248 research outputs found
Evaluating potential effects of solar power facilities on wildlife from an animal behavior perspective
Solar power is a renewable energy source with great potential to help meetincreasing global energy demands and reduce our reliance on fossil fuels.However, research is scarce on how solar facilities affect wildlife. With inputfrom professionals in ecology, conservation, and energy, we conducted aresearch-prioritization process and identified key questions needed to betterunderstand impacts of solar facilities on wildlife. We focused on animalbehavior, which can be used to identify population responses before mortal-ity or other fitness consequences are documented. Behavioral studies canalso offer approaches to understand the mechanisms leading to negativeinteractions (e.g., collision, singeing, avoidance) and provide insight into mit-igating effects. Here, we review how behavioral responses to solar facilities, including perception, movement, habitat use, and interspecific interactionsare priority research areas. Addressing these themes will lead to a morecomprehensive understanding of the effects of solar power on wildlife andguide future mitigatio
The inflammatory response in transgastric surgery: gastric content leak leads to localized inflammatory response and higher adhesive disease
Risk of gastric spillage during transgastric surgery is a potential complication of NOTES procedures. The aim of this study was to determine risk outcomes from gastric spillage in a rat survival model by measuring local and systemic inflammatory markers, adhesive disease, and morbidity.
We performed a minilaparotomy with needle aspiration of 2 ml of gastric contents mixed with 2 ml of sterile saline (study group, SG) or 4 ml of sterile saline (control group, CG) injected into the peritoneal cavity of 60 male rats. Inflammatory markers (TNFα, IL-6, and IL-10) were analyzed at 1, 3, 6, and 24 h postoperatively by obtaining plasma levels and peritoneal washings. At necropsy, the peritoneal cavity was examined grossly for adhesions.
Adhesions were seen more frequently in the SG versus the CG (100% vs. 33.3%, p < 0.014). There was a significant difference in the peritoneal TNFα levels in the SG compared with the CG, which peaked 1 h after surgery (p < 0.02). Both peritoneal IL-6 and IL-10 levels were higher in the SG versus the CG, which peaked 3 h after surgery (p < 0.005 and p < 0.001, respectively). All peritoneal inflammatory markers returned to undetectable levels at 24 h for both groups. Plasma cytokines were undetectable at all time intervals.
The inflammatory response was found to be a localized and not systemic event, with plasma cytokine levels remaining normal while peritoneal washings revealed a brisk, short-lived localized inflammatory response. There was a significantly higher rate of adhesive disease in the SG compared with the CG; this, however did not translate into a difference in apparent clinical outcome. We conclude that gastric leakage in this NOTES rodent model induces a localized inflammatory response, followed by mild to moderate adhesive disease. This may be important in human NOTES
First Test Results of the Trans-Impedance Amplifier Stage of the Ultra-fast HPSoC ASIC
We present the first results from the HPSoC ASIC designed for readout of
Ultra-fast Silicon Detectors. The 4-channel ASIC manufactured in 65 nm CMOS by
TSMC has been optimized for 50 um thick AC-LGAD. The evaluation of the analog
front end with \b{eta}-particles impinging on 3x3 AC-LGAD arrays (500 um pitch,
200x200 um2 metal) confirms a fast output rise time of 600 ps and good timing
performance with a jitter of 45 ps. Further calibration experiments and TCT
laser studies indicate some gain limitations that are being investigated and
are driving the design of the second-generation pre-amplification stages to
reach a jitter of 15 ps.Comment: 7 pages, 6 figure
Influence of through-flow on linear pattern formation properties in binary mixture convection
We investigate how a horizontal plane Poiseuille shear flow changes linear
convection properties in binary fluid layers heated from below. The full linear
field equations are solved with a shooting method for realistic top and bottom
boundary conditions. Through-flow induced changes of the bifurcation thresholds
(stability boundaries) for different types of convective solutions are deter-
mined in the control parameter space spanned by Rayleigh number, Soret coupling
(positive as well as negative), and through-flow Reynolds number. We elucidate
the through-flow induced lifting of the Hopf symmetry degeneracy of left and
right traveling waves in mixtures with negative Soret coupling. Finally we
determine with a saddle point analysis of the complex dispersion relation of
the field equations over the complex wave number plane the borders between
absolute and convective instabilities for different types of perturbations in
comparison with the appropriate Ginzburg-Landau amplitude equation
approximation. PACS:47.20.-k,47.20.Bp, 47.15.-x,47.54.+rComment: 19 pages, 15 Postscript figure
Use of Displacement Damage Dose in an Engineering Model of GaAs Solar Cell Radiation Damage
Current methods for calculating damage to solar cells are well documented in the GaAs Solar Cell Radiation Handbook (JPL 96-9). An alternative, the displacement damage dose (D(sub d)) method, has been developed by Summers, et al. This method is currently being implemented in the SAVANT computer program
Observations of DG Tauri with the Keck Interferometer
