277 research outputs found
First record of the non-native pacu, \u3cem\u3ePiaractus brachypomus\u3c/em\u3e, in Lago Petén-Itzá, Guatemala, Central America
We documented the first record of the non-native species Piaractus brachypomus (Characiformes: Serrasalmidae) in Lago Petén-Itzá, Petén, Guatemala. One brined specimen was donated by a local fisherman in San Benito, El Petén. The captured specimen was reportedly collected in the southern basin of the lake. We used the mitochondrial gene cytochrome oxidase I (COI) to validate identity of the specimen. We hypothesize that the local aquarium trade is the most likely source of introduction of the non-native Pacu in Lago Petén-Itzá.
Documentamos el primer registro de la especie no nativa Piaractus brachypomus (Characiformes: Serrasalmidae) en el lago Petén Itzá, Petén, Guatemala. Un espécimen colectado en la cuenca sur del lago por pescadores locales de San Benito, Petén nos fue donado. La identificación a nivel de especie fue realizada utilizando el gen mitocondrial citocromo oxidasa I (COI). Hipotetizamos que individuos provenientes de acuarios ornamentales son la fuente más plausible de la introducción del pez no nativo Pacu en el lago Petén Itzá
Variants Cause Spastic Paraplegia Associated with Cerebral Hypomyelination
Oculodentodigital dysplasia is an autosomal dominant disorder due to variants characterized by dysmorphic features. Neurologic symptoms have been described in some patients but without a clear neuroimaging pattern. To understand the pathophysiology underlying neurologic deficits in oculodentodigital dysplasia, we studied 8 consecutive patients presenting with hereditary spastic paraplegia due to variants. Clinical disease severity was highly variable. Cerebral MR imaging revealed variable white matter abnormalities, consistent with a hypomyelination pattern, and bilateral hypointense signal of the basal ganglia on T2-weighted images and/or magnetic susceptibility sequences, as seen in neurodegeneration with brain iron accumulation diseases. Patients with the more prominent basal ganglia abnormalities were the most disabled ones. This study suggests that -related hereditary spastic paraplegia is a complex neurodegenerative disease affecting both the myelin and the basal ganglia. variants should be considered in patients with hereditary spastic paraplegia presenting with brain hypomyelination, especially if associated with neurodegeneration and a brain iron accumulation pattern
The Frequencies of Different Inborn Errors of Metabolism in Adult Metabolic Centres: Report from the SSIEM Adult Metabolic Physicians Group
There are few centres which specialise in the care of adults with inborn errors of metabolism (IEM). To anticipate facilities and staffing needed at these centres, it is of interest to know the distribution of the different disorders
Onset of Superfluidity in 4He Films Adsorbed on Disordered Substrates
We have studied 4He films adsorbed in two porous glasses, aerogel and Vycor,
using high precision torsional oscillator and DC calorimetry techniques. Our
investigation focused on the onset of superfluidity at low temperatures as the
4He coverage is increased. Torsional oscillator measurements of the 4He-aerogel
system were used to determine the superfluid density of films with transition
temperatures as low as 20 mK. Heat capacity measurements of the 4He-Vycor
system probed the excitation spectrum of both non-superfluid and superfluid
films for temperatures down to 10 mK. Both sets of measurements suggest that
the critical coverage for the onset of superfluidity corresponds to a mobility
edge in the chemical potential, so that the onset transition is the bosonic
analog of a superconductor-insulator transition. The superfluid density
measurements, however, are not in agreement with the scaling theory of an onset
transition from a gapless, Bose glass phase to a superfluid. The heat capacity
measurements show that the non-superfluid phase is better characterized as an
insulator with a gap.Comment: 15 pages (RevTex), 21 figures (postscript
Opportunities for mesoscopics in thermometry and refrigeration: Physics and applications
This review presents an overview of the thermal properties of mesoscopic
structures. The discussion is based on the concept of electron energy
distribution, and, in particular, on controlling and probing it. The
temperature of an electron gas is determined by this distribution:
refrigeration is equivalent to narrowing it, and thermometry is probing its
convolution with a function characterizing the measuring device. Temperature
exists, strictly speaking, only in quasiequilibrium in which the distribution
follows the Fermi-Dirac form. Interesting nonequilibrium deviations can occur
due to slow relaxation rates of the electrons, e.g., among themselves or with
lattice phonons. Observation and applications of nonequilibrium phenomena are
also discussed. The focus in this paper is at low temperatures, primarily below
4 K, where physical phenomena on mesoscopic scales and hybrid combinations of
various types of materials, e.g., superconductors, normal metals, insulators,
and doped semiconductors, open up a rich variety of device concepts. This
review starts with an introduction to theoretical concepts and experimental
results on thermal properties of mesoscopic structures. Then thermometry and
refrigeration are examined with an emphasis on experiments. An immediate
application of solid-state refrigeration and thermometry is in ultrasensitive
radiation detection, which is discussed in depth. This review concludes with a
summary of pertinent fabrication methods of presented devices.Comment: Close to the version published in RMP; 59 pages, 35 figure
Composição bromatológica da digitaria e do Tangola, sob diferentes lâminas de irrigação e adubação nitrogenada.
