Preliminary estimate of contribution of Arctic nitrogen fixation to the global nitrogen budget

Dinitrogen (N-2) fixation is the source of all biologically available nitrogen on earth, and its presence or absence impacts net primary production and global biogeochemical cycles. Here, we report rates of 3.5-17.2 nmol N L-1 d(-1) in the ice-free coastal Alaskan Arctic to show that N-2 fixation in the Arctic Ocean may be an important source of nitrogen to a seasonally nitrogen-limited system. If widespread in surface waters over ice-free shelves throughout the Arctic, N-2 fixation could contribute up to 3.5 Tg N yr(-1) to the Arctic nitrogen budget. At these rates, N-2 fixation occurring in ice-free summer waters would offset up to 27.1% of the Arctic denitrification deficit and contribute an additional 2.7% to N-2 fixation globally, making it an important consideration in the current debate of whether nitrogen in the global ocean is in steady state. Additional investigations of high-latitude marine diazotrophic physiology are required to refine these N-2 fixation estimates

FILTRO BOLHA E BIG NUDGING: A DECOMOCRACIA PARTICIPATIVA NA ERA DOS ALGORÍTIMOS

This article works with the hypothesis that there is a current correlation – although it may initially seem strange or distant – between the following concepts: democracy, Artificial Intelligence (A.I), big data and machine learning. It argues that democracy - with regard to political participation in the choices of the State - is directly impacted today by two major technological factors: a) the idea of the filter bubble, a concept created to delimit the result from the performance of the algorithms that are used in online activities to personalize the content presented to the user based on their activities; and b) through Big Nudging, a term used to define the combination of nudging techniques – architecture of choice – with big data tools, in which the profiles of citizens are collected, constructed and used as guidelines for the elaboration of government policies and ideological manipulation. Furthermore, it argues that although technology can be a possible threat to political participation, there is a relevant positive point, which consists of the approximation of participatory spheres through the resources of social networks. With regards to the methodology, the objectives are explored by the inductive method, in a descriptive and explanatory way, mainly based on bibliographic texts and research on the subject. Key-words: Nudging; Artificial intelligence; Filter Bubble; Democracy; Big data.  O presente artigo trabalha com a hipótese de que há uma correlação atual – embora possa parecer inicialmente estranha ou distante– entre os seguintes conceitos: democracia, Inteligência Artificial (I.A), big data e machine learning. Sustenta que a democracia – no que tange à participação política nas escolhas do Estado – é frontalmente impactada, hoje, por dois grandes fatores tecnológicos: a) a ideia de filtro bolha, conceito criado para delimitar o resultado proveniente da atuação dos algoritmos que são utilizados nas atividades online para personalizar o conteúdo apresentado ao usuário a partir de suas atividades; e b) por meio do Big Nudging, termo cunhado para definir a combinação de técnicas de nudging – arquitetura da escolha – com as ferramentas de big data, na qual os perfis dos cidadãos são coletados, construídos e utilizados como diretrizes para a elaboração de políticas governamentais públicas e manipulação ideológica. Ademais, defende que embora a tecnologia possa ser uma eventual ameaça para a participação política, existe um ponto positivo relevante, residente na aproximação das esferas participativas por meio dos recursos das redes sociais. No que tange à metodologia, os objetivos são explorados a partir do método indutivo, de maneira descritiva e explicativa, pautando-se precipuamente em textos bibliográficos e pesquisas sobre a temática. Palavras-chave: Nudging; Inteligência Artificial; Filtro Bolha; Democracia; Big Data

POTENCIAL DO RESÍDUO DE EXTRAÇÃO DE ÓLEO DO EUCALIPTO NA ADSORÇÃO DE COBRE(II)

