401 research outputs found
ISOLATION AND CHARACTERIZATION OF ARGINASE ISOZYMES FROM BOVINE LIVER AND BRAIN
A chromatographic method was developed to isolate arginase isozymes from bovine brain and liver. The purified proteins were characterized as to their native molecular weight, subunit structure, amino acid composition, hexose content, behavior on disc gel electrophoresis, and reaction with polyclonal antibodies raised against a liver arginase antigen. An arginase-specific messenger RNA preparation was also isolated from liver polysomes using immunological techniques.
Two liver and four brain arginases were purified, having similar native molecular weights, yet different subunit compositions, and displaying varying affinities for the Mn(\u272+) ion that is required for complete enzymatic activity. The amino acid compositions of all six proteins are closely related, although there are some noticeable disparities, particularly with respect to alanine.
When analyzed by disc gel electrophoresis, a bovine liver or brain arginase enzyme will appear as a diffuse band. The carbohydrate moiety of these molecules may be responsible for this pattern, but a variable loss of Mn(\u272+) in the electric field also contributes to the diffuseness, since the migration of each isozyme was observed to change if separated by electrophoresis in the presence of added Mn(\u272+) or EDTA.
Several distinct antigenic determinants were recognized by anti-liver arginase antibodies. Two of the bovine brain arginase proteins identified in this work share one of these immunological sites with the liver enzyme, while the other two arginases isolated from brain tissue hold a separate determinant in common with it. Bovine liver arginase antibodies were also observed to cross-react with the arginase enzyme in a mouse liver homogenate.
An arginase enriched mRNA preparation was translated in a cell-free system. After immunoprecipitation and SDS electrophoresis, the translated products migrated to the same positions as authentic liver arginase isozymes
Comparison of RGP fitting capabilities: MasterVue vs. EyeSys
The advent of computer aided videokeratology has many practitioners hopeful that the fitting of rigid gas permeable contact lenses will become more efficient and successful than diagnostic and empirical methods; therefore making an RGP lens more often the lens of choice. This is especially important in a day when the growth of managed health care necessitates less doctor time per patient. The EyeSys Corneal Analysis System and the MasterVue System both claim to provide these benefits using somewhat different fitting strategies. This study assesses the success of each method of lens fitting according to patient satisfaction and on-eye lens performance.
Twenty-nine subjects were initially fitted with one lens generated by the MasterVue System and one lens generated by the EyeSys Corneal Topography System. The authors graded the lens position, edge pattern, apical pattern, visual acuity, over-refraction and overall outcome. Subjects were asked to grade vision, lens comfort and preferred eye. The only areas where one system\u27s lens statistically performed better was subjective comfort and preferred eye. In both cases the MasterVue did better than the EyeSys. The authors feel the difference in comfort was due to the fact that the MasterVue usually designed a larger lens than the EyeSys. However, neither system performed well overall. Only 12.5% of the patients who were followed at the dispense were allowed to keep and wear their lenses.
While there are some cases where a detailed topographical map of the cornea is very helpful in fitting certain patients, particularly those with irregular corneas, the study indicates both systems in their current form are not accurate enough to be used in the fitting of the average low myope to make their use cost effective
Enumerating the Digitally Convex Sets of Powers of Cycles and Cartesian Products of Paths and Complete Graphs
Given a finite set , a convexity , is a collection of subsets
of that contains both the empty set and the set and is closed under
intersections. The elements of are called convex sets. The
digital convexity, originally proposed as a tool for processing digital images,
is defined as follows: a subset is digitally convex if, for
every , we have implies . The number of
cyclic binary strings with blocks of length at least is expressed as a
linear recurrence relation for . A bijection is established between
these cyclic binary strings and the digitally convex sets of the
power of a cycle. A closed formula for the number of digitally convex sets of
the Cartesian product of two complete graphs is derived. A bijection is
established between the digitally convex sets of the Cartesian product of two
paths, , and certain types of binary arrays.Comment: 16 pages, 3 figures, 1 tabl
Bringing Math to Life: Provide Students Opportunities to Connect their Lives to Math
Math journals provide students with opportunities to articulate their understanding of math concepts and/or their frustrations with the gaps in those understandings. Their use supports metacognitive thinking to enhance understanding and application. This study took a look at the use of math journals by fourth grade students as a conduit for critical thinking, reflection, and real world math application. For this study, student journal entries consisted of identification of a real-life event, the use of a problem-solving strategy learned during class instruction, narrative of both the problem’s description as well as the rationale for choosing the problem, and the use of a numeric or pictorial model with solution. Students shared his/her journal entry with the entire class. Through this research, I witnessed evidence of growth in mathematical understanding, computing and a deeper connection to math’s many real-life applications in the lives of elementary students
Protocol for a realist review of complex interventions to prevent adolescents from engaging in multiple risk behaviours
Objectives - Adolescent risk behaviours are a key health concern. The purpose of this research is to gain a deeper understanding of how, why, for whom, and in what circumstances complex adolescent risk behaviour prevention programmes are most successful.
