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131.
132.
Sybryn L. Maes Michael P. Perring Margot Vanhellemont Leen Depauw Jan Van den Bulcke Guntis Brmelis Jrg Brunet Guillaume Decocq Jan den Ouden Werner Hrdtle Radim Hdl Thilo Heinken Steffi Heinrichs Bogdan Jaroszewicz Martin Kopecký Frantiek Mli Monika Wulf Kris Verheyen 《Global Change Biology》2019,25(1):201-217
Forecasting the growth of tree species to future environmental changes requires a better understanding of its determinants. Tree growth is known to respond to global‐change drivers such as climate change or atmospheric deposition, as well as to local land‐use drivers such as forest management. Yet, large geographical scale studies examining interactive growth responses to multiple global‐change drivers are relatively scarce and rarely consider management effects. Here, we assessed the interactive effects of three global‐change drivers (temperature, precipitation and nitrogen deposition) on individual tree growth of three study species (Quercus robur/petraea, Fagus sylvatica and Fraxinus excelsior). We sampled trees along spatial environmental gradients across Europe and accounted for the effects of management for Quercus. We collected increment cores from 267 trees distributed over 151 plots in 19 forest regions and characterized their neighbouring environment to take into account potentially confounding factors such as tree size, competition, soil conditions and elevation. We demonstrate that growth responds interactively to global‐change drivers, with species‐specific sensitivities to the combined factors. Simultaneously high levels of precipitation and deposition benefited Fraxinus, but negatively affected Quercus’ growth, highlighting species‐specific interactive tree growth responses to combined drivers. For Fagus, a stronger growth response to higher temperatures was found when precipitation was also higher, illustrating the potential negative effects of drought stress under warming for this species. Furthermore, we show that past forest management can modulate the effects of changing temperatures on Quercus’ growth; individuals in plots with a coppicing history showed stronger growth responses to higher temperatures. Overall, our findings highlight how tree growth can be interactively determined by global‐change drivers, and how these growth responses might be modulated by past forest management. By showing future growth changes for scenarios of environmental change, we stress the importance of considering multiple drivers, including past management and their interactions, when predicting tree growth. 相似文献
133.
Keeley L. Zimmerman Armin D. Jamshidi Andreana Buckenberger Richard A. Satterlie 《Invertebrate Biology》2019,138(3)
We used fluorescently labeled phalloidin to examine the subumbrellar musculature of the scyphozoan jellyfish Aurelia aurita in a developmental series from ephyra to adult medusa. In the ephyra, the swim musculature includes a disc‐like sheet of circular muscle, in addition to two radial bands of muscle in each of the eight ephyral arms. The radial muscle bands join with the circular muscle, and both circular and radial muscle act together during each swim contraction. As the ephyra grows into a juvenile medusa, arms tissue is resorbed as the bell tissue grows outward, so eventually, the ephyral arms disappear. During this process, the circular muscle disc also grows outward and the radial muscle bands of the arms also disappear. At this time, a marginal gap appears at the bell margin, which is devoid of circular muscle cells, but has a loose arrangement of radial muscle fibers. This marginal gap is preserved as the medusa grows, and contributes to the floppy nature of the bell margin. Radial distortions in the circular muscle layer involve muscle fibers that run in random directions, with a primarily radial orientation. These are believed to be remnants of the radial muscle of the ephyral arms, and the distortions decrease in number and extent as the medusa grows. Since the mechanics of swimming changes from drag‐based paddling in the ephyra to marginal rowing in the adult medusa, the development of the marginal gap and the presence of radial distortions should be considered in terms of this mechanical transition. 相似文献
134.
The tandem PDZ domains of syntenin promote cell invasion 总被引:1,自引:0,他引:1
Meerschaert K Bruyneel E De Wever O Vanloo B Boucherie C Bracke M Vandekerckhove J Gettemans J 《Experimental cell research》2007,313(9):1790-1804
Syntenin is a tandem PDZ protein that has recently been shown to be overexpressed in several cancer cells and tissues, and that might play an active role in tumor cell invasion and metastasis. Here we show that overexpression of the tandem PDZ domains of syntenin in non-invasive cells is necessary and sufficient to stimulate these cells to invade a collagen I matrix, and this effect can be regulated by ligand binding to the PDZ domains. Furthermore, we show that syntenin-induced invasion requires signaling through ras, rho and PI3K/MAPK signaling pathways and involves changes in cell-cell adhesion. Inversely, when we used RNA interference to inhibit syntenin expression in different invasive cancer cell lines, we observed a drastically decreased ability of these cells to migrate and invade into collagen type I or Matrigel. RNAi-treated cells also show increased cell aggregation, indicating that syntenin is important for cell-cell adhesion in epithelial cells. Together, these results suggest that downregulation of syntenin by RNA interference could provide a means of inhibiting tumor invasion and possibly metastasis in different cancers, and point to syntenin as a potential cancer biomarker and drug target. 相似文献
135.
