Path integral quantization of electrodynamics in dielectric media

In the present paper we study the Faddeev-Popov path integral quantization of electrodynamics in an inhomogenious dielectric medium. We quantize all polarizations of the photons and introduce the corresponding ghost fields. Using the heat kernel technique, we express the heat kernel coefficients in terms of the dielectricity $\epsilon (x)$ and calculate the ultra violet divergent terms in the effective action. No cancellation between ghosts and "non-physical" degrees of freedom of the photon is observed.Comment: 10 pages, Latex, submitted to J.Phys.A, revised (a misprint in the bibliography

Strong damping of phononic heat current by magnetic excitations in SrCu_2(BO_3)_2

Measurements of the thermal conductivity as a function of temperature and magnetic field in the 2D dimer spin system SrCu$_2$(BO$_3$)$_2$ are presented. In zero magnetic field the thermal conductivity along and perpendicular to the magnetic planes shows a pronounced double-peak structure as a function of temperature. The low-temperature maximum is drastically suppressed with increasing magnetic field. Our quantitative analysis reveals that the heat current is due to phonons and that the double-peak structure arises from pronounced resonant scattering of phonons by magnetic excitations.Comment: a bit more than 4 pages, 2 figures included; minor changes to improve the clarity of the presentatio

Scheme for generating entangled states of two field modes in a cavity

This paper considers a two-level atom interacting with two cavity modes with equal frequencies. Applying a unitary transformation, the system reduces to the analytically solvable Jaynes-Cummings model. For some particular field states, coherent and squeezed states, the transformation between the two bare basis's, related by the unitary transformation, becomes particularly simple. It is shown how to generate, the highly non-classical, entangled coherent states of the two modes, both in the zero and large detuning cases. An advantage with the zero detuning case is that the preparation is deterministic and no atomic measurement is needed. For the large detuning situation a measurement is required, leaving the field in either of two orthogonal entangled coherent states.Comment: Accepted in J. Mod. Opt.; 12 pages; Replaced with revised version. Extended discussion of experimental realizations, earlier studies in the field and on the frequency dependence in the adiabatic eliminatio

Genetic variants of Anaplasma phagocytophilum from 14 equine granulocytic anaplasmosis cases

<p>Abstract</p> <p>Background</p> <p>Equine Granulocytic Anaplasmosis (EGA) is caused by <it>Anaplasma phagocytophilum</it>, a tick-transmitted, obligate intracellular bacterium. In Europe, it is transmitted by <it>Ixodes ricinus</it>. A large number of genetic variants of <it>A. phagocytophilum </it>circulate in nature and have been found in ticks and different animals. Attempts have been made to assign certain genetic variants to certain host species or pathologies, but have not been successful so far. The purpose of this study was to investigate the causing agent <it>A. phagocytophilum </it>of 14 cases of EGA in naturally infected horses with molecular methods on the basis of 4 partial genes (<it>16S rRNA</it>, <it>groEL</it>, <it>msp2</it>, and <it>msp4</it>).</p> <p>Results</p> <p>All DNA extracts of EDTA-blood samples of the horses gave bands of the correct nucleotide size in all four genotyping PCRs. Sequence analysis revealed 4 different variants in the partial <it>16S rRNA</it>, <it>groEL </it>gene and <it>msp2 </it>genes, and 3 in the <it>msp4 </it>gene. One <it>16S rRNA </it>gene variant involved in 11 of the 14 cases was identical to the "prototype" variant causing disease in humans in the amplified part [GenBank: <ext-link ext-link-id="U02521" ext-link-type="gen">U02521</ext-link>]. Phylogenetic analysis revealed as expected for the <it>groEL </it>gene that sequences from horses clustered separately from roe deer. Sequences of the partial <it>msp2 </it>gene from this study formed a separate cluster from ruminant variants in Europe and from all US variants.</p> <p>Conclusions</p> <p>The results show that more than one variant of <it>A. phagocytophilum </it>seems to be involved in EGA in Germany. The comparative genetic analysis of the variants involved points towards different natural cycles in the epidemiology of <it>A. phagocytophilum</it>, possibly involving different reservoir hosts or host adaptation, rather than a strict species separation.</p

Confounding conventional wisdom: political not principled differences in the transatlantic regulatory relationship

