1/1000 rad declined to 65%‐75% of the frequencies obtained through micro tremor measurement. We propose a structural model that consists of a joint spring, column, beam, and hanging wall, based on previously reported experiments. In this study, it was clarified that the dominant frequencies determined by the analysis of the proposed structural model were in good agreement with the frequencies obtained through earthquake monitoring.
Accommodation
Authors: Tracer David P.
Published: October 2018

Accommodation is a concept describing a morphological or physiological response to a stressor that results in some measure of reduced or suboptimal functioning. It is often contrasted with the concept of adaptation defined as a response that fully maintains an organism's physiological functioning within its preferred range.
Adiposity
Authors: Demerath Ellen Wrchota
Published: October 2018

Adiposity is the amount of adipose tissue relative to body size. The primary function of adipose tissue is to control the storage and release of energy to other tissues in the form of triglycerides. Humans are characterized by high levels of adiposity, with rapid increases in infancy and puberty, particular in females. These species characteristics reflect natural selection in the context of unpredictable food supplies, and rapid postnatal brain growth supported by maternal energy stores during human evolution. Adiposity is under polygenic control, but diet, activity, and environmental factors interact with genomic variation to produce considerable human variation across individuals and populations. Weight and height indices provide simple and useful but sometimes invalid approximations of adiposity. Obesity, or excessive adiposity, is a novel phenomenon reflecting recent changes in the environment and increases the risk of numerous chronic diseases due to activation of the immunological system, among other physiologic changes.
Adolescent growth spurt
Authors: Gurri Francisco D.
Published: October 2018

The adolescent growth spurt refers to the rapid increase in height and weight that begins with puberty, lasts throughout adolescence, and stops with the cessation of linear growth. The spurt precedes and follows a series of hormonal, physiological, psychological, and behavioral changes that turn juvenile males and females into reproductive adults. Its age of onset will vary by sex, and across populations, and children in developed nations have experienced a secular reduction since the second half of the nineteenth century. The adolescent growth spurt may be species specific and may have appeared with
Homo sapiens sapiens
approximately 125,000 years ago in Africa.
Alu
elements
Authors: Watkins W. Scott
Published: October 2018

Alu
elements are a prolific class of short interspersed elements (SINEs) that have expanded rapidly in the genomes of primates during the last 65 million years.
Alu
elements are non‐autonomous and utilize the endonuclease/reverse transcriptase produced by long interspersed elements (LINEs) to copy and insert into new locations throughout the genome in a process known as retrotransposition.
Alu
insertions produce homoplasy‐free genetic markers with known ancestral states. Subsets of lineage‐specific and polymorphic
Alu
elements have been instrumental for resolving phylogenetic relationships among primates and for understanding genetic differentiation in humans.
Alu
elements contribute to genetic disease through insertional mutagenesis and non‐allelic homologous recombination. Ongoing retrotransposition and
Alu
‐mediated recombination are important evolutionary forces that continue to create new genetic diversity and reshape the genomes of humans and other primates.
Anthroponoses
Authors: Muehlenbein Michael P.
Published: October 2018

Anthroponoses are infectious organisms that cause pathogenic disease and are specifically spread from humans to other animal species. They pose a significant threat to the conservation of endangered species, particularly nonhuman primates that are genetically closely related to us, and usually immunologically‐naive to our pathogens, and have protracted reproductive rates. A minimum of seven different pathogens have been confirmed using genetic analyses to have been transmitted from humans to wild primates, and the likely number of these transmission events is much higher. In the absence of education and regulation, the problem of anthroponoses will continue as a result of increased tourism, research, and environmental encroachment.
Arambourg, Camille
Authors: Coppens Yves
Published: October 2018

Camille Arambourg (1885–1969) was a French paleontologist and Professor at the National Museum of Natural History in Paris. A field scientist, Arambourg worked extensively in the Maghreb but also in Ethiopia in the early 1930s and the late 1960s. He amassed huge collections of fossil vertebrates, including a significant number of hominins (Australopithecusand early species of the genusHomo). His classic synthesis on human evolution,La Genèse de l'Humanité, was translated into many languages.
A
tapuerca
Authors: Quam Rolf M.
Published: October 2018

