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131.
Marie M Meyerholz Kirsten Mense Michael Lietzau Ana Kassens Matthias Linden Hendrike Knaack Elisa Wirthgen Andreas Hoeflich Mariam Raliou Christophe Richard Olivier Sandra Hans-Joachim Schuberth Martina Hoedemaker Marion Schmicke 《Journal of veterinary science (Suw?n-si, Korea)》2015,16(4):413-421
This study was conducted to determine if the main components of the somatotropic axis change during the early phase of pregnancy in the maternal blood system and whether differences exist on day 18 after pregnancy recognition by the maternal organism. Blood samples of pregnant heifers (Holstein Friesian; n = 10 after embryo transfer) were obtained on the day of ovulation (day 0), as well as on days 7, 14, 16 and 18 and during pregnant, non-pregnant and negative control cycles. The oncentrations of progesterone (P4), oestrogen, growth hormone (GH), insulin-like growth factor-1 and -2 (IGF1, -2) and IGF-binding protein-2, -3 and -4 (IGFBP2, -3, -4) were measured. The mRNA expressions of growth hormone receptor 1A, IGF1, IGF2, IGFBP2, IGFBP3 and IGFBP4 were detected using RT-qPCR in liver biopsy specimens (day 18). In all groups, total serum IGF1 decreased from day 0 to 16. Notably, IGFBP4 maternal blood concentrations were lower during pregnancy than during non-pregnant cycles and synchronized control cycles. It can be speculated that the lower IGFBP4 in maternal blood may result in an increase of free IGF1 for local action. Further studies regarding IGFBP4 concentration and healthy early pregnancy are warranted. 相似文献
132.
Maike HEPPELMANN Karoline KRACH Lars KRUEGER Philipp BENZ Kathrin HERZOG Marion PIECHOTTA Martina HOEDEMAKER Heinrich BOLLWEIN 《The Journal of reproduction and development》2015,61(6):565-569
The objective of this study was to examine the effects of metritis and subclinical hypocalcemia on reduction
of uterine size in dairy cows using ultrasonography and sonomicrometry. Four piezoelectric crystals were
implanted via laparotomy into the myometrium of the pregnant uterine horn of 12 pluriparous Holstein Friesian
cows 3 weeks before the calculated calving date. Sonometric measurements were conducted daily from 2 days
before parturition (= Day 0) until Day 14 after calving and then every other day until Day 28. Distances
between adjacent crystals were expressed in relation to reference values obtained before calving. The diameter
of the formerly pregnant uterine horn was measured using transrectal B-Mode sonography starting on Day 10.
Cows were retrospectively divided into the following groups: cows without metritis (M–; n = 7), cows with
metritis (M+; n = 5), cows with normocalcemia (SH–; Ca > 2.0 mmol/l on Days 1 to 3; n = 5) and cows with
subclinical hypocalcemia (SH+; Ca < 2.0 mmol/l in at least one sample between Days 1 and 3; n = 7).
Metritis did not affect (P > 0.05) sonometric measurements, but the diameter of the formerly pregnant horn
was larger (P ≤ 0.05) between Days 15 and 21 in M+ cows than in M‒ cows. Reduction in uterine length in
hypocalcemic cows was delayed (P ≤ 0.05) between Days 8 and 21 compared with normocalcemic cows, but the
uterine horn diameter was not related to calcium status. In conclusion, both diseases affected reduction of
uterine size until Day 28. Cows with metritis had a larger uterine diameter, possibly attributable to
accumulation of lochia, and cows with subclinical hypocalcemia had delayed reduction of uterine length,
presumably related to reduction of myometrial contractility. 相似文献
133.
Heathlands are endangered by both atmospheric nutrient deposition and natural succession. High-intensity management measures are considered necessary, as low-intensity measures (e.g. mowing, prescribed burning) are not able to compensate for atmospheric nutrient loads. Choppering (i.e. the near-complete removal of the O-layer) has several advantages over sod-cutting, including less waste material, faster vegetation recovery and lower costs. This raises the question addressed in this study as to the extent to which choppering and sod-cutting affect nutrient budgets in dry heathlands.We compared the quantities of N, Ca, K, Mg, and P removed by choppering and sod-cutting in the Lueneburg Heath (NW Germany). Nutrient balances were calculated by analysing atmospheric inputs, elevated leaching rates following management, and output due to the removal of above-ground biomass and humus horizons.Nutrient loss was particularly high after removal of O- and A-horizons. In contrast, increased leaching after management was of minor importance for nutrient budgets. Although considerably more nutrients were removed by sod-cutting than by choppering (e.g. N: 1712/1008 kg ha−1), nutrient output by choppering was still sufficient to compensate for 60.7 years of net N-input. Choppering was able to remove more N per volume unit than sod-cutting due to higher N-contents in the organic layer than in the A-horizon. For this reason, choppering is more economical than sod-cutting and, thus, should be considered the preferable method at sites not dominated by Molinia caerulea. A combination of high-intensity measures with prescribed burning would appear to be suitable as this would ensure more selective removal of N. 相似文献
134.
