Synthesis and Magnetic Characterization of Graphite-Coated Iron Nanoparticles

Graphite-coated iron nanoparticles were prepared from magnetite nanoparticles by chemical vapour deposition (CVD) under methane and hydrogen atmosphere. After being purified from carbon excess, graphite-coated iron nanoparticles were tested for morphological and magnetic properties. It was found that, during the thermal process, magnetite nanoparticles 6 nm in size coalesce and transform into graphite-coated iron 200 nm in size, as revealed by scanning electron microscopy (SEM). Raman characterization assessed that high-quality graphite coats the iron core. Magnetic measurements revealed the phase change (magnetite to iron) as an increase in the saturation magnetization from 50 to 165 emu/g after the CVD process

Atividade antibacteriana e antifúngica de extratos etanólicos de Aster lanceolatus Willd., Asteraceae.

Conhecida popularmente como áster-arbustiva, margarida-de-são-miguel e monte-cassino, Aster lanceolatus é uma planta ornamental de corte. Sabendo-se que não existem estudos que atestem a atividade biológica desta espécie, procurou-se neste trabalho atividades antibacteriana e antifúngica. Para tanto se utilizaram extratos brutos etanólicos de duas porções distintas, das flores e dos caules com folhas. Para a atividade antibacteriana, oito bactérias patogênicas foram submetidas a ensaio de difusão em gel e concentração inibitória mínima. Demonstrou-se atividade do extrato bruto etanólico de flores contra Streptococcus pyogenes, em difusão em gel e atividade de extrato bruto etanólico de caules e folhas contra Salmonella typhimurium e Streptococcus pyogenes em concentração inibitória mínima. Para a atividade antifúngica, utilizaram-se três fungos patogênicos em ensaios de crescimento micelial em placas e bioautografia direta. No ensaio de crescimento micelial em placas verificou-se a inibição de Fusarium oxysporum e na bioautografia direta, inibição do Cylindrocladium spathulatum. Os resultados delinearam uma nova fonte de pesquisa, as plantas ornamentais. Estas podem ser fonte de constituintes químicos capazes de servirem como protótipos para novos agentes terapêuticos e para tratamento sanitário de plantas medicinais

AVALIAÇÃO DO EFEITO DO EXTRATO ETANÓLICO DE ASTER LANCEOLATUS

This paper evalueted antibacterial activity of ethanolic extract from Aster lanceolatus Willd., on control bacterial plate. Were used ethanolic extract from Aster lanceolatus there was inhibition on bacterials tested. Key words: Aster, bacterial plaque, phytotherapy.Este trabalho teve como objetivo avaliar a atividade antibacteriana do extrato etanólico das partes aéreas de Aster lanceolatus Willd. no controle de bactérias presentes na placa dentária. Utilizando-se extrato bruto etanólico de Aster lanceolatus, conseguiu-se inibição dos microorganismos testados. Palavras-chave: Aster, placa bacteriana, fitoterapia

Adaptive Melanin Response of the Soil Fungus Aspergillus niger to UV Radiation Stress at “Evolution Canyon”, Mount Carmel, Israel