The Sierra de Atapuerca in northern Spain is renowned for the presence of numerous Pleistocene and Holocene sites which have yielded abundant human fossils and archaeological materials. The Sima del Elefante site documents the earliest human occupation in Europe, at just over a million years ago. The human fossils from the site of Gran Dolina have been attributed to a new species of hominin,
Homo antecessor
, and show evidence of early cannibalistic practices. The Sima de los Huesos has yielded thousands of human bones dating to around 430,000 years ago and representing Neandertal ancestors. The site has been interpreted as documenting early funerary practices and perhaps symbolic behavior. Evidence of human presence in the Sierra during the Late Pleistocene is also found at the Galería de Estatuas site as well as several open air localities. The more recent prehistoric sites of El Mirador and El Portalón contain evidence of human activities during Neolithic and Bronze Age times.
Biocultural models
Authors: Zuckerman Molly K.
Published: October 2018

Since the middle of the twentieth century, the biocultural or biosocial approach has acted as a unifying and integrative perspective within anthropology, particularly within the fields of biological anthropology and medical anthropology. Multiple definitions exist, but, overall, the approach emphasizes and models the interaction of biology and culture within any given human phenomena, attending to how these two variables are intractably intertwined, and focusing on the dynamic, dialectical interactions that occur between humans and their environments. The approach arose from the combined influences of the population approach, the ecological approach, human adaptability, political economy, and processual ecology. Anthropologists have used the approach and models translated from it as flexible interpretive tools for conducting research that crosscuts various intellectual traditions and perspectives, and brings time‐depth, an evolutionary perspective, and attention to environmental change to considerations of human health, disease, biology, behavior, and culture.
Black, Davidson
Authors: Sigmon Becky A.
Published: October 2018

The earliest known fossil evidence of
Homo erectus
in China was found at Choukoutien (Zhoukoudian), in 1923 and 1927, when Davidson Black (1884–1934) described and placed the fossils into the new taxon,
Sinanthropus pekinensis
. Between 1929 and 1934, Black described and published on further fossil material found at Choukoutien, including a skull found in 1929. He made casts of these fossils and filmed his preparation of the casting of the
Sinanthropus
skull. This skull was lost, along with the other
Sinanthropus
fossils, during World War II. The casts he made of the fossils found at Choukoutien from 1929 to 1934 remain priceless to science.
B
oas,
F
ranz
Authors: Goodman Alan H.
Published: October 2018

Franz Boas (1858–1942) was the foremost proponent of an integrated anthropology. He pioneered research in linguistics, cultural anthropology, archaeology, and physical anthropology. His most enduring work in physical anthropology tested the stability of European racial types. Boas concluded that cranial forms and racial types were plastic, not fixed. He was an early antiracist and called for the independence of the science of culture from race biology.
Genetic bottleneck
Authors: Kitchen Andrew
Published: October 2018

Genetic bottlenecks occur when populations rapidly decrease in size and result in a reduction in genetic diversity. The reduction in diversity is the product of fewer individuals contributing alleles to the gene pool and the rapid effects of genetic drift in smaller populations. The effects of bottlenecks on reducing genetic diversity in a population are long lasting and occur throughout the genome. The effect of severe genetic bottlenecks experienced when populations are founded by a small group of individuals is termed the founder effect.
Catch‐up growth
Authors: Bekelman Traci A.
Published: October 2018

Catch‐up growth refers to a growth trajectory in which a child's height velocity increases beyond what is expected for a child of that age and sex after a period of growth restriction. Understanding catch‐up growth allows biological anthropologists to answer questions about (1) how children adapt their growth and development in response to changes in the environment, and (2) whether the opportunities for growing taller, that were lost due to adverse conditions, can be recuperated.
Primate conservation
Authors: Kling Katherine , Wright Patricia C.
Published: October 2018