Pommet M Redl A Guilbert S Morel MH 《Journal of agricultural and food chemistry》2005,53(10):3943-3949
Wheat gluten structure was modified in different ways: Disulfide bonds were reduced by sulfitolysis, or protein chains were enzymatically hydrolyzed at three different degrees of proteolysis. A kinetic study of the thermal reactivity of the modified glutens showed that gluten aggregation kinetic was slowed in consequence to the shift of gluten size distribution toward smaller proteins. In contrary to sulfitolysis, proteolysis also affected the gluten reactivity potential because of the formation of numerous nonreactive species. Moreover, the thermally induced browning reaction was greatly enhanced by proteolysis, which increased the amount of free amine residues, substrates of the Maillard reaction. On the contrary, a whitening effect was observed for reduced gluten with bisulfite. Proteolysis was also found to decrease plasticized gluten viscosity, to increase gluten-based materials water solubility, and to enhance gluten adhesiveness properties but to reduce its mechanical performance. Sulfitolysis was considered as a possible way of extending gluten processability by extrusion or injection molding, whereas proteolysis was found to confer enhanced gluten stickiness that suggests new potential end uses of gluten in the pressure sensitive adhesives domain. 相似文献
135.
In der Agrarlandschaft der Uckermark wurden auf Schlägen eines viehlos wirtschaftenden Marktfruchtbetriebes und eines Betriebes mit kombinierter Pflanzen‐ und Tierproduktion der Einfluß pflanzen‐ und düngungsspezifischer Wirkungen auf mikrobielle Aktivitäten und Mikroorganismenpopulationen im Boden und im Rhizophärenraum von Kultur‐ und Wildpflanzen untersucht und in Verbindung mit Feldversuchsergebnissen ausgewertet. Die Ergebnisse zeigen, daß Kultur‐ und Wildpflanzen insbesondere im Jugendstadium und zur Hauptvegetation auf unterschieldlichen Böden und bei differenzierter Bewirtschaftung in ihrem Rhizosphärenraum die Mikroflóra und die allgemeinen mikro‐biellen Aktivitäten unterschiedlich beeinflussen können. Beim N‐Umsatz im Boden (Ammonifikation, Nitrifikation) zeichneten sich keine bewirtschaftungsbedingten Unterschiede ab. Die Bedeutung der in der Rhizosphäre angereicherten bzw. durch organische Düngung stimulierten Pseudomonas spp. und Agrobacterium spp. für die Pflanzen wird diskutiert. 相似文献
136.
Verena Riedinger Marion Renner Maj Rundlöf Ingolf Steffan-Dewenter Andrea Holzschuh 《Landscape Ecology》2014,29(3):425-435
Previous studies focused mainly on the provision of ecosystem services by species movements between semi-natural and managed habitats, whereas data on spillover effects between two managed habitats or between habitats that provide target resources in non-overlapping time periods are lacking. We studied densities of three pollinator groups on sunflower fields as a late mass-flowering crop in 16 landscapes that differed in the relative cover of oil-seed rape as an early mass-flowering crop, in the relative cover of sunflowers and in the relative cover of semi-natural habitats. Our aim was to evaluate dynamics between two crops with non-overlapping flowering periods. Densities of bumble bees in late-flowering sunflower fields were enhanced by early-flowering oil-seed rape. Highest bumble bee densities in the late-flowering crop were reached in landscapes that combined high relative covers of oil-seed rape and semi-natural habitats. Further, low relative covers of oil-seed rape in spring led to decreased bumble bee densities in late-flowering sunflower fields in landscapes with high relative covers of sunflower fields (dilution effect), whereas in landscapes with high relative covers of oil-seed rape, no dilution of bumble bees was found. Thus, our results indicate that early mass-flowering crops can mitigate pollinator dilution in crops flowering later in the season. We conclude that the management of landscape-scale patterns of early and late mass-flowering crops together with semi-natural habitats could be used to ensure crop pollination services. Similar processes could also apply for other species groups and may be an important, but so far disregarded, determinant of population densities in agroecosystems. 相似文献
137.