Methods and analysis - To understand how adolescent risk behaviour prevention programmes work in a real life context, a realist synthesis will be undertaken, operationalised in four phases.
Phase one - Developing a framework to map the theoretical and conceptual landscape of adolescent risk behaviour prevention. Guided by stakeholder consultation.
Phase two - Formulating initial programme theories through exploration of the literature, along with primary data from professional stakeholder interviews.
Phase three - Refining programme theories through more purposeful, in depth screening of the literature, along with primary qualitative data, from young people and professionals. Data will be collected through semi structured focus groups, to explore specific elements of the emerging programme theories.
Phase four - Testing programme theories through interviews with youth workers, following consultation with young people, using vignettes to explore the relationship between specific programme theories. This relatively novel method of primary and secondary data integration within a realist synthesis will provide deeper insight in to young peoples lived experience of risk behaviour prevention programmes, while maintaining transparency in the process of programme theory development.
Methods and analysis
Data analysis - A realist logic of analysis will be used to align data from each phase with context mechanism outcome configurations or specific elements thereof. Substantive theory will then be sought to understand and explain the findings.
Ethics and dissemination - This study has been approved by the Ethics committee at Northumbria University, UK. Findings will be disseminated through knowledge exchange with stakeholders, publications in peer-reviewed journals, conference presentations, and formal and informal reports
Alcohol Consumption Levels and Health Care Utilization in Germany: Results from the GEDA 2014/2015-EHIS Study
Abstract:Aims: Due to large inconsistencies in previous studies, it remains unclear how alcohol use is related to health care utilization. The aim of this study was to examine associations between alcohol drinking status with utilization of outpatient and inpatient health care services in Germany. Methodology: Survey data of the GEDA 2014/2015-EHIS study with n = 23,561 German adults were analyzed (response rate: 27 %). Respondents were categorized as lifetime abstainers, former drinkers, and non-weekly drinkers, as well as weekly low-risk drinkers and risky drinkers. Outpatient services included GP, specialist, and hospital visits; inpatient services included hospital overnight stays in the last 12 months. For both settings, binary logistic regression models were applied, adjusted for possible confounders. Results: For specialist visits, elevated odds were found among former drinkers (odds ratio (OR) = 1.93, 95 % confidence interval (95 % CI) = 1.50-2.49), non-weekly drinkers (OR = 1.24, 95 % CI = 1.05-1.47), weekly low-risk drinkers (OR = 1.39, 95 % CI = 1.17-1.67), and risky drinkers (OR = 1.28, 95 % CI = 1.04-1.57) compared to lifetime abstainers. In contrast, lower odds for inpatient service use were found among non-weekly drinkers (OR = 0.76, 95 % CI = 0.62-0.93), low-risk drinkers (OR = 0.66, 95 % CI = 0.53-0.81), and risky drinkers (OR = 0.65, 95 % CI = 0.51-0.84). No differences were observed for GP and outpatient hospital visits. Conclusions: While the increased odds of consulting a specialist are consistent with higher health care needs among former and current drinkers, the lower use of inpatient care among current drinkers is contrary to known health risks associated with alcohol consumption and evidence from hospitalized populations. The findings also highlight the need to differentiate between lifetime abstainers and former drinkers in their use of health services
Queen-produced volatiles change dynamically during reproductive swarming and are associated with changes in honey bee (Apis mellifera) worker behavior
International audienceAbstractDuring colony fission, honey bee workers are exquisitely sensitive to the presence of their queen in airborne swarms and bivouacs and will abandon swarming if she is absent. However, it is not known whether swarming queens produce a chemical bouquet that is distinct from non-swarming queens, containing either unique chemicals or altered proportions of chemicals. We found that queens emitted higher quantities and greater numbers of unique volatiles at liftoff than they did prior to swarming or in clustered bivouacs, and swarming workers tended to be attracted to these liftoff volatile blends. Pentadecane and heptadecane were collected most frequently and emitted in significantly higher quantities by queens at liftoff; these compounds have been described as pheromone components in other social insects, but not yet in honey bees. Our results suggest that volatile emission by queens is more dynamic than previously thought and that changes in their chemical signals may play a role in regulating the behavior of swarming workers