Primate conservation is a field of acknowledged need but often undefined practice. With conservation efforts aimed at the protection and perpetuation of primate species across the globe, reaching audiences even beyond primate‐range countries, primate conservation is well situated to impact both humans and nonhuman primates alike. Approaches to primate conservation as well as foundational underpinnings are covered here in addition to noted challenges and directions for future expansion and improvement.
Conserved regions (human accelerated regions)
Authors: Jagoda Evelyn , Capellini Terence D.
Published: October 2018

Conserved regions are portions of the genome that exhibit a high degree of sequence similarity or percent nucleotide identity across taxonomic groups. Conserved sequences have maintained high levels of identity because of conserved functional usage. This entry then discusses accelerated regions. These are regions that are generally conserved in a taxon, but have undergone rapid changes in one species or clade. Given the focus of current scientific investigation on uncovering the mechanisms underlying the uniqueness of the human condition, much focus has been on the identification of human accelerated regions (HARs), regions that have rapidly evolved in humans compared to closely related primates, and mammals in general.
Craniofacial development, normal and abnormal
Authors: Richtsmeier Joan T. , Perrine Susan M. Motch
Published: October 2018

Craniofacial development is an extraordinarily complex process that begins with the formation of the neural tube in utero and continues through adulthood. Growth and development of the cartilage and bony head skeletons that function to support and protect the brain and other soft tissues has been of primary concern to anthropologists due to our interest in fossilized and archaeologically recovered skeletal remains, and the availability of museum skeletal collections. However, an understanding of craniofacial development requires consideration of all cranial tissues and their coordinated developmental trajectories, pre‐ and postnatally. Change in the behaviors of cells that constitute a specific cell lineage or that form a specific tissue can cause changes in differential growth that result in fundamental, global alterations in craniofacial morphology. Knowledge of the embryonic source and developmental contributions of specific cells and tissues to craniofacial morphology helps to clarify the integration of these processes across developmental time and space and adds to our understanding of craniofacial development, disease, and evolution.
Craniofacial morphology and adaptation
Authors: Sardi Marina L.
Published: October 2018

Skull morphology of human populations has been the focus of numerous studies spanning more than a century. Analysis indicates that there is a strong genetic influence on morphology, thus allowing the estimation of relatedness between populations. Craniofacial morphology is also influenced by environmental factors, such as climate and diet.
Hominin dental evolution
Authors: Delezene Lucas K. , Ungar Peter S.
Published: October 2018

Teeth play a prominent role in paleoanthropological research. Details of tooth size, shape, and structure are used to delineate species and to provide insight into the social behavior, life history, and ecological strategies of extinct species. Further, enamel stable isotopes, dental microwear, and food residue analyses are used to capture dietary behaviors at different temporal scales within an individual's life. Thus, teeth provide an excellent source of information about the evolution and ecology of our extinct relatives.
Diets (primates)
Authors: Cassalett Santiago , Rothman Jessica M.
Published: October 2018

Few topics in the primate literature have received more attention than the topic of primate diets. Primates have been shown to consume a wide diversity of foods and primate diets can vary tremendously between seasons and habitats. Food can be considered a selective force, influencing key aspects of primate behavior, ecology, and morphology in relation to environmental heterogeneity. In this article, we provide an overview of the variety of diets consumed by species across the Primate Order. By no means should this be viewed as a complete listing of what is known about primate diets, but it may serve as a starting point for those interested in the subject.
Dispersal
Authors: Jack Katharine M.
Published: October 2018

Dispersal of one or both sexes from the natal (birth) group is a feature common to most social mammals. Which sex disperses is largely a function of the food supply and its concomitant effect on within‐ and between‐group foraging competition. In many species exhibiting male‐biased dispersal, males will continue to move between groups throughout their lives. Known as secondary dispersal, this phenomenon has only rarely been reported for female dispersing primates. Natal dispersal is thought to be an adaptation for avoiding inbreeding, while secondary dispersal is better explained as a mechanism of intrasexual mating competition. Our knowledge of dispersal in primates is naturally limited due to the difficulties of tracking the dispersing sex. However, given the ramifications of dispersal on both group structure and the resultant social relationships within groups, this is an important area for further research.
Ecological communities
Authors: Lambert Joanna E.
Published: October 2018

