Ökologischer Landbau zwischen Vision und Realität

Der Bio-Sektor und seine Akteure scheinen in ihren Strukturen, Funktions- und Handlungsweisen der konventionellen Landwirtschaft immer ähnlicher zu werden. Die daraus resultierenden Effekte und notwendigen Maßnahmen wurden auf der 8.Wissenschaftstagung in Kassel erörtert

Konventionalisierungsfalle? was tun?

Der Öko-Landbau schrieb in den letzten Jahren Erfolgsgeschichte: Der Biosektor und seine Akteure scheinen in ihren Strukturen, Funktions- und Handlungsweisen der konventionellen Landwirtschaft immer ähnlicher zu werden. Während die einen Werte- und Sinnverlust beklagen, begrüßen die anderen Wachstum und öffentliche Anerkennung. Maßnahmen zur Überwindung dieses Spannungsfeldes wurden im März 2005 auf der Wissenschaftstagung zum Ökologischen Landbau im Rahmen eines Symposiums erörtert

Deletion of the Ca2+-activated potassium (BK) alpha-subunit but not the BK-beta-1-subunit leads to progressive hearing loss

The large conductance voltage- and Ca2+-activated potassium (BK) channel has been suggested to play an important role in the signal transduction process of cochlear inner hair cells. BK channels have been shown to be composed of the pore-forming alpha-subunit coexpressed with the auxiliary beta-1-subunit. Analyzing the hearing function and cochlear phenotype of BK channel alpha-(BKalpha–/–) and beta-1-subunit (BKbeta-1–/–) knockout mice, we demonstrate normal hearing function and cochlear structure of BKbeta-1–/– mice. During the first 4 postnatal weeks also, BKalpha–/– mice most surprisingly did not show any obvious hearing deficits. High-frequency hearing loss developed in BKalpha–/– mice only from ca. 8 weeks postnatally onward and was accompanied by a lack of distortion product otoacoustic emissions, suggesting outer hair cell (OHC) dysfunction. Hearing loss was linked to a loss of the KCNQ4 potassium channel in membranes of OHCs in the basal and midbasal cochlear turn, preceding hair cell degeneration and leading to a similar phenotype as elicited by pharmacologic blockade of KCNQ4 channels. Although the actual link between BK gene deletion, loss of KCNQ4 in OHCs, and OHC degeneration requires further investigation, data already suggest human BK-coding slo1 gene mutation as a susceptibility factor for progressive deafness, similar to KCNQ4 potassium channel mutations. © 2004, The National Academy of Sciences. Freely available online through the PNAS open access option

Solvent and thermal stability, and pH kinetics, of proline-specific dipeptidyl peptidase IV-like enzyme from bovine serum

Proline-specific dipeptidyl peptidase-like (DPP IV; EC 3.4.14.5) activity in bovine serum has attracted little attention despite its ready availability and the paucity of useful proline-cleaving enzymes. Bovine serum DPP IV-like peptidase is very tolerant of organic solvents, particularly acetonitrile: upon incubation for 1 h at room temperature in 70% acetonitrile, 47% dimethylformamide, 54% DMSO and 33% tetrahydrofuran (v/v concentrations) followed by dilution into the standard assay mixture, the enzyme retained half of its aqueous activity. As for thermal performance in aqueous buffer, its relative activity increased up to 50 ◦C. Upon thermoinactivation at 71 ◦C, pH 8.0 (samples removed periodically, cooled on ice, then assayed under optimal conditions), residual activities over short times fit a first-order decay with a k-value of 0.071±0.0034 min−1. Over longer times, residual activities fit to a double exponential decay with k1 and k2 values of 0.218±0.025 min−1 (46±4% of overall decay) and 0.040±0.002 min−1 (54±4% of overall decay), respectively. The enzyme’s solvent and thermal tolerances suggest that it may have potential for use as a biocatalyst in industry. Kinetic analysis with the fluorogenic substrate Gly-Pro-7-aminomethylcoumarin over a range of pH values indicated two pK values at 6.18±0.07 and at 9.70±0.50. We ascribe the lower value to the active site histidine; the higher may be due to the active site serine or to a free amino group in the substrate

Diphenyl diselenide protects neuronal cells against oxidative stress and mitochondrial dysfunction : involvement of the glutathione-dependent antioxidant system

