Plasma cholesterol levels and short-term adaptations of metabolism and milk production during feed restriction in early lactating dairy cows on pasture

Low plasma total cholesterol (TC) concentrations are characteristic during the negative energy balance in early lactating dairy cows. The objective was to investigate short-term effects of different TC concentrations during an aggravated energy deficiency through a 1-week concentrate withdrawal on adaptations of metabolism and milk production. Multiparous Holstein cows (n = 15) were investigated during 3 week beginning at 24 ± 7 DIM (mean ± SD). Cows were kept on pasture and received additional concentrate in experimental week 1 and 3, while in week 2, concentrate was withdrawn. Blood was sampled once and milk twice daily. Based on their average TC concentration during week 1 (prior to concentrate withdrawal), cows were retrospectively assigned into a high (H-Chol; n = 8, TC ≥ 3.36 mmol/L) and a low TC groups (L-Chol; n = 7, TC < 3.36 mmol/L). Concentrations of phospholipids and lipoproteins were higher in H-Chol compared to L-Chol throughout the study (p < 0.05). During concentrate withdrawal, milk yield, glucose and insulin concentrations decreased similarly in both groups, while milk fat, milk acetone and plasma BHB were higher in H-Chol compared to L-Chol (p < 0.05). Compared to initial values, plasma NEFA, TAG and VLDL increased in both groups within 2 days after concentrate withdrawal (p < 0.05). Concentrations of NEFA during week 2 were greater in L-Chol compared to H-Chol (p < 0.05). Despite reintroduction of concentrate, milk yield in H-Chol remained lower for two more days compared to week 1 (p < .05), whereas milk yield recovered immediately in L-Chol. Activity of aspartate aminotransferase was higher in H-Chol compared to L-Chol in week 2 (p < 0.05). Greater plasma TC concentrations were associated with a reduced increase of NEFA. Further research is warranted if TC concentrations are related to adipose tissue mobilization and fatty acid turnover.     

Potential Nitrate Leaching Under Common Landscaping Plants

Two Elsholtzia haichowensis S. populations, copper-tolerant (TLS) and non-tolerant (HA) ones were studied in hydroponic experiment for the nitrogen assimilation and plant growth under excess Cu conditions. The results demonstrated that there were surely the differences in nitrogen assimilation and plant growth between the two populations. Excess Cu caused evident decreases in the shoot and root biomass and root/shoot biomass ratio in HA population while no significant changes happened in TLS population. In addition, in HA population, excess Cu also induced apparent declines in activities of nitrate reductase (NR, EC 1.6.6.1) and glutamine synthetase (GS, EC 6.3.1.2) in the leaves and roots as well as the contents of nitrate, ammonium and amino acids in the roots. In TLS population, excess Cu did not significantly affect the NR activities in the leaves and roots and the nitrate content in the roots, and apparently elevated the root ammonium and amino acids contents, although it also clearly reduced the GS activities in the leaves and roots. Besides, with the addition of Cu in the culture solution, the Cu contents in the leaves and roots of the two populations markedly increased. But this increase was significantly lower in TLS population than that in HA population; the fact might be partly responsible for the relative stabilization of nitrogen assimilation in TLS population compared to that in HA population.     

Butterfly dispersal in inhospitable matrix: rare,risky, but long-distance

Metapopulation models typically assume that suitable habitats occupied by local populations and unsuitable matrix separating them form a ‘black-and-white’ landscape mosaic, in which dispersal is primarily determined by the spatial configuration of habitat patches. In reality, however, the matrix composition is also likely to influence dispersal. Using intensive mark-recapture surveys we investigated inter-patch movements in Maculinea (Phengaris) nausithous and M. teleius occurring sympatrically in six metapopulations. Three of these metapopulations had the matrix dominated by forest, an inhospitable environment for grassland butterflies, whereas in the remaining three the matrix was mostly composed of open environments. Dispersal parameters derived with the Virtual Migration model revealed significant differences between both groups of metapopulations. Both species had a lower propensity to emigrate from their natal habitat patches, and they suffered substantially higher dispersal mortality in the metapopulations with forest matrix. On the other hand, mean dispersal distances were roughly an order of magnitude longer in forest matrix as compared with open landscapes (ca. 500–1,500 vs. 100–200 m). Our results suggest that inhospitable forest matrix induces strong selection against dispersal, leading to a reduced emigration rate. At the same time, the selection may promote emigrants with good dispersal abilities, which are able to perform long-distance movements. Thus, while it is generally believed that a matrix structurally similar to the habitat of a species should improve the functional connectivity of habitat patches, our findings imply that this may not necessarily be the case.     