An ecological community is an assemblage of sympatric species. Primates are found in communities in North America (Mexico), Central America, South America, Asia, Africa, and Madagascar. Differences in community structure are the result of a broad range of biotic and abiotic factors, including total forested area, biogeography, rates of speciation, extinction and colonization, biotic productivity of the region, altitude, and latitude. The interactions between primates and other species in a community can have either negative, positive, or neutral effects on each of the two interacting species, depending upon whether the interaction is competitive, parasitic, predatory, mutualistic, or an ammensalism/commensalism.
Essential amino acid
Authors: Gruca Margaret A. , Dufour Darna L.
Published: October 2018

Amino acids are the building blocks for tissue protein in all animals. They are classified into two traditional subgroups: essential and nonessential. Essential amino acids are defined as those amino acids that cannot be synthesized solely using existing metabolites and enzymes within the body (de novo) and therefore require a dietary source. As novel functions of amino acids have been discovered, the classification of amino acids has expanded beyond the classic definitions of “essential” and “nonessential” to assess dietary need for optimal growth, development, reproduction, and immune function.
Fertility
Authors: Leslie Paul W.
Published: October 2018

Fertility and fecundity are related terms: fecundity refers to the biological capacity or potential for reproduction, while fertility refers to the actual production of live offspring. Biological fecundity is a necessary precondition for fertility, but a wide array of influences of environment and of individual behavior modify that potential and shape achieved fertility. Human populations vary greatly in both the level and timing of fertility. Much of this variation can be understood in terms of pathways linking patterns of behavior and environmental conditions to reproductive physiology, especially ovarian function, through the study of reproductive ecology. Evolutionary theory, especially life‐history theory, provides a basis for an integrated understanding of the biological aspects of reproduction and their relationship to the social and biophysical environments.
Forensic anthropology
Authors: Dirkmaat Dennis , Garvin Heather , Cabo Luis L.
Published: October 2018

The field of forensic anthropology is a scientific discipline, within the broader field of physical anthropology, which is focused on the analysis and interpretation of human remains in medicolegal contexts. Historically, the role of the forensic anthropologist was aimed at providing a biological profile derived from the detailed study of the skeletal tissues, which included an assessment of age, sex, stature, and ancestry of the individual, in order to assist in identifying the unknown person. Since then, the field has expanded to include the forensic archaeological recovery of remains as well as forensic taphonomic and trauma evaluations. As such, the forensic anthropologist is tasked with not only aiding in uncovering the identity of the individual, but also the circumstances surrounding their death. Forensic anthropologists are employed in a variety of settings, including academia, medical examiners' offices, government agencies, and human rights agencies.
G
arn,
S
tanley
M.
Authors: LaVelle Marquisa
Published: October 2018

Stanley Marion Garn (1922–2007) received his undergraduate and graduate education at Harvard college under the tutelage of Ernest Albert Hooton. In 1952 he became chair of the Department of Growth and Genetics at the Fels Research Institute in Ohio. Subsequently he joined the Center for Human Growth and Development at the University of Michigan as Professor of Nutrition in the School of Public Health and of Anthropology. He retired as Emeritus in 1993. Garn's research encompassed sociocultural interactions of nutrition and genetics in relation to lifelong human growth processes and documenting worldwide human biological variation. Garn served as president of the American Association of Physical Anthropologists (1965–67) and was an elected member of the National Academy of Sciences (1976). An excellent teacher, renowned for his clarity and wit in research presentations, and notable for his ingenious approaches to complex biological problems, Garn had a prolific publishing record, including six books and more than 800 articles, that has generated more than 20,000 citations.
Genetic adaptation
Authors: Johnston Susan L.
Published: October 2018

Genetic adaptation has played a significant role in modern human population biology, particularly in supporting population survival in the face of major environmental stressors. Specific genetic adaptations reflect the impact of natural selection acting on trait variation in populations. Human biologists have identified a number of traits unique to particular populations and environmental contexts that appear to represent selection of phenotypes that are able to resist infection by potentially lethal diseases, afford protection from the effects of severe cold or hypoxia, or improve survival under low energy conditions—among other capabilities. These traits range from simple polymorphisms to complex traits involving multiple genes and effects. In the last decade or so, research has increasingly focused on direct study of genetic variability made possible by the mapping of the human genome and utilizing a variety of new tools and approaches.
Gona
Authors: Semaw Sileshi , Rogers Michael J.
Published: October 2018