The transatlantic complaints over hormone-treated beef and genetically modified organisms before the World Trade Organisation (WTO) seem to confirm two separate but related conventional wisdoms about the transatlantic economic relationship: that it is highly conflictual and that many of the conflicts are rooted in profoundly different approaches to regulation. This article argues that neither of the two conventional wisdoms is accurate. Rather, it contends that they are products of two, compounding analytical shortcomings: one methodological, one empirical. The methodological shortcoming takes the form of an implicit selection bias. While WTO complaints are high profile they are rare and extreme examples; it is, therefore, unsound to generalise from them to the regulatory relationship as a whole. The empirical shortcoming has to do with neither the beef hormones nor the GMO dispute demonstrating what it is purported to. The article thus serves as a cautionary tale about the dangers of relying on obvious cases and the need to question whether evidence really does support a prevailing popular narrative

Developing assessments for child exposure to intimate partner violence in Switzerland – A study of medico-legal reports in clinical settings

Purpose: Evidence to inform assessment of needs of children exposed to intimate partner violence (IPV) in health settings is limited. A Swiss hospital-based medico-legal consultation for adult victims of violence also detects children’s exposure to IPV and refers cases to the Pediatrics Child Abuse and Neglect Team. Based on a conceptual ecological framework, this study examined the nature and circumstances of children’s exposure to IPV described in accounts collected by nurses in consultations with adult IPV victims. Methods: From 2011-2014, 438 parents (88% female) of 668 children aged 0 to 18 sought medico-legal care from the Violence Medical Unit in Lausanne Switzerland, following assaults by intimate partners (85% male). As part of the consultation, nurses completed a semi-structured questionnaire with victimized parents, recording their answers in the patient file. Victims’ statements about the abuse, their personal, family and social contexts, and their children’s exposure to IPV were analyzed. Descriptive statistics and qualitative thematic content analyses were conducted to identify, from the victimized parents’ accounts, elements useful to understand the nature and circumstances of children’s exposure and involvement during violent events. Results: Parent statements on specific violent events described children being present in 75% of the cases. Children were said to be exposed to, and responded to, severe physical violence, serious threats and insults, in the context of repeated assaults and coercive control. Families, especially mothers, were often coping with additional socio-economic vulnerabilities. Conclusions: Implications for further developing assessments of children living with IPV, especially in health settings were identified

A inserção do Brasil no mercado mundial de alumínio: incorporando contribuições da Ecologia Política para a Saúde Coletiva

O presente artigo discute a inserção do Brasil no mercado mundial de alumínio a partir dos referenciais teóricos da ecologia política, da economia política do território e da saúde coletiva. A conjuntura contemporânea da economia mundial tem sido pautada pela desregulamentação e liberalização, característicos do ideário neoliberal propalado pelas nações centrais. A maior participação do Brasil nesse mercado tem sido realizada a partir do aumento da produção e exportação de commodities agrárias e metálicas, como o alumínio. Nesse sentido, a partir dos paradigmas da ecologia política, o texto propõe uma análise das consequências socioambientais, assim como sobre novas territorialidades que se produzem e reproduzem dentro de uma lógica econômica que privilegia as nações centrais. Do mesmo modo, procura-se compreender os dilemas da saúde coletiva sob uma perspectiva holística e integradora na qual se articula aos modelos de desenvolvimento econômico. Percebe-se que a produção e exportação de alumínio primário, apesar de apresentar um valor agregado maior, esconde um conjunto difuso de impactos que afetam o ambiente e a saúde coletiva

FATORES DETERMINANTES PARA O AVANÇO DA ENERGIA EÓLICA NO ESTADO DO CEARÁ FRENTE AOS DESAFIOS DAS MUDANÇAS CLIMÁTICAS

O trabalho identifica fatores determinantes para o avanço da geração da energia eólica frente aos desafios das mudanças climáticas. A pesquisa empregou métodos qualitativos para a obtenção de dados e configura-se como descritiva e exploratória. Foram realizadas entrevistas semiestruturadas com participantes do setor eólico, tomando o estado do Ceará como unidade de estudo. Os resultados indicam que as percepções e pressões dos stakeholders, as políticas públicas e os investimentos tecnológicos são determinantes para que a participação da energia eólica na matriz energética Brasileira seja ampliada. A perspectiva de um preço mais competitivo do KWh produzido é vital para o crescimento dos investimentos na implantação de parques eólicos. As empresas estão investindo na eficiência operacional dos aerogeradores e na adequação tecnológicas as características dos ventos do Nordeste Brasileiro. O diálogo com a comunidade revela-se também determinante para a viabilidade de implantação dos parques eólicos. A pesquisa aponta um cenário de incertezas para a segurança energética do país, no qual as empresas planejam suas estratégias com base nos benefícios oriundos de uma intensa participação do governo para alavancar este setor