Procurando loci associados a variáveis do solo através de um varrimento molecular exploratório do genoma no pseudometalófito Cistus ladanifer L.

O uso do varrimento molecular do genoma juntamente com dados ambientais dá-nos a possibilidade de identificar marcadores moleculares com relevância ambiental. Neste trabalho foram analisadas 33 populações do pseudometalófito Mediterrâneo Cistus ladanifer L. (Cistaceae) com marcadores moleculares AFLP. Aplicámos Equações de Estimação Generalizadas (GEE) para estudar a correlação entre a distribuição de alelos AFLP e as diferentes características dos solos (pH, razão Ca:Mg e teores totais dos elementos vestigiais Mn, Ni, Pb, Sb e Zn). A análise GEE incluiu informação prévia das linhagens cloroplastidiais para eliminar o efeito da filogeografia. Eliminámos, também, os falsos positivos através do teste de Mann-Whitney e da observação da distribuição geográfica dos alelos. Os resultados mostraram que os teores totais de Mn têm influência na distribuição de alelos de C. ladanifer e que esse efeito foi o mais elevado relativamente a todas as outras variáveis do solo. Pelo contrário, a razão Ca:Mg parece não ter nenhum efeito selectivo em C. ladanifer, o que é confirmado pelo conhecimento relativo às suas necessidades em cálcio. Finalmente, detectámos um alelo possivelmente relacionado com a tolerância de C. ladanifer a solos com elevadas concentrações de Mn. Esta informação pode ser usada na selecção de indivíduos tolerantes a elevadas concentrações de metais tóxicos, Mn em particular, para uso na fitorremediação de solos contaminados

Fungos potencialmente ocratoxígenos em café.

Micotoxinas. Fatores que influenciam a produção de micotoxinas. Influência da atividade de água. Fungos associados aos frutos e grãos de café. Fungos produtores de OTA. Ocratoxina em café. Alteração da qualidade provocada por fungos associados aos grãos de café. Interação da OTA e outras micotoxinas. Considerações finais.bitstream/item/65527/1/2003-DOC-0053.pd

Compact Cryogenic Source of Periodic Hydrogen and Argon Droplet Beams for Relativistic Laser-Plasma Generation

We present a cryogenic source of periodic streams of micrometer-sized hydrogen and argon droplets as ideal mass-limited target systems for fundamental intense laser-driven plasma applications. The highly compact design combined with a high temporal and spatial droplet stability makes our injector ideally suited for experiments using state-of-the-art high-power lasers in which a precise synchronization between the laser pulses and the droplets is mandatory. We show this by irradiating argon droplets with multi-Terawatt pulses.Comment: To be published in Review of Scientific Instrument

Identification of the major active ingredients in illegal pesticide seized by Brazilian Federal Police and quantification of metsulfuron-methyl and tebuconazole

A compilação de relatórios forenses de agrotóxicos, objetos de apreensões pela Polícia Federal no Brasil, mostrou que metsulfurom-metílico, imidacloprido, fipronil, tebuconazol, clorimurom-etílico e glifosato são os principais ingredientes ativos (IA) importados ilegalmente. Apesar destes IA não estarem entre os agrotóxicos mais comercializados no país, o alto preço das formulações correspondentes legalmente registradas pode estimular esta atividade ilegal. Com base neste estudo, amostras de agrotóxicos contrabandeados apreendidos contendo tebuconazol e metsulfurom-metílico foram analisadas quantitativamente utilizando cromatografia a gás e líquida, respectivamente. Tebuconazol, em apresentações líquidas e sólidas, apresentou concentrações concordantes com as informações dos rótulos, enquanto que a maioria das amostras de metsulfurom-metílico, rotuladas como 600 g kg-1, apresentaram concentrações mais baixas nas análises químicas (média de 337,0 g kg-1 + 2,0).The compilation of forensic reports from pesticides seized by the Federal Police in Brazil showed that metsulfuron-methyl, imidacloprid, fipronil, tebuconazole, clorimuron-ether and glyphosate were the dominant active ingredients (AI) illegally imported. Despite these AI were not among the most traded pesticides in Brazil, high prices of corresponding legal formulations may stimulate this illegal activity. Based on this study, smuggled pesticides containing tebuconazole and metsulfuron-methyl were seized and quantitatively analyzed using gas and liquid chromatography, respectively. Tebuconazole results, in liquid and solid presentations, were in accordance with the information on the label, while most metsulfuron-methyl samples, labeled as 600 g kg-1, showed lower concentrations in chemical analysis (mean of 337.0 g kg-1 + 2.0)

Genetic topography and cortical cell loss in Huntington's disease link development and neurodegeneration