The Gona Paleoanthropological Research Project study area, in the Afar region of Ethiopia, is among the most important in East Africa for investigating the biological and behavioral evolution of ancestral hominins over the past six million years. Well known for yielding the earliest Oldowan stone artifacts dated to 2.6 million years ago, Gona is located just southwest of Hadar, famous for the discovery of the 3.2‐million‐year‐old “Lucy” skeleton. Extensive and systematic field and laboratory research since 1999 at Gona has resulted in the discovery of numerous hominins and archaeological sites from several important time intervals in human evolution.
G
orjanović‐
K
ramberger,
D
ragutin
Authors: Radovčić Jakov
Published: October 2018

Gorjanović‐Kramberger was an experienced Croatian paleontologist and geologist, who is best known for his work on the Krapina Neandertal site. Methodologically ahead of his time, he pioneered a number of field and laboratory techniques. In 1906, he published a lengthy monograph on the Krapina Neandertals, containing the first detailed analysis of the Neandertal fossils within their geological and archaeological frameworks. He contended that Neandertals possessed considerable morphological variation. Observing many similar anatomical traits between the Krapina Neandertals and much younger Upper Paleolithic human remains from Moravia and recent populations, Gorjanović‐Kramberger proposed that these ancient humans were on the lineage leading to modern humans. Thus, he envisaged morphological, and therefore biological continuity between Neandertals and modern
Homo sapiens
.
Grouping patterns in nonhuman primates
Authors: Isbell Lynne A.
Published: October 2018

Traditionally, primate grouping patterns have been classified by the number and sex of adults traveling together: solitary foragers, pairs, extended families, single‐male/multi‐female groups, multi‐male/multi‐female groups, multi‐level groups, and fission–fusion groups. It has long been assumed that larger, more complex groups evolved from simpler grouping patterns, but this has been challenged recently by an evolutionary framework in which it is argued that solitary foraging led to the evolution of large, multi‐male/multi‐female groups, which later gave rise to pairs and single‐male/multi‐female groups at approximately the same time. Regardless of how they might have occurred, evolutionary transitions cannot account for variation in grouping patterns at the population and group level. Alternatives include demographic, phylogenetic, and ecological frameworks. While the demographic approach appears to be limited, phylogenetic constraints may explain similar grouping patterns within genera that have extensive geographic distributions, whereas shared ecological conditions may better explain convergence in grouping patterns among unrelated species.
Growth spurts
Authors: Lampl Michelle
Published: October 2018

Growth spurts, abrupt proliferative surges, have been commonly observed for centuries. Detailed scientific documentation of their time course and biology are only just emerging. Traditional academic concepts derived from annual measurement protocols include the brain growth spurt, and the infancy, mid‐childhood, and adolescent growth spurts, thought to occur over months or years and to reflect broad hormonal and energetic strategies. These constructions are embedded in theoretical scenarios of modern human evolutionary history. Empirical growth studies document that these classical growth spurt phenotypes reflect undersampling. Daily sampling clarifies that physical growth spurts actually occur in minutes to hours, in both skeletal and head dimensions, and are how children grow across all ages. Knowing when growth actually occurs permits discovery of biological mechanisms underlying both normal and abnormal growth, offers the opportunity to test previously held assumptions, and may contribute to a refinement of long‐held viewpoints involving growth‐mediated adaptive strategies in human biology.
Handedness
Authors: Marchant Linda F.
Published: October 2018

In humans, the tendency to use, prefer, or favor one hand over the other is characterized by a strong skew for right‐handedness, typically a 9:1 ratio. In nonhuman primates, patterns of laterality are more diverse, may vary within and between species, and exhibit the strongest directional asymmetries when primates engage in fine motor manipulation of food or objects.
Skeletal histomorphometry
Authors: Stout Samuel D. , Cole Mary E.
Published: October 2018

