Characterization of beta-adrenergic receptors by (3H) isoproterenol in adipocytes of humans and rats

The specific binding of (3H) isoproterenol to isolated fat cells of human and rat was characterized. Binding of (3H) isoproterenol to isolated fat cells of rat was saturable with 420 pmol of (3H) isoproterenol bound/100 mg of lipid. Half-maximal saturation occurred at 5 microM providing an estimate of the equilibrium dissociation constant, KD, for the interaction of (3H) isoproterenol with its binding sites. Kinetic analysis of (3H) isoproterenol binding provided a value of 2.01 x 10(4) min-1. M-1 for the forward bimolecular rate constant, k1. Dissociation of (3H) isoproterenol was a first order reaction with a rate constant, k2, of 0.62 x 10(-1) min-1. The ratio k2/k1 = 3.07 microM provides an independent measurement of the KD for the interaction of (3H) isoproterenol with its binding sites which is in agreement with the values obtained by steady state analysis (3 to 5 microM). The apparent equilibrium dissociation constant, KD, for the interaction of (3H) isoproterenol with its receptor in human fat cells obtained by steady state analysis was 1 to 0.9 microM. Scatchard- and Hill-analysis suggest the possibility of different negatively cooperative interactions among the binding sites in human and rat. beta-Adrenergic agonists competed for the binding sites. The order of potency was isoproterenol greater than epinephrine greater than norepinephrine. Compounds such as DOPA, dopamine and (m-Hydroxyphenyl)2-methyl-aminoethanol which are structurally related to catecholamines had little or no affinity for (3H) isoproterenol binding sites.     

An improved breeding method for solitarious locusts

In order to unravel the physiological, endocrine, and behavioral differences between gregarious and solitarious forms of the desert locust, Schistocerca gregaria (Forsk.) (Orthoptera, Acrididae), a constant supply of rather large numbers of solitary individuals has to be guaranteed. This represents a bottleneck, mainly because of the intensity of the labor involved and limited laboratory accommodation. The method we describe here substantially reduces the space and manpower needed. The survival rate we obtained in the solitarised population was relatively high, reaching about 55%. The optimal rearing temperature proved to be 32–36 °C. Cabbage leaves and oat flakes sufficed for feeding all year round. Special racks have been designed that enable high density stacking and easy handling. The solitarisation process was monitored over ten consecutive generations. Changes in morphometrics, eye stripes, color, and behavior were recorded, of which only morphometrics, temperature related development, and mortality are discussed. A shift towards the solitarious phase was recorded, with clear differences between gregarious, 1^st generation and 7^th to 10^th generation solitarious locusts.     

Evaluating the effectiveness of retention forestry to enhance biodiversity in production forests of Central Europe using an interdisciplinary,multi‐scale approach

Retention forestry, which retains a portion of the original stand at the time of harvesting to maintain continuity of structural and compositional diversity, has been originally developed to mitigate the impacts of clear‐cutting. Retention of habitat trees and deadwood has since become common practice also in continuous‐cover forests of Central Europe. While the use of retention in these forests is plausible, the evidence base for its application is lacking, trade‐offs have not been quantified, it is not clear what support it receives from forest owners and other stakeholders and how it is best integrated into forest management practices. The Research Training Group ConFoBi (Conservation of Forest Biodiversity in Multiple‐use Landscapes of Central Europe) focusses on the effectiveness of retention forestry, combining ecological studies on forest biodiversity with social and economic studies of biodiversity conservation across multiple spatial scales. The aim of ConFoBi is to assess whether and how structural retention measures are appropriate for the conservation of forest biodiversity in uneven‐aged and selectively harvested continuous‐cover forests of temperate Europe. The study design is based on a pool of 135 plots (1 ha) distributed along gradients of forest connectivity and structure. The main objectives are (a) to investigate the effects of structural elements and landscape context on multiple taxa, including different trophic and functional groups, to evaluate the effectiveness of retention practices for biodiversity conservation; (b) to analyze how forest biodiversity conservation is perceived and practiced, and what costs and benefits it creates; and (c) to identify how biodiversity conservation can be effectively integrated in multi‐functional forest management. ConFoBi will quantify retention levels required across the landscape, as well as the socio‐economic prerequisites for their implementation by forest owners and managers. ConFoBi's research results will provide an evidence base for integrating biodiversity conservation into forest management in temperate forests.     

Synthesis of 1,5-Anhydrohexitol Nucleosides as Mimics of AZT,D4T and DDC

Abstract

1,5-Anhydrohexitol congeners of AZT, D4T and DDC were synthesized. These compounds did not show anti-HIV activity.

     

Targeted molecular trait stacking in cotton through targeted double‐strand break induction

Recent developments of tools for targeted genome modification have led to new concepts in how multiple traits can be combined. Targeted genome modification is based on the use of nucleases with tailor‐made specificities to introduce a DNA double‐strand break (DSB) at specific target loci. A re‐engineered meganuclease was designed for specific cleavage of an endogenous target sequence adjacent to a transgenic insect control locus in cotton. The combination of targeted DNA cleavage and homologous recombination–mediated repair made precise targeted insertion of additional trait genes (hppd, epsps) feasible in cotton. Targeted insertion events were recovered at a frequency of about 2% of the independently transformed embryogenic callus lines. We further demonstrated that all trait genes were inherited as a single genetic unit, which will simplify future multiple‐trait introgression.     

Test-Retest Reliability of Innovated Strength Tests for Hip Muscles

The burden of hip muscles weakness and its relation to other impairments has been well documented. It is therefore a pre-requisite to have a reliable method for clinical assessment of hip muscles function allowing the design and implementation of a proper strengthening program. Motor-driven dynamometry has been widely accepted as the gold-standard for lower limb muscle strength assessment but is mainly related to the knee joint. Studies focusing on the hip joint are less exhaustive and somewhat discrepant with regard to optimal participants position, consequently influencing outcome measures. Thus, we aimed to develop a standardized test setup for the assessment of hip muscles strength, i.e. flexors/extensors and abductors/adductors, with improved participant stability and to define its psychometric characteristics. Eighteen participants performed unilateral isokinetic and isometric contractions of the hip muscles in the sagittal and coronal plane at two separate occasions. Peak torque and normalized peak torque were measured for each contraction. Relative and absolute measures of reliability were calculated using the intraclass correlation coefficient and standard error of measurement, respectively. Results from this study revealed higher levels of between-day reliability of isokinetic/isometric hip abduction/flexion peak torque compared to existing literature. The least reliable measures were found for hip extension and adduction, which could be explained by a less efficient stabilization technique. Our study additionally provided a first set of reference normalized data which can be used in future research.