Responses to lead in the freshwater isopods Asellus Aquaticus and A. Meridianus

There is now an increasing awareness of the deterioration of the environment caused by human activities and much research and debate has centred on this subject in recent years. Current and Increasing concern is focused on the release of heavy metals into the environment. In aquatic environments, the concentrations of heavy metals are generally very low, although higher natural concentrations occur in rivers and estuaries which are associated with outcropping metalliferous lodes. As a result, the concentrations of heavy metals in natural waters can easily increase to levels that aquatic organisms have not previously encountered. The introduction of metals by industrial effluents and domestic sewage (Holdgate 1979) and aerial fallout (Peyton et aI. 1976) to aquatic environments can cause heavy metal loads to rise far above natural levels, with subsequent effects on the ecology of the area concerned. In view of this, it was decided to concentrate on the heavy metal lead, in the investigations, because of its potential role as an environmental pollutant caused by its release into the environment. The freshwater isopods, AselIus aquaticus and A. meridianus were used in the study and experiments concerned with the effects of acute lethal and sub lethal concentrations of lead on various aspects of the physiology of the two species were carried out

Health services research doctoral core competencies

This manuscript presents an initial description of doctoral level core competencies for health services research (HSR). The competencies were developed by a review of the literature, text analysis of institutional accreditation self-studies submitted to the Council on Education for Public Health, and a consensus conference of HSR educators from US educational institutions. The competencies are described in broad terms which reflect the unique expertise, interests, and preferred learning methods of academic HSR programs. This initial set of core competencies is published to generate further dialogue within and outside of the US about the most important learning objectives and methods for HSR training and to clarify the unique skills of HSR training program graduates

Buffy the vampire slayer: what being Jewish has to do with it

This article examines the whiteness in the television series Buffy the Vampire Slayer. The author argues that the show’s overwhelming whiteness is a product of a generalized white anxiety about the numerical loss of white dominance across the United States and, in particular, in California. The article goes on to think through the role that Jewishness plays in the program, discussing the relationship between the apparently Anglo-American Buffy, played by a Jewish actor, and her sidekick, Willow, who is characterized as Jewish but is played by a non-Jewish actor. The evil master in the first series is given Nazi characteristics and the destruction that he wants to inflict carries connotations of the Holocaust. Structurally, Buffy is produced as the Jew who saves the United States from this demonic destruction. In this traumatic renarrativising, the Holocaust comes to stand for the white-experienced crisis of the loss of white supremacy in the United States. With this reading we can begin to understand the show’s popularity among early adult, predominantly white Americans

Author Correction: SciPy 1.0: fundamental algorithms for scientific computing in Python.

An amendment to this paper has been published and can be accessed via a link at the top of the paper

Failure of human rhombic lip differentiation underlies medulloblastoma formation

Medulloblastoma (MB) comprises a group of heterogeneous paediatric embryonal neoplasms of the hindbrain with strong links to early development of the hindbrain 1–4. Mutations that activate Sonic hedgehog signalling lead to Sonic hedgehog MB in the upper rhombic lip (RL) granule cell lineage 5–8. By contrast, mutations that activate WNT signalling lead to WNT MB in the lower RL 9,10. However, little is known about the more commonly occurring group 4 (G4) MB, which is thought to arise in the unipolar brush cell lineage 3,4. Here we demonstrate that somatic mutations that cause G4 MB converge on the core binding factor alpha (CBFA) complex and mutually exclusive alterations that affect CBFA2T2, CBFA2T3, PRDM6, UTX and OTX2. CBFA2T2 is expressed early in the progenitor cells of the cerebellar RL subventricular zone in Homo sapiens, and G4 MB transcriptionally resembles these progenitors but are stalled in developmental time. Knockdown of OTX2 in model systems relieves this differentiation blockade, which allows MB cells to spontaneously proceed along normal developmental differentiation trajectories. The specific nature of the split human RL, which is destined to generate most of the neurons in the human brain, and its high level of susceptible EOMES +KI67 + unipolar brush cell progenitor cells probably predisposes our species to the development of G4 MB

A História da Alimentação: balizas historiográficas

Os M. pretenderam traçar um quadro da História da Alimentação, não como um novo ramo epistemológico da disciplina, mas como um campo em desenvolvimento de práticas e atividades especializadas, incluindo pesquisa, formação, publicações, associações, encontros acadêmicos, etc. Um breve relato das condições em que tal campo se assentou faz-se preceder de um panorama dos estudos de alimentação e temas correia tos, em geral, segundo cinco abardagens Ia biológica, a econômica, a social, a cultural e a filosófica!, assim como da identificação das contribuições mais relevantes da Antropologia, Arqueologia, Sociologia e Geografia. A fim de comentar a multiforme e volumosa bibliografia histórica, foi ela organizada segundo critérios morfológicos. A seguir, alguns tópicos importantes mereceram tratamento à parte: a fome, o alimento e o domínio religioso, as descobertas européias e a difusão mundial de alimentos, gosto e gastronomia. O artigo se encerra com um rápido balanço crítico da historiografia brasileira sobre o tema

The Field Guide to Photographing Landscapes

128 hal.: ill.; 23 cm