1,221 research outputs found
Changes in chemical composition and bioassay assessment of nutritional potentials of almond fruit waste as an alternative feedstuff for livestock
Changes in chemical composition upon processing and bioassay assessment of nutritional potentials of almond fruit waste as an alternative feedstuff were conducted using day-oldcockerels.Proximate analyses revealed that AFW contained valuable nutrients, carbohydrate/dry matter, protein, fat, fiber, mineral matter (ash). The concentration of some of these nutrients increased as the raw AFW was treated. The raw AFW gave on analysis quantitatively highconcentrations of the chemical compounds, tannins, hydrocyanides, phytic acid and other unquantified chemical compounds like oxalates assessed qualitatively. Subjecting raw AFW to lactic fermentation and enzymes treatments reduced the levels of the phytochemicals. Bioassay of the treated and untreated AFW using day-old cockerels and considering performance parameters showed that treated AFW improved feed intake, body weight gain and feed conversion ratio even better than the results obtained on these indices on the reference diet (p0.05). Untreated AFW elicited misperformance and high mortality of the test birds. It was concluded that the nutritional value of AFW, if could be used as an alternative feedstuff for animals, must be given adequate treatments
Predicting performance of constant flow depth filtration using constant pressure filtration data
This paper describes a method of predicting constant flow filtration capacities using constant pressure datasets collected during the purification of several monoclonal antibodies through depth filtration. The method required characterisation of the fouling mechanism occurring in constant pressure filtration processes by evaluating the best fit of each of the classic and combined theoretical fouling models. The optimised coefficients of the various models were correlated with the corresponding capacities achieved during constant flow operation at the specific pressures performed during constant pressure operation for each centrate. Of the classic and combined fouling models investigated, the Cake-Adsorption fouling model was found to best describe the fouling mechanisms observed for each centrate at the various different pressures investigated. A linear regression model was generated with these coefficients and was shown to predict accurately the capacities at constant flow operation at each pressure. This model was subsequently validated using an additional centrate and accurately predicted the constant flow capacities at three different pressures (0.69, 1.03 and 1.38 bar). The model used the optimised Cake-Adsorption model coefficients that best described the flux decline during constant pressure operation. The proposed method of predicting depth filtration performance proved to be faster than the traditional approach whilst requiring significantly less material, making it particularly attractive for early process development activities
A Framework for Assessing the Solutions in Chromatographic Process Design and Operation for Large Scale Manufacture
Chromatographic separation of biopharmaceuticals is complex and tools for the prediction of performance and the trade-offs necessary for efficient operation are limited and time-consuming. This complexity is due to the large number of possible column aspect ratios that satisfy process and economic needs. This paper demonstrates a framework for the design and analysis of chromatographic steps. The functionalities are illustrated by application to a Protein A separation where the effects of column diameter, bed length and linear flow rate on cost of goods (COG/g) and productivity (g/h) are investigated so as to identify the optimal operating strategy. Results are presented as a series of ‘windows of operation’ to address key design and operating decisions. The tool allows the designer to customise limiting constraints based on product and process specific knowledge. Results indicate the significant impact on COG/g of column over-sizing and how this can be balanced by increased levels of productivity
A Framework for Assessing the Solutions in Chromatographic Process Design and Operation for Large Scale Manufacture
Chromatographic separation of biopharmaceuticals is complex and tools for the prediction of performance and the trade-offs necessary for efficient operation are limited and time-consuming. This complexity is due to the large number of possible column aspect ratios that satisfy process and economic needs. This paper demonstrates a framework for the design and analysis of chromatographic steps. The functionalities are illustrated by application to a Protein A separation where the effects of column diameter, bed length and linear flow rate on cost of goods (COG/g) and productivity (g/h) are investigated so as to identify the optimal operating strategy. Results are presented as a series of ‘windows of operation’ to address key design and operating decisions. The tool allows the designer to customise limiting constraints based on product and process specific knowledge. Results indicate the significant impact on COG/g of column over-sizing and how this can be balanced by increased levels of productivity
Relationship between endophenotype and phenotype in ADHD