Species composition influences soil nutrient depletion and plantphysiology in prairie agroenergy feedstocks
High-diversity mixtures of perennial tallgrass prairie vegetation could be useful biomass feed-stocks for marginal farmland in the Midwestern United States. These agroenergy crops can help meet cel-lulosic agrofuel targets while also enhancing other ecosystem services on the landscape. One proposedadvantage of high-diversity prairie biomass feedstocks is that they should become nutrient limited at aslower rate than monoculture feedstocks. In this study, we examine rates of soil nutrient depletion and thephysiology and performance of a focal species (switchgrass,Panicum virgatumL.) in four prairie agroen-ergy feedstocks with different species composition and diversity. The feedstocks in this study were a1-species switchgrass monoculture, a 5-species mixture of C4grasses, a 16-species mixture of C3and C4grasses, forbs, and legumes, and a 32-species mixture of C3and C4grasses, forbs, legumes, and sedges. Toassess feedstock effects on soil, we measured changes in soil N/P/K over afive-year period. We also per-formed a greenhouse study, in which we grew switchgrass plants infield soil conditioned by each feed-stock. To assess feedstock effects on plant function, we measured four physiological traits (photosyntheticrate, chlorophyll concentration, leafflorescence, leaf N concentration) on switchgrass plants within eachfeedstock in thefield. In the soil analysis, we found that the 5-species feedstock displayed higher rates ofsoil N/P/K depletion than other feedstocks. In the greenhouse analysis, we found that switchgrass plantsgrown in soil conditioned by the 5-species feedstock were smaller than plants grown in soil conditionedby other feedstocks. In the physiological analysis, we found that switchgrass plants in the 5-species feed-stock had lower leaf N, photosynthesis, chlorophyll concentration, and higherflorescence than switchgrassplants growing in other feedstocks. Collectively, our results show that prairie agroenergy feedstocks withdifferent species composition and diversity have different rates of soil nutrient depletion, which influencesthe physiology and performance of plants within the feedstock. These differences would ultimately impactthe ecosystem services (e.g., biomass production, need for fertilizer) that these prairie agroenergyfeedstocks provide
Blue Growth: A Transitions Approach to Developing Sustainable Pathways
The sustainable management of Blue Growth is an urgent issue for coastal states. Marine industries have rapidly expanded over the last two decades and this is projected to continue with the European Green Deal and post-COVID economic recovery policies. The intensification of Blue Growth could have adverse socio-ecological implications and must, therefore, be managed in terms of sustainability, natural resource boundaries, and coastal community well-being. Managing Blue Growth in a sustainable manner however, is challenging due to the longstanding inefficiencies and inertia of existing marine governance regimes. Adopting a transitions approach has been advanced as a way of steering regime change so that it is not inhibited by these persistent problems. This paper reports on four case studies that adopt transitions thinking and use the multi-level perspective as a broad analytical framework through which to understand institutional dynamics, drivers and responses within core marine sectors. Our case studies analysis reveals several significant pressures for regime change within key marine sectors. These pressures need to be addressed through the adoption of a transition management approach. By adopting this approach and engaging key stakeholders, national and EU marine governance authorities can develop sustainable Blue Growth pathways that minimize the impact of continued growth on communities and the marine environment, maximizing the implementation of sustainable practices and addressing issues such as biodiversity loss and climate change
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