Bone tissue remodels throughout the lifespan to renew old tissue, repair damage, and adapt to changing mechanical loading. The resulting basic structural unit (BSU), known as a secondary osteon in cortical bone and a hemi‐osteon in cancellous bone, has particular anthropological relevance. Osteon population density is used to estimate age at death and remodeling rate, which is linked to skeletal health. BSUs also serve as markers of bone quality. Mechanical loading influences the number and geometry of vascular and cellular pores that penetrate BSUs, and the orientation of collagen fibers within the bone tissue of the BSU. Changes in porosity and collagen fiber orientation with age contribute to declining bone strength.
Infinite allele model
Authors: Gatenbee Chandler
Published: October 2018

In 1964, Motoo Kimura and James Crow developed the infinite allele model in an effort to predict the upper limit of genetic diversity that could be observed at a selectively neutral locus in an isolated population of finite size. In such a system, the balance between genetic drift and mutation determines the equilibrium amount of diversity, as the former removes variation, while the latter introduces it. As it is assumed that each allele is neither advantageous nor deleterious, and thus selectively neutral, the infinite allele model provides a framework for modeling the neutral theory of molecular evolution.
Keith,Arthur
Authors: Tuttle Russell H.
Published: October 2018

Sir Arthur Keith (1866–1955) was an eminent British human anatomist, comparative functional morphologist, and physical anthropologist. Many of his paleoanthropological judgments were incorrect and, on topics that could affect social policy and pacific human relationships, biased and wrongheaded. His enduring work, based on solid field observations and morphological and physiological studies on extant primates, not only confirmed the closeness of apes to humans but also suggests selective mechanisms in the evolution of human upright posture and bipedal locomotion.
Kinship
Authors: Berman Carol M.
Published: October 2018

Kin preferences are a major component of social structure among nonhuman primates and humans. Their study provides important insights into the origins of human cooperation and social structure. Maternal kin recognize each other through common, long‐term ties with mothers. Paternal kinship recognition is more limited and less well understood. Kin favoritism and incest avoidance are widespread wherever circumstances permit, although precise patterns of kin‐related behavior vary widely among and within species. The reproductive benefits of kin favoritism are beginning to be understood better, as are roles and limitations of kin selection as an explanatory framework.
Lactation and weaning
Authors: Quinn Elizabeth A.
Published: October 2018

Lactation is one of the defining characteristics of mammals, including humans. Lactation is the direct transfer of maternal resources to offspring via a specialized substance called milk. Both the composition of milk and the characteristics (duration, frequency, intensity, etc.) of lactation are highly species specific, reflecting considerable evolutionary selection on lactation and milk. Studies of lactation by anthropologists cut across all subfields of anthropology. Within biological anthropology, lactation and milk composition have been studied in human and nonhuman primates, greatly enhancing current understanding of the central importance of lactation in these groups and the highly specialized adaptations in primates and humans for lactation. This entry briefly discusses the evolution of lactation, primate studies, and current understanding of mammary anatomy, milk synthesis, and composition. A growing body of research by anthropologists is radically reshaping our understanding of variability in the human milk phenotype and the impact such variability has on infant, and ultimately adult, development. The discussion concludes by looking at some ongoing debates about lactation in biological anthropology, including the meaning and practice of weaning in a cross‐cultural and historical perspective.
Livingstone,Frank
Authors: Long Jeffrey C.
Published: October 2018

Frank Livingstone was a founder of the discipline of anthropological genetics. His major research contribution connected human genetic adaptation to the ecology of agriculture and the falciparum variety of the disease malaria. Livingstone was an opponent of the practice of classifying people into races, and he was an early user of computer simulations to analyze the evolutionary processes. Livingstone had a lasting impact on the field of biological anthropology through decades of teaching and mentoring students.
Manipulation
Authors: Marzke Mary W.
Published: October 2018

Capacity for skillful manipulation of objects is shared by humans with all nonhuman primates. Distinctive anatomical features enhance human dexterity and control of tools by accommodating the thumb, fingers, and palm to object shapes, sizes, and stresses on joints. Fossil hominin hands reveal a complex evolutionary history of these features.