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We sampled individual growth rings from three ancient remnant bald cypress (Taxodium distichum) trees from a massive buried deposit at the mouth of the Altamaha River on the Georgia Coast to determine the best technique for radiocarbon (14C) dating pretreatment. The results of our comparison of traditional ABA pretreatment and holocellulose and α-cellulose fractions show no significant differences among the pretreatments (<1 sigma) thereby suggesting that ABA pretreatment will prove sufficient for the development of a high-resolution 14C tree-ring chronology based on these ancient bald cypresses which will indicate whether the U.S. Southeast is subject to a regional radiocarbon offset.
Analysis of human remains and a copper band found in the center of a Late Archaic (ca. 5000–3000 cal BP) shell ring demonstrate an exchange network between the Great Lakes and the coastal southeast United States. Similarities in mortuary practices suggest that the movement of objects between these two regions was more direct and unmediated than archaeologists previously assumed based on “down-the-line” models of exchange. These findings challenge prevalent notions that view preagricultural Native American communities as relatively isolated from one another and suggest instead that wide social networks spanned much of North America thousands of years before the advent of domestication.
The relationship between depression and sexual behaviour among men who have sex with men (MSM) is poorly understood.
To investigate prevalence and correlates of depressive symptoms (Patient Health Questionnaire-9 score ≥10) and the relationship between depressive symptoms and sexual behaviour among MSM reporting recent sex.
The Attitudes to and Understanding of Risk of Acquisition of HIV (AURAH) is a cross-sectional study of UK genitourinary medicine clinic attendees without diagnosed HIV (2013–2014).
Among 1340 MSM, depressive symptoms (12.4%) were strongly associated with socioeconomic disadvantage and lower supportive network. Adjusted for key sociodemographic factors, depressive symptoms were associated with measures of condomless sex partners in the past 3 months (≥2 (prevalence ratio (PR) 1.42, 95% CI 1.17–1.74; P=0.001), unknown or HIV-positive status (PR 1.43, 95% CI 1.20–1.71; P<0.001)), sexually transmitted infection (STI) diagnosis (PR 1.46, 95% CI 1.19–1.79; P<0.001) and post-exposure prophylaxis use in the past year (PR 1.83, 95% CI 1.33–2.50; P<0.001).
Management of mental health may play a role in HIV and STI prevention.
Body composition of animals and man is generally assumed to be a regulated phenomenon. Understanding the factors that are involved in such regulation is important in at least two different contexts. The obesity epidemic sweeping across developed nations has been described by the WHO as the greatest health threat facing Western societies. Understanding the underlying physiological factors that lead sectors of the population to fail in their attempts to regulate body mass and composition are of key importance in the drive to develop pharmaceutical remedies for this serious condition. A knock on effect for the agricultural sector however is the consumer demand for leaner animal products. This places a premium on understanding how body composition is regulated in livestock. Moreover the financial rewards for improving the energetic efficiency of production provide an additional incentive for understanding the details of energy regulation that underlie control of body composition. While direct genetic and physiological studies of livestock are feasible the mouse provides a convenient model animal that can inform our understanding of the conserved physiological mechanisms in both man and other animals. The key advantages of using the mouse in this context are that its small size and short breeding cycle enable experiments to be performed rapidly. Measuring physiological components of energy balance in mice is easily performed. In addition the mouse genome has been sequenced and the tools for performing large scale gene expression studies are already commercially available, opening up the capacity to perform integrative physiological studies form the level of the genome to the whole animal. Several genetic models of mice are known which have monogenic forms of extreme obesity. The best known of these is the ob/ob mouse, which is deficient in production of the adipokine leptin. However, many other single gene mutants are known which generate similar effects. Dissecting the loci of such effects has enabled us to construct a working model of how adiposity is signalled in the brain via the melanocortin system and how feedback loops including this system may contribute to regulation of energy balance. While some individuals have been identified that have similar genetic disruptions these are very rare, and it is clear that variation in human and livestock body composition generally reflects polygenic effects. More useful models may therefore be mice that have been selected for many generations for traits that impact on their body composition. The short generation time of the mouse has been extremely useful in the generation of such lines. My own group has been collaborating with the University of Edinburgh where such long-term selection experiment was initiated in the 1970s. We have in particular been quantifying the energy balance of mice long term selected for fat and lean body composition. We first showed that these polygenic effects do not seem to include polymorphisms within the leptin signalling system. By comparing total energy intake, with measures of resting energy expenditure the contribution of different energy compartments to energy balance can be assessed. These studies indicated that the major difference in energy regulation between the lines is that the lean line diverts substantially more energy into activity than the fat line. Direct measures of activity have been made to confirm this effect with mixed results. Using passive infrared detection devices the converse result is found – that the lean mice are less active, but using running wheels the logged activity matches the measured energy balance. These data indicate that the factors influencing energy balance reflect complex polygenic effects that reach far outside the leptin signalling system. The mouse is an ideal tool to explore these effects with implications for both the livestock industry and the obesity epidemic.