The objective of this work was to evaluate the potential of the residues from the eucalyptus oil extraction in the adsorption of copper (Cu). FTIR and TGA analyzes showed that biomass is a typical lignocellulosic material. The adsorption capacity of Cu(II) increased toward higher pH values, demonstrating that electrostatic attraction is an important process controlling adsorption. Adsorption reached equilibrium in 60 min of contact time with a rate of 0.338 g.mg−1 min−1, according to the pseudo-second order model. The equilibrium adsorption fit best to the Langmuir model with a maximum adsorption capacity of 45.05 mg.g-1 at 25ºC. The Dubinin-Radushkevich model showed that the adsorption process is physical in nature due to its low adsorption free energy (E) of 0.3469 kJ.mol-1. The agro-industrial waste evaluated herein has a high potential to be used as an adsorbent for Cu(II) and, probably, for other bivalent metals present in contaminated and wastewater, due to its high adsorption capacity and simple pre-treatment procedure.El objetivo de este trabajo fue evaluar el potencial de los residuos de la extracción del aceite de eucalipto en la adsorción de cobre (Cu). Los análisis FTIR y TGA mostraron que la biomasa es un material lignocelulósico típico. La capacidad de adsorción de Cu(II) aumentó hacia valores de pH más altos, lo que demuestra que la atracción electrostática es un proceso importante que controla la adsorción. La adsorción alcanzó el equilibrio en 60 min de tiempo de contacto con una velocidad de 0,338 g.mg−1 min−1, según el modelo de pseudo segundo orden. La adsorción en equilibrio se ajustó mejor al modelo de Langmuir con una capacidad máxima de adsorción de 45,05 mg.g-1 a 25ºC. El modelo de Dubinin-Radushkevich mostró que el proceso de adsorción es de naturaleza física debido a su baja energía libre de adsorción (E) de 0.3469 kJ.mol-1. El residuo agroindustrial aquí evaluado tiene un alto potencial para ser utilizado como adsorbente de Cu(II) y, probablemente, de otros metales bivalentes presentes en aguas contaminadas y residuales, debido a su alta capacidad de adsorción y sencillo procedimiento de pretratamiento.Este trabalho teve como objetivo avaliar o potencial dos resíduos provenientes da extração do óleo do eucalipto na adsorção de cobre (Cu). Análises de FTIR e TGA demonstraram que a biomassa é um material tipicamente lignocelulósico. A capacidade de adsorção de Cu(II) aumenta com o aumento do pH, demonstrando que a atração eletrostática é um importante processo no controle da adsorção. A adsorção alcançou equilíbrio em 60 min de tempo de contato com taxa de 0,338 g.mg−1 min−1 a 25ºC de acordo com o modelo de pseudossegunda ordem. A adsorção em equilíbrio se ajustou melhor ao modelo de Langmuir com capacidade máxima de adsorção de 45,05 mg.g-1 a 25ºC. O modelo de Dubinin-Radushkevich demonstrou que processo de adsorção é de natureza física por ter baixa energia livre de adsorção (E) de 0,3469 kJ.mol-1. O resíduo agroindustrial aqui avaliado apresentou elevado potencial para ser utilizado como adsorvente de Cu(II) e, provavelmete, de demais metais bivalentes presentes em águas contaminadas e água residuais, devido sua elevada capacidade de adsorção e processo de tratamento simplificado

Measuring the health impact of human rights violations related to Australian asylum policies and practices: A mixed methods study

This article has been made available through the Brunel Open Access Publishing Fund - Copyright @ 2009 Johnston et al.BACKGROUND: Human rights violations have adverse consequences for health. However, to date, there remains little empirical evidence documenting this association, beyond the obvious physical and psychological effects of torture. The primary aim of this study was to investigate whether Australian asylum policies and practices, which arguably violate human rights, are associated with adverse health outcomes. METHODS: We designed a mixed methods study to address the study aim. A cross-sectional survey was conducted with 71 Iraqi Temporary Protection Visa (TPV) refugees and 60 Iraqi Permanent Humanitarian Visa (PHV) refugees, residing in Melbourne, Australia. Prior to a recent policy amendment, TPV refugees were only given temporary residency status and had restricted access to a range of government funded benefits and services that permanent refugees are automatically entitled to. The quantitative results were triangulated with semi-structured interviews with TPV refugees and service providers. The main outcome measures were self-reported physical and psychological health. Standardised self-report instruments, validated in an Arabic population, were used to measure health and wellbeing outcomes. RESULTS: Forty-six percent of TPV refugees compared with 25% of PHV refugees reported symptoms consistent with a diagnosis of clinical depression (p = 0.003). After controlling for the effects of age, gender and marital status, TPV status made a statistically significant contribution to psychological distress (B = 0.5, 95% CI 0.3 to 0.71, p </= 0.001) amongst Iraqi refugees. Qualitative data revealed that TPV refugees generally felt socially isolated and lacking in control over their life circumstances, because of their experiences in detention and on a temporary visa. This sense of powerlessness and, for some, an implicit awareness they were being denied basic human rights, culminated in a strong sense of injustice. CONCLUSION: Government asylum policies and practices violating human rights norms are associated with demonstrable psychological health impacts. This link between policy, rights violations and health outcomes offers a framework for addressing the impact of socio-political structures on health.This research was supported by an Australian National and Medical Research Council PhD Scholarship (N. 251782) and a Victorian Health Promotion Foundation research grant (No. 2002-0280)

A novel genetic variant of Streptococcus pneumoniae serotype 11A discovered in Fiji.

