100 research outputs found
The alignment of the polarization of HAe/Be stars with the interstellar magnetic field
We present a study of the correlation between the direction of the symmetry
axis of the circumstellar material around intermediate mass young stellar
objects and that of the interstellar magnetic field. We use CCD polarimetric
data on 100 Herbig Ae/Be stars. A large number of them shows intrinsic
polarization, which indicates that their circumstellar envelopes are not
spherical. The interstellar magnetic field direction is estimated from the
polarization of field stars. There is an alignment between the position angle
of the Herbig Ae/Be star polarization and that of the field stars for the most
polarized objects. This may be an evidence that the ambient interstellar
magnetic field plays a role in shaping the circumstellar material around young
stars of intermediate mass and/or in defining their angular momentum axis.Comment: ApJ accepte
Prevalence of major and minor electrocardiographic abnormalities and their relationship with cardiovascular risk factors in Angolans
Aims: To identify the prevalence of major and minor electrocardiographic abnormalities and their association with the main risk factors for cardiovascular disease in a population in the province of Bengo, northern Angola. Methods: A cross-sectional community-based study was conducted and a representative random sample stratified by sex and age was selected. In total, 2379 black individuals were included in the final analysis. A standard 12-lead ECG was recorded from all participants, analyzed and processed by the University of Glasgow software, and coded by the Minnesota code. Results: 22.3% of participants had minor electrocardiographic abnormalities and 4.58% major ECG abnormalities. The most common minor ECG abnormalities were abnormal T wave inversion, minor isolated ST abnormalities, and premature beats. The most common major ECG abnormalities were Left ventricular hypertrophy with major ST-T abnormalities, Ventricular conduction defects, and major Q-wave abnormalities. Hypertension, diabetes mellitus, hypercholesterolemia, alcohol consumption, and smoking, were significantly associated with major and minor electrocardiographic abnormalities. Conclusions: In this study, several participants had minor and major electrocardiographic abnormalities. Minor electrocardiographic abnormalities were more prevalent in men and major abnormalities in women. The electrocardiographic abnormalities had significant associations with the main cardiovascular risk factors.info:eu-repo/semantics/publishedVersio
IEC 61499 REPLICATION FOR FAULT TOLERANT SYSTEM
The IEC 61499 was developed thinking about the new generation of distributed control and automation systems. This provides essential resources for the development of distributed systems such as encapsulation, portability and reconfiguration. In this sense, and to ensure confidence in the operation should be implemented fault tolerance techniques dealing with hardware failures and errors off software associated with us where the distributed application runs. In this paper, we propose an approach to deal with failures in distributed systems tolerance problems, based on a replication model based on replication software/hardware as a means to achieve confidence in the operation.info:eu-repo/semantics/publishedVersio
Reliability of Replicated Distributed Control Systems Applications Based on IEC 61499
The use of industrial and domestic equipment is increasingly dependent on computerized control systems. This evolution awakens in the users the feeling of reliability of the equipment, which is not always achieved. However, system designers implement fault-tolerance methodologies and attributes to eliminate faults or any error in the system.
Industrially, the increase in system reliability is achieved by the redundancy of control systems based on the replication of conventional and centralized programmable logic controllers. In distributed systems, reliability is achieved by replicating and distributing the most critical elements, leaving a single copy of the remaining components. On the other hand, given the nature of the distributed systems, it will also be necessary to ensure that the data set received by each of the replicas has the same order. Thus, any change in the order and data set received will result in different results, in each of the replicas, which may manifest in erroneous behavior.