Over the past 30 years, the number of US doctoral anthropology graduates has increased by about 70%, but there has not been a corresponding increase in the availability of new faculty positions. Consequently, doctoral degree-holding archaeologists face more competition than ever before when applying for faculty positions. Here we examine where US and Canadian anthropological archaeology faculty originate and where they ultimately end up teaching. Using data derived from the 2014–2015 AnthroGuide, we rank doctoral programs whose graduates in archaeology have been most successful in the academic job market; identify long-term and ongoing trends in doctoral programs; and discuss gender division in academic archaeology in the US and Canada. We conclude that success in obtaining a faculty position upon graduation is predicated in large part on where one attends graduate school.
While geochemical analysis of obsidian artifacts is now widely applied around the world, both new instrumental methods and new research questions continue to be applied in archaeology. In the Mediterranean, many analytical methods have been employed and proven successful in distinguishing all of the island sources. In this study, results are presented from the virtually non-destructive, LA-ICP-MS multi-element analysis of 95 carefully selected obsidian artifacts from four neolithic period sites in southwestern Sardinia. The patterns of exploitation of specific Monte Arci obsidian subsources revealed in this study support a down-the-line model of obsidian trade during the neolithic period, but with chronological changes that are best explained by increased socioeconomic complexity.
The seventh annual Teaching and Learning Conference (TLC) was held in Philadelphia, Pennsylvania, from February 5 to 7, 2010, with 224 attendees onsite. The theme for the meeting was “Advancing Excellence in Teaching Political Science.” Using the working-group model, the TLC track format encourages in-depth discussion and debate on research dealing with the scholarship of teaching and learning.
X-ray fluorescence spectrometry (XRF) and micro-X-ray diffraction (μXRD) were used to analyze the composition of pigments on a pastel drawing, Special No. 32, by Georgia O’Keeffe. XRF analyses showed that, among other pigments present in the drawing, the red, orange, and yellow pigments may possibly be identified with lead- and chromium-based pigments: lead chromates, red and yellow lead oxides, and/or lead carbonates, plus calcium-based pastel fillers, such as whiting or gypsum. XRD examination of a sample removed from a dark mottled area of coral red pastel confirmed that this pigment layer, which is associated with a darkened appearance and high Pb:Cr ratios, matches the red lead oxide, minium (2PbO⋅PbO2).
