8,358 research outputs found
Snakebite on the hand: Lessons from two clinical cases illustrating difficulties of Surgical Indication
Direct Measurement of Coating Thermal Noise in Optical Resonators
The best measurements of space and time currently possible (e.g.
gravitational wave detectors and optical reference cavities) rely on optical
resonators, and are ultimately limited by thermally induced fluctuations in the
reflective coatings which form the resonator. We present measurements of
coating thermal noise in the audio band and show that for a standard ion beam
sputtered coating, the power spectrum of the noise does not have the expected
power-law behavior
Genome-scale approach proves that the lungfish-coelacanth sister group is the closest living relative of tetrapods with the BEST program
The origin of tetrapods has not been resolved for decades. Three principal hypotheses (lungfish-tetrapod, coelacanth-tetrapod, or lungfish-coelacanth sister group) have been proposed. We used the Bayesian method under the coalescence model with the latest program (BEST) to perform a phylogenetic analysis for seven relevant taxa and 43 nuclear genes encoding amino acid residues with the jackknife method for taxon sub-sampling. The results, combined with those of other three genome-scale approaches, successfully prove the hypothesis that lungfishes and coelacanths form a monophyletic sister group and are equally related to tetrapods supported by high Bayesian posterior probabilities of the branch (a lungfish-coelacanth clade) and high taxon jackknife supports
Six years of study on fast growing forest plantations catchments in the Northwest of Spain
Data on water balance in three fast growing forest plantations experimental catchments in the northwest of Spain are presented. Two watersheds are covered by Eucalyptus globulus and other is covered by Pinus pinaster. During the six years of study severa1 perturbations occurred. In 1989 two consecutives wildfires affected to one E. globulus watershed. The second fire also bumed the other eucalyptus watershed. All eucalyptus were felled since 1991 to 1992. Also 25% of the watershed area in the pine catchment was cutted in 1991. Quick changes in the hydrologycal regimen took place after these perturbations. The very fast recovering capacity after fire and cutting of Eucalyptus globulus facilitated the retum to pre-fire hydrologic parameter values within only a few years. Before perturbations occurred, nutrient balances were very conservative, and were similar among the cathments. This indicates a good performance on the part of both tree plantations. Water comsumption for pine and eucalyptus stands was very similar
Parametric instabilities in the LCGT arm cavity
We evaluated the parametric instabilities of LCGT (Japanese interferometric
gravitational wave detector project) arm cavity. The number of unstable modes
of LCGT is 10-times smaller than that of Advanced LIGO (U.S.A.). Since the
strength of the instabilities of LCGT depends on the mirror curvature more
weakly than that of Advanced LIGO, the requirement of the mirror curvature
accuracy is easier to be achieved. The difference in the parametric
instabilities between LCGT and Advanced LIGO is because of the thermal noise
reduction methods (LCGT, cooling sapphire mirrors; Advanced LIGO, fused silica
mirrors with larger laser beams), which are the main strategies of the
projects. Elastic Q reduction by the barrel surface (0.2 mm thickness
TaO) coating is effective to suppress instabilities in the LCGT arm
cavity. Therefore, the cryogenic interferometer is a smart solution for the
parametric instabilities in addition to thermal noise and thermal lensing.Comment: 6 pages,3 figures. Amaldi7 proceedings, J. Phys.: Conf. Ser.
(accepted
A fluorescence in situ staining method for investigating spores and vegetative cells of Clostridia by confocal laser scanning microscopy and structured illuminated microscopy
Non-pathogenic spore-forming Clostridia are of increasing interest due to their application in biogas production
and their capability to spoil different food products. The life cycle for Clostridium includes a spore stage that can
assist in survival under environmentally stressful conditions, such as extremes of temperature or pH. Due to their
size, spores can be investigated by a range of microscopic techniques, many of which involve sample pretreatment.
We have developed a quick, simple and non-destructive fluorescent staining procedure that allows a
clear differentiation between spores and vegetative cells and effectively stains spores, allowing recovery and
tracking in subsequent experiments. Hoechst 34580, Propidium iodide and wheat germ agglutinin WGA 488
were used in combination to stain four strains of Clostridia at different life cycle stages. Staining was conducted
without drying the sample, preventing changes induced by dehydration and cells observed by confocal laser
scanner microscopy or using a super-resolution microscope equipped with a 3D-structured illumination module.
Dual staining with Hoechst/Propidium iodide differentiated spores from vegetative cells, provided information
on the viability of cells and was successfully applied to follow spore production induced by heating. Superresolution
microscopy of spores probed by Hoechst 34580 also allowed chromatin to be visualised. Direct
staining of a cheese specimen using Nile Red and Fast Green allowed in situ observation of spores within the
cheese and their position within the cheese matrix. The proposed staining method has broad applicability and
can potentially be applied to follow Clostridium spore behaviour in a range of different environments
Is Strategy Different for Very Small and New Firms?
In this paper, we argue that much of the small business strategic management literature has drawn too heavily from work done on large, established firms. We build upon the notions of the liabilities of smallness and newness to discuss how microenterprises and very new firms are different in regards to their strategic analysis, strategic content, strategic resources, and strategic processes. We note that there are a number of important and non-obvious questions that need to be asked that have implications for the most common firms in the world, those that are very small
Campylobacter: Animal Reservoirs, Human Infections, and Options for Control
Campylobacteriosis is a frequently diagnosed disease in humans. Most infections are considered foodborne and are caused by Campylobacter jejuni and C. coli. The animal reservoirs of these Campylobacter species, and the sources and routes of transmission, are described and discussed in this chapter. Most warm-blooded animals can be colonized by Campylobacter, but avian species, and in particular poultry, are preferred hosts. Much of the world’s poultry production is colonized by Campylobacter. Source attribution studies estimate that 20–40% of cases are attributed to the handling and consumption of chicken meat, while up to 80% of cases are due to Campylobacter found in the chicken reservoir. The difference suggests that routes other than through the food chain, i.e., environmental contamination, are important. The epidemiology of infections in humans differs between industrialized and low- and middle-income countries. Thus, the most effective interventions would be targeted to primary production. To date, only improved biosecurity is available. If effectively implemented, strict biosecurity can reduce the number of Campylobacter-positive flocks, but implementation to this level has proved difficult for the poultry industry. Available interventions in chicken processing plants can substantially reduce Campylobacter numbers on carcasses and consequently reduce the risk to humans. Public health strategies therefore utilize control programs, which aim at reducing the level of Campylobacter by measures along the food chain. It is now recognized that commercially acceptable complementary interventions for primary production, such as vaccines and feed additives, are urgently needed. Once Campylobacter in poultry is controlled then other minor sources of Campylobacter including contaminated drinking water, direct contact with (pet) animals, and other food items (e.g., red meat and milk) can be addressed
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