159 research outputs found
Kinetics of biodegradation of diethylketone by Arthrobacter viscosus
The performance of an Arthrobacter
viscosus culture to remove diethylketone from aqueous
solutions was evaluated. The effect of initial
concentration of diethylketone on the growth of the
bacteria was evaluated for the range of concentration
between 0 and 4.8 g/l, aiming to evaluate a possible
toxicological effect. The maximum specific growth
rate achieved is 0.221 h-1 at 1.6 g/l of initial
diethylketone concentration, suggesting that for
higher concentrations an inhibitory effect on the
growth occurs. The removal percentages obtained
were approximately 88%, for all the initial concentrations
tested. The kinetic parameters were estimated
using four growth kinetic models for biodegradation
of organic compounds available in the literature. The
experimental data found is well fitted by the Haldane
model (R2 = 1) as compared to Monod model
(R2 = 0.99), Powell (R2 = 0.82) and Loung model
(R2 = 0.95). The biodegradation of diethylketone
using concentrated biomass was studied for an initial
diethylketone concentration ranging from 0.8–3.9 g/l
in a batch with recirculation mode of operation. The
biodegradation rate found followed the pseudo-second
order kinetics and the resulting kinetic parameters
are reported. The removal percentages obtained
were approximately 100%, for all the initial concentrations
tested, suggesting that the increment on the
biomass concentration allows better results in terms
of removal of diethylketone. This study showed that
these bacteria are very effective for the removal of
diethylketone from aqueous solutions.The authors would like to gratefully acknowledge the financial support of this project by the Fundacao para a Ciencia e Tecnologia (FCT), Ministerio da Ciencia e Tecnologia, Portugal and Fundo Social Europeu (FSE). Cristina Quintelas thanks FCT for a Post-Doc grant
Women's Education Level, Maternal Health Facilities, Abortion Legislation and Maternal Deaths: A Natural Experiment in Chile from 1957 to 2007
The aim of this study was to assess the main factors related to maternal mortality reduction in large time series available in Chile in context of the United Nations' Millennium Development Goals (MDGs).Time series of maternal mortality ratio (MMR) from official data (National Institute of Statistics, 1957-2007) along with parallel time series of education years, income per capita, fertility rate (TFR), birth order, clean water, sanitary sewer, and delivery by skilled attendants were analysed using autoregressive models (ARIMA). Historical changes on the mortality trend including the effect of different educational and maternal health policies implemented in 1965, and legislation that prohibited abortion in 1989 were assessed utilizing segmented regression techniques.During the 50-year study period, the MMR decreased from 293.7 to 18.2/100,000 live births, a decrease of 93.8%. Women's education level modulated the effects of TFR, birth order, delivery by skilled attendants, clean water, and sanitary sewer access. In the fully adjusted model, for every additional year of maternal education there was a corresponding decrease in the MMR of 29.3/100,000 live births. A rapid phase of decline between 1965 and 1981 (-13.29/100,000 live births each year) and a slow phase between 1981 and 2007 (-1.59/100,000 live births each year) were identified. After abortion was prohibited, the MMR decreased from 41.3 to 12.7 per 100,000 live births (-69.2%). The slope of the MMR did not appear to be altered by the change in abortion law.Increasing education level appears to favourably impact the downward trend in the MMR, modulating other key factors such as access and utilization of maternal health facilities, changes in women's reproductive behaviour and improvements of the sanitary system. Consequently, different MDGs can act synergistically to improve maternal health. The reduction in the MMR is not related to the legal status of abortion
Neuropsychological Correlates of Cystic Fibrosis in Patients 5 to 8 Years Old
Intellectual, academic, and neuropsychological tests were administered to 20 children with cystic fibrosis (CF). Results were compared to test results from 20 controls matched for gender, age, and socioeconomic status. No differences between the groups were found. For children with CF, Verbal IQ, sensory-perceptual skills, and incidental learning correlated (rs = .39-.67) with Shwachman criteria of disease severity, with significant positive relations with the Growth and Nutrition measure, an index of the severity of the disease. Processing of tactile-perceptual information may be particularly vulnerable to disease severity. This study provides more information than previously available on the neuropsychological status of young children with CF, and it offers some hypotheses regarding the relation between disease severity and neuropsychological function.published_or_final_versio
Metagenomic Analysis of Respiratory Tract DNA Viral Communities in Cystic Fibrosis and Non-Cystic Fibrosis Individuals