Oxidative stress and mitochondrial dysfunction are critical events in neurodegenerative diseases; therefore, molecules that increase cellular antioxidant defenses represent a future pharmacologic strategy to counteract such conditions. The aim of this study was to investigate the potential protective effect of (PhSe)2 on mouse hippocampal cell line (HT22) exposed to tert-BuOOH (in vitro model of oxidative stress), as well as to elucidate potential mechanisms underlying this protection. Our results showed that tert-BuOOH caused time- and concentration- dependent cytotoxicity, which was preceded by increased oxidants production and mitochondrial dysfunction. (PhSe)2 pre-incubation significantly prevented these cytotoxic events and the observed protective effects were paralleled by the upregulation of the cellular glutathione-dependent antioxidant system: (PhSe)2 increased GSH levels (> 60%), GPx activity (6.9-fold) and the mRNA expression of antioxidant enzymes Gpx1 (3.9-fold) and Gclc (2.3-fold). Of note, the cytoprotective effect of (PhSe)2 was significantly decreased when cells were treated with mercaptosuccinic acid, an inhibitor of GPx, indicating the involvement of GPx modulation in the observed protective effect. In summary, the present findings bring out a new action mechanism concerning the antioxidant properties of (PhSe)2. The observed upregulation of the glutathione-dependent antioxidant system represents a future pharmacologic possibility that goes beyond the well-known thiol-peroxidase activity of this compound

Decreased and Heterogeneous Neutralizing Antibody Responses Against RBD of SARS-CoV-2 Variants After mRNA Vaccination.

The rapid spread of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) emerging variants raises concerns about their capacity to evade immune protection provided by natural infection or vaccination. The receptor-binding domain (RBD) of the viral spike protein is the major target of neutralizing antibodies, and viral variants accumulate mutations in this region. In this study, we determined the antibody neutralization capacity against the RBD of SARS-CoV-2 variants Alpha (B.1.1.7), Gamma (P.1), Epsilon (B.1.427), Kappa (B.1.617.1), and Delta (B.1.617.2) in a cohort of healthcare workers naturally infected or receiving COVID-19 mRNA vaccines from Moderna or Pfizer-BioNTech. We show that the five RBD variants displayed an augmented binding to ACE2 compared to the original Wuhan strain. The most significant increase was observed in variants Epsilon and Delta, containing mutation L452R. Using a flow cytometry cell-based assay, we found that SARS-CoV-2-infected subjects presented low levels of RBD-specific neutralizing antibodies against all variants analyzed, except Alpha. However, the neutralizing activity incremented considerably after a subsequent mRNA-vaccine dose, to levels significantly higher than those in naïve individuals receiving two vaccine doses. Importantly, we observed partially impaired neutralizing responses against most variants in fully vaccinated individuals. Variants Gamma and Kappa encompassing RBD E484K/Q mutations presented the highest neutralizing resistance. Furthermore, a wide heterogeneity in the magnitude of RBD-specific neutralizing responses against all tested SARS-CoV-2 variants following both mRNA vaccines was detected. Altogether, our findings provide important knowledge regarding SARS-CoV-2 vaccine-induced immunity, and should be very useful to guide future vaccination regimens and personalized vaccine approaches

The 2015 drought in Washington State: a harbinger of things to come?

Washington State experienced widespread drought in 2015 and the largest burned area in the observational record, attributable in part to exceptionally low winter snow accumulation and high summer temperatures. We examine 2015 drought severity in the Cascade and Olympic mountains relative to the historical climatology (1950-present) and future climate projections (mid-21st century) for a mid-range global greenhouse gas emissions scenario. Although winter precipitation was near normal, the regional winter temperature anomaly was +2.1 degrees C (+2.0 sigma) in 2015, consistent with projections of a +2.3 degrees C (+2.2 sigma temperature change and near normal precipitation in the future, relative to the climatology. April 1 snow water equivalent in 2015, -325 mm (-1.5..), and the future, -252 mm (-1.1 sigma), were substantially lower than the climatology. Wildfire potential, as indicated by dead fuel moisture content, was higher in 2015 than mid-21st century mean projections. In contrast to most historical droughts, which have been driven by precipitation deficits, our results suggest that 2015 is a useful analog of typical conditions in the Pacific Northwest by the mid-21st century

Term Matrix: a novel Gene Ontology annotation quality control system based on ontology term co-annotation patterns.

Biological processes are accomplished by the coordinated action of gene products. Gene products often participate in multiple processes, and can therefore be annotated to multiple Gene Ontology (GO) terms. Nevertheless, processes that are functionally, temporally and/or spatially distant may have few gene products in common, and co-annotation to unrelated processes probably reflects errors in literature curation, ontology structure or automated annotation pipelines. We have developed an annotation quality control workflow that uses rules based on mutually exclusive processes to detect annotation errors, based on and validated by case studies including the three we present here: fission yeast protein-coding gene annotations over time; annotations for cohesin complex subunits in human and model species; and annotations using a selected set of GO biological process terms in human and five model species. For each case study, we reviewed available GO annotations, identified pairs of biological processes which are unlikely to be correctly co-annotated to the same gene products (e.g. amino acid metabolism and cytokinesis), and traced erroneous annotations to their sources. To date we have generated 107 quality control rules, and corrected 289 manual annotations in eukaryotes and over 52 700 automatically propagated annotations across all taxa