Cortical cell loss is a core feature of Huntington Disease (HD), beginning many years before clinical motor diagnosis, during the premanifest stage. However, it is unclear how genetic topography relates to cortical cell loss. Here, we explore the biological processes and cell types underlying this relationship and validate this using cell-specific post-mortem data. Eighty premanifest participants on average 15 years from disease onset and 71 controls were included. Using volumetric and diffusion MRI we extracted HD-specific whole brain maps where lower grey matter volume and higher grey matter mean diffusivity, relative to controls, were used as proxies of cortical cell loss. These maps were combined with gene expression data from the Allen Human Brain Atlas (AHBA) to investigate the biological processes relating genetic topography and cortical cell loss. Cortical cell loss was positively correlated with the expression of developmental genes (i.e. higher expression correlated with greater atrophy and increased diffusivity) and negatively correlated with the expression of synaptic and metabolic genes that have been implicated in neurodegeneration. These findings were consistent for diffusion MRI and volumetric HD-specific brain maps. As wild type Huntingtin is known to play a role in neurodevelopment, we explored the association between wild type Huntingtin (HTT) expression and developmental gene expression across the AHBA. Co-expression network analyses in 134 human brains free of neurodegenerative disorders was also performed. HTT expression was correlated with the expression of genes involved in neurodevelopment while co-expression network analyses also revealed that HTT expression was associated with developmental biological processes. Expression weighted cell-type enrichment (EWCE) analyses were used to explore which specific cell-types were associated with HD cortical cell loss and these associations were validated using cell specific single nucleus RNAseq (snRNAseq) data from post-mortem HD brains. The developmental transcriptomic profile of cortical cell loss in preHD was enriched in astrocytes and endothelial cells, while the neurodegenerative transcriptomic profile was enriched for neuronal and microglial cells. Astrocyte-specific genes differentially expressed in HD post-mortem brains relative to controls using snRNAseq were enriched in the developmental transcriptomic profile, while neuronal and microglial-specific genes were enriched in the neurodegenerative transcriptomic profile Our findings suggest that cortical cell loss in preHD may arise from dual pathological processes, emerging as a consequence of neurodevelopmental changes, at the beginning of life, followed by neurodegeneration in adulthood, targeting areas with reduced expression of synaptic and metabolic genes. These events result in age-related cell death across multiple brain cell types

Quark Number Susceptibility with Finite Chemical Potential in Holographic QCD

We study the quark number susceptibility in holographic QCD with a finite chemical potential or under an external magnetic field at finite temperature. We first consider the quark number susceptibility with the chemical potential. We observe that approaching the critical temperature from high temperature regime, the quark number susceptibility divided by temperature square develops a peak as we increase the chemical potential, which confirms recent lattice QCD results. We discuss this behavior in connection with the existence of the critical end point in the QCD phase diagram. We also consider the quark number susceptibility under the external magnetic field. We predict that the quark number susceptibility exhibits a blow-up behavior at low temperature as we raise the value of the magnetic field. We finally spell out some limitations of our study.Comment: 25 pages, 3 figures, published versio

Socioeconomic status, non-communicable disease risk factors, and walking speed in older adults: multi-cohort population based study.

To assess the association of low socioeconomic status and risk factors for non-communicable diseases (diabetes, high alcohol intake, high blood pressure, obesity, physical inactivity, smoking) with loss of physical functioning at older ages. Multi-cohort population based study. 37 cohort studies from 24 countries in Europe, the United States, Latin America, Africa, and Asia, 1990-2017. 109 107 men and women aged 45-90 years. Physical functioning assessed using the walking speed test, a valid index of overall functional capacity. Years of functioning lost was computed as a metric to quantify the difference in walking speed between those exposed and unexposed to low socioeconomic status and risk factors. According to mixed model estimations, men aged 60 and of low socioeconomic status had the same walking speed as men aged 66.6 of high socioeconomic status (years of functioning lost 6.6 years, 95% confidence interval 5.0 to 9.4). The years of functioning lost for women were 4.6 (3.6 to 6.2). In men and women, respectively, 5.7 (4.4 to 8.1) and 5.4 (4.3 to 7.3) years of functioning were lost by age 60 due to insufficient physical activity, 5.1 (3.9 to 7.0) and 7.5 (6.1 to 9.5) due to obesity, 2.3 (1.6 to 3.4) and 3.0 (2.3 to 4.0) due to hypertension, 5.6 (4.2 to 8.0) and 6.3 (4.9 to 8.4) due to diabetes, and 3.0 (2.2 to 4.3) and 0.7 (0.1 to 1.5) due to tobacco use. In analyses restricted to high income countries, the number of years of functioning lost attributable to low socioeconomic status by age 60 was 8.0 (5.7 to 13.1) for men and 5.4 (4.0 to 8.0) for women, whereas in low and middle income countries it was 2.6 (0.2 to 6.8) for men and 2.7 (1.0 to 5.5) for women. Within high income countries, the number of years of functioning lost attributable to low socioeconomic status by age 60 was greater in the United States than in Europe. Physical functioning continued to decline as a function of unfavourable risk factors between ages 60 and 85. Years of functioning lost were greater than years of life lost due to low socioeconomic status and non-communicable disease risk factors. The independent association between socioeconomic status and physical functioning in old age is comparable in strength and consistency with those for established non-communicable disease risk factors. The results of this study suggest that tackling all these risk factors might substantially increase life years spent in good physical functioning

