26 research outputs found

    Decreased body mass index in the preclinical stage of autosomal dominant Alzheimer’s disease

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    The relationship between body-mass index (BMI) and Alzheimer´s disease (AD) has been extensively investigated. However, BMI alterations in preclinical individuals with autosomal dominant AD (ADAD) have not yet been investigated. We analyzed cross-sectional data from 230 asymptomatic members of families with ADAD participating in the Dominantly Inherited Alzheimer Network (DIAN) study including 120 preclinical mutation carriers (MCs) and 110 asymptomatic non-carriers (NCs). Differences in BMI and their relation with cerebral amyloid load and episodic memory as a function of estimated years to symptom onset (EYO) were analyzed. Preclinical MCs showed significantly lower BMIs compared to NCs, starting 11.2 years before expected symptom onset. However, the BMI curves begun to diverge already at 17.8 years before expected symptom onset. Lower BMI in preclinical MCs was significantly associated with less years before estimated symptom onset, higher global Aβ brain burden, and with lower delayed total recall scores in the logical memory test. The study provides cross-sectional evidence that weight loss starts one to two decades before expected symptom onset of ADAD. Our findings point toward a link between the pathophysiology of ADAD and disturbance of weight control mechanisms. Longitudinal follow-up studies are warranted to investigate BMI changes over time

    The composition and weathering of the continents over geologic time

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    The composition of continental crust records the balance between construction by tectonics and destruction by physical and chemical erosion. Quantitative constraints on how igneous addition and chemical weathering have modified the continents’ bulk composition are essential for understanding the evolution of geodynamics and climate. Using novel data analytic techniques we have extracted temporal trends in sediments’ protolith composition and weathering intensity from the largest available compilation of sedimentary major element compositions: ∼15,000 samples from 4.0 Ga to the present. We find that the average Archean upper continental crust was silica-rich and had a similar compositional diversity to modern continents. This is consistent with an early Archean, or earlier, onset of plate tectonics. In the Archean, chemical weathering sequestered ∼25 % more CO2 per mass eroded for the same weathering intensity than in subsequent time periods, consistent with carbon mass balance despite higher Archean outgassing rates and more limited continental exposure. Since 2.0 Ga, over long (>0.5 Gyr) timescales, crustal weathering intensity has remained relatively constant. On shorter timescales over the Phanerozoic, weathering intensity is correlated to global climate state, consistent with a weathering feedback acting in response to changes in CO2 sources or sinks

    [Accepted Manuscript] Presymptomatic atrophy in autosomal dominant Alzheimer's disease: A serial MRI study.

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    Identifying at what point atrophy rates first change in Alzheimer's disease is important for informing design of presymptomatic trials. Serial T1-weighed magnetic resonance imaging scans of 94 participants (28 noncarriers, 66 carriers) from the Dominantly Inherited Alzheimer Network were used to measure brain, ventricular, and hippocampal atrophy rates. For each structure, nonlinear mixed-effects models estimated the change-points when atrophy rates deviate from normal and the rates of change before and after this point. Atrophy increased after the change-point, which occurred 1-1.5 years (assuming a single step change in atrophy rate) or 3-8 years (assuming gradual acceleration of atrophy) before expected symptom onset. At expected symptom onset, estimated atrophy rates were at least 3.6 times than those before the change-point. Atrophy rates are pathologically increased up to seven years before "expected onset". During this period, atrophy rates may be useful for inclusion and tracking of disease progression

    Eficiência de lagoas de polimento no pós-tratamento de reator UASB no tratamento de águas residuárias de suinocultura

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    Avaliou-se o desempenho de um sistema de lagoas seriadas que recebeu efluentes de reator UASB, no tratamento de águas residuárias de suinocultura. O sistema foi composto de reator anaeróbio de chicanas (RAC), reator UASB, em escala real, e uma série de lagoas (uma lagoa facultativa e três de maturação), em escala piloto. As análises físico-químicas realizadas foram: pH, demanda bioquímica de oxigênio (DBO), demanda química de oxigênio (DQO), sólidos suspensos totais (SST), sólidos suspensos voláteis (SSV), nitrogênio amoniacal (N-am.), fósforo total (Pt), coliformes totais (CT) e Escherichia coli (EC). As lagoas de pós-tratamento contribuíram eficientemente para remoção de nutrientes, matéria orgânica e sólidos, fornecendo um efluente com qualidade para o reuso agrícola ou lançamento em corpos d'água

    Avaliação de desempenho de lagoa de polimento para pós-tratamento de reator anaeróbio de manta de lodo (UASB) no tratamento de águas residuárias de suinocultura Evaluation of the performance of a polishing pond for the post-treatment of the effluent from an upflow anaerobic sludge blanket (UASB) reactor treating swine wastewater