Vitrification of fully grown and growing porcine oocytes using germinal vesicle transfer

The survival rate of vitrified germinal vesicle (GV) stage porcine oocytes is very low, and it is not known if the vitrification damages the nucleus, cytoplasm or both. We have evaluated the eventual GV or cytoplasmic damage in fully grown (FG) and growing vitrified oocytes. Fifty-five percent of nonvitrified FG cumulus-denuded oocytes reached the metaphase II (MII) stage in culture. When growing oocytes from preantral (PA) and early antral (EA) follicles were matured in vitro, almost all oocytes were arrested at the GV stage (GV stage: PA 88.9 and EA 79.5%, respectively). When fresh GVs from FG, PA and EA oocytes were transferred into fresh enucleated FG oocytes and matured in vitro, some of them reached the MII stage (MII stage: FG/FG 57.5%, PA/FG 9.3% and EA/FG 35.3%, respectively). The maturation rate of vitrified FG oocytes was only 6.1% but increased dramatically when vitrified GVs from FG, PA and EA oocytes were transferred into fresh enucleated FG oocytes (MII stage: VitFG/FG 43.9%, VitPA/FG 7.1% and VitEA/FG 26.3%, respectively). These results were not significantly different from those for the nonvitrified groups (MII stage: FG/FG 57.5%, PA/FG 9.3% and EA/FG 35.3%, respectively). We activated the reconstructed oocytes that received fresh or vitrified GVs (FG/FG, EA/FG, VitFG/FG and VitEA/FG) and examined their embryonic development. Cleaved embryos (nonvitrified groups 13.0-61.8%, vitrified groups 33.3-40.0%) and blastocysts (nonvitrified groups 0.0-18.2%, vitrified groups 0.0-2.9%) were obtained after activation. These results demonstrate that vitrified porcine GVs maintain maturational and developmental competence and that vitrification predominantly damages the cytoplasm.     

A spatial assessment of Culicoides spp. distribution and bluetongue disease risk areas in Austria

Bluetongue disease (BT) was introduced into Central Europe in the summer of 2006 and has since affected most European countries. In this study we analysed the distribution of the biting midge vector Culicoides spp. in Austria and modelled Bluetongue disease risk zones. Culicoides spp. abundance data was collected from weekly catches of 14 months from 54 trapping locations. The corresponding weather data mean temperature (p < 0.001), wind (p < 0.001), relative humidity (p = 0.019) and altitude (p = 0.059) were identified as predictors on Culicoides spp. distribution in a regression model (R 2.8.0). The majority of catches were detected at temperatures above 10 degrees C and at relative humidities between 65-80%. The point data of these parameters originating from 186 meteorological stations were interpolated using the Geostatistical Analyst Kriging tool (ESRI ArcGIS 9.3). To create seasonal risk maps we overlaid regions with optimal temperature and humidity conditions with domestic ruminants density data. Our results show that the summer season holds the greatest risk of a BT epidemic with 25.9% of the analysed area providing optimal conditions for vector abundance and 12.4% showing contact risk with ruminant hosts. This project (1) provides fundamental data on the Culicoides spp. distribution in Austria, (2) determines limiting climatic parameters on vector abundance and (3) identifies risk areas by including areas of possible host-parasite-interactions. These high-risk areas can subsequently be given special attention for precautionary monitoring and surveillance measures.     

