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991.
Johannes Grunow 《International journal of biometeorology》1963,7(1):35-43
Zusammenfassung Der Carotin-, Chlorophyll a- und b-Gehalt (Pigment) in Gras von Weiden in 600 m Höhe am nördlichen Alpenrand (Südbayern) und der Vitamin A-Gehalt im Milchfett von Kühen im Stall nach Fütterung mit dem Gras wurde bestimmt und mit den Ergebnissen der meteorologischen Beobachtungen verglichen. Die Pigmentbildung in den Pflanzen wurde durch warme strahlungsreiche Witterung gefördert und durch starke TemperaturrückgÄnge und Bodenfröste gehemmt. Sie war ausserdem vom Standort abhÄngig: an S-HÄngen und auf Höhen in strahlungsgünstiger Lage war in sonnigen Perioden der Carotingehalt hoch, in Niederungen mit hÄufiger Nebelbildung, auf schattigen HÄngen und in Tallagen mit Kaltluft tief. In Witterungsperioden mit Bewölkung glich der höhere Anteil der Himmelsstrahlung die Expositionsunterschiede wieder aus. Extrem grosse Licht- und WÄrmeeinwirkungen sommerlicher Hitzeperioden hemmten die Pigmentbildung; der Milch Vitamin A-Gehalt zeigte gleichsinnige Schwankungen.
Carotine, chlorophyll a and b (pigment) in some types of meadow grass (600 m) at the northern rim of the Alps and the vitamin A content in milk from cows in stables fed on this grass was determined and correlated with meteorological data. The pigment formation in the grass was enhanced by radiation-rich warm weather and was impeded by a fall in temperature and ground frosts. The carotine content was high in grass from south slopes and on hills in a favourable position for radiation during sunny periods and low in grass from low sites with cold air.During periods of cloudy weather the greater amount of sky radiation compensated for the smaller amount of exposure in the less favourable sites. Extremely strong effects of light and warmth during summer heat periods inhibited the pigment formation and there was also a similar change in the vitamin A content of the milk.
Résumé La teneur en carotène et en chlorophylle a et b (pigment) de quelques herbes de prairies du nord des Alpes (Bavière) et la teneur en vitamine A du lait des vaches qui en furent nourries en étables ont été comparées à des données méteorologiques. La formation des pigments des herbages était accrue par un temps chaud et ensoleillé et était diminué par les chutes de température et le refroidissement du sol. Le taux de carotène des herbes des pentes exposées au sud et sur les collines était élevé durant les périodes de soleil, et bas dans les fonds de vallées exposées à l'air froid et sur les pentes à l'ombre. Pendant les périodes nuageuses, la plus grande luminosité du ciel compensait les différences dans 1'exposition.La formation de pigments était ralentie en été pendant les périodes de grandes chaleurs et d'irradiation extrèmes. Le contenu du lait en vitamine A montrait des variations dans le mÊme sens.相似文献
992.
Using the Connectivity Map to discover compounds influencing human osteoblast differentiation
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993.
Benedikt Weber Manuel Hora Pamina Kazman Christoph Göbl Carlo Camilloni Bernd Reif Johannes Buchner 《Journal of molecular biology》2018,430(24):4925-4940
The antibody light chain (LC) consists of two domains and is essential for antigen binding in mature immunoglobulins. The two domains are connected by a highly conserved linker that comprises the structurally important Arg108 residue. In antibody light chain (AL) amyloidosis, a severe protein amyloid disease, the LC and its N-terminal variable domain (VL) convert to fibrils deposited in the tissues causing organ failure. Understanding the factors shaping the architecture of the LC is important for basic science, biotechnology and for deciphering the principles that lead to fibril formation. In this study, we examined the structure and properties of LC variants with a mutated or extended linker. We show that under destabilizing conditions, the linker modulates the amyloidogenicity of the LC. The fibril formation propensity of LC linker variants and their susceptibility to proteolysis directly correlate implying an interplay between the two LC domains. Using NMR and residual dipolar coupling-based simulations, we found that the linker residue Arg108 is a key factor regulating the relative orientation of the VL and CL domains, keeping them in a bent and dense, but still flexible conformation. Thus, inter-domain contacts and the relative orientation of VL and CL to each other are of major importance for maintaining the structural integrity of the full-length LC. 相似文献
994.
995.
Suppression of oxidative phosphorylation confers resistance against bevacizumab in experimental glioma
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Jule A. Eriksson Christina Wanka Michael C. Burger Hans Urban Ines Hartel Janusz von Renesse Patrick N. Harter Michel Mittelbronn Joachim P. Steinbach Johannes Rieger 《Journal of neurochemistry》2018,144(4):421-430
996.
The transcription factor prospero homeobox protein 1 is a direct target of SoxC proteins during developmental vertebrate neurogenesis
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997.
998.
