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51.
52.
Against a backdrop of increasing climate change, the effects of site conditions, drought events and ozone stress on the size-growth
relationship in Norway spruce (Picea abies [L.] Karst.) and European beech (Fagus sylvatica [L.]) stands are analyzed. The size-growth relationship is represented by a straight line defined by intercept and slope
of a simple linear equation with stem diameter at height 1.30 m as independent variable and annual stem diameter increment
at height 1.30 as dependent variable. On the basis of 64 long-term experimental plots dating back to 1871 and representing
an ecological gradient from fertile to poor sites, it is shown that poorer sites exhibit shallower slopes of the linear size-growth
relationships than fertile sites. Annual measurements of the size-growth relationship, including the extremely dry years of
1976 and 2003, also showed that lower stand growth rates result in shallower size-growth relationship slopes. By comparing
stands with and without experimental twice-ambient ozone exposure between 2000 and 2007, it was found that ozone stress can
significantly reduce the slope of the size-growth relationship. This indicates that limiting site condition, whether acute
or chronic in nature, distinctly reduces the superiority of tall trees, and that a lower degree of resource limitation increases
the steepness of the size-growth relationship. The causes for this behavior and the consequences for stand dynamics, silvicultural
treatment and prognostication by models are discussed. 相似文献
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Food Biophysics - The stabilization of interfaces with mixed emulsifiers composed of natural ingredients is of increasing interest in order to modulate stability of food colloids. To this purpose,... 相似文献
56.
Andreas B. Herrmann Martha-Lena Müller Martin F. Orth Jörg P. Müller Alma Zernecke Andreas Hochhaus Thomas Ernst Elke Butt Jochen J. Frietsch 《Journal of cellular and molecular medicine》2020,24(5):2942-2955
Chronic myeloid leukaemia (CML) is a clonal myeloproliferative stem cell disorder characterized by the constitutively active BCR-ABL tyrosine kinase. The LIM and SH3 domain protein 1 (LASP1) has recently been identified as a novel BCR-ABL substrate and is associated with proliferation, migration, tumorigenesis and chemoresistance in several cancers. Furthermore, LASP1 was shown to bind to the chemokine receptor 4 (CXCR4), thought to be involved in mechanisms of relapse. In order to identify potential LASP1-mediated pathways and related factors that may help to further eradicate minimal residual disease (MRD), the effect of LASP1 on processes involved in progression and maintenance of CML was investigated. The present data indicate that not only overexpression of CXCR4, but also knockout of LASP1 contributes to proliferation, reduced apoptosis and migration as well as increased adhesive potential of K562 CML cells. Furthermore, LASP1 depletion in K562 CML cells leads to decreased cytokine release and reduced NK cell-mediated cytotoxicity towards CML cells. Taken together, these results indicate that in CML, reduced levels of LASP1 alone and in combination with high CXCR4 expression may contribute to TKI resistance. 相似文献
57.
Hai‐Dong Li Linfang Tang Chenxi Jia Marcel Holyoak Jochen Fründ Xiaoqun Huang Zhishu Xiao 《Ecology letters》2020,23(8):1252-1262
Understanding how biodiversity and interaction networks change across environmental gradients is a major challenge in ecology. We integrated metacommunity and metanetwork perspectives to test species’ functional roles in bird–plant frugivory interactions in a fragmented forest landscape in Southwest China, with consequences for seed dispersal. Availability of fruit resources both on and under trees created vertical feeding stratification for frugivorous birds. Bird–plant interactions involving birds feeding only on‐the‐tree or both on and under‐the‐tree (shared) had a higher centrality and contributed more to metanetwork organisation than interactions involving birds feeding only under‐the‐tree. Moreover, bird–plant interactions associated with large‐seeded plants disproportionately contributed to metanetwork organisation and centrality. Consequently, on‐the‐tree and shared birds contributed more to metanetwork organisation whereas under‐the‐tree birds were more involved in local processes. We would expect that species’ roles in the metanetwork will translate into different conservation values for maintaining functioning of seed‐dispersal networks. 相似文献
58.
Martin Pckert Adrien Favre Jan Schnitzler Jochen Martens Yue‐Hua Sun Dieter Thomas Tietze Frank Hailer Ingo Michalak Patrick Strutzenberger 《Ecology and evolution》2020,10(17):9283-9300
Encompassing some of the major hotspots of biodiversity on Earth, large mountain systems have long held the attention of evolutionary biologists. The region of the Qinghai‐Tibet Plateau (QTP) is considered a biogeographic source for multiple colonization events into adjacent areas including the northern Palearctic. The faunal exchange between the QTP and adjacent regions could thus represent a one‐way street (“out of” the QTP). However, immigration into the QTP region has so far received only little attention, despite its potential to shape faunal and floral communities of the QTP. In this study, we investigated centers of origin and dispersal routes between the QTP, its forested margins and adjacent regions for five clades of alpine and montane birds of the passerine superfamily Passeroidea. We performed an ancestral area reconstruction using BioGeoBEARS and inferred a time‐calibrated backbone phylogeny for 279 taxa of Passeroidea. The oldest endemic species of the QTP was dated to the early Miocene (ca. 20 Ma). Several additional QTP endemics evolved in the mid to late Miocene (12–7 Ma). The inferred centers of origin and diversification for some of our target clades matched the “out of Tibet hypothesis’ or the “out of Himalayas hypothesis” for others they matched the “into Tibet hypothesis.” Three radiations included multiple independent Pleistocene colonization events to regions as distant as the Western Palearctic and the Nearctic. We conclude that faunal exchange between the QTP and adjacent regions was bidirectional through time, and the QTP region has thus harbored both centers of diversification and centers of immigration. 相似文献
59.
Federico Lucantoni Manuela Salvucci Heiko Dussmann Jochen H.M. Prehn 《Biochimica et Biophysica Acta (BBA)/Molecular Cell Research》2021,1868(10):119095
BCL2 family proteins are important regulators of mitochondrial outer membrane permeabilization (MOMP). In recent years, BCL2 family proteins have also been linked to the regulation of mitochondrial bioenergetics and dynamics. Given their overexpression in breast cancer cells, we sought to explore whether two key members of this family, BCL2 and BCL(X)L impacted on mitochondrial fusion/fission processes. By employing a single cell imaging and RNA sequencing we found that overexpression of BCL2 or BCL(X)L increases mitochondrial dynamics and alters the expression profile of genes involved in this process. Collectively, our data show that overexpression of BCL2 proteins regulates mitochondrial dynamics in breast cancer tumor cells. 相似文献
60.
Loos Jacqueline Krauss Jochen Lyons Ashley Föst Stephanie Ohlendorf Constanze Racky Severin Röder Marina Hudel Lennart Herfert Volker Tscharntke Teja 《Biodiversity and Conservation》2021,30(8-9):2415-2432
Biodiversity and Conservation - Across Europe, calcareous grasslands become increasingly fragmented and their quality deteriorates through abandonment and land use intensification, both affecting... 相似文献