Bark gnawing of forest trees by voles during the growing season

This study investigated the impact of small rodents on young trees during three growing seasons (2018–2020) in the Czech Republic. Tree damage by small rodents, the quantity and quality of herbaceous plant biomass and the species composition of small mammals were monitored at two sites in European beech forest plantations. The number of trees damaged during three growing seasons correlated positively with fibre content and negatively with nitrogen content in herbaceous plant biomass. The importance of winter precipitation is reflected in the positive correlation with nitrogen content in herbaceous plant biomass. The observed tree-gnawing damage correlated positively with the abundance of one rodent species only—the bank vole. The highest damage occurred after the concurrence of a dry winter and a higher number of voles. Given current climate variability, this situation could become more common in the future. Gnawing may be a limiting factor for the successful restoration of trees with thin bark—in our case, European beech. In addition, the proportion of this woody species should be increased to achieve a more stable and closer composition in the Czech Republic.

     

Beobachtungen über Fett und Aleuron in Erdnuß (Arachis hypogaea) und Walnuß (Juglans regia)

Zusammenfassung Färbung mit Ölrot in 60% Triäthylphosphat und Fluorochromierung mit Nilblausulfat bringt Sphärosomen und Reservefett gleichermaßen zur Darstellung. Letzteres gibt sich nach Färbung oder OsO₄-Dampf-Fixierung in den Kotyledonarzellen vonArachis hypogaea als zusammenhängende Masse zu erkennen, die sich in den Hohlräumen eines plasmatischen Netzes zwischen Stärke- und Aleuronkörnern erstreckt. Diese Aleuronkörner dürften plasmatischen Ursprungs sein und wahrscheinlich durch innere Sekretion des ER (Graham et al. 1962) entstehen. In den Kotyledonen vonJuglans regia ist außerdem eine granuläre oder tröpfchenförmige, stark osmiophile, wahrscheinlich an ungesättigten Fettsäuren reiche, Lipidphase vorhanden.Die Wichtigkeit streng wasserfreier Präparation für die Mikroskopie luft-trockener Gewebe wird hervorgehoben.

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Staining with oilred in 60% triethylphosphate and fluorochroming with Nile blue sulfate exhibits spherosomes and reserve fat in the same way. After staining or OsO₄ vapor fixation the fat in the cotyledonar cells ofArachis hypogaea is to recognise as a coherent mass extending through the cavities of a plasmatic network between starch and aleuron grains. These aleuron grains may be of protoplasmatic origin and probably made by internal secretion of the ER (Graham et al. 1962). In the cotyledons ofJuglans regia there is moreover a granulare or droplike, very osmiophilic lipid phase probably rich in unsaturated fatty acids.The importance of a perfectly water free preparation is emphased for the microscopy of air drough tissues.

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Résumé Coloration par huile-rouge avec 60% triethylphosphate et par le fluorochrome sulfate du Nile-bleu figure également les sphérosomes et les huile grasses. Les dernières représentent par coloration ou fixation avec vaporeux OsO₄ dans les cellules cotyledonaires deArachis hypogaea une matière cohérente qui s'étende à travers les cavités d'un réseau plasmatique parmi les grains d'amidon et d'aleuron. Ces grains d'aleuron sont peut-être d'origine plasmatique et probablements faits par sécrétion interne du ER (Graham et al. 1962). Dans les cotylédons deJuglans regia existe en outre une granulaire ou goutelette, très osmiophilique phase lipide, probablement riche d'acides sébaciques insaturés.L'importance d'une préparation parfaite sans l'eau est mise en évidence pour la microscopie des tissus secs.

     

Anodic TiO₂ nanotube layers electrochemically filled with MoO₃ and their antimicrobial properties

In the present work, the authors produce a Ti surface with a TiO? nanotube coating and investigate the electrochemical filling of these layers with MoO?. The authors demonstrate that using a potential cycling technique, a homogenous MoO? coating can be generated. Controllable and variable coating thicknesses are achieved by a variation of the number of cycles. Thicknesses from a few nanometers to complete filling of the nanotube layers can be obtained. A thermal treatment is used to convert the as-deposited amorphous MoO(x) phases into MoO?. These MoO? loaded nanotube layers were then investigated regarding their antimicrobial properties using strains of Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. The authors found that the combination of crystalline MoO? on TiO? nanotubes shows excellent antimicrobial properties.