Neutrino telescopes and high-energy cosmic neutrinos

In this review paper, we present the main aspects of high-energy cosmic neutrino astrophysics. We begin by describing the generic expectations for cosmic neutrinos, including the effects of propagation from their sources to the detectors. Then we introduce the operating principles of current neutrino telescopes, and examine the main features (topologies) of the observable events. After a discussion of the main background processes, due to the concomitant presence of secondary particles produced in the terrestrial atmosphere by cosmic rays, we summarize the current status of the observations with astrophysical relevance that have been greatly contributed by IceCube detector. Then, we examine various interpretations of these findings, trying to assess the best candidate sources of cosmic neutrinos. We conclude with a brief perspective on how the field could evolve within a few years

EeV Astrophysical neutrinos from FSRQs?

Flat Spectrum Radio Quasars (FSRQ) are the most powerful blazars in the gamma-ray band. Although they are supposed to be good candidates in producing high energy neutrinos, no secure detection of FSRQs has been obtained up to now, except for a possible case of PKS B1424-418. In this work, we compute the expected flux of high energy neutrinos from FSRQs using standard assumptions for the properties of the radiation fields filling the regions surrounding the central supermassive black hole. We obtain as a result that high energy neutrinos are naturally expected from FSRQs in the sub-EeV-EeV energy range and not at PeV energies. This justifies the non-observation of neutrinos from FSRQs with the present technology, since only neutrinos below 10 PeV have been observed. We found that for a non-negligible range of the parameters the cumulative flux from FSRQs is comparable to or even exceeds the expected cosmogenic neutrino flux. This result is intriguing and highlights the importance to disentangle these point-source emissions from the diffuse cosmogenic background.Comment: 9 pages, 7 figures, accepted for publication in A&

Effects of semantic relationship and preactivation on memory updating.

Semantic relationship modulates working memory (WM) processes by promoting recall but impairing recognition. Updating is a core mechanism of WM responsible for its stability and flexibility; it allows maintenance of relevant information while removing no-longer relevant one. To our knowledge, no studies specifically investigated how WM updating may benefit from the processing of semantically related material. In the current study, two experiments were run with this aim. In Experiment 1, we found an advantage for semantically related words (vs. unrelated) regardless of their association type (i.e., taxonomic or thematic). A second experiment was run boosting semantic association through preactivation. Findings replicated those of Experiment 1 suggesting that preactivation was effective and improved semantic superiority. In sum, we demonstrated that long-term semantic associations benefitted the updating process, or more generally, overall WM function. In addition, pre-activating semantic nodes of a given word appears likely a process supporting WM and updating; thus, this may be the mechanism favoring word process and memorization in a semantically related text

Impactos das mudanças climáticas sobre a distribuição espacial da podridão cinzenta em videira no Brasil.

Resumo: A podridão cinzenta, causada pelo fungo Botryotinia fuckeliana (Botrytis cinerea), existente em praticamente todos os vinhedos do mundo, causa sérias reduções na qualidade e na quantidade de uva produzida. O estudo teve como objetivo avaliar os impactos das mudanças climáticas na favorabilidade de ocorrência da podridão cinzenta da videira no Brasil. Foram utilizadas informações de temperatura média e período de molhamento foliar do período de referência (1961 ? 1990) e do futuro (2011 ? 2040, 2041 ? 2070 e 2071 ? 2100) para o Brasil, dos cenários A2 e B1, organizadas no banco de dados em Sistema de Informações Geográficas (SIG) Idrisi 32. A favorabilidade foi obtida aplicando-se equações lógicas, de acordo com as condições e restrições de período de molhamento foliar e temperatura média, resultando em mapas de distribuição espacial da podridão cinzenta no Brasil. De modo geral, é esperado um quadro positivo para o futuro, pois as áreas onde a condição para o desenvolvimento da doença era muito favorável diminuem, e as áreas de condição desfavorável apresentam um aumento principalmente durante o inverno. Abstract; The gray mold, caused by the fungus Botryotinia fuckeliana (Botrytis cinerea), which exists in almost all vineyards in the world, causes serious reductions in quality and quantity of grapes produced. The study aimed to evaluate the impacts of climate change on the favorability of occurrence of gray rot of grapevine in Brazil. Information was collected from average temperature and leaf wetness of the reference period (1961 - 1990) and future (2011 - 2040, 2041 - 2070 and 2071 - 2100) for Brazil, organized in the database in a Geographic Information System (GIS) Idrisi 32. The favorability was obtained by applying logic equations, according to the conditions and restrictions of leaf wetness and average temperature, resulting in maps of spatial distribution of gray mold in Brazil. In general, it can be expected a positive picture for the future, because the areas where the condition for the development of the disease was very favorable decreased, and the areas of unfavorable condition showed an increase mainly during the winter

CHANTI: a Fast and Efficient Charged Particle Veto Detector for the NA62 Experiment at CERN

The design, construction and test of a charged particle detector made of scintillation counters read by Silicon Photomultipliers (SiPM) is described. The detector, which operates in vacuum and is used as a veto counter in the NA62 experiment at CERN, has a single channel time resolution of 1.14 ns, a spatial resolution of ~2.5 mm and an efficiency very close to 1 for penetrating charged particles

Evaluation of an in-house molecular HIV-1 test to assess mother-to-child HIV-1 transmission in Angola (the APEHC cohort)

Poster presented at the 17th Annual International Meeting of the Institute of Human Virology. Baltimore, 27-30 September 2015"Mother-to-child-transmission (MTCT) rate has decreased sharply in recent years in most of the sub-Saharan Africa, however 220,000 children acquired HIV-1 in 2014. PCR detection of proviral DNA is the most sensitive method for early infant diagnosis (EID) of HIV-1 infection. Commercial kits are available but they have poor sensitivity with divergent non-B subtypes and high costs (≈30€ per test) which limit their use in resource-limited settings. The HIV-1 epidemic in Angola is driven by highly divergent strains of all group M subtypes, except B, as well as multiple recombinant forms (CRFs and URFs) making EID a challenge in this setting. The aim of this study was to develop and validate a qualitative, inexpensive and sensitive “inhouse” HIV-1 EID assay on heel prick dried blood spots (DBS) from infants of the Hospital da Divina Providência (HDP) in Luanda, Angola and determine the current HIV-1 MTCT rate in the Angolan PErinatal HIV Cohort (APEHC)."Fundação para a Ciência e a Tecnologia - Portugal ; European Unio

Cosmic Microwave Background Temperature at Galaxy Clusters

We have deduced the cosmic microwave background (CMB) temperature in the Coma cluster (A1656, $z=0.0231$), and in A2163 ($z=0.203$) from spectral measurements of the Sunyaev-Zel'dovich (SZ) effect over four passbands at radio and microwave frequencies. The resulting temperatures at these redshifts are $T_{Coma} = 2.789^{+0.080}_{-0.065}$ K and $T_{A2163} = 3.377^{+0.101}_{-0.102}$ K, respectively. These values confirm the expected relation $T(z)=T_{0}(1+z)$, where $T_{0}= 2.725 \pm 0.002$ K is the value measured by the COBE/FIRAS experiment. Alternative scaling relations that are conjectured in non-standard cosmologies can be constrained by the data; for example, if $T(z) = T_{0}(1+z)^{1-a}$ or $T(z)=T_{0}[1+(1+d)z]$, then $a=-0.16^{+0.34}_{-0.32}$ and $d = 0.17 \pm 0.36$ (at 95% confidence). We briefly discuss future prospects for more precise SZ measurements of $T(z)$ at higher redshifts.Comment: 13 pages, 1 figure, ApJL accepted for publicatio