Adipose tissue produces signals that can have a profound effect on many physiological functions, including energy expenditure and food intake. The hypothesis that variation in food intake of sheep resulting from differences in animal fatness can be predicted from effects of animal fatness on energetic efficiency was subjected to three tests. First, an existing food intake model was adapted to account for effects of animal fatness, as estimated by condition score, on food intake. Parameter values were derived from data obtained with two of five treatment groups of an experiment where ewe lambs were fed either chopped hay or pelleted concentrates. The model predicted the intake of the remaining three treatment groups satisfactorily. The energy intake model was subsequently extended with a protein module based upon a Gompertz curve to simulate changes in body weight and condition score. The model predicted these changes satisfactorily for most treatment groups during the experimental period of 50 weeks. In a last test, the final body weights and body lipid contents of animals fed either hay or concentrates for a period of 3 years were predicted. The predictions for final body weight (77 or 118 kg) and lipid content in the empty body (26 or 58 %) were within the range of expectations for sheep with access to hay or concentrates, respectively. The biological implications of the hypothesis that body fatness acts upon voluntary intake via its effects on energetic efficiency are discussed.
Maya Blue is an unusual blue pigment consisting of a clay-organic complex of indigo and the unusual clay mineral palygorskite (also called attapulgite). Used on pottery, sculpture, and murals from the Preclassic to Late Colonial periods largely in Mesoamerica, blue was the color of sacrifice and ritual. Did the palygorskite used to make Maya Blue come from a restricted source in Yucatán like Shepard, Arnold, Arnold and Bohor believed, or from widespread sources like Littmann argued? This report presents the results of a pilot study comparing INAA and LA-ICP-MS analysis of 33 palygorskite samples collected from different parts of the Maya area. These data reveal that it is possible to discriminate mineral source locations, and that it should be possible to determine whether the palygorskite used to make Maya Blue came from widespread sources or was traded widely from one or a few sources. Consideration of contextual information such as agency, landscape and language suggest that the Shepard/Arnold/Bohor hypothesis is more plausible than that of Littmann. No matter which hypothesis is supported, however, each has significant implications for the relationship of the diffusion of Maya Blue (or the knowledge of its production) to Maya social organization.
Both long-distance and localized chemical relationships in pottery and their implications for studies of Gulf lowland exchange can be examined with instrumental neutron activation. New pottery samples from Classic period (A.D. 300-900) contexts in the western lower Papaloapan basin were subjected to chemical compositional analysis. The sample represents three groups, coarse utility jars, common orange slipped serving bowls, and fine paste, higher-value white slipped serving bowls. At an intraregional scale, four localities in the western basin were sampled, but not all proved to be compositionally distinct. A mangrove zone pottery group contrasts compositionally with groups from riverine farmlands to the west. At a larger interregional scale, pottery from neighboring geomorphological areas as well as distant alluvial systems up and down the Gulf lowlands yielded chemically distinct groups. Considerable intraregional trade is suggested, but little is evident at the interregional scale. The interregional analysis is the first integrated overview of Gulf lowland ceramic chemical compositions, and the intraregional analysis begins assessment of Classic period pottery production and exchange within the western lower Papaloapan basin. Methodologically, we use sand sources in the region to determine if differences in tempering of pastes are likely to account for differences in compositional groups.
For decades archaeologists have struggled with the problem of accurately determining organic and mineral-based paints in pottery from the American Southwest. Using Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS), we have developed a simple and cost-effective method that permits classification of painted surfaces into mineral and organic-based categories. By applying this method to Mesa Verde and Mancos Black-on-white pottery from the Mesa Verde Region, we were able to distinguish easily between mineral and organic-based paints. Preliminary data also suggest that multiple sub-groups of mineral-based paints exist within these ceramic types, indicating that multiple recipes for manufacturing paint may have been employed by prehistoric potters from this region.
There are now 91 records of individual Nathusius' pipistrelle Pipistrellus nathusii examined ‘in the hand’ in the U.K., and bat detector records from a further 36 localities in Britain and Ireland. These records are distributed throughout all months of the year with clear peaks in spring and autumn suggesting migratory movements into and out of the British Isles in autumn and spring, respectively. Three maternity colonies have been located and the species must now also be regarded as a resident breeding species in Britain and Ireland.