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    Avaliou-se o desempenho de uma lagoa de polimento, no tratamento de efluentes de águas residuárias de suinocultura de um reator anaeróbio de manta de lodo (UASB). O sistema foi composto de decantador, reator UASB, em escala real, e lagoa de polimento em escala experimental. As análises físico-químicas realizadas foram: temperatura, pH, demanda bioquímica de oxigênio (DBO), demanda química de oxigênio (DQO), sólidos suspensos totais (SST) e sólidos suspensos voláteis (SSV), nitrogênio total kjedhal (NTK), nitrogênio amoniacal (N-am.) e orgânico (N-org.), fósforo total (Pt), coliformes totais e termotolerantes. A lagoa de polimento apresentou alto desempenho, com remoção média de 58,9% de DBO, 60,1% de NTK, 57% de N-am. e 95,34% de coliformes termotolerantes.The performance of a polishing pond for treating swine wastewater from an upflow anaerobic sludge blanket (UASB) reactor was evaluated. The system was assembled with a slat settler, followed by an UASB reactor, on a real scale, and a post-treatment pond, on a demonstration scale. The following parameters were analyzed: temperature, pH, biochemical oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), volatile suspended solids (VSS), total Kjedahl nitrogen (NTK), ammonia nitrogen (N-am.), organic nitrogen, total phosphorus, and total and thermotolerant coliforms. The polishing pond was highly efficient, removing an average of 58.9% of BOD, 60.1% of NTK, 57% of N-am., and 95.34% of thermotolerant coliforms

    Synergistic effects of combining morphological and molecular data in resolving the phylogeny of butterflies and skippers

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    Phylogenetic relationships among major clades of butterflies and skippers have long been controversial, with no general consensus even today. Such lack of resolution is a substantial impediment to using the otherwise well studied butterflies as a model group in biology. Here we report the results of a combined analysis of DNA sequences from three genes and a morphological data matrix for 57 taxa (3258 characters, 1290 parsimony informative) representing all major lineages from the three putative butterfly super-families (Hedyloidea, Hesperioidea and Papilionoidea), plus out-groups representing other ditrysian Lepidoptera families. Recently, the utility of morphological data as a source of phylogenetic evidence has been debated. We present the first well supported phylogenetic hypothesis for the butterflies and skippers based on a total-evidence analysis of both traditional morphological characters and new molecular characters from three gene regions (COI, EF-1α and wingless). All four data partitions show substantial hidden support for the deeper nodes, which emerges only in a combined analysis in which the addition of morphological data plays a crucial role. With the exception of Nymphalidae, the traditionally recognized families are found to be strongly supported monophyletic clades with the following relationships: (Hesperiidae+(Papilionidae+(Pieridae+(Nymphalidae+(Lycaenidae+Riodinidae))))). Nymphalidae is recovered as a monophyletic clade but this clade does not have strong support. Lycaenidae and Riodinidae are sister groups with strong support and we suggest that the latter be given family rank. The position of Pieridae as the sister taxon to nymphalids, lycaenids and riodinids is supported by morphology and the EF-1α data but conflicted by the COI and wingless data. Hedylidae are more likely to be related to butterflies and skippers than geometrid moths and appear to be the sister group to Papilionoidea+Hesperioidea

    Nibrin, a novel DNA double-strand break repair protein, is mutated in Nijmegen breakage syndrome

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    Nijmegen breakage syndrome (NBS) is an autosomal recessive chromosomal instability syndrome characterized by microcephaly, growth retardation, immunodeficiency, and cancer predisposition. Cells from NBS patients are hypersensitive to ionizing radiation with cytogenetic features indistinguishable from ataxia telangiectasia. We describe the positional cloning of a gene encoding a novel protein, nibrin. It contains two modules found in cell cycle checkpoint proteins, a forkhead-associated domain adjacent to a breast cancer carboxy-terminal domain. A truncating 5 bp deletion was identified in the majority of NBS patients, carrying a conserved marker haplotype. Five further truncating mutations were identified in patients with other distinct haplotypes. The domains found in nibrin and the NBS phenotype suggest that this disorder is caused by defective responses to DNA double-strand breaks

    Tratamento de águas residuárias da suinocultura utilizando-se filtros orgânicos Treatment of swine wastewater using organic filters

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    O tratamento primário da água residuária de suinocultura pode ser feito por filtragem; para isto, torna-se oportuno o estudo de materiais alternativos a serem utilizados como meio filtrante e, com este intuito, foram utilizados o bagaço de cana-de-açúcar, a casca de arroz, a casca de café, o fino de carvão vegetal, o sabugo de milho e a serragem de madeira, acondicionados em tubos de PVC de diâmetro de 100 mm, constituindo colunas de 500 mm de altura. O sistema de filtragem foi mantido sob escoamento permanente, com fluxo em meio saturado, e pequena ou nenhuma alteração foi detectada na concentração de N-total, Ca, Mg e Zn no efluente do filtro, enquanto que as concentrações de P-total, Na e K aumentaram no efluente obtido em filtros de casca de arroz, casca de café e sabugo de milho. Significativa redução na concentração de Cu foi constatada para todos os materiais utilizados como filtro, atingindo-se eficiência de remoção de até 43,6%. Eficiências de remoção superiores a 90% foram obtidas para sólidos sedimentáveis enquanto a remoção de sólidos totais ficou abaixo de 33,0%.<br>The primary treatment of swine wastewater can be done by filtration. To this end, the study of alternative materials as a filter media is necessary. With this objective, rice husk, coffee straw, sugar-cane trash, triturated corncob, wood sawdust and fine vegetable coal were used as media, conditioned in PVC tubes of 100 mm in diameter and 500 mm in height. The filtering system was maintained under saturated flow conditions. Little or no change was detected in the concentration of N-total, Ca, Mg and Zn in the effluent of the filter, although the concentration of P-total and K increased in the effluents of the filters of rice husk, coffee straw, triturate corncob, reaching a maximum removal efficiency of 43.6%. Removal efficiencies of sedimentable solids higher than 90.0% were obtained in all materials employed as a filtration media, although total solids removal efficiency was less than 33.0%
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