Ultrahigh energy neutrinos at the pierre auger observatory

The observation of ultrahigh energy neutrinos (UHEs) has become a priority in experimental astroparticle physics. UHEs can be detected with a variety of techniques. In particular, neutrinos can interact in the atmosphere (downward-going ) or in the Earth crust (Earth-skimming ), producing air showers that can be observed with arrays of detectors at the ground. With the surface detector array of the Pierre Auger Observatory we can detect these types of cascades. The distinguishing signature for neutrino events is the presence of very inclined showers produced close to the ground (i.e., after having traversed a large amount of atmosphere). In this work we review the procedure and criteria established to search for UHEs in the data collected with the ground array of the Pierre Auger Observatory.This includes Earth-skimming as well as downward-going neutrinos. No neutrino candidates have been found, which allows us to place competitive limits to the diffuse flux of UHEs in the EeV range and above

Description of Atmospheric Conditions at the Pierre Auger Observatory using the Global Data Assimilation System (GDAS)

Atmospheric conditions at the site of a cosmic ray observatory must be known for reconstructing observed extensive air showers. The Global Data Assimilation System (GDAS) is a global atmospheric model predicated on meteorological measurements and numerical weather predictions. GDAS provides altitude-dependent profiles of the main state variables of the atmosphere like temperature, pressure, and humidity. The original data and their application to the air shower reconstruction of the Pierre Auger Observatory are described. By comparisons with radiosonde and weather station measurements obtained on-site in Malarg\"ue and averaged monthly models, the utility of the GDAS data is shown

Ionizing radiation reduces the capacity of activated macrophages to induce T-cell proliferation, but does not trigger dendritic cell-mediated non-targeted effects.

Purpose: Previous investigations revealed influences of irradiation up to 2Gy on the cytokine secretion profile of inflammatory and peritoneal mouse macrophages (pMCYRILLIC CAPITAL LETTER EF). This raised the question if those alterations impact on dendritic cells and consecutive T-cell responses. Further, the impact of irradiation directly on pMCYRILLIC CAPITAL LETTER EF capacity to induce T-cell responses was analyzed. Materials and methods: pMCYRILLIC CAPITAL LETTER EF were LPS-activated, irradiated and the expression of activation markers was assessed. Treated pMCYRILLIC CAPITAL LETTER EF were co-incubated with T-cells to investigate proliferation. To verify modulating properties of pMCYRILLIC CAPITAL LETTER EF supernatants isolated 24 h after irradiation, bone marrow-derived dendritic cells (BMDC) were co-incubated with supernatants and activation markers as well as the BMDC-induced proliferation of T-cells were measured. Results: pMCYRILLIC CAPITAL LETTER EF showed a highly significantly decreased major histocompatibility complexII (MHCII) expression within a dose range from 0.7-2Gy. Further, the proliferation rate of cluster of differentiation 4(+) (CD4(+)) T-cells was decreased after co-incubation particularly with 2 Gy irradiated pMCYRILLIC CAPITAL LETTER EF. The co-incubation of BMDC with supernatants of activated, irradiated pMCYRILLIC CAPITAL LETTER EF significantly reduced the CD40 expression, but did not impact on the BMDC-derived induction of T-cell proliferation. Conclusions: Inflammatory macrophages being exposed to irradiation have the potential to modulate consecutive adaptive immune reactions. But supernatants of irradiated macrophages do not influence the dendritic cells (DC)-mediated induction of T cell proliferation

Interconnection between DNA damage, senescence, inflammation, and cancer.

In order to deal with endogenous and exogenous factors, including radiation or pathogens, cells evolved different strategies. This includes highly complex processes such as DNA damage response, senescence, cell death, and inflammatory reactions. Recent research indicates an interconnection between the mentioned cellular pathways whilst all of them seem to play a role in induction and progression, but also the prevention of cancerous diseases and therefore qualify for potential prevention and treatment strategies. On the basis of their pivotal functions in cancer biology in general, each of the cellular processes represents promising single therapeutic targets. Further, due to their strong interconnection, targeting all of them in a multimodal approach could be another promising strategy to treat cancer. We, therefore, review the mechanisms of DNA damage induction, detection and repair as well as the induction of cell death. Further, features of senescence and mechanism of inflammation induction and abrogation are outlined. A special focus is set on how senescence and inflammation are related to diseases and how targeting them could contribute to improvement of cancer therapies

The nature and origin of ultra high-energy cosmic rays

Contains fulltext : 103833.pdf (publisher's version ) (Open Access

A search for anisotropy in the arrival directions of ultra high energy cosmic rays recorded at the Pierre Auger Observatory

Contains fulltext : 93734.pdf (publisher's version ) (Closed access) Contains fulltext : 93734-1.pdf (preprint version ) (Open Access

Minds, Machines and Searle

Searle's celebrated Chinese Room Argument has shaken the foundations of Artificial Intelligence. Many refutations have been attempted, but none seem convincing. This paper is an attempt to sort out explicitly the assumptions and the logical, methodological and empirical points of disagreement. Searle is shown to have underestimated some features of computer modeling, but the heart of the issue turns out to be an empirical question about the scope and limits of the purely symbolic (computational) model of the mind. Nonsymbolic modeling turns out to be immune to the Chinese Room Argument. The issues discussed include the Total Turing Test, modularity, neural modeling, robotics, causality and the symbol-grounding problem