The human respiratory tract is constantly exposed to a wide variety of viruses, microbes and inorganic particulates from environmental air, water and food. Physical characteristics of inhaled particles and airway mucosal immunity determine which viruses and microbes will persist in the airways. Here we present the first metagenomic study of DNA viral communities in the airways of diseased and non-diseased individuals. We obtained sequences from sputum DNA viral communities in 5 individuals with cystic fibrosis (CF) and 5 individuals without the disease. Overall, diversity of viruses in the airways was low, with an average richness of 175 distinct viral genotypes. The majority of viral diversity was uncharacterized. CF phage communities were highly similar to each other, whereas Non-CF individuals had more distinct phage communities, which may reflect organisms in inhaled air. CF eukaryotic viral communities were dominated by a few viruses, including human herpesviruses and retroviruses. Functional metagenomics showed that all Non-CF viromes were similar, and that CF viromes were enriched in aromatic amino acid metabolism. The CF metagenomes occupied two different metabolic states, probably reflecting different disease states. There was one outlying CF virome which was characterized by an over-representation of Guanosine-5′-triphosphate,3′-diphosphate pyrophosphatase, an enzyme involved in the bacterial stringent response. Unique environments like the CF airway can drive functional adaptations, leading to shifts in metabolic profiles. These results have important clinical implications for CF, indicating that therapeutic measures may be more effective if used to change the respiratory environment, as opposed to shifting the taxonomic composition of resident microbiota
Women from the Middle East and North Africa in Europe: Understanding their marriage and family dynamics
The aim of this article is to assist the understanding of social workers in Europe of marriage and family dynamics among women from Middle East and North African countries who have moved to Europe. The focus of this article is on husband selection processes and family dynamics after marriage in Egypt, which is used as a case study reflecting culture and norms surrounding marriage in this region. This article reports on the findings of doctoral studies which examined marriage patterns and family dynamics in North Africa and in particular in Egypt where more in-depth data were available. The authors reflect issues surrounding values and process of marriage not only in terms of the implications for practice with social work clients or service users, but also in relation to the potential of women from this region who may join the social care workforce
Birds use structural properties when selecting materials for different parts of their nests
Bird nests can have various roles but all act as the location for incubation, so at least have to serve to hold and support the incubating bird and its clutch of eggs. Nest construction is species specific and the use of materials varies between different parts of the nest. At present we know very little about the role that these materials play in the structural characteristics of the nest. This study examined materials from deconstructed nests from four species of thrush (Turdidae) and two species of finch (Fringillidae) that all constructed nests made of woody stems. It was hypothesised that structural properties would vary within the different regions of a nest, with thicker and stronger materials being found in parts of the nest needing the most support. Secondly, it was predicted that structural properties would vary little between nests of members of the same family, but would be quite different between nests of different families. Nests were deconstructed to quantify the materials used in the cup lining, and the upper and lower parts of the outer nest. The 20 thickest pieces of material were selected from each nest part and for each piece, and their diameter and mass quantified. Each piece was then subjected to a three-point bending test using an Instron universal testing machine to determine its rigidity and bending strength. Placement of materials in the nest was non-random in all species. The materials used in the outer part of the nest were thicker, stronger and stiffer than those materials found in the cup lining. The extent to which these structural properties varied between families depended on where the material was taken from the nest. Both strength and rigidity strongly positively correlated with the diameter of the piece of material. We hypothesise that birds are not directly aware of the structural properties of the material per se but rather assess diameter and mass of the material when they pick it up by the bill. Using this information they decide on whether the piece is suitable for that appropriate stage of nest construction
Evaluación del uso del preservativo femenino promovido desde un programa de educación para la salud: un enfoque cualitativo
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