Objetivando avaliar o efeito de diferentes níveis de irrigação e de adubação nitrogenada sobre o teor de fibra em detergente neutro (FDN), fibra em detergente ácido (FDA) e teor de proteína bruta (PB) dos capins Tangola (Brachiaria spp.) e Digitaria (Digitaria sp), foi conduzido um experimento na Embrapa Meio-Norte, em Parnaíba, Pi. O delineamento experimental foi de blocos casualizados, em esquema fatorial 2 x 3 x 4, com três repetições; sendo duas gramíneas, três níveis de irrigação (80%, 50% e 20% da evaporação do Tanque Classe A) e quatro níveis de nitrogênio (100; 250; 400 e 550 kg ha/ano). As adubações nitrogenadas foram fracionadas e aplicadas, na forma de uréia e em cobertura, após cada um dos quatro cortes realizados no período. A Digitaria sp apresentou maiores teores de FDN em relação ao Tangola em todos os níveis de adubação nitrogenada e no maior nível de irrigação aplicada. Com relação ao teor de FDA a Digitaria foi inferior ao Tangola apenas no nível intermediário de irrigação e no maior nível de adubação nitrogenada. A adubação nitrogenada afetou positivamente o teor de proteína bruta de ambas as gramíneas
Fatores associados à inadequação do uso da assistência pré-natal
OBJECTIVE: To identify factors associated with inadequacy of prenatal care utilization in urban community. METHODS: A cross-sectional study of a systematic sample stratified by maternity hospital, consisting of hospital births in the municipality of São Luís, Brazil, was carried out from March 1997 to February 1998. Socioeconomic and demographic factors, reproductive health, morbidity during pregnancy, and utilization of prenatal care services were studied. Mothers answered a standardized questionnaire before hospital discharge. The adequacy of prenatal care utilization was analyzed by means of two indexes: APNCU (Adequacy of Prenatal Care Utilization) and a new index based on the recommendations of the Brazilian Ministry of Health. RESULTS: There were interviewed 2,831 women who delivered at 10 public and private maternity hospitals. The inadequacy of prenatal care utilization was 49.2% according to the APNCU index and 24.5% when determined by the Brazilian index. Prenatal care at public services, low maternal schooling, low income, having no partner, and absence of maternal diseases during pregnancy were associated with inadequacy of prenatal care use according to both indexes. High parity and maternal age of 35 years or more were also associated with inadequacy, whereas primiparity, morbidity, and young maternal age (OBJETIVO: Identificar fatores associados à inadequação do uso da assistência pré-natal em comunidade urbana. MÉTODOS: Foi realizado estudo transversal em amostra sistemática, estratificada por maternidades, de todos os nascimentos hospitalares do município de São Luís, MA, no período de março de 1997 a fevereiro de 1998. Foram avaliados indicadores socioeconômicos e demográficos, de saúde reprodutiva, morbidade na gravidez e utilização de serviços pré-natais. Utilizou-se questionário padronizado respondido pelas puérperas antes da alta hospitalar. A adequação do uso da assistência pré-natal foi analisada pelo índice "Adequacy of Prenatal Care Utilization" (APNCU) e por um novo índice proposto, baseado nas recomendações do Ministério da Saúde, Brasil. RESULTADOS: Foram entrevistadas 2.831 puérperas, atendidas em dez unidades de saúde pública e privada. A inadequação do uso da assistência pré-natal foi de 49,2% pelo índice APNCU, e de 24,5% pelo novo índice proposto. Mulheres atendidas em serviços públicos de saúde, de baixa escolaridade e baixa renda familiar, sem companheiro ou com doença durante a gravidez, tiveram maiores percentuais de inadequação do uso do atendimento pré-natal, pelos dois índices analisados. Pelo novo índice proposto, maiores percentuais de inadequação foram associados à alta paridade e idade materna, enquanto baixa idade materna
Recessive Ataxia Diagnosis Algorithm for the Next Generation Sequencing Era
OBJECTIVE: Differential diagnosis of autosomal recessive cerebellar ataxias can be challenging. A ranking algorithm named RADIAL that predicts the molecular diagnosis based on the clinical phenotype of a patient has been developed to guide genetic testing and to align genetic findings with the clinical context. METHODS: An algorithm that follows clinical practice, including patient history, clinical, magnetic resonance imaging, electromyography, and biomarker features, was developed following a review of the literature on 67 autosomal recessive cerebellar ataxias and personal clinical experience. Frequency and specificity of each feature were defined for each autosomal recessive cerebellar ataxia, and corresponding prediction scores were assigned. Clinical and paraclinical features of patients are entered into the algorithm, and a patient's total score for each autosomal recessive cerebellar ataxia is calculated, producing a ranking of possible diagnoses. Sensitivity and specificity of the algorithm were assessed by blinded analysis of a multinational cohort of 834 patients with molecularly confirmed autosomal recessive cerebellar ataxia. The performance of the algorithm was assessed versus a blinded panel of autosomal recessive cerebellar ataxia experts. RESULTS: The correct diagnosis was ranked within the top 3 highest‐scoring diagnoses at a sensitivity and specificity of >90% for 84% and 91% of the evaluated genes, respectively. Mean sensitivity and specificity of the top 3 highest‐scoring diagnoses were 92% and 95%, respectively. The algorithm outperformed the panel of ataxia experts (p = 0.001). INTERPRETATION: Our algorithm is highly sensitive and specific, accurately predicting the underlying molecular diagnoses of autosomal recessive cerebellar ataxias, thereby guiding targeted sequencing or facilitating interpretation of next‐generation sequencing data
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