Ripple and kink dynamics

We propose a relevant modification of the Nishimori-Ouchi model [{\em Phys. Rev. Lett.} {\bf 71}, 197 (1993)] for granular landscape erosion. We explicitly introduce a new parameter: the angle of repose $\theta_r$, and a new process: avalanches. We show that the $\theta_r$ parameter leads to an asymmetry of the ripples, as observed in natural patterns. The temporal evolution of the maximum ripple height $h_{max}$ is limited and not linear, according to recent observations. The ripple symmetry and the kink dynamics are studied and discussed.Comment: 7 pages, 10 figure, RevTe

Discrepancies Between Perceptions of the Parent-Adolescent Relationship and Early Adolescent Depressive Symptoms:An Illustration of Polynomial Regression Analysis

Adolescence is a critical period for the development of depressive symptoms. Lower quality of the parent-adolescent relationship has been consistently associated with higher adolescent depressive symptoms, but discrepancies in perceptions of parents and adolescents regarding the quality of their relationship may be particularly important to consider. In the present study, we therefore examined how discrepancies in parents' and adolescents' perceptions of the parent-adolescent relationship were associated with early adolescent depressive symptoms, both concurrently and longitudinally over a 1-year period. Our sample consisted of 497 Dutch adolescents (57 % boys, M (age) = 13.03 years), residing in the western and central regions of the Netherlands, and their mothers and fathers, who all completed several questionnaires on two occasions with a 1-year interval. Adolescents reported on depressive symptoms and all informants reported on levels of negative interaction in the parent-adolescent relationship. Results from polynomial regression analyses including interaction terms between informants' perceptions, which have recently been proposed as more valid tests of hypotheses involving informant discrepancies than difference scores, suggested the highest adolescent depressive symptoms when both the mother and the adolescent reported high negative interaction, and when the adolescent reported high but the father reported low negative interaction. This pattern of findings underscores the need for a more sophisticated methodology such as polynomial regression analysis including tests of moderation, rather than the use of difference scores, which can adequately address both congruence and discrepancies in perceptions of adolescents and mothers/fathers of the parent-adolescent relationship in detail. Such an analysis can contribute to a more comprehensive understanding of risk factors for early adolescent depressive symptoms.</p

Spatio-temporal ecology of sympatric felids on Borneo. Evidence for resource partitioning?

Niche differentiation, the partitioning of resources along one or more axes of a species’ niche hyper-volume, is widely recognised as an important mechanism for sympatric species to reduce interspecific competition and predation risk, and thus facilitate co-existence. Resource partitioning may be facilitated by behavioural differentiation along three main niche dimensions: habitat, food and time. In this study, we investigate the extent to which these mechanisms can explain the coexistence of an assemblage of five sympatric felids in Borneo. Using multi-scale logistic regression, we show that Bornean felids exhibit differences in both their broad and fine-scale habitat use. We calculate temporal activity patterns and overlap between these species, and present evidence for temporal separation within this felid guild. Lastly, we conducted an all-subsets logistic regression to predict the occurrence of each felid species as a function of the co-occurrence of a large number of other species and showed that Bornean felids co-occurred with a range of other species, some of which could be candidate prey. Our study reveals apparent resource partitioning within the Bornean felid assemblage, operating along all three niche dimension axes. These results provide new insights into the ecology of these species and the broader community in which they live and also provide important information for conservation planning for this guild of predators

Responses of Sunda clouded leopard population density to anthropogenic disturbance and refining estimates of their conservation status in Sabah

Extensive areas of tropical forests have been, and continue to be, disturbed as a result of selective timber extraction. Although such anthropogenic disturbance typically results in the loss of biodiversity, many species persist, and their conservation in production landscapes could be enhanced by a greater understanding of how biodiversity responds to forest management practices. We conducted intensive camera-trap surveys of eight protected forest areas in Sabah, Malaysian Borneo, and developed estimates of Sunda clouded leopard Neofelis diardi population density from spatially explicit capture–recapture analyses of detection data to investigate how the species’ abundance varies across the landscape and in response to anthropogenic disturbance. Estimates of population density from six forest areas were 1.39–3.10 individuals per 100 km2. Our study provides the first evidence that the population density of the Sunda clouded leopard is negatively affected by hunting pressure and forest fragmentation, and that among selectively logged forests, time since logging is positively associated with abundance. We argue that these negative anthropogenic impacts could be mitigated with improved logging practices, such as reducing the access of poachers by effective gating and destruction of road access points, and by the deployment of anti-poaching patrols. By calculating a weighted mean population density estimate from estimates developed here and from the literature, and by extrapolating this value to an estimate of current available habitat, we estimate there are 754 (95% posterior interval 325–1,337) Sunda clouded leopards in Sabah