We present the first science results from the Keck Interferometer, a
direct-detection infrared interferometer utilizing the two 10-meter Keck
telescopes. The instrument and system components are briefly described. We then
present observations of the T Tauri object DG Tau, which is resolved by the
interferometer. The resolved component has a radius of 0.12 to 0.24 AU,
depending on the assumed stellar and extended component fluxes and the model
geometry used. Possible origins and implications of the resolved emission are
discussed.Comment: 10 pages, 2 figures, to appear in ApJ Letter
Restoration of biogeomorphic systems by creating windows of opportunity to support natural establishment processes
In degraded landscapes, recolonization by pioneer vegetation is often halted by the presence of persistent environmental stress. When natural expansion does occur, it is commonly due to the momentary alleviation of a key environmental variable previously limiting new growth. Thus, studying the circumstances in which expansion occurs can inspire new restoration techniques, wherein vegetation establishment is provoked by emulating natural events through artificial means. Using the salt-marsh pioneer zone on tidal flats as a biogeomorphic model system, we explore how locally raised sediment bed forms, which are the result of natural (bio)geomorphic processes, enhance seedling establishment in an observational study. We then conduct a manipulative experiment designed to emulate these facilitative conditions in order to enable establishment on an uncolonized tidal flat. Here, we attempt to generate raised growth-promoting sediment bed forms using porous artificial structures. Flume experiments demonstrate how these structures produce a sheltered hydrodynamic environment in which suspended sediment and seeds preferentially settle. The application of these structures in the field led to the formation of stable, raised sediment platforms and the spontaneous recruitment of salt-marsh pioneers in the following growing season. These recruits were composed primarily of the annual pioneering Salicornia genus, with densities of up to 140 individuals/m2 within the structures, a 60-fold increase over ambient densities. Lower abundances of five other perennial species were found within structures that did not appear elsewhere in the pioneer zone. Furthermore, recruits grew to be on average three times greater in mass inside of the structures than in the neighboring ambient environment. The success of this restoration design may be attributed to the combination of three factors: (1) enhanced seed retention, (2) suppressed mortality, and (3) accelerated growth rates on the elevated surfaces generated by the artificial structures. We argue that restoration approaches similar to the one shown here, wherein the conditions for natural establishment are actively mimicked to promote vegetation development, may serve as promising tools in many biogeomorphic ecosystems, ranging from coastal to arid ecosystems
Multisite Phosphorylation Provides an Effective and Flexible Mechanism for Switch-Like Protein Degradation
Phosphorylation-triggered degradation is a common strategy for elimination of regulatory proteins in many important cell signaling processes. Interesting examples include cyclin-dependent kinase inhibitors such as p27 in human and Sic1 in yeast, which play crucial roles during the G1/S transition in the cell cycle. In this work, we have modeled and analyzed the dynamics of multisite-phosphorylation-triggered protein degradation systematically. Inspired by experimental observations on the Sic1 protein and a previous intriguing theoretical conjecture, we develop a model to examine in detail the degradation dynamics of a protein featuring multiple phosphorylation sites and a threshold site number for elimination in response to a kinase signal. Our model explains the role of multiple phosphorylation sites, compared to a single site, in the regulation of protein degradation. A single-site protein cannot convert a graded input of kinase increase to much sharper output, whereas multisite phosphorylation is capable of generating a highly switch-like temporal profile of the substrate protein with two characteristics: a temporal threshold and rapid decrease beyond the threshold. We introduce a measure termed temporal response coefficient to quantify the extent to which a response in the time domain is switch-like and further investigate how this property is determined by various factors including the kinase input, the total number of sites, the threshold site number for elimination, the order of phosphorylation, the kinetic parameters, and site preference. Some interesting and experimentally verifiable predictions include that the non-degradable fraction of the substrate protein exhibits a more switch-like temporal profile; a sequential system is more switch-like, while a random system has the advantage of increased robustness; all the parameters, including the total number of sites, the threshold site number for elimination and the kinetic parameters synergistically determine the exact extent to which the degradation profile is switch-like. Our results suggest design principles for protein degradation switches which might be a widespread mechanism for precise regulation of cellular processes such as cell cycle progression
Wild food plants and fungi used in the mycophilous Tibetan community of Zhagana (Tewo County, Gansu, China)
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