Self Interacting Dark Matter in the Solar System

Weakly coupled, almost massless, spin 0 particles have been predicted by many extensions of the standard model of particle physics. Recently, the PVLAS group observed a rotation of polarization of electromagnetic waves in vacuum in the presence of transverse magnetic field. This phenomenon is best explained by the existence of a weakly coupled light pseudoscalar particle. However, the coupling required by this experiment is much larger than the conventional astrophysical limits. Here we consider a hypothetical self-interacting pseudoscalar particle which couples weakly with visible matter. Assuming that these pseudoscalars pervade the galaxy, we show that the solar limits on the pseudoscalar-photon coupling can be evaded.Comment: 17 pages, 2 figure

Open Heavy Flavor Production in QCD -- Conceptual Framework and Implementation Issues

Heavy flavor production is an important QCD process both in its own right and as a key component of precision global QCD analysis. Apparent disagreements between fixed-flavor scheme calculations of b-production rate with experimental measurements in hadro-, lepto-, and photo-production provide new impetus to a thorough examination of the theory and phenomenology of this process. We review existing methods of calculation, and place them in the context of the general PQCD framework of Collins. A distinction is drawn between scheme dependence and implementation issues related to quark mass effects near threshold. We point out a so far overlooked kinematic constraint on the threshold behavior, which greatly simplifies the variable flavor number scheme. It obviates the need for the elaborate existing prescriptions, and leads to robust predictions. It can facilitate the study of current issues on heavy flavor production as well as precision global QCD analysis.Comment: 13 pages, 10 figures, Proceedings of Ringberg Workshop: New Trends in HERA Physics 2001, Munich, German

Anthropogenic food subsidies reshape the migratory behaviour of a long-distance migrant

Bird migratory journeys are often long and hostile, requiring high energetic expenditure, and thus forcing birds to pause between migratory flights. Stopover sites allow migrants to replenish fuel reserves and rest, being crucial for the success of migration. Worldwide, the increasing accumulation of waste on landfills and rubbish dumps has been described to provide superabundant food resources for many bird species not only during the breeding and wintering seasons but also during migration, being used as stopover sites. Using GPS-tracking data of juvenile white storks (Ciconia ciconia) during their first migration from the Iberia Peninsula to the sub-Saharan wintering grounds, we uncover the effects of stopping en route on individual migratory perfor-mance. Particularly, we examine the benefits of stopping at artificial sites (landfills and rubbish dumps) when com-pared to natural stopover sites (wetlands, agricultural or desert areas) and explore the influence of anthropogenic food resources on storks' migratory strategies. Overall, white storks spent up to one-third of the migration in stopovers. We found that birds that stopped for longer periods made more detours, increasing migration duration by half a day for each stopover day. Stopping more often did not reflect on increasing in-flight energetic efficiency nor the likelihood of completing the migration. Juvenile storks used artificial sites in 80 % of the stopover days, spending 45 % less time and 10 % less energy foraging than when using natural stopovers. While stopping in landfills did not translate into differences in migratory performance, individuals in poor body condition possibly rely on these sites to improve body weight before proceed-ing, enabling them to successfully complete migration. Artificial stopover sites are attractive and likely increase the number and duration of stops for white storks. Even though the consequences of arriving late at the wintering grounds are unknown, it can lead to cascading consequences, influencing individual fitness and population dynamics.Peer reviewe

Breakdown of anomalous channeling with ion energy for accurate strain determination in gan-based heterostructures

The influence of the beam energy on the determination of strain state with ion channeling in GaN-based heterostructures (HSs) is addressed. Experimental results show that anomalous channeling may hinder an accurate analysis due to the steering effects at the HS interface, which are more intense at lower ion energies. The experimental angular scans have been well reproduced by Monte Carlo simulations, correlating the steering effects with the close encounter probability at the interface. Consequently, limitations in the determination of the strain state by ion channeling can be overcome by selecting the adequate beam energy

Estudio experimental comparativo de la analgesia intraoperatoria con remifentanilo en el perro

En este artículo se comparan las propiedades analgésicas del remifentanilo y el fentanilo y se estudian la estabilidad cardiovascular, respiratoria y calidad d ela recuperción en perros anestesiados 11 Beagle con medetomidina, propofol, isoflurano y atracurio. Los analgésicos empleados fueron fentanilo, remifentanilo y un placebo. Los resultados muestran menores necesidades de anestésico con ambos opiodes, mejor estabilidad cardiovascular y menores tiempos de recuperación con remifentanilo. Ambos fármacos proporcionan buena calidad analgésica y recuperación.

Data Collection for the Fourth Multicentre Confidential Enquiry into Perioperative Equine Fatalities (CEPEF4) Study:New Technology and Preliminary Results

It is almost 20 years since the largest observational, multicentre study evaluating the risks of mortality associated with general anaesthesia in horses. We proposed an internet-based method to collect data (cleaned and analysed with R) in a multicentre, cohort, observational, analytical, longitudinal and prospective study to evaluate peri-operative equine mortality. The objective was to report the usefulness of the method, illustrated with the preliminary data, including outcomes for horses seven days after undergoing general anaesthesia and certain procedures using standing sedation. Within six months, data from 6701 procedures under general anaesthesia and 1955 standing sedations from 69 centres were collected. The results showed (i) the utility of the method; also, that (ii) the overall mortality rate for general anaesthesia within the seven-day outcome period was 1.0%. In horses undergoing procedures other than exploratory laparotomy for colic (“noncolics”), the rate was lower, 0.6%, and in “colics” it was higher, at 3.4%. For standing sedations, the overall mortality rate was 0.2%. Finally, (iii) we present some descriptive data that demonstrate new developments since the previous CEPEF2. In conclusion, horses clearly still die unexpectedly when undergoing procedures under general anaesthesia or standing sedation. Our method is suitable for case collection for future studies

Influenza vaccination among multiple sclerosis patients during the COVID-19 pandemic

In the context of the COVID-19 pandemic, the co-circulation of influenza and SARS-CoV-2 viruses may have severe complications for vulnerable populations. For this reason, the World Health Organization pointed to the 2020–2021 anti-influenza campaign as being of special relevance. Our aim was to assess the 2020–2021 influenza vaccination coverage, and its associated factors, among patients in a Spanish multiple sclerosis (MS) unit. A cross–sectional study was conducted. People attending the MS unit of the Clinical Hospital of Zaragoza during 2020 were included. Variables were obtained by reviewing records. Associations with 2020–2021 influenza vaccination were analyzed using bivariate analysis and a multiple logistic regression model. A total of 302 patients were studied; 62.6% were women, whose mean age (standard deviation) was 47.3 (11.5) years. The 2020–2021 influenza vaccination coverage was 55.3% (59.8% in women and 47.8% in men). A total of 89.7% had at least one other indication for vaccination (e.g., immunosuppressive treatment in 225 patients). The variables associated with getting vaccinated were being female (adjusted odds ratio (95% confidence interval) (aOR (95%CI) = 2.12 (1.12–3.99)), having received the 2019–2020 influenza vaccine (aOR (95%CI) = 31.82 (14.71–68.86)) and being born in Spain (aOR (95%CI) = 12.91 (1.07–156.28)). Coverage is moderate compared to other countries. It is necessary to develop strategies to improve it, especially in men and those born outside Spain

Gel-free/label-free analysis to study the proteome of botrytis cinerea

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