2,819 research outputs found
Divergence terms in the supertrace heat asymptotics for the de Rham complex on a manifold with boundary
We use invariance theory to determine the coefficient
in the supertrace for the twisted de Rham complex with absolute boundary
conditions.Comment: 19 pages, LaTeX, Theorem 1.2 correcte
Honey bee foraging distance depends on month and forage type
To investigate the distances at which honey bee foragers collect nectar and pollen, we analysed 5,484 decoded waggle dances made to natural forage sites to determine monthly foraging distance for each forage type. Firstly, we found significantly fewer overall dances made for pollen (16.8 %) than for non-pollen, presumably nectar (83.2 %; P < 2.2 × 10−23). When we analysed distance against month and forage type, there was a significant interaction between the two factors, which demonstrates that in some months, one forage type is collected at farther distances, but this would reverse in other months. Overall, these data suggest that distance, as a proxy for forage availability, is not significantly and consistently driven by need for one type of forage over the other
Gastrocutaneous Closure Device
A gastrocutaneous closure device allows gastrocutaneous fistula closure from external abdominal access through the fistula site. Access through the fistula ensures accurate closure placement on the interior lumen wall of the stomach. A closure or clip has a plurality of prongs defined by a deformable material, such that the prongs extend radially from a central hub in an arcuate or curved, semicircular shape. The arcuate shape converges towards a central point or axis at a distal end, and the proximate end of the prongs attaches to the central hub such that the prongs radiate from the hub and the distal end curves back toward the axis through the hub. The deformable prongs may therefore radially compress or retract to define a larger or smaller diameter. The fistula lies on the axis such that the biased, inserted prongs pull the inner stomach wall closed around the healing fistula
Pole structure of the Hamiltonian -function for a singular potential
We study the pole structure of the -function associated to the
Hamiltonian of a quantum mechanical particle living in the half-line
, subject to the singular potential . We show that
admits nontrivial self-adjoint extensions (SAE) in a given range of values
of the parameter . The -functions of these operators present poles
which depend on and, in general, do not coincide with half an integer (they
can even be irrational). The corresponding residues depend on the SAE
considered.Comment: 12 pages, 1 figure, RevTeX. References added. Version to appear in
Jour. Phys. A: Math. Ge
An experimental and predictive study of the tumbling generating characteristics of four-value cylinder heads under steady flow conditions
The Role of Gut Adaptation in the Potent Effects of Multiple Bariatric Surgeries on Obesity and Diabetes
Bariatric surgical procedures such as vertical sleeve gastrectomy (VSG) and Roux-en-Y gastric bypass (RYGB) are the most potent treatments available to produce sustained reductions in body weight and improvements in glucose regulation. While traditionally these effects are attributed to mechanical aspects of these procedures, such as restriction and malabsorption, a growing body of evidence from mouse models of these procedures points to physiological changes that mediate the potent effects of these surgeries. In particular, there are similar changes in gut hormone secretion, bile acid levels, and composition after both of these procedures. Moreover, loss of function of the nuclear bile acid receptor (FXR) greatly diminishes the effects of VSG. Both VSG and RYGB are linked to profound changes in the gut microbiome that also mediate at least some of these surgical effects. We hypothesize that surgical rearrangement of the gastrointestinal tract results in enteroplasticity caused by the high rate of nutrient presentation and altered pH in the small intestine that contribute to these physiological effects. Identifying the molecular underpinnings of these procedures provides new opportunities to understand the relationship of the gastrointestinal tract to obesity and diabetes as well as new therapeutic strategies to harness the effectiveness of surgery with less-invasive approaches
The trace of the heat kernel on a compact hyperbolic 3-orbifold
The heat coefficients related to the Laplace-Beltrami operator defined on the
hyperbolic compact manifold H^3/\Ga are evaluated in the case in which the
discrete group \Ga contains elliptic and hyperbolic elements. It is shown
that while hyperbolic elements give only exponentially vanishing corrections to
the trace of the heat kernel, elliptic elements modify all coefficients of the
asymptotic expansion, but the Weyl term, which remains unchanged. Some physical
consequences are briefly discussed in the examples.Comment: 11 page
Heat trace asymptotics with singular weight functions
We study the weighted heat trace asymptotics of an operator of Laplace type
with Dirichlet boundary conditions where the weight function exhibits radial
blowup. We give formulas for the first few terms in the expansion in terms of
geometrical data
The Medical Research Council (UK)/Uganda Virus Research Institute Uganda Research Unit on AIDS--'25 years of research through partnerships'.
For the past 25Â years, the Medical Research Council/Uganda Virus Research Institute Uganda Research Unit on AIDS has conducted research on HIV-1, coinfections and, more recently, on non-communicable diseases. Working with various partners, the research findings of the Unit have contributed to the understanding and control of the HIV epidemic both in Uganda and globally, and informed the future development of biomedical HIV interventions, health policy and practice. In this report, as we celebrate our silver jubilee, we describe some of these achievements and the Unit's multidisciplinary approach to research. We also discuss the future direction of the Unit; an exemplar of a partnership that has been largely funded from the north but led in the south
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