Short‐term degradation of semiarid grasslands—results from a controlled‐grazing experiment in Northern China

The assessment of grassland degradation due to overgrazing is a global challenge in semiarid environments. In particular, investigations of beginning steppe degradation after a change or intensification of the land use are needed in order to detect and adjust detrimental land‐use management rapidly and thus prevent severe damages in these sensitive ecosystems. A controlled‐grazing experiment was established in Inner Mongolia (China) in 2005 that included ungrazed (UG) and heavily grazed plots with grazing intensities of 4.5 (HG4.5) and 7.5 (HG7.5) sheep per hectare. Several soil and vegetation parameters were investigated at all sites before the start of the experiment. Topsoil samples were analyzed for soil organic C (SOC), total N (N_tot), total S (S_tot), and bulk density (BD). As vegetation parameters, aboveground net primary productivity (ANPP), tiller density (TD), and leaf‐area index (LAI) were determined. After 3 y of the grazing experiment, BD increased and SOC, N_tot, S_tot, ANPP, and LAI significantly decreased with increasing grazing intensity. These sensitive parameters can be regarded as early‐warning indicators for degradation of semiarid grasslands. Vegetation parameters were, however, more sensitive not only to grazing but also to temporal variation of precipitation between 2006 and 2008. Contrary, soil parameters were primarily affected by grazing and resistant against climatic variations. The assessment of starting conditions in the study area and the application of defined grazing intensities is essential for the investigation of short‐term degradation in semiarid environments.     

Plasma and urine responses are lower for acylated vs nonacylated anthocyanins from raw and cooked purple carrots

The bioavailability of acylated vs nonacylated anthocyanins and the effect of cooking and dose on the comparative bioavailability were investigated in a clinical feeding study using purple carrots as the anthocyanin source. Treatments were purple carrots as follows: 250 g raw (463 micromol of anthocyanins: 400 micromol acylated, 63 micromol nonacylated), 250 g cooked (357 micromol of anthocyanins: 308.5 micromol acylated, 48.5 micromol nonacylated), and 500 g cooked (714 micromol of anthocyanins: 617 micromol acylated, 97 micromol nonacylated). Four of the five carrot anthocyanins were found intact in plasma by 30 min after carrot consumption and peaked between 1.5 and 2.5 h. Acylation of anthocyanins resulted in an 11-14-fold decrease in anthocyanin recovery in urine and an 8-10-fold decrease in anthocyanin recovery in plasma. Cooking increased the recovery of nonacylated anthocyanins but not acylated anthocyanins. Large dose size significantly reduced recovery of both acylated and nonacylated anthocyanins, suggesting saturation of absorption mechanisms.     

Die Not des deutschen Waldes

Ohne Zusammenfassung     

Die Not des deutschen Waldes

Ohne Zusammenfassung     

Molecular analysis of the Arbuscular mycorrhiza symbiosis

The molecular analysis of the arbuscular mycorrhizal (AM) symbiosis started at the beginning of this decade. The paper summarises the work of the ‘Laboratorium für Molekulare Genetik arbuskulärer Mykorrhiza’ at the MPI für terrestrische Mikrobiologie in Marburg on three major topics. Firstly, the plant response to the mycorrhizal colonisation was analysed using both, targeted and non‐targeted approaches. As an example, the localisation of the gst1 mRNA in potato mycorrhiza is shown. Second, molecular techniques were established to analyse gene expression of the fungal partner of the symbiosis. We present a differential RNA display analysis of spore germination in two AM fungi and the cloning of a gene from Glomus mosseae that shows expression at all stages of the fungal life cycle. In the last part, we introduce the work we are carrying out with a new root endophytic fungus, Piriformospora indica. Infection experiments on maize showed that despite the fungus performs as a root necrotroph, it has a positive effect on plant growth.     

Investigation on the efficacy of meloxicam in sows with mastitis-metritis-agalactia syndrome

The efficacy of meloxicam in the treatment of sows with mastitis-metritis-agalactia syndrome was investigated in comparison with flunixin. Basic therapy comprised administration of an antibiotic and oxytocin. A total of 200 sows and litters were examined in a double-blind clinical study with observations up to 8 days after the first treatment. The primary parameter, the clinical index score on day 2, consisting of rectal temperature, feed intake, general demeanour, respiratory rate, vaginal discharge, degree of inflammation of mammary glands, milk flow and nursing behaviour, revealed a significant (P < or = 0.05) non-inferiority of meloxicam in comparison with flunixin implying equal efficacy of both drugs. No significant differences were noted in the distribution of clinical efficacy scores within both groups at each day of examination. The differences in litter weight and daily weight gain per piglet were not significant between the two test groups. The mortality rates until day 8 of the study were without significant difference between groups. In piglets of diseased litters, however, the mortality rate was 50% lower in the meloxicam group in comparison with the reference group, this difference reaching statistical significance (P < or = 0.05).     