<p>Abstract</p> <p>Background</p> <p>It has been hypothesized that genetic and environmental factors relate to psychiatric disorders through the effect of intermediating, vulnerability traits called endophenotypes. The study had a threefold aim: to examine the predictive validity of an endophenotypic construct for the ADHD diagnosis, to test whether the magnitude of group differences at the endophenotypic and phenotypic level is comparable, and to investigate whether four factors (gender, age, IQ, rater bias) have an effect (moderation or mediation) on the relation between endophenotype and phenotype.</p> <p>Methods</p> <p>Ten neurocognitive tasks were administered to 143 children with ADHD, 68 non-affected siblings, and 120 control children (first-borns) and 132 children with ADHD, 78 non-affected siblings, and 113 controls (second-borns) (5 – 19 years). The task measures have been investigated previously for their endophenotypic viability and were combined to one component which was labeled 'the endophenotypic construct': one measure representative of endophenotypic functioning across several domains of functioning.</p> <p>Results</p> <p>The endophenotypic construct classified children with moderate accuracy (about 50% for each of the three groups). Non-affected children differed as much from controls at the endophenotypic as at the phenotypic level, but affected children displayed a more severe phenotype than endophenotype. Although a potentially moderating effect (age) and several mediating effects (gender, age, IQ) were found affecting the relation between endophenotypic construct and phenotype, none of the effects studied could account for the finding that affected children had a more severe phenotype than endophenotype.</p> <p>Conclusion</p> <p>Endophenotypic functioning is moderately predictive of the ADHD diagnosis, though findings suggest substantial overlap exists between endophenotypic functioning in the groups of affected children, non-affected siblings, and controls. Results suggest other factors may be crucial and aggravate the ADHD symptoms in affected children.</p
A Cross-Sectional Survey on Knowledge and Perceptions of Health Risks Associated with Arsenic and Mercury Contamination from Artisanal Gold mining in Tanzania.
An estimated 0.5 to 1.5 million informal miners, of whom 30-50% are women, rely on artisanal mining for their livelihood in Tanzania. Mercury, used in the processing gold ore, and arsenic, which is a constituent of some ores, are common occupational exposures that frequently result in widespread environmental contamination. Frequently, the mining activities are conducted haphazardly without regard for environmental, occupational, or community exposure. The primary objective of this study was to assess community risk knowledge and perception of potential mercury and arsenic toxicity and/or exposure from artisanal gold mining in Rwamagasa in northwestern Tanzania. A cross-sectional survey of respondents in five sub-villages in the Rwamagasa Village located in Geita District in northwestern Tanzania near Lake Victoria was conducted. This area has a history of artisanal gold mining and many of the population continue to work as miners. Using a clustered random selection approach for recruitment, a total of 160 individuals over 18 years of age completed a structured interview. The interviews revealed wide variations in knowledge and risk perceptions concerning mercury and arsenic exposure, with 40.6% (n=65) and 89.4% (n=143) not aware of the health effects of mercury and arsenic exposure respectively. Males were significantly more knowledgeable (n=59, 36.9%) than females (n=36, 22.5%) with regard to mercury (x²=3.99, p<0.05). An individual's occupation category was associated with level of knowledge (x²=22.82, p=<0.001). Individuals involved in mining (n=63, 73.2%) were more knowledgeable about the negative health effects of mercury than individuals in other occupations. Of the few individuals (n=17, 10.6%) who knew about arsenic toxicity, the majority (n=10, 58.8%) were miners. The knowledge of individuals living in Rwamagasa, Tanzania, an area with a history of artisanal gold mining, varied widely with regard to the health hazards of mercury and arsenic. In these communities there was limited awareness of the threats to health associated with exposure to mercury and arsenic. This lack of knowledge, combined with minimal environmental monitoring and controlled waste management practices, highlights the need for health education, surveillance, and policy changes
The diagnosis of colorectal cancer in patients with symptoms: finding a needle in a haystack
Patients often see primary care physicians with symptoms that might signal colorectal cancer but are also common in adults without cancer. Physicians and patients must then make a difficult decision about whether and how aggressively to evaluate the symptom. Favoring referral is that missed diagnoses lead to unnecessary testing, prolonged uncertainty, and continuing symptoms; also, the physician will suffer chagrin. It is not clear that diagnostic delay leads to progression to a more advanced stage. Against referral is that proper evaluation includes colonoscopy, with attendant inconvenience, discomfort, cost, and risk. The article by Hamilton et al, published this month in BMC Medicine, provides strong estimates of the predictive value of the various symptoms and signs of colorectal cancer and show how much higher predictive values are with increasing age and male sex. Unfortunately, their results also make clear that most colorectal cancers present with symptoms with low predictive values, < 1.2%. Models that include a set of predictive variables, that is, risk factors, age, sex, screening history, and symptoms, have been developed to guide primary prevention and clinical decision-making and are more powerful than individual symptoms and signs alone. Although screening for colorectal cancer is increasing in many countries, cancers will still be found outside screening programs so primary care physicians will remain at the front line in the difficult task of distinguishing everyday symptoms from life-threatening cancer
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