Proteolytic cleavage of the Chlamydia pneumoniae major outer membrane protein in the absence of Pmp10 总被引:1,自引:0,他引:1
The genome of the obligate intracellular bacteria Chlamydia pneumoniae contains 21 genes encoding polymorphic membrane proteins (Pmp). While no function has yet been attributed to the Pmps, they may be involved in an antigenic variation of the Chlamydia surface. It has previously been demonstrated that Pmp10 is differentially expressed in the C. pneumoniae CWL029 isolate. To evaluate whether the absence of Pmp10 in the outer membrane causes further changes to the C. pneumoniae protein profile, we subcloned the CWL029 isolate and selected a clone with minimal Pmp10 expression. Subsequently, we compared the proteome of the CWL029 isolate with the proteome of the subcloned strain and identified a specific cleavage of the C-terminal part of the major outer membrane protein (MOMP), which occurred only in the absence of Pmp10. In contrast, when Pmp10 was expressed we predominantly observed full-length MOMP. No other proteins appeared to be regulated according to the presence or absence of Pmp10. These results suggest a close association between MOMP and Pmp10, where Pmp10 may protect the C-terminal part of MOMP from proteolytic cleavage. 相似文献
136.
Van Leene J Stals H Eeckhout D Persiau G Van De Slijke E Van Isterdael G De Clercq A Bonnet E Laukens K Remmerie N Henderickx K De Vijlder T Abdelkrim A Pharazyn A Van Onckelen H Inzé D Witters E De Jaeger G 《Molecular & cellular proteomics : MCP》2007,6(7):1226-1238
Defining protein complexes is critical to virtually all aspects of cell biology because many cellular processes are regulated by stable protein complexes, and their identification often provides insights into their function. We describe the development and application of a high throughput tandem affinity purification/mass spectrometry platform for cell suspension cultures to analyze cell cycle-related protein complexes in Arabidopsis thaliana. Elucidation of this protein-protein interaction network is essential to fully understand the functional differences between the highly redundant cyclin-dependent kinase/cyclin modules, which are generally accepted to play a central role in cell cycle control, in all eukaryotes. Cell suspension cultures were chosen because they provide an unlimited supply of protein extracts of actively dividing and undifferentiated cells, which is crucial for a systematic study of the cell cycle interactome in the absence of plant development. Here we report the mapping of a protein interaction network around six known core cell cycle proteins by an integrated approach comprising generic Gateway-based vectors with high cloning flexibility, the fast generation of transgenic suspension cultures, tandem affinity purification adapted for plant cells, matrix-assisted laser desorption ionization tandem mass spectrometry, data analysis, and functional assays. We identified 28 new molecular associations and confirmed 14 previously described interactions. This systemic approach provides new insights into the basic cell cycle control mechanisms and is generally applicable to other pathways in plants. 相似文献
137.
138.
Sylwia Struk Anse Jacobs Elena Snchez Martín‐Fontecha Kris Gevaert Pilar Cubas Sofie Goormachtig 《Plant, cell & environment》2019,42(2):387-409
Protein–protein interactions (PPIs) represent an essential aspect of plant systems biology. Identification of key protein players and their interaction networks provide crucial insights into the regulation of plant developmental processes and into interactions of plants with their environment. Despite the great advance in the methods for the discovery and validation of PPIs, still several challenges remain. First, the PPI networks are usually highly dynamic, and the in vivo interactions are often transient and difficult to detect. Therefore, the properties of the PPIs under study need to be considered to select the most suitable technique, because each has its own advantages and limitations. Second, besides knowledge on the interacting partners of a protein of interest, characteristics of the interaction, such as the spatial or temporal dynamics, are highly important. Hence, multiple approaches have to be combined to obtain a comprehensive view on the PPI network present in a cell. Here, we present the progress in commonly used methods to detect and validate PPIs in plants with a special emphasis on the PPI features assessed in each approach and how they were or can be used for the study of plant interactions with their environment. 相似文献
139.
140.
First Nations status and emergency department triage scores in Alberta: a retrospective cohort study
Patrick McLane Cheryl Barnabe Leslee Mackey Lea Bill Katherine Rittenbach Brian R. Holroyd Anne Bird Bonnie Healy Kris Janvier Eunice Louis Rhonda J. Rosychuk 《CMAJ》2022,194(2):E37
Background:Previous studies have found that race is associated with emergency department triage scores, raising concerns about potential health care inequity. As part of a project on quality of care for First Nations people in Alberta, we sought to understand the relation between First Nations status and triage scores.Methods:We conducted a population-based retrospective cohort study of health administrative data from April 2012 to March 2017 to evaluate acuity of triage scores, categorized as a binary outcome of higher or lower acuity score. We developed multivariable multilevel logistic mixed-effects regression models using the levels of emergency department visit, patient (for patients with multiple visits) and facility. We further evaluated the triage of visits related to 5 disease categories and 5 specific diagnoses to better compare triage outcomes of First Nations and non–First Nations patients.Results:First Nations status was associated with lower odds of receiving higher acuity triage scores (odds ratio [OR] 0.93, 95% confidence interval [CI] 0.92–0.94) compared with non–First Nations patients in adjusted models. First Nations patients had lower odds of acute triage for all 5 disease categories and for 3 of 5 diagnoses, including long bone fractures (OR 0.82, 95% CI 0.76–0.88), acute upper respiratory infection (OR 0.90, 95% CI 0.84–0.98) and anxiety disorder (OR 0.67, 95% CI 0.60–0.74).Interpretation:First Nations status was associated with lower odds of higher acuity triage scores across a number of conditions and diagnoses. This may reflect systemic racism, stereotyping and potentially other factors that affected triage assessments.Health outcomes are markedly worse for First Nations than non–First Nations people. Although this is largely because of inequities in the social determinants of health,1–4 inequities in the provision of health care also exist.5,6 Emergency departments serve as a point of accessible health care. Status First Nations patients make up 4.8% of unique patients and 9.4% of emergency visits in Alberta,7 and Canadian studies describe First Nations patients’ experiences with racism when seeking emergency care.8,9Evaluating triage contributