Modulation of the activity of the mitochondrial BK-channel and the permeability transition pore by hypoxia and apoptotic factors

Magdeburg, Univ., Fak. für Naturwiss., Diss., 2010

Analyse der literarischen Übersetzung des Werkes „Out of Africa“ von Karen Blixen

Die vorliegende Arbeit unternimmt den Versuch, anhand einer Analyse aufzuzeigen, inwiefern die Funktionen des von der Übersetzungswissenschaftlerin Christiane Nord geschaffenen Vier-Funktionen-Modells in der Übersetzung vertreten sind. Für die Analyse wurde die deutsche Übersetzung von Karen Blixens autobiografischem Werk „Out of Africa“ ausgewählt. Alle Funktionen, Übersetzungslösungen und -fehler werden anhand von Beispielen aufgezeigt und analysiert.

Anurans of the Serra do Caraça, southeastern Brazil: species composition and phenological patterns of calling activity

Annual patterns of calling and breeding activity of 38 anuran species were studied at Serra do Caraça, an 11,233 ha reserve located in a contact zone between Cerrado and Atlantic forest at the southern Espinhaço range, southeastern Brazil. Five patterns were evident: (1) species that call year-round or nearly year-round with larger aggregations generally observed in the rainy months, (2) species with opportunistic calling activity associated with rainfall during the wettest months of the year, (3) winter species, (4) explosive breeders with intense calling activity triggered by heavy rains during the rainy season or only in the beginning of the rainy season, and (5) summer species with variable breeding seasons. Both the monthly number of species with calling males and the monthly number of species that showed the maximum class of calling males were positively correlated with both mean monthly temperature and monthly precipitation.

The use of triphenyltetrazolium chloride in the study of dehydrogenase activity of Brucellae

Experiments for the investigation of dehydrogenase activity of washed cells of a strains of Br. abortus and another of Br. suis in presence of different single added substrates are reported. The activity was measured as the amount of formazan produced by the reduction of 2, 3, 5-triphenyltetrazolum chloride acting as a hydrogen ions acceptor, at pH 7.0. In a general manner the dehydrogenase activity of Br. suis was much more intense than that of Br. abortus (fig. 5). In the conditions of the experiments Br. abortus oxidized L-arabinose, D-galactose, D-glucose, glycerol, D-xylose, DL-alanine, D-fructose, and D-sorbitol. Brucella suis oxidized D-xylose, L-arabinose, D-glucose, D-galactose, DL-alanine, sodium acetate, maltose, glycine, D-fructose, and D-sorbitol. Glycerol was oxidized by Br. abortus but its oxidation by Br. suir was very slight. Sodium acetate and maltose were intensely oxidized by Br. suir but not by Br. abortus. The sites of more intense enzymatic acitivity were seen as small red colored round granules located in one pole of the cells.

Competitive interactions between species of fresh-water snails: I. Laboratory. IC. Comparative survival of Biomphalaria glabrata and B. Straminea kept out of water

Biomphalaria glabrata and B. straminea were submitted to an out-door laboratory experiment for testing their comparative ability to resist desiccation. Results have shown that B. straminea is significantly higher resistant than B. glabrata. After five months under such distressing condition the survival ratios were: B. glabrata 8.1 per cent and B. straminea 18.4 per cent.

Relationship of physical activity with motor skills, aerobic fitness and body fat in preschool children: a cross-sectional and longitudinal study (Ballabeina).

Adiposity, low aerobic fitness and low levels of activity are all associated with clustered cardiovascular disease risk in children and their high prevalence represents a major public health concern. The aim of this study is to investigate the relationship of objectively measured physical activity (PA) with motor skills (agility and balance), aerobic fitness and %body fat in young children. This study is a cross-sectional and longitudinal analyses using mixed linear models. Longitudinal data were adjusted for baseline outcome parameters. In all, 217 healthy preschool children (age 4-6 years, 48% boys) participated in this study. PA (accelerometers), agility (obstacle course), dynamic balance (balance beam), aerobic fitness (20-m shuttle run) and %body fat (bioelectric impedance) at baseline and 9 months later. PA was positively associated with both motor skills and aerobic fitness at baseline as well as with their longitudinal changes. Specifically, only vigorous, but not total or moderate PA, was related to changes in aerobic fitness. Higher PA was associated with less %body fat at baseline, but not with its change. Conversely, baseline motor skills, aerobic fitness or %body fat were not related to changes in PA. In young children, baseline PA was associated with improvements in motor skills and in aerobic fitness, an important determinant of cardiovascular risk.

Evolution of insulin sensitivity and its variability in out-of-hospital cardiac arrest (OHCA) patients treated with hypothermia.

INTRODUCTION: Therapeutic hypothermia (TH) is often used to treat out-of-hospital cardiac arrest (OHCA) patients who also often simultaneously receive insulin for stress-induced hyperglycaemia. However, the impact of TH on systemic metabolism and insulin resistance in critical illness is unknown. This study analyses the impact of TH on metabolism, including the evolution of insulin sensitivity (SI) and its variability, in patients with coma after OHCA. METHODS: This study uses a clinically validated, model-based measure of SI. Insulin sensitivity was identified hourly using retrospective data from 200 post-cardiac arrest patients (8,522 hours) treated with TH, shortly after admission to the intensive care unit (ICU). Blood glucose and body temperature readings were taken every one to two hours. Data were divided into three periods: 1) cool (T <35°C); 2) an idle period of two hours as normothermia was re-established; and 3) warm (T >37°C). A maximum of 24 hours each for the cool and warm periods was considered. The impact of each condition on SI is analysed per cohort and per patient for both level and hour-to-hour variability, between periods and in six-hour blocks. RESULTS: Cohort and per-patient median SI levels increase consistently by 35% to 70% and 26% to 59% (P <0.001) respectively from cool to warm. Conversely, cohort and per-patient SI variability decreased by 11.1% to 33.6% (P <0.001) for the first 12 hours of treatment. However, SI variability increases between the 18th and 30th hours over the cool to warm transition, before continuing to decrease afterward. CONCLUSIONS: OCHA patients treated with TH have significantly lower and more variable SI during the cool period, compared to the later warm period. As treatment continues, SI level rises, and variability decreases consistently except for a large, significant increase during the cool to warm transition. These results demonstrate increased resistance to insulin during mild induced hypothermia. Our study might have important implications for glycaemic control during targeted temperature management.

Out of sight, out of mind? Educational outcomes of children with parents working abroad.

Impact of parental emigration on educational outcomes of children is theoretically ambiguous. Using novel data I collected on migration experience and its timing, family background and school performance of lower secondary pupils in Poland, I analyse the question empirically. Migration is mostly temporary in nature, with one parent engaging in employment abroad. As many as 63% of migrant parents have vocational qualifications, 29% graduated from high school, 4% have no qualifications and the remaining 4% graduated from university. Almost 18% of children are affected by parental migration. Perhaps surprisingly, estimates suggest that parental employment abroad has a positive immediate impact on a pupil’s grade. Parental education appears pivotal; children of high school graduates benefit most. Longer term effects appear more negative, however, suggesting that a prolonged migration significantly lowers a child’s grade. Interestingly, siblings’ foreign experiences exert a large, positive impact on pupils’ grades.

Ectodysplasin has a dual role in ectodermal organogenesis: inhibition of Bmp activity and induction of Shh expression.

Ectodermal organogenesis is regulated by inductive and reciprocal signalling cascades that involve multiple signal molecules in several conserved families. Ectodysplasin-A (Eda), a tumour necrosis factor-like signalling molecule, and its receptor Edar are required for the development of a number of ectodermal organs in vertebrates. In mice, lack of Eda leads to failure in primary hair placode formation and missing or abnormally shaped teeth, whereas mice overexpressing Eda are characterized by enlarged hair placodes and supernumerary teeth and mammary glands. Here, we report two signalling outcomes of the Eda pathway: suppression of bone morphogenetic protein (Bmp) activity and upregulation of sonic hedgehog (Shh) signalling. Recombinant Eda counteracted Bmp4 activity in developing teeth and, importantly, inhibition of BMP activity by exogenous noggin partially restored primary hair placode formation in Eda-deficient skin in vitro, indicating that suppression of Bmp activity was compromised in the absence of Eda. The downstream effects of the Eda pathway are likely to be mediated by transcription factor nuclear factor-kappaB (NF-kappaB), but the transcriptional targets of Edar have remained unknown. Using a quantitative approach, we show in cultured embryonic skin that Eda induced the expression of two Bmp inhibitors, Ccn2/Ctgf (CCN family protein 2/connective tissue growth factor) and follistatin. Moreover, our data indicate that Shh is a likely transcriptional target of Edar, but, unlike noggin, recombinant Shh was unable to rescue primary hair placode formation in Eda-deficient skin explants.

Association of hemolytic activity of Pseudomonas entomophila, a versatile soil bacterium, with cyclic lipopeptide production.

Pseudomonas entomophila is an entomopathogenic bacterium that is able to infect and kill Drosophila melanogaster upon ingestion. Its genome sequence suggests that it is a versatile soil bacterium closely related to Pseudomonas putida. The GacS/GacA two-component system plays a key role in P. entomophila pathogenicity, controlling many putative virulence factors and AprA, a secreted protease important to escape the fly immune response. P. entomophila secretes a strong diffusible hemolytic activity. Here, we showed that this activity is linked to the production of a new cyclic lipopeptide containing 14 amino acids and a 3-C(10)OH fatty acid that we called entolysin. Three nonribosomal peptide synthetases (EtlA, EtlB, EtlC) were identified as responsible for entolysin biosynthesis. Two additional components (EtlR, MacAB) are necessary for its production and secretion. The P. entomophila GacS/GacA two-component system regulates entolysin production, and we demonstrated that its functioning requires two small RNAs and two RsmA-like proteins. Finally, entolysin is required for swarming motility, as described for other lipopeptides, but it does not participate in the virulence of P. entomophila for Drosophila. While investigating the physiological role of entolysin, we also uncovered new phenotypes associated with P. entomophila, including strong biocontrol abilities.

Daily pattern of flight activity of Aedes albifasciatus in Central Argentina

Aedes albifasciatus is an important common mosquito in Central Argentina. Its a confirmed vector of the Western Equine Encephalitis and is responsible for loss of milk production in dairy cattle during peak populations. This paper reports the flight activity pattern of Ae. albifasciatus for different seasons, in the southern coast of the Mar Chiquita Lake (Central Argentina). Data were collected by sampling two sites between 1992 and 1993 with CDC traps and human-bait captures. Adult mosquito population density, estimated by CDC trapping and human-bait, were highly correlated. However, when compared to other species, the proportion of Ae. albifasciatus was higher in human-bait collections. Adult female populations were active only when temperature were higher than 6§C. Two daily biting peaks were observed (dusk and dawn) during the spring, summer and autumn, and only one peak during winter (around 15:00 pm). Adult abundance was significantly correlated (R²= 0.71; p<0.01) with temperature and illumination.

Detection of promoter activity by flow cytometric analysis of GFP reporter expression.

Low efficiency of transfection is often the limiting factor for acquiring conclusive data in reporter assays. It is especially difficult to efficiently transfect and characterize promoters in primary human cells. To overcome this problem we have developed a system in which reporter gene expression is quantified by flow cytometry. In this system, green fluorescent protein (GFP) reporter constructs are co-transfected with a reference plasmid that codes for the mouse cell surface antigen Thy-1.1 and serves to determine transfection efficiency. Comparison of mean GFP expression of the total transfected cell population with the activity of an analogous luciferase reporter showed that the sensitivity of the two reporter systems is similar. However, because GFP expression can be analyzed at the single-cell level and in the same cells the expression of the reference plasmid can be monitored by two-color fluorescence, the GFP reporter system is in fact more sensitive, particularly in cells which can only be transfected with a low efficiency.

Ultraviolet induction of antifungal activity in plants.

Ultraviolet-C irradiation as a method to induce the production of plant compounds with antifungal properties was investigated in the leaves of 18 plant species. A susceptibility assay to determine the antifungal susceptibility of filamentous fungi was developed based on an agar dilution series in microtiter plates. UV irradiation strongly induced antifungal properties in five species against a clinical Fusarium solani strain that was responsible for an onychomycosis case that was resistant to classic pharmacological treatment. The antifungal properties of three additional plant species were either unaffected or reduced by UV-C irradiation. This study demonstrates that UV-C irradiation is an effective means of modulating the antifungal activity of very diverse plants from a screening perspective.