In this paper, the interactions and the erroneous behavior of the replicas are explained, depending on the data set received, in a fault tolerant distributed system. Its tendency, behavior and possible influences on reliability are presented, considering the failure rate and availability based on the mean time to failure.info:eu-repo/semantics/publishedVersio
Caso incomum de filariose linfática mediastinal com estenose da artéria pulmonar
E descrito um caso incomum de filariose linfática, devido a Wuchereria Bancrofti, com localização dos vermes nos linfonodos e linfáticos do mediastino. A intensa reação do conjuntivo mediastinal, provavelmente desencadeada por macrofilárias mortas, determinou no paciente - de 9 anos, residente em Belém, Estado do Pará - estreitamento do tronco e dos ramos principais da artéria pulmonar, defeito tido, inicialmente, como de natureza congênita. O exame histopatológico de duas dentre várias formações nodulares encontradas no mediastino, durante o ato operatório,permitiu, no entanto, estabelecer-se a verdadeira causa da alteração exibida pelo paciente. O achado representa uma formà curiosa de infecção por W. bancrofti, completamente inesperada, quando se considera que a prevalência da bancroftose é, hoje, muito baixa na cidade de Belém. Segundo dados oficiais, o índice de microfilaremia atingiu, em 1985, nessa cidade, cerca de 0,1% apenas, enquanto que, há algumas décadas, era ele estimado em mais de 10%.An unusual case of bancroftian filariasis caused by the presence of macrofilariae in the mediastinal lymphatic vessels is presented. The considerable tissue reaction developed in the mediastinum, probably in relation to products released by dead worms, provoked a severe constriction of the trunk and main branches ofthe pulmonary artery, which conducted to a initial diagnosis of congenital heart disease. The patient, a 9-year-old boy living in Belém-Pará, was admitted to the Belém Hospital and operated at the heart unit, on March 1983. Several fibrous masses were found in the anterior mediastinum, some of them being close to the bifurcation of the pulmonary trunk. The artery presented a severe constriction and a thickened wall. Two of the fibrous nodules were removed for histopathological examination and the sections showed that the masses consisted of lymph nodes surrounded by fibrous tissue and dilated lymphatic vessels. Lying inside the vessels there were numerous sections of filarial worms, recognized as mature females of Wuchereria bancrofti. Some of the worms had died and become calcified. Blood films obtained from the patient after the operation were negative for microfilariae. However, a member of his family, a 14-year-old sister, had been given a course of diethylcarbamazine (DEC), in January of the same year, because, in a routine examination, microfilariae of Wuchereria bancrofti had been demonstrated in her peripheral blood
Novel liposomes for Alzheimers disease treatment
This work was supported by the strategic programme UID/BIA/04050/2019, funded by national
funds through the FCT IP, and project FUN2CYT: Harnessing the potential for biomedical applications of pleiotropic
cytokines LIF and oncostatin M (PTDC/BTM-MAT/30568/2017, POCI-01-0145-FEDER-030568) supported by POCI
through FEDER and FCT IP.info:eu-repo/semantics/publishedVersio
Role of malnutrition and parasite infections in the spatial variation in children’s anaemia risk in Northern Angola
Anaemia has a significant impact on child development and mortality and is a severe public health problem in most countries in sub-Saharan Africa. Nutritional and infectious causes of anaemia are geographically variable and anaemia maps based on information on the major aetiologies of anaemia are important for identifying communities most in need and the relative contribution of major causes. We investigated the consistency between ecological and individual-level approaches to anaemia mapping, by building spatial anaemia models for children aged ≤15 years using different modeling approaches. We aimed to a) quantify the role of malnutrition, malaria, Schistosoma haematobium and soil-transmitted helminths (STH) for anaemia endemicity in children aged ≤15 years and b) develop a high resolution predictive risk map of anaemia for the municipality of Dande in Northern Angola. We used parasitological survey data on children aged ≤15 years to build Bayesian geostatistical models of malaria (PfPR≤15), S. haematobium, Ascaris lumbricoides and Trichuris trichiura and predict small-scale spatial variation in these infections. The predictions and their associated uncertainty were used as inputs for a model of anemia prevalence to predict small-scale spatial variation of anaemia. Stunting, PfPR≤15, and S. haematobium infections were significantly associated with anaemia risk. An estimated 12.5%, 15.6%, and 9.8%, of anaemia cases could be averted by treating malnutrition, malaria, S. haematobium, respectively. Spatial clusters of high risk of anaemia (>86%) were identified. Using an individual-level approach to anaemia mapping at a small spatial scale, we found that anaemia in children aged ≤15 years is highly heterogeneous and that malnutrition and parasitic infections are important contributors to the spatial variation in anemia risk. The results presented in this study can help inform the integration of the current provincial malaria control program with ancillary micronutrient supplementation and control of neglected tropical diseases, such as urogenital schistosomiasis and STH infection
Prevalence of atrial fibrillation in Bengo Province, Angola: results from a population-based study