Persistent and novel threats to the biodiversity of Kazakhstan’s steppes and semi-deserts 总被引:1,自引:0,他引:1
Johannes Kamp Maxim A. Koshkin Tatyana M. Bragina Todd E. Katzner E. J. Milner-Gulland Dagmar Schreiber Robert Sheldon Alyona Shmalenko Ilya Smelansky Julien Terraube Ruslan Urazaliev 《Biodiversity and Conservation》2016,25(12):2521-2541
Temperate grasslands have suffered disproportionally from conversion to cropland, degradation and fragmentation. A large proportion of the world’s remaining near-natural grassland is situated in Kazakhstan. We aimed to assess current and emerging threats to steppe and semi-desert biodiversity in Kazakhstan and evaluate conservation research priorities. We conducted a horizon-scanning exercise among conservationists from academia and practice. We first compiled a list of 45 potential threats. These were then ranked by the survey participants according to their perceived severity, the need for research on them, and their novelty. The highest-ranked threats were related to changes in land use (leading to habitat loss and deterioration), direct persecution of wildlife, and rapid infrastructure development due to economic and population growth. Research needs were identified largely in the same areas, and the mean scores of threat severity and research need were highly correlated. Novel threats comprised habitat loss by photovoltaic and wind power stations, climate change and changes in agriculture such as the introduction of biofuels. However, novelty was not correlated with threat severity or research priority, suggesting that the most severe threats are the established ones. Important goals towards more effective steppe and semi-desert conservation in Kazakhstan include more cross-sector collaboration (e.g. by involving stakeholders in conservation and agriculture), greater allocation of funds to under-staffed areas (e.g. protected area management), better representativeness and complementarity in the protected area system and enhanced data collection for wildlife monitoring and threat assessments (including the use of citizen-science databases). 相似文献
999.
Thomas K. Lameris Thijs P. M. Fijen Ruslan Urazaliev Genrietta Pulikova Paul F. Donald Johannes Kamp 《Biodiversity and Conservation》2016,25(12):2381-2400
Since the collapse of the Soviet Union in 1991, the abundance and distribution of many central Asian steppe birds have been affected by changes in agricultural land management, such as the abandonment of large areas of cropland and changing grazing patterns. However, the underlying population processes that drive patterns of abundance and distribution are poorly understood. We compared the population ecology of the Black Lark Melanocorypha yeltoniensis on natural steppe and abandoned cropland. Between 2009 and 2013, we used distance sampling to quantify Black Lark population density, monitored 220 nests to assess reproductive performance, and modelled habitat selection at several scales. Arthropod food availability was compared using pitfall traps. Mean population densities were three times higher on abandoned cropland compared to those in steppe, and varied with time since abandonment. Nest survival rates were significantly lower on abandoned cropland compared to steppe, probably due to higher predation pressure. Chick growth rates were also lower on abandoned cropland, despite higher insect availability in this habitat. Habitat selection was strongly influenced by grazing intensity and vegetation structure. We suggest that Black Larks are generally attracted to abandoned cropland because of its suitable vegetation structure and higher food availability. The results of a fecundity model suggested that the number of breeding attempts on abandoned cropland necessary to produce the same number of fledglings as one nesting attempt in steppe habitat was 2.04 in 2011 and 3.62 in 2013. However, a phenological analysis revealed that there were only two peaks in first egg dates, making more than two re-nesting attempts per year unlikely. Therefore, abandoned cropland could, at least in some years, be an ecological trap for the species. Our results illustrate that the effects of land-use change on animal populations should not only be assessed using species densities, but also incorporate detailed demographic analyses. If current densities in steppe habitat corresponded to maximum carrying capacity, overall population densities of Black Larks are likely to decline in the near future as availability of abandoned cropland as nesting habitat is currently decreasing. 相似文献
1000.
Strong and stable geographic differentiation of swamp buffalo maternal and paternal lineages indicates domestication in the China/Indochina border region 总被引:2,自引:0,他引:2
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Yi Zhang Yongfang Lu Marnoch Yindee Kuan‐Yi Li Hsiao‐Yun Kuo Yu‐Ten Ju Shaohui Ye Md Omar Faruque Qiang Li Yachun Wang Vu Chi Cuong Lan Doan Pham Bounthong Bouahom Bingzhuang Yang Xianwei Liang Zhihua Cai Dianne Vankan Wallaya Manatchaiworakul Nonglid Kowlim Somphot Duangchantrasiri Worawidh Wajjwalku Ben Colenbrander Yuan Zhang Peter Beerli Johannes A. Lenstra J. Stuart F. Barker 《Molecular ecology》2016,25(7):1530-1550
The swamp type of the Asian water buffalo is assumed to have been domesticated by about 4000 years BP, following the introduction of rice cultivation. Previous localizations of the domestication site were based on mitochondrial DNA (mtDNA) variation within China, accounting only for the maternal lineage. We carried out a comprehensive sampling of China, Taiwan, Vietnam, Laos, Thailand, Nepal and Bangladesh and sequenced the mtDNA Cytochrome b gene and control region and the Y‐chromosomal ZFY, SRY and DBY sequences. Swamp buffalo has a higher diversity of both maternal and paternal lineages than river buffalo, with also a remarkable contrast between a weak phylogeographic structure of river buffalo and a strong geographic differentiation of swamp buffalo. The highest diversity of the swamp buffalo maternal lineages was found in south China and north Indochina on both banks of the Mekong River, while the highest diversity in paternal lineages was in the China/Indochina border region. We propose that domestication in this region was later followed by introgressive capture of wild cows west of the Mekong. Migration to the north followed the Yangtze valley as well as a more eastern route, but also involved translocations of both cows and bulls over large distances with a minor influence of river buffaloes in recent decades. Bayesian analyses of various migration models also supported domestication in the China/Indochina border region. Coalescence analysis yielded consistent estimates for the expansion of the major swamp buffalo haplogroups with a credibility interval of 900 to 3900 years BP. The spatial differentiation of mtDNA and Y‐chromosomal haplotype distributions indicates a lack of gene flow between established populations that is unprecedented in livestock. 相似文献