Electrohydrodynamic behavior in twisted-wedge nematic structures

A new type of domain for nematic liquid crystals with a twisted-wedge structure is presented. This new type of domain appears from the low frequency range to 10 kHz. This behavior was observed for square and pulsed excitations. The liquid crystal was N-(p-methoxybenzylidene)-p'-butylaniline) (MBBA) used at room temperature. These domains offer a higher degree of complexity than conventional Williams domains. The corresponding stability chart is presented

Responses of Sunda clouded leopard Neofelis diardi population density to anthropogenic disturbance: refining estimates of its conservation status in Sabah

Extensive areas of tropical forests have been, and continue to be, disturbed as a result of selective timber extraction. Although such anthropogenic disturbance typically results in the loss of biodiversity, many species persist, and their conservation in production landscapes could be enhanced by a greater understanding of how biodiversity responds to forest management practices. We conducted intensive camera-trap surveys of eight protected forest areas in Sabah, Malaysian Borneo, and developed estimates of Sunda clouded leopard Neofelis diardi population density from spatially explicit capture–recapture analyses of detection data to investigate how the species’ abundance varies across the landscape and in response to anthropogenic disturbance. Estimates of population density from six forest areas were 1.39–3.10 individuals per 100 km2. Our study provides the first evidence that the population density of the Sunda clouded leopard is negatively affected by hunting pressure and forest fragmentation, and that among selectively logged forests, time since logging is positively associated with abundance. We argue that these negative anthropogenic impacts could be mitigated with improved logging practices, such as reducing the access of poachers by effective gating and destruction of road access points, and by the deployment of anti-poaching patrols. By calculating a weighted mean population density estimate from estimates developed here and from the literature, and by extrapolating this value to an estimate of current available habitat, we estimate there are 754 (95% posterior interval 325–1,337) Sunda clouded leopards in Sabah

Effect of beta-adrenergic stimulation on whole-body and abdominal subcutaneous adipose tissue lipolysis in lean and obese men

AIMS/HYPOTHESIS: Obesity is characterised by increased triacylglycerol storage in adipose tissue. There is in vitro evidence for a blunted beta-adrenergically mediated lipolytic response in abdominal subcutaneous adipose tissue (SAT) of obese individuals and evidence for this at the whole-body level in vivo. We hypothesised that the beta-adrenergically mediated effect on lipolysis in abdominal SAT is also impaired in vivo in obese humans. METHODS: We investigated whole-body and abdominal SAT glycerol metabolism in vivo during 3 h and 6 h [2H5]glycerol infusions. Arterio-venous concentration differences were measured in 13 lean and ten obese men after an overnight fast and during intravenous infusion of the non-selective beta-adrenergic agonist isoprenaline [20 ng (kg fat free mass)(-1) min(-1)]. RESULTS: Lean and obese participants showed comparable fasting glycerol uptake by SAT (9.7+/-3.4 vs 9.3+/-2.5% of total release, p=0.92). Furthermore, obese participants showed an increased whole-body beta-adrenergically mediated lipolytic response versus lean participants. However, their fasting lipolysis was blunted [glycerol rate of appearance: 7.3+/-0.6 vs 13.1+/-0.9 micromol (kg fat mass)(-1) min(-1), p<0.01], as was the beta-adrenergically mediated lipolytic response per unit SAT [Delta total glycerol release: 140+/-71 vs 394+/-112 nmol (100 g tissue)(-1) min(-1), p<0.05] compared with lean participants. Net triacylglycerol flux tended to increase in obese compared with lean participants during beta-adrenergic stimulation [Delta net triacylglycerol flux: 75+/-32 vs 16+/-11 nmol (100 g tissue)(-1) min(-1), p=0.06]. CONCLUSIONS/INTERPRETATION: We demonstrated in vivo that beta-adrenergically mediated lipolytic response is impaired systematically and in abdominal SAT of obese versus lean men. This may be important in the development or maintenance of increased triacylglycerol stores and obesity

Ferroelectric ordering in chiral smectic C^* liquid crystals determined by nonchiral intermolecular interactions

General microscopic mechanism of ferroelectric ordering in chiral smectic C* liquid crystals is considered. It is shown that if the mesogenic molecules have a sufficiently low symmetry, the spontaneous polarization is proportional to one of the biaxial vector order parameters of the smectic C phase. This order parameter may be determined by intermolecular interactions which are not sensitive to molecular chirality. At the same time, the polarization is also proportional to a pseudoscalar parameter which vanishes if the molecules are nonchiral. The general statistical theory of ferroelectric ordering is illustrated by two particular models. The first model is based on electrostatic quadrupole-quadrupole interactions, and it enables one to obtain explicit analytical expressions for the spontaneous polarization. In the second model, the molecular chirality and polarity are determined by a pair of off-center nonparallel dipoles. For this case, the spontaneous polarization is calculated numerically as a function of temperature. The theory provides a more general interpretation of the previous approaches including the classical Boulder model

Nurses and medical assistants taking charge: task-shifting HIV care and HAART initiation in resource-constrained and rural Malawi

Mexico AIDS Conference 200