AFLP analysis of Russian <Emphasis Type="Italic">Alternaria tenuissima</Emphasis> populations from wheat kernels and other hosts

Alternaria tenuissima is a common pathogen on a number of plants described in several geographic regions of the world. Genetic variation within and between Russian Far East, North West and Caucasus populations of A. tenuissima from wheat was examined. In addition, genetic differences between isolates from various hosts were estimated. In total, 101 isolates of A. tenuissima were studied using amplified fragment length polymorphism (AFLP) with four primer combinations. Wright’s fixation index (F _st), gene flow (N _m) and gene diversity (H _s) were calculated. AFLP banding patterns indicated significant genetic distance and at the same time a low level of gene flow between the Far East and the two other groups of isolates originating from the European part of country. The degree of similarity between the North West and Caucasus populations was very high, as was the migration rate. Isolates analysed by UPGMA-based cluster analysis were grouped according to location of origin but irrespective of plant host. Based on the F _st value, the group of isolates originating from wheat and barley were not found to differ significantly from each other.     

Critical discussion of perpendicular to grain tension testing of structural timber – case study on the European hardwoods ash,beech and maple

ABSTRACT

Knowledge about perpendicular to grain tension behavior of wood is essential, since in construction tension stresses perpendicular to grain cannot be avoided completely. Especially for hardwoods, the data basis is scarce. EN 338 design values are with 0.6 N/mm² characteristic strength set very low. The US-American National Design Specifications even set this value to zero and make local reinforcements mandatory. This paper compares strength and stiffness values attained with newly-designed, little, prismatic specimens and EN 408 structural timber specimens to evaluate the current European design values. Little specimen’s characteristic strength values range from 7.2 to 10.6?N/mm² and are assumed to be real material properties. EN 408 specimen values are with approximately 4.0?N/mm² lower. These lower values are mainly due to stress peaks introduced by the force introduction. Strength values attained for the medium-dense European hardwoods beech, ash and maple exceed EN 338 design values by a factor of six to seven. Adaptation of the EN 338 design value is not recommended, though. The abundance of influencing factors makes clear that the design value and the ensuing design code have to be synchronized carefully by tedious testing in order to make use of the perpendicular to grain tension strength potential of the selected hardwoods.     

Comparison of acid-detergent lignin,alkaline-peroxide lignin,and acid-detergent insoluble ash as internal markers for predicting fecal output and digestibilily by caltie offered bermudagrass hays of varying nutrient composition

Background： The potential for acid-detergent insoluble ash （ADIA）, alkaline-peroxide lignin （APL）, and acid-detergent lignin （ADL） to predict fecal output （FO） and dry matter digestibility （DMD） by cattle offered bermudagrass [Cynodon doctylon （L） Pers.] hays of different qualities was evaluated. Eight ruminally cannulated cows （594 ± 35.5 kg） were allocated randomly to 4 hay diets： low （L）, medium low （ML）, medium high （MH）, and high （H） crude protein （CP） concentration （79, 111,131, and 164 g CP/kg on a DM basis, respectively）. Diets were offered in 3 periods with 2 diet replicates per period and were rotated across cows between periods. Cows were individually fed 20 g DM/kg of body weight in equal feedings at 08：00 and 16：00 h for a 10-d adaptation followed by a 5-d total fecal collection. Actual DM intake （DMI）, DMD, and FO were determined based on hay offered, ort, and feces excreted. These components were then analyzed for ADL, APL, and ADIA concentration to determine marker recovery and marker-based estimates of FO and DMD. Results： Forage DMI was affected by diet （P = 0.02）, and DMI from MH and H was greater （P 〈 0.05） than from L. Apparent DMD tended （P = 0.08） to differ among diets while FO （P = 0.20） was not affected by diet treatments. Average ADL recovery （1.16） was greater （P 〈 0.05） than that of ADIA （1.03） and APL （1.06）, but ADIA and APL did not differ （P = 0.42）. Estimates of FO and DMD derived using APL and ADIA were not different （P≥0.05） from total fecal collection while those using ADL differed （P 〈 0.05）. There was no diet by marker interaction （P≥ 0.22） for either FO or DMD. Conclusion： Acid-detergent insoluble ash and APL accurately predicted FO and DMD of cattle fed bermudagrass hay of varying nutrient composition. These internal markers may facilitate studies involving large numbers of animals and forages. Results from such studies may be used to develop improve