90 research outputs found

    Protein import machineries in endosymbiotic organelles

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    Abstract.: Chloroplast and mitochondria, the two organelles with an accepted endosymbiotic origin, have developed multiple translocation pathways to ensure the subcellular allocation of proteins synthesized by cytosolic ribosomes, and to guarantee their assembly into functional complexes in coordination also with organellar-encoded subunits. The evolution of different protein import machineries was thus essential for the development of these two organelles within cells. A general overview of the translocation machineries in chloroplast and mitochondrial membranes involved in targeting and import of nuclearencoded proteins, with special focus on plant cells where the two organelles coexist, is expounde

    DOC-turnover and microbial biomass production

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    Uptake data of seven sugars (mono- and disaccharides) were used to calculate DOC-turnover and microbial biomass production. The sugars investigated in this study represent 1-2% of the DOC and up to30 % of the free dissolved carbohydrates. The uptake measurements were not based on a kinetic approach. Uniformly labelled 14C-carbohydrates were added to the samples, the concentrations reaching maximally 10% of the corresponding natural substrate concentration. Taking the natural substrate concentration into account, it is possible to calculate the actual uptake rates, turnover times and microbial C-production. An investigation in the Kiel Fjord during 1978/79 shows turnover times for glucose between 1.7 and 600 hours. The microbial biomass production varies between 0.01 and 10 ÎĽg C l-1 h-1, i.e. 0.2 - 83% of the primary production. The ratio between incorporation and gross uptake is between 0.62 and 0.95, which supports the assumption that free dissolved carbohydrates are biochemically wellutilized substrates. The relation to exudates is discussed

    The implementation of initial data populations of environmental data and creation of a primary working database

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    Biological and environmental changes are creating a growing demand for historical and global data sets. Comparing up-to-date ecological and biological findings with historical statements has become a major part of scientific work in the field of ecology. This evaluation and comparison procedure is very time-consuming while the availability of raw data is very low. Comparisons between original findings – if available – require a lot of work from print publication to digitalization or transformation to appropriate data formats. The effective use of working capacity is a general issue and has become important, should the use of information technologies be invoked to minimize time-wasting copy and paste operations. In this paper we aim to present a working repository for terrestrial biological data. The implementation of this type of data repository will provide various services to participating scientists as long as the final aim is the publication of these repositories. Furthermore, the security and long-term availability of environmental data is an issue of increasing importance to the scientific community. Unrepeatable sampling events and any data thus obtained are precious in time series analysis. For this reason, a well-structured storage of data is necessary for easy accessibility, retrieval and comparability. This is an important issue for the community of environmental scientists. The need to construct and implement repositories should prevail against all hitches and we are therefore describing our on-going task with the primary population of this kind of data repository. A biological and ecological information system is a matter of public interest and should also be a key issue for ecologists

    The microphytobenthos of Königshafen — spatial and seasonal distribution on a sandy tidal flat

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    A microphytobenthic species composition of a tidal flat in the northern Wadden Sea was analysed regarding cell numbers and biomass (in carbon units). The three sampling sites differed in tidal inundation from 15 cm to about 90 cm water depth at high tide. The sediment was sandy at all three stations. A cluster analysis revealed a separation of the benthic diatoms into three areas: aNereis-Corophium-belt, a seagrass-bed and theArenicola-flat. Small epipsammic diatoms were most abundant and dominated the microalgal biomass. A microphytobenthic “spring bloom” even started beneath the ice cover of the flat in January. Lowest values of cell numbers and biomass of benthic microalgae were found in summer. Highest values were measured in the uppermost area (Nereis-Corophium-belt), and only here was an autumnal increase of benthic microalgae found. Further cluster analysis within each of the three areas revealed seasonal differences although the majority of species were present all year round. Many species were most abundant in spring, and some showed a bimodal distribution (spring-autumn) in the year of investigatio