BACKGROUND:Adaptation is an evolutionary process in which traits in a population are tailored by natural selection to better meet the challenges presented by the local environment. The major discussion relating to natural selection concerns the portraying of the cause and effect relationship between a presumably adaptive trait and selection agents generating it. Therefore, it is necessary to identify trait(s) that evolve in direct response to selection, enhancing the organism's fitness. "Evolution Canyon" (EC) in Israel mirrors a microcosmic evolutionary system across life and is ideal to study natural selection and local adaptation under sharply, microclimatically divergent environments. The south-facing, tropical, sunny and xeric "African" slope (AS) receives 200%-800% higher solar radiation than the north-facing, temperate, shady and mesic "European" slope (ES), 200 meters apart. Thus, solar ultraviolet radiation (UVR) is a major selection agent in EC influencing the organism-environment interaction. Melanin is a trait postulated to have evolved for UV-screening in microorganisms. Here we investigate the cause and effect relationship between differential UVR on the opposing slopes of EC and the conidial melanin concentration of the filamentous soil fungus Aspergillus niger. We test the working hypothesis that the AS strains exhibit higher melanin content than strains from the ES resulting in higher UV resistance. METHODOLOGY/PRINCIPAL FINDINGS:We measured conidial melanin concentration of 80 strains from the EC using a spectrophotometer. The results indicated that mean conidial melanin concentration of AS strains were threefold higher than ES strains and the former resisted UVA irradiation better than the latter. Comparisons of melanin in the conidia of A. niger strains from sunny and shady microniches on the predominantly sunny AS and predominantly shady ES indicated that shady conditions on the AS have no influence on the selection on melanin; in contrast, the sunny strains from the ES displayed higher melanin concentrations. CONCLUSIONS/SIGNIFICANCE:We conclude that melanin in A. niger is an adaptive trait against UVR generated by natural selection

Growth and Asymmetry of Soil Microfungal Colonies from “Evolution Canyon,” Lower Nahal Oren, Mount Carmel, Israel

Fluctuating asymmetry is a contentious indicator of stress in populations of animals and plants. Nevertheless, it is a measure of developmental noise, typically obtained by measuring asymmetry across an individual organism's left-right axis of symmetry. These individual, signed asymmetries are symmetrically distributed around a mean of zero. Fluctuating asymmetry, however, has rarely been studied in microorganisms, and never in fungi.We examined colony growth and random phenotypic variation of five soil microfungal species isolated from the opposing slopes of “Evolution Canyon,” Mount Carmel, Israel. This canyon provides an opportunity to study diverse taxa inhabiting a single microsite, under different kinds and intensities of abiotic and biotic stress. The south-facing “African” slope of “Evolution Canyon” is xeric, warm, and tropical. It is only 200 m, on average, from the north-facing “European” slope, which is mesic, cool, and temperate. Five fungal species inhabiting both the south-facing “African” slope, and the north-facing “European” slope of the canyon were grown under controlled laboratory conditions, where we measured the fluctuating radial asymmetry and sizes of their colonies. from the “African” slope were more asymmetric than those from the “European” slope.Our study suggests that fluctuating radial asymmetry has potential as an indicator of random phenotypic variation and stress in soil microfungi. Interaction of slope and species for both growth rate and asymmetry of microfungi in a common environment is evidence of genetic differences between the “African” and “European” slopes of “Evolution Canyon.

Freedom of Information in France: Law and Practice

In France, a legislation on freedom of information (FOI) granted every person the right to obtain communication of documents held by an administration within the framework of its public service mission, regardless of their form or medium, in 1978. This marked a stark break away from a tradition of administrative secrecy and sought to improve the relations between the French State and its citizens. The French FOI act aims to find a balance between the right to access public information (a democratic requirement and a prerequisite for the exercise of fundamental rights), and other competing interests (privacy, competition, and public order and security). This equilibrium is constantly reshaped under the influence of technological developments and an increasing commodification of public information. Changes and adaptation occur through legislative changes (such as the 2016 statute on ‘Republique numérique’) and through practice, for example, through the combined interaction of an independent authority—the Commission d’accès aux documents administratifs (CADA)—and the French administrative judge, the Council of State. This chapter seeks to provide an assessment of how the law works in practice, thanks to interviews with senior practitioners in this matter such as legislators, judges, and information commissioners and the analysis of empirical data such as CADA’s annual reports, opinions, and advice. Three main issues emerge from this assessment: firstly, administrative inertia is still very strong nearly 40 years after the first FOIA was adopted; secondly, the exceptions to the principle of access to administrative documents have grown over time, reducing the actual scope of FOI; thirdly, fragmentation of the special regimes may lead to more confusion than transparency