Whole Earth Telescope observations of BPM 37093: a seismological test of crystallization theory in white dwarfs

BPM 37093 is the only hydrogen-atmosphere white dwarf currently known which has sufficient mass (~ 1.1 M_sun) to theoretically crystallize while still inside the ZZ Ceti instability strip (T_eff ~ 12,000 K). As a consequence, this star represents our first opportunity to test crystallization theory directly. If the core is substantially crystallized, then the inner boundary for each pulsation mode will be located at the top of the solid core rather than at the center of the star, affecting mainly the average period spacing. This is distinct from the "mode trapping" caused by the stratified surface layers, which modifies the pulsation periods more selectively. In this paper we report on Whole Earth Telescope observations of BPM 37093 obtained in 1998 and 1999. Based on a simple analysis of the average period spacing we conclude that a large fraction of the total stellar mass is likely to be crystallized.Comment: 7 pages, 3 figures, 3 tables, accepted for Astronomy & Astrophysic

The biology of inequalities in health: The LIFEPATH project

Socioeconomic differences in health have been consistently observed worldwide. Physical health deteriorates more rapidly with age among men and women with lower socioeconomic status (SES) than among those with higher SES. The biological processes underlying these differences are best understood by adopting a life course approach. In this paper we introduce the pan- European LIFEPATH project which uses multiple cohorts - including biomarker data - to investigate ageing as a phenomenon with two broad stages across life: build-up and decline. The ‘build-up’ stage, from conception and early intra-uterine life to late adolescence or early twenties, is characterised by rapid successions of developmentally and socially sensitive periods. The second stage, starting in early adulthood, is a period of ‘decline’ from maximum attained health to loss of function, overt disease and death. LIFEPATH adopts a study design that integrates social science and public health approaches with biology (including molecular epidemiology), using well-characterised population cohorts and omics measurements (particularly epigenomics). LIFEPATH includes information and biological samples from 17 cohorts, including several with extensive phenotyping and repeat biological samples, and a very large cohort (1 million individuals) without biological samples (WHIP, from Italy). The countries that are covered by the cohorts are France, Italy, Portugal, Ireland, UK, Finland, Switzerland and Australia. These cohorts are only a small proportion of all cohorts available in Europe, but we have chosen them for the combination of good measures of socioeconomic status, risk factors for non-communicable diseases (NCDs) and biomarkers already measured (or availability of blood samples for further testing). The majority of cohorts include ‘hard’ outcomes (diabetes, cancer, Cardiovascular Disease (CVD), total mortality), and the extensively phenotyped cohorts also include several measurements of the functional components of healthy ageing, including frailty, impaired vision, cognitive function, renal and brain function, osteoporosis, sleep disturbances and mental health. All age groups are represented with two birth cohorts, one cohort of adolescents and several cohorts encompassing young adults (age 18 and above). Furthermore, there is a strong representation of elderly subjects in seven cohorts. The specific objectives of the project are: (a) to show that healthy ageing is an achievable goal for society; (b) to improve the understanding of the mechanisms through which healthy ageing pathways diverge by SES, by investigating life course biological pathways using omic technologies; (c) to examine the consequences of the current economic recession on health and the biology of ageing (and the consequent increase in social inequalities); (d) to provide updated, relevant and innovative evidence for healthy ageing policies (particularly ‘health in all policies’) using both observational studies and an experimental approach based on a reanalysis of data from a ‘conditional cash transfer’ randomised experiment in New York and new data collected as part of an earned income tax credit randomised experiment in Atlanta and New York. To achieve these objectives, data are used from three categories of studies: 1. national census-based followup data to obtain mortality by socioeconomic status; 2. cohorts with intense phenotyping and repeat biological samples; 3. large cohorts with biological samples. With these objectives and methodologies, LIFEPATH seeks to provide updated, relevant and innovative evidence to underpin future policies and strategies for the promotion of healthy ageing, targeted disease prevention and clinical interventions that address the issue of social disparities in ageing and the social determinants of health. The present paper describes the design and some initial results of LIFEPATH as an example of the integration of social and biological sciences to provide evidence for public health policies