    Some like it cold: understanding the survival strategies of psychrophiles

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    Much of the Earth's surface, both marine and terrestrial, is either periodically or permanently cold. Although habitats that are largely or continuously frozen are generally considered to be inhospitable to life, psychrophilic organisms have managed to survive in these environments. This is attributed to their innate adaptive capacity to cope with cold and its associated stresses. Here, we review the various environmental, physiological and molecular adaptations that psychrophilic microorganisms use to thrive under adverse conditions. We also discuss the impact of modern “omic” technologies in developing an improved understanding of these adaptations, highlighting recent work in this growing field.http://embor.embopress.org/content/15/5/508hb201

    Challenges in supporting lay carers of patients at the end of life: results from focus group discussions with primary healthcare providers

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    Background: Family caregivers (FCGs) of patients at the end of life (EoL) cared for at home receive support from professional and non-professional care providers. Healthcare providers in general practice play an important role as they coordinate care and establish contacts between the parties concerned. To identify potential intervention targets, this study deals with the challenges healthcare providers in general practice face in EoL care situations including patients, caregivers and networks. Methods: Focus group discussions with general practice teams in Germany were conducted to identify barriers to and enablers of an optimal support for family caregivers. Focus group discussions were analysed using content analysis. Results: Nineteen providers from 11 general practices took part in 4 focus group discussions. Participants identified challenges in communication with patients, caregivers and within the professional network. Communication with patients and caregivers focused on non-verbal messages, communicating at an appropriate time and perceiving patient and caregiver as a unit of care. Practice teams perceive themselves as an important part of the healthcare network, but also report difficulties in communication and cooperation with other healthcare providers. Conclusion: Healthcare providers in general practice identified relational challenges in daily primary palliative care with potential implications for EoL care. Communication and collaboration with patients, caregivers and among healthcare providers give opportunities for improving palliative care with a focus on the patient-caregiver dyad. It is insufficient to demand a (professional) support network; existing structures need to be recognized and included into the care

    International challenges without borders: a descriptive study of family physicians' educational needs in the field of diabetes

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    <p>Abstract</p> <p>Background</p> <p>The optimal care of persons with diabetes by general practitioners and family physicians (GP/FP) is complex and requires multiple competencies. This is a fairly unrecognized key challenge in the healthcare systems. In some cases, local and national Continuous Professional Development (CPD) initiatives target these challenges; however there have been few international initiatives, possibly because challenges emerging from different studies have not been linked across national boundaries. In this context, the authors have compiled data about gaps and/or barriers inherent to GP/FP care of persons with type 2 diabetes from Austria, Canada, Germany and the United Kingdom.</p> <p>Methods</p> <p>Secondary analyzes of pre-existing studies were conducted to identify challenges in the care of patients with type 2 diabetes as faced by GPs/FPs. Two sources of data were reviewed: unpublished research data from collaborating organizations and articles from a literature search (in English and German). Articles retrieved were scanned by the research team for relevance to the study objectives and to extract existing gaps and barriers. The identified challenges were then categorized along three major axes: (1) phase of the continuum of care {from screening to management}; (2) learning domain {knowledge, skills, attitudes, behavior, context}; and (3) by country/region. Compilation and categorization were performed by qualitative researchers and discrepancies were resolved through discussion until concordance was achieved.</p> <p>Results and discussion</p> <p>Thirteen challenges faced by GPs/FPs in the care for patients with type 2 diabetes were common in at least 3 of the 4 targeted countries/regions. These issues were found across the entire continuum of care and included: pathophysiology of diabetes, diagnostic criteria, treatment targets assessment, drugs' modes of action, decision-making in therapies, treatment guidelines, insulin therapy, adherence, management of complications, lifestyle changes, team integration, bureaucracy and third-party payers. The issues reported were not restricted to the physicians' knowledge, but also related to their skills, attitudes, behaviours and context.</p> <p>Conclusions</p> <p>This study revealed challenges faced by GPs/FPs when caring for patients with diabetes, which were similar across international and health system borders. Common issues might be addressed more efficiently through international educational designs, adapted to each country's healthcare system, helping develop and maintain physicians' competencies.</p
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