Introdução: A fibrilhação auricular é a arritmia sustentada mais comum na população adulta com significado clínico, representando um importante problema de saúde pública. Não existe na literatura dados publicados acerca da prevalência da fibrilhação auricular em Angola. Objetivo: O presente estudo foi realizado com o objetivo de determinar a prevalência de fibrilhação auricular numa população do Bengo, uma província do norte de Angola, estratificada por sexo e idade e análise da sua relação com alguns fatores de risco cardiovascular. Materiais e Métodos: Os dados são provenientes do estudo CardioBengo, um estudo transversal de base comunitária, do qual foi selecionada uma amostra aleatória de indivíduos com idades compreendidas entre os 15 e os 84 anos. No total foram incluídos 2 379 indivíduos na análise final. Resultados: A idade média dos participantes foi de 35 anos e 63% da amostra era do sexo feminino. Verificou-se que a frequência de consumo de álcool era de 35,8%, a prevalência de acidente vascular isquémico ou acidente isquémico transitório foi de 0,4%; insuficiência cardíaca congestiva, 0,3%; doença cardíaca isquémica, 0,3% e hipertrofia ventricular esquerda, 37,2%. A fibrilhação auricular foi identificada em dois indivíduos, o que representa uma prevalência de 0,084%. Conclusão: O nosso estudo mostra uma baixa prevalência de fibrilhação auricular, quando comparada com as encontradas em estudos realizados em países desenvolvidos, mas semelhante à encontrada em estudos da África Subsariana.ABSTRACT - Introduction: Atrial fibrillation is the most common sustained arrhythmia of clinical significance in the adult population, representing an important public health problem. Literature on the prevalence of atrial fibrillation in Angola is unavailable. Objective: The goal of this paper is to determine the prevalence of atrial fibrillation in a population from Bengo, a province from northern Angola, stratified by sex and age and analyze its relationship with some cardiovascular risk factors. Material and Methods: The data were obtained from the CardioBengo study, a cross-sectional community-based study, from which a random sample of individuals aged between 15 and 84 years was selected. In total, 2,379 individuals were included in the final analysis. Results: The average age of the participants was 35 years old, and 63% of the sample was female. The following prevalence rates were noted: prior stroke or transient ischaemic attack, 0.4%; congestive heart failure, 0.3%; ischaemic heart disease, 0.3% and left ventricular hypertrophy, 37.2%. Atrial fibrillation was found in two individuals, reflecting a prevalence of 0.084%. Conclusion: Our study reports a low prevalence of atrial fibrillation compared to rates found in studies conducted in developed countries but similar to other studies from Sub-Saharan Africa.info:eu-repo/semantics/publishedVersio
Ocular findings in patients with systemic sclerosis
OBJECTIVE: To evaluate the frequency and characteristics of ocular manifestations in outpatients with systemic sclerosis. METHODS: In this cross-sectional study, 45 patients with systemic sclerosis were enrolled. Data regarding demographics, disease duration and subtype, age at diagnosis, nailfold capillaroscopic pattern and autoantibody profile were collected, and a full ophthalmic examination was conducted. Parametric (Student's t-test) and nonparametric (Mann-Whitney U test) tests were used to compare continuous variables. Fisher's exact test was used to compare categorical data. P values < 0.05 were considered significant. RESULTS: Twenty-three subjects (51.1%) had eyelid skin changes; 22 (48.9%) had keratoconjunctivitis sicca, 19 (42.2%) had cataracts, 13 (28.9%) had retinal microvascular abnormalities and 6 (13.3%) had glaucoma. Eyelid skin changes were more frequent in patients with the diffuse subtype of systemic sclerosis and were associated with a younger age and an earlier age at diagnosis. Cataracts were presumed to be age-related and secondary to corticosteroid treatment. There was no association between demographic, clinical or serological data and keratoconjunctivitis sicca. The retinal microvascular abnormalities were indistinguishable from those related to systemic hypertension and were associated with an older age and a severe capillaroscopic pattern. CONCLUSIONS: Eyelid skin abnormalities and keratoconjunctivitis sicca were the most common ocular findings related to systemic sclerosis. Some demographic and clinical data were associated with some ophthalmic features and not with others, showing that the ocular manifestations of systemic sclerosis are characterized by heterogeneity and reflect the differences in the implicated pathophysiological mechanisms
Effect of hydrogen peroxide on natural phytoplankton and bacterioplankton in a drinking water reservoir: mesocosm-scale study.
Cyanobacterial blooms are increasingly reported worldwide, presenting a challenge to water treatment plants and concerning risks to human health and aquatic ecosystems. Advanced oxidative processes comprise efficient and safe methods for water treatment. Hydrogen peroxide (H2O2) has been proposed as a sustainable solution to mitigate bloom-forming cyanobacteria since this group presents a higher sensitivity compared to other phytoplankton, with no major risks to the environment at low concentrations. Here, we evaluated the effects of a single H2O2 addition (10 mg L−1) over 120 h in mesocosms introduced in a reservoir located in a semi-arid region presenting a Planktothrix-dominated cyanobacterial bloom. We followed changes in physical and chemical parameters and in the bacterioplankton composition. H2O2 efficiently suppressed cyanobacteria, green algae, and diatoms over 72 h, leading to an increase in transparency and dissolved organic carbon, and a decrease in dissolved oxygen and pH, while nutrient concentrations were not affected. After 120 h, cyanobacterial abundance remained low and green algae became dominant. 16S rRNA sequencing revealed that the original cyanobacterial bloom was composed by Planktothrix, Cyanobium and Microcystis. Only Cyanobium increased in relative abundance at 120 h, suggesting regrowth. A prominent change in the composition of heterotrophic bacteria was observed with Exiguobacterium, Paracoccus and Deinococcus becoming the most abundant genera after the H2O2 treatment. Our results indicate that this approach is efficient in suppressing cyanobacterial blooms and improving water quality in tropical environments. Monitoring changes in abiotic parameters and the relative abundance of specific bacterial taxa could be used to anticipate the regrowth of cyanobacteria after H2O2 degradation and to indicate where in the reservoir H2O2 should be applied so the effects are still felt in the water treatment plant intake
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