Managing city forests for or in spite of recreation? Perspectives of forest managers 总被引:1,自引:0,他引:1
This paper provides insights into foresters’ perceptions of forest recreation and its management. It is based on qualitative interviews with foresters in Berlin and the region of Stuttgart, Germany (N = 16). The results highlight the lack of strategic planning concerned with recreation management at both locations. Moreover, recreation management seems to depend mostly on the local forester in charge. Foresters’ perceptions of recreation, in turn, appear to be closely linked with how they perceive their work. Three narratives of the foresters’ self-perception are constructed that address three key items: perception of foresters’ skills and tasks, perception of the societal and political context of the foresters’ work and of their own scope of action in this context, and visions for future recreation management. The first narrative emphasises classical forestry and silvicultural aspects; the second understands foresters as multifunctional service providers for communal clients; and the last criticises the classical orientation of forestry and highlights new challenges for foresters in urban areas. These three views of recreation management in urban forests relate to classical forestry culture in different ways: either embodying this culture; differentiating from it; or adopting a new view which challenges this culture. Further research needs are discussed. The paper lastly argues for increased awareness of the importance of the social dimensions of forest management as one of the crucial future challenges for the forestry profession. 相似文献
138.
John Ellis Cheryl Waldner Sheryl Gow Marion Jackson 《Canadian journal of veterinary research》2013,77(3):205-210
Bovine respiratory syncytial virus (BRSV) is a primary agent of pneumonia in calves that causes damage to pulmonary epithelium and results in respiratory distress. This retrospective cumulative analysis of data from 681 calves experimentally infected with BRSV was undertaken to determine if there was an association of both the partial pressure of oxygen in arterial blood (PaO2) and the lactate concentration in arterial blood with lung lesion severity, as well as to estimate the potential predictive value of these 2 parameters in assessing disease progression. The PaO2 was highly significantly associated with the extent of lung lesions and was considered highly predictive of lesion severity. Although the arterial blood lactate concentration was also significantly associated with lung disease, the results were not consistent for all days after challenge. Also, the lactate level was usually within the reference interval. Thus, the usefulness of the arterial blood lactate concentration in predicting the course of BRSV-associated pneumonia is limited in the clinical setting. 相似文献
139.
There is currently, widespread interest in the assessment of ecosystem services, and the new insights that the concept provides in understanding the ecology of landscapes and the science of sustainability. Three major assessment frameworks can be identified in the contemporary literature, namely one based on habitats, one based on the identification of the system elements that delivers the service, and one based on the understanding of places. Although all are useful for supporting decision making in relation to sustainable development, different situations require different perspectives, and so it is important to understand their advantages and drawbacks. Moreover, it is important to determine how they relate to other approaches used, for example, in landscape planning, so that the contribution that ecosystem assessments can make to sustainability debates can be better understood. The aim of this paper is to describe the strengths of the place-based approach because it is more easily overlooked as an assessment option. In particular we will argue that a place-based approach can help us better understand issues of multi-functionality, the valuation of natural capital and the role of landscape in framing debates about ecosystem services and sustainability. An appreciation of these issues will enable researchers interested in landscape to key questions and priorities in relation to questions of sustainability. Although it is useful to consider different assessment perspectives separately, we conclude that in practice, the habitat and systems approaches can form part of a place-based assessment, just as a better understanding of place can enrich assessments that spring from these more natural science approaches. Nevertheless, in designing analytical strategies to take the ecosystem approach forward, we suggest that it is vital to consider these different perspectives in order to build assessments that are relevant, legitimate and credible, and which can effectively address the problems of sustainability that emerge at the landscape scale. 相似文献
140.
Khuda S Slate A Pereira M Al-Taher F Jackson L Diaz-Amigo C Bigley EC Whitaker T Williams K 《Journal of agricultural and food chemistry》2012,60(17):4204-4211
Immunodetection of allergens in dark chocolate is complicated by interference from the chocolate components. The objectives of this study were to establish reference materials for detecting multiple allergens in dark chocolate and to determine the accuracy and precision of allergen detection by enzyme-linked immunosorbent assay (ELISA) before and after chocolate processing. Defatted peanut flour, whole egg powder, and spray-dried milk were added to melted chocolate at seven incurred levels and tempered for 4 h. Allergen concentrations were measured using commercial ELISA kits. Tempering decreased the detection of casein and β-lactoglobulin (BLG), but had no significant effect on the detection of peanut and egg. Total coefficients of variation were higher in tempered than untempered chocolate for casein and BLG, but total and analytical CVs were comparable for peanut and egg. These findings indicate that processing has a greater effect on recovery and variability of casein and BLG than peanut and egg detection in a dark chocolate matrix. 相似文献