We validated doubly-labelled water (DLW) by comparison to indirect calorimetry and food intake–mass balance in eight Labrador dogs (24–32 kg) over 4 d. We used several alternative equations for calculating CO2 production, based on the single- and two-pool models and used two alternative methods for evaluating the elimination constants: two-sample and multiple-sampling. In all cases the DLW technique overestimated the direct estimate of CO2 production. The greatest overestimates occurred with the single-pool model. Using two samples, rather than multiple samples, to derive the elimination constants produced slightly more discrepant results. Discrepancies greatly exceeded the measured analytical precision of the DLW estimates. The higher values with DLW probably occurred because the dogs were extremely active during the 1 h in each 24 spent outside the chamber. Estimates of CO2 production from food intake–mass balance, which include this activity, produced a much closer comparison to DLW (lowest mean discrepancy 0·3 % using the observed group mean dilution space ratio and an assumption that the mass changes reflected changes in hydration for all except one animal). We recommend an equilibration time of 6 h and use of the two-pool model based on the observed population dilution space for future studies of energy demands in dogs of this body mass.
Brown long-eared bats Plecotus auritus occupying 30 summer roosts in north-east Scotland were studied over 15 years. During this time 1365 bats were ringed, and a further 720 recaptures were made. Individual bats showed a high degree of roost fidelity, returning to one main roost site; < 1% of recaptured bats had moved among roost sites, and all recorded movements (n = 5) were < 300 m. Adults of both sexes were loyal to the roost sites at which they were first captured, indicating long-term use of roosts. At least some juveniles (n = 32) of both sexes returned to the natal roost. Mark–recapture estimates indicated that colonies of this species were substantially larger (c. 30–50 individuals) than assumed in previous studies. Plecotus auritus differs from most other temperate zone, vespertilionid species in that there was no evidence of sexual segregation during summer, with males present in all colonies throughout the period of occupancy. Population structure in summer seems to be consistent with a metapopulation model, with discrete sub-populations showing minimal interchange. The group size, colony composition and population structure described in this species may be associated with the wing shape (particularly aspect ratio) and foraging behaviour of P. auritus. It is postulated that relative motility, linked to wing structure, may affect the distribution of individuals, and may have implications for the genetic structure of this species. Correlations between aspect ratio and both colony size and migratory behaviour, across British bat species, indicate that wing shape could be an important factor contributing to patterns of social behaviour and genetic structuring in bats.
When bats emerge from colonies to feed and drink their emergence patterns deviate systematically from those expected at random (Kunz, 1974; Swift, 1980; Bullock et al., 1987; Brigham & Fenton, 1986). In particular, many bats appear to group together as they emerge, and form into ‘clusters’ or ‘outbursts’ (but see McAney & Fairley, 1988; Kunz & Anthony, 1995 for exceptions). The function of this clustering behaviour has been the topic of recent debate, with some authors favouring the hypothesis that the behaviour is an artefact of large numbers of animals moving through a restricted space (Kalcounis & Brigham, 1994) and others suggesting the behaviour has a more significant biological function such as protection from predation (Leen & Novick, 1977; Speakman, Stone & Kerslake, 1995) or information transfer (Wilkinson, 1992).
A collection (164) of isolates of Bordetella bronchiseptica
made predominantly from cats (132)
but also from dogs (15), pigs (12) and other species was examined by pulsed
electrophoresis following macrorestriction digestion with XbaI.
isolate was analysed twice
and the patterns were entirely reproducible. The isolates fell into 17
different strains (>3 bands different) and within strains there were
numerous subtypes. Feline isolates fell into 12 of
the 17 strains. In general, cats housed together had similar or identical
strains and subtypes of
B. bronchiseptica. There was no difference in the PFGE patterns
of isolates made from carrier
cats and those from cats with respiratory disease. Isolates from pigs and
dogs were in general
similar to the feline isolates and there was no great evidence for
species specificity. The PFGE
pattern of feline and canine isolates were more related to whether the
animals were housed
together rather than whether they came from dogs or cats.