OBJECTIVES: As part of annual cross-sectional Streptococcus pneumoniae carriage surveys in Fiji (2012-2015), we detected pneumococci in over 100 nasopharyngeal swabs that serotyped as '11F-like' by microarray. We examined the genetic basis of this divergence in the 11F-like capsular polysaccharide (cps) locus compared to the reference 11F cps sequence. The impact of this diversity on capsule phenotype, and serotype results using genetic and serologic methods were determined. METHODS: Genomic DNA from representative 11F-like S. pneumoniae isolates obtained from the nasopharynx of Fijian children was extracted and subject to whole genome sequencing. Genetic and phylogenetic analyses were used to identify genetic changes in the cps locus. Capsular phenotypes were evaluated using the Quellung reaction and latex agglutination. RESULTS: Compared to published 11F sequences, the wcwC and wcrL genes of the 11F-like cps locus are phylogenetically divergent, and the gct gene contains a single nucleotide insertion within a homopolymeric region. These changes within the DNA sequence of the 11F-like cps locus have modified the antigenic properties of the capsule, such that 11F-like isolates serotype as 11A by Quellung reaction and latex agglutination. CONCLUSIONS: This study demonstrates the ability of molecular serotyping by microarray to identify genetic variants of S. pneumoniae and highlights the potential for discrepant results between phenotypic and genotypic serotyping methods. We propose that 11F-like isolates are not a new serotype but rather are a novel genetic variant of serotype 11A. These findings have implications for invasive pneumococcal disease surveillance as well as studies investigating vaccine impact

Neurological, Psychiatric, and Biochemical Aspects of Thiamine Deficiency in Children and Adults.

Thiamine (vitamin B1) is an essential nutrient that serves as a cofactor for a number of enzymes, mostly with mitochondrial localization. Some thiamine-dependent enzymes are involved in energy metabolism and biosynthesis of nucleic acids whereas others are part of the antioxidant machinery. The brain is highly vulnerable to thiamine deficiency due to its heavy reliance on mitochondrial ATP production. This is more evident during rapid growth (i.e., perinatal periods and children) in which thiamine deficiency is commonly associated with either malnutrition or genetic defects. Thiamine deficiency contributes to a number of conditions spanning from mild neurological and psychiatric symptoms (confusion, reduced memory, and sleep disturbances) to severe encephalopathy, ataxia, congestive heart failure, muscle atrophy, and even death. This review discusses the current knowledge on thiamine deficiency and associated morbidity of neurological and psychiatric disorders, with special emphasis on the pediatric population, as well as the putative beneficial effect of thiamine supplementation in autism spectrum disorder (ASD) and other neurological conditions

Impact of exposure measurement error in air pollution epidemiology: effect of error type in time-series studies

<p>Abstract</p> <p>Background</p> <p>Two distinctly different types of measurement error are Berkson and classical. Impacts of measurement error in epidemiologic studies of ambient air pollution are expected to depend on error type. We characterize measurement error due to instrument imprecision and spatial variability as multiplicative (i.e. additive on the log scale) and model it over a range of error types to assess impacts on risk ratio estimates both on a per measurement unit basis and on a per interquartile range (IQR) basis in a time-series study in Atlanta.</p> <p>Methods</p> <p>Daily measures of twelve ambient air pollutants were analyzed: NO₂, NO_x, O₃, SO₂, CO, PM₁₀mass, PM_2.5mass, and PM_2.5components sulfate, nitrate, ammonium, elemental carbon and organic carbon. Semivariogram analysis was applied to assess spatial variability. Error due to this spatial variability was added to a reference pollutant time-series on the log scale using Monte Carlo simulations. Each of these time-series was exponentiated and introduced to a Poisson generalized linear model of cardiovascular disease emergency department visits.</p> <p>Results</p> <p>Measurement error resulted in reduced statistical significance for the risk ratio estimates for all amounts (corresponding to different pollutants) and types of error. When modelled as classical-type error, risk ratios were attenuated, particularly for primary air pollutants, with average attenuation in risk ratios on a per unit of measurement basis ranging from 18% to 92% and on an IQR basis ranging from 18% to 86%. When modelled as Berkson-type error, risk ratios per unit of measurement were biased away from the null hypothesis by 2% to 31%, whereas risk ratios per IQR were attenuated (i.e. biased toward the null) by 5% to 34%. For CO modelled error amount, a range of error types were simulated and effects on risk ratio bias and significance were observed.</p> <p>Conclusions</p> <p>For multiplicative error, both the amount and type of measurement error impact health effect estimates in air pollution epidemiology. By modelling instrument imprecision and spatial variability as different error types, we estimate direction and magnitude of the effects of error over a range of error types.</p

Pollen and Phytoliths from Fired Ancient Potsherds as Potential Indicators for Deciphering Past Vegetation and Climate in Turpan, Xinjiang, NW China

It is demonstrated that palynomorphs can occur in fired ancient potsherds when the firing temperature was under 350°C. Pollen and phytoliths recovered from incompletely fired and fully fired potsherds (ca. 2700 yrs BP) from the Yanghai Tombs, Turpan, Xinjiang, NW China can be used as potential indicators for reconstructing past vegetation and corresponding climate in the area. The results show a higher rate of recovery of pollen and phytoliths from incompletely fired potsherds than from fully fired ones. Charred phytoliths recovered from both fully fired and incompletely fired potsherds prove that degree and condition of firing result in a permanent change in phytolith color. The palynological data, together with previous data of macrobotanical remains from the Yanghai Tombs, suggest that temperate vegetation and arid climatic conditions dominated in the area ca. 2700 yrs BP