High Energy Neutrino Astronomy: Towards Kilometer-Scale Detectors

Of all high-energy particles, only neutrinos can directly convey astronomical information from the edge of the universe---and from deep inside the most cataclysmic high-energy processes. Copiously produced in high-energy collisions, travelling at the velocity of light, and not deflected by magnetic fields, neutrinos meet the basic requirements for astronomy. Their unique advantage arises from a fundamental property: they are affected only by the weakest of nature's forces (but for gravity) and are therefore essentially unabsorbed as they travel cosmological distances between their origin and us. Many of the outstanding mysteries of astrophysics may be hidden from our sight at all wavelengths of the electromagnetic spectrum because of absorption by matter and radiation between us and the source. For example, the hot dense regions that form the central engines of stars and galaxies are opaque to photons. In other cases, such as supernova remnants, gamma ray bursters, and active galaxies, all of which may involve compact objects or black holes at their cores, the precise origin of the high-energy photons emerging from their surface regions is uncertain. Therefore, data obtained through a variety of observational windows---and especially through direct observations with neutrinos---may be of cardinal importance. In this talk, the scientific goals of high energy neutrino astronomy and the technical aspects of water and ice Cherenkov detectors are examined, and future experimental possibilities, including a kilometer-square deep ice neutrino telescope, are explored.Comment: 13 pages, Latex, 6 postscript figures, uses aipproc.sty and epsf.sty. Talk presented at the International Symposium on High Energy Gamma Ray Astronomy, Heidelberg, June 200

When the heart kills the liver: acute liver failure in congestive heart failure

Congestive heart failure as a cause of acute liver failure is rarely documented with only a few cases

Offspring Hormones Reflect the Maternal Prenatal Social Environment: Potential for Foetal Programming?

Females of many species adaptively program their offspring to predictable environmental conditions, a process that is often mediated by hormones. Laboratory studies have shown, for instance, that social density affects levels of maternal cortisol and testosterone, leading to fitness-relevant changes in offspring physiology and behaviour. However, the effects of social density remain poorly understood in natural populations due to the difficulty of disentangling confounding influences such as climatic variation and food availability. Colonially breeding marine mammals offer a unique opportunity to study maternal effects in response to variable colony densities under similar ecological conditions. We therefore quantified maternal and offspring hormone levels in 84 Antarctic fur seals (Arctocephalus gazella) from two closely neighbouring colonies of contrasting density. Hair samples were used as they integrate hormone levels over several weeks or months and therefore represent in utero conditions during foetal development. We found significantly higher levels of cortisol and testosterone (both P < 0.001) in mothers from the high density colony, reflecting a more stressful and competitive environment. In addition, offspring testosterone showed a significant positive correlation with maternal cortisol (P < 0.05). Although further work is needed to elucidate the potential consequences for offspring fitness, these findings raise the intriguing possibility that adaptive foetal programming might occur in fur seals in response to the maternal social environment. They also lend support to the idea that hormonally mediated maternal effects may depend more strongly on the maternal regulation of androgen rather than cortisol levels

Trend-TDT – a transmission/disequilibrium based association test on functional mini/microsatellites

<p>Abstract</p> <p>Background</p> <p>Minisatellites and microsatellites are associated with human disease, not only as markers of risk but also involved directly in disease pathogenesis. They may play significant roles in replication, repair and mutation of DNA, regulation of gene transcription and protein structure alteration. Phenotypes can thus be affected by mini/microsatellites in a manner proportional to the length of the allele. Here we propose a new method to assess the linear trend toward transmission of shorter or longer alleles from heterozygote parents to affected child.</p> <p>Results</p> <p>This test (trend-TDT) performs better than other TDT (Transmission/Disequilibrium Test) type tests, such as TDT_maxand TDT_L/S, under most marker-disease association models.</p> <p>Conclusion</p> <p>The trend-TDT test is a more powerful association test when there is a biological basis to suspect a relationship between allele length and disease risk.</p

Study of intrinsic risk factors for falls in institutionalized elderly people

Esta pesquisa teve como objetivo identificar a presença de fatores intrínsecos que predispõem a quedas em idosos moradores em instituições de longa permanência na cidade de Goiânia (GO). Trata-se de estudo descritivo transversal realizado em seis instituições de longa permanência para idosos existentes na cidade de Goiânia. A amostra da investigação constou de 95 idosos que atenderam aos critérios de inclusão e exclusão. Utilizou-se um questionário contendo dados clínicos relacionados às condições de saúde-doença; dados cognitivos; avaliação da capacidade para as atividades básicas de vida diária e avaliação do equilíbrio e marcha. Os idosos avaliados, no geral, apresentam vários fatores de risco, apontados pela literatura, para quedas, tais como: relato de dificuldade motora em membros inferiores (90%), déficit visual (81,1%), uso de três ou mais medicamentos (59,7%), suspeita de depressão (37,9%), falta de equilíbrio em apoio unipodal (37,9%) e altura do passo anormalmente diminuída (32,6%). As informações obtidas nos permitem apontar condições determinantes que aumentam a possibilidade dos eventos queda acontecerem na amostra estudada, sinalizando à necessidade de que estratégias de promoção de saúde, prevenção de agravos e reabilitação devam ser tomadas. _________________________________________________________________________________________ ABSTRACTThe objective of this research was to identify intrinsic risk factors that predispose elderly people living in long-term institutions in the city of Goiânia (GO) to falls. The present descriptive transversal study was carried out in six long-term institutions for seniors in the city of Goiânia. The investigated sample consisted of 95 elderly that fitted the inclusion and exclusion criteria. A questionnaire was used for collecting clinical data related to health-disease conditions; cognitive data; capacity to develop basic daily life activities and equilibrium and gait. In general terms, as pointed out the literature, the examined elderly presented different fall risk factors such as: motor difficulty in lower limbs (90%), visual deficit (81,1%), use of 3 or more kinds of medicines (59,7%), suspected depression (37,9%), lack of equilibrium/unstable unipodal support (37,9%) abnormally decreased height in step (32,6%). The obtained data allow us to set indicators for the increase in falls among the studied sample, demonstrating the need for creating strategies for health promotion, prevention of injuries and rehabilitation

The Mitochondrial Ca(2+) Uniporter: Structure, Function, and Pharmacology.

Mitochondrial Ca(2+) uptake is crucial for an array of cellular functions while an imbalance can elicit cell death. In this chapter, we briefly reviewed the various modes of mitochondrial Ca(2+) uptake and our current understanding of mitochondrial Ca(2+) homeostasis in regards to cell physiology and pathophysiology. Further, this chapter focuses on the molecular identities, intracellular regulators as well as the pharmacology of mitochondrial Ca(2+) uniporter complex