New Sensitivity to Solar WIMP Annihilation using Low-Energy Neutrinos

Dark matter particles captured by the Sun through scattering may annihilate and produce neutrinos, which escape. Current searches are for the few high-energy neutrinos produced in the prompt decays of some final states. We show that interactions in the solar medium lead to a large number of pions for nearly all final states. Positive pions and muons decay at rest, producing low-energy neutrinos with known spectra, including nuebar through neutrino mixing. We demonstrate that Super-Kamiokande can thereby provide a new probe of the spin-dependent WIMP-proton cross section. Compared to other methods, the sensitivity is competitive and the uncertainties are complementary.Comment: 5 pages, 4 figure

Boundary-layer effects on the reflection of sound waves and weak shock waves at shallow incidence

When either a plane acoustic wave or a weak shock wave is incident upon an infinite wall, the boundary-layer correction to the reflected wave becomes large if the angle between the wave front and the normal to the wall approaches zero. It is shown that transformation to moving coordinates leads to transonic flow problems whose solution permits removal of the singular behavior in each of these cases. Wenn eine ebene Schallwelle oder ein schwacher Stoss so auf eine Wand auftrifft, dass der Winkel zwischen der Wellenfront und der Wandnormalen gegen Null geht, so wird die Korrektur der reflektierten Welle wegen der Wandgrenzschicht gross. In der vorliegenden Arbeit wird gezeigt, dass eine Transformation auf bewegte Koordinaten auf ein transonisches Problem führt, dessen Lösung die Singularität in beiden Fällen vermeidet.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43361/1/33_2005_Article_BF01603823.pd

Социально ориентированные программы, KIDS SAVE LIVES (Дети спасают жизни), World Restart a Heart (Перезапусти сердце) и другие кампании для повышения выживаемости при внебольничной остановке сердца

Sudden out-of-hospital cardiac arrest (OHCA) is the third leading cause of death in industrialized nations.While educating lay bystanders in CPR is clearly the most important way to increase survival in this third leading cause of death and the community programs are helpful, it is less easy to reach the entire population if programs are not obligatory. Therefore experts see the need for obligatory inclusion of CPR education in schools. And this is exactly our clear expectation to all politicians involved in health care and school politics worldwide. Until this is reality in all countries, we invite everyone to help to convince the responsible politicians and to take part in campaigns like KIDS SAVE LIVES and WRAH.Внезапная внебольничная остановка сердца (ВОС) — третья по частоте причина смерти в развитых странах.Обучение основам СЛР лиц без медицинского образования — наиболее важная стратегия повышения выживаемости при остановке сердца. Программы, включающие такое обучение, весьма эффективны, однако полного охвата населения достичь очень трудно вследствие их необязательного статуса. В связи с этим, по мнению экспертов, СЛР необходимо ввести в школьную программу в качестве обязательного предмета. Именно этого мы ждем от политиков, ответственных за систему здравоохранения и образование, во всех странах. Пока наша цель не достигнута, мы призываем всех помочь нам убедить ответственных лиц и принять участие в таких кампаниях, как KIDS SAVE LIVES и World Restart a Heart

A new cell primo-culture method for freshwater benthic diatom communities

A new cell primo-culture method was developed for the benthic diatom community isolated from biofilm sampled in rivers. The approach comprised three steps: (1) scraping biofilm from river pebbles, (2) diatom isolation from biofilm, and (3) diatom community culture. With a view to designing a method able to stimulate the growth of diatoms, to limit the development of other microorganisms, and to maintain in culture a community similar to the original natural one, different factors were tested in step 3: cell culture medium (Chu No 10 vs Freshwater “WC” medium modified), cell culture vessel, and time of culture. The results showed that using Chu No 10 medium in an Erlenmeyer flask for cell culture was the optimal method, producing enough biomass for ecotoxicological tests as well as minimising development of other microorganisms. After 96 h of culture, communities differed from the original communities sampled in the two rivers studied. Species tolerant of eutrophic or saprobic conditions were favoured during culture. This method of diatom community culture affords the opportunity to assess, in vitro, the effects of different chemicals or effluents (water samples andindustrial effluents) on diatom communities, as well as on diatom cells, from a wide range of perspectives

Effects of Silver Nanoparticles on Primary Mixed Neural Cell Cultures: Uptake, Oxidative Stress and Acute Calcium Responses

In the body, nanoparticles can be systemically distributed and then may affect secondary target organs, such as the central nervous system (CNS). Putative adverse effects on the CNS are rarely investigated to date. Here, we used a mixed primary cell model consisting mainly of neurons and astrocytes and a minor proportion of oligodendrocytes to analyze the effects of well-characterized 20 and 40 nm silver nanoparticles (SNP). Similar gold nanoparticles served as control and proved inert for all endpoints tested. SNP induced a strong size-dependent cytotoxicity. Additionally, in the low concentration range (up to 10 μg/ml of SNP), the further differentiated cultures were more sensitive to SNP treatment. For detailed studies, we used low/medium dose concentrations (up to 20 μg/ml) and found strong oxidative stress responses. Reactive oxygen species (ROS) were detected along with the formation of protein carbonyls and the induction of heme oxygenase-1. We observed an acute calcium response, which clearly preceded oxidative stress responses. ROS formation was reduced by antioxidants, whereas the calcium response could not be alleviated by antioxidants. Finally, we looked into the responses of neurons and astrocytes separately. Astrocytes were much more vulnerable to SNP treatment compared with neurons. Consistently, SNP were mainly taken up by astrocytes and not by neurons. Immunofluorescence studies of mixed cell cultures indicated stronger effects on astrocyte morphology. Altogether, we can demonstrate strong effects of SNP associated with calcium dysregulation and ROS formation in primary neural cells, which were detectable already at moderate dosage