Computing Hitting Set Kernels By AC0-Circuits

Theory of Computing Systems - Given a hypergraph H = (V,E), what is the smallest subset $X subseteq V$ such that e ∩ X≠∅ holds for all e ∈ E? This problem, known as the...     

Natural links: naturalistic golf courses as wildlife habitat

Worldwide, there are over 25,000 golf courses. In the United States, there are approximately 15,000, with developers building about 350 new courses each year. Japan, Taiwan, China, and other countries are experiencing a similar golf boom. Some developers regard golf course development as one of the fastest growing types of land development in the world. Typically considered by ecologists to be an environmental problem, scientists are now reexamining golf courses to assess their potential to be wildlife habitat. Can naturalistic courses (those with substantial amounts of native wildlife habitat) actually benefit wildlife populations, especially birds, and still be attractive to golfers? My ecological research with a well-known naturalized links-style golf course in Kansas suggests that a naturalistic golf course can support significant numbers of birds, including many threatened species. When compared to a nearby natural area, the golf course equaled the natural area in total bird species richness but not in the relative abundance of specific kinds of birds. Naturalistic golf courses, while not natural areas, can complement biological reserves, military reservations, greenbelts, parks, farms, backyards and other units of the regional habitat mosaic. The large amount of habitat on naturalistic courses also reduces water runoff, irrigation, and chemical inputs. Furthermore, raising the profile of naturally landscaped golf courses can engage thousands of additional people in wildlife habitat preservation issues. Naturalistic courses are growing in popularity and the golfing community is responsive to aesthetic and environmental concerns. With the involvement of ecologists, this burgeoning interest in natural habitats on golf courses may significantly increase the amount of wildlife habitat, especially if designers build these kinds of courses in urban areas and on degraded landscapes such as landfills, quarries, and eroded lands.     

In-vivo confocal scanning laser microscopy of the cerebral microcirculation

Confocal scanning laser microscopy (CSLM) was used to study the microcirculation of the brain neocortex in anaesthetized rats. After removal of the dura mater, implantation of a closed cranial window, and intravenous injection of fluorescein, three-dimensional reconstructions of cortical capillaries were performed down to a depth of 250 μm below the pial surface. Using a one-dimensional approach (single line scanning), erythrocyte (negative contrast in fluorescently labelled plasma) and leucocyte (labelled with rhodamine 6 G) velocity and supply rate in cortical capillaries were measured. The effect of CO₂-inhalation on capillary blood flow dynamics was studied. Capillaries were imaged continuously for up to 1 h without changes in flow or fluorescence pattern. However, by increasing the laser power 10–100-fold, aggregate formation was induced and capillaries were occluded, possibly due to damage to vascular endothelium. We conclude that CSLM can be used to study morphological and dynamic aspects of fluorescently labelled subsurface structures in organs of experimental animals.     

Filaments for Incandescent Lamps with Energy Conserving Envelopes

The design considerations for filaments in energy conserving incandescent lamps are described. Such lamps require compact high emissivity filaments to absorb infrared radiation reflected from heat mirrored focusing envelopes. The relationships between the electrical parameters in the radiation returning environment and in the clear surroundings are developed. Efficiency experiments with filaments of various geometries under conditions of radiation return were performed. A highly compact coiled coil filament seems most promising for development. A calculation is presented of the filament emissivity as a function of spacing of the windings in a coil. Measurements of the emissivity as a function of the pitch of a coiled coil filament agree with the calculation.     

The mediation of mothers' self-fulfilling effects on their children's alcohol use: Self-verification, informational conformity, and modeling processes.

This research examined whether self-fulfilling prophecy effects are mediated by self-verification, informational conformity, and modeling processes. The authors examined these mediational processes across multiple time frames with longitudinal data obtained from two samples of mother-child dyads (N? = 486; N? = 287), with children's alcohol use as the outcome variable. The results provided consistent support for the mediational process of self-verification. In both samples and across several years of adolescence, there was a significant indirect effect of mothers' beliefs on children's alcohol use through children's self-assessed likelihood of drinking alcohol in the future. Comparatively less support was found for informational conformity and modeling processes as mediators of mothers' self-fulfilling effects. The potential for self-fulfilling prophecies to produce long-lasting changes in targets' behavior via self-verification processes are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

塑料加工过程中的红外加热技术简介

介绍了红外加热技术的原理、优势及其在塑料橡胶工业中的应用;同时也介绍了世界领先的红外技术咨询专家及红外辐射器提供者德国贺利氏特种光源集团在中国的工作。     

Stability Studies of Agrifood Reference Materials Under Different Conditions of Storage by Near-Infrared Spectroscopy

Reference materials (RM) play an increasingly important role for laboratories. The aim of this work is to compare different conditions of storage and assess the stability of agrifood external reference materials (ERM). These materials could be used as tools by laboratories notably for their quality control procedure. However, as the other RM, their stability must be assessed during stability studies. The determination of the limiting date of stability (LDS), defined as the period during which analytes called marker of stability are still considered as stable, is used on this purpose. The influences of the environmental factor were tested by the application of full experimental designs with two tested environmental factors: the temperature (storage at +4 °C or +20 ± 10 °C) and the composition of the atmosphere (absence or presence of gases in the packaging). Thus, the setting under vacuum increases clearly the stability for the studied analyte. Almost all ERM stored in the best conditions have a determined LDS higher than those stored in current condition of storage. Indeed, the bread wheat ERM LDS is higher than the current storage of 24 months     

Al-Cr-O thin films as an efficient hydrogen barrier

Thin Al-Cr-O films are proposed as hydrogen permeation barriers. Layers of a few microns in thickness are able to suppress hydrogen permeability by a factor of 2000 to 3500 at temperatures of 700 °C, as has been found in our gas phase permeation experiments. We attribute this excellent efficiency to a dense layer morphology and the possible (pre)-formation of solid solutions in corundum-type structure. These films are deposited by pulsed arc evaporation in a batch-type production system at substrate temperatures of 550 °C.     

Improving Implicit Stochastic Reservoir Optimization Models with Long-Term Mean Inflow Forecast

This technical note introduces a reservoir operation model based on implicit stochastic optimization (ISO) in which the release policy is guided by the forecast of the mean inflow for a given future horizon rather than by the prediction of the current-month inflow, such as in typical ISO models. The model also does not require the forecast of all inflows for the future horizon and shows to be more efficient in finding less vulnerable release policies when compared to several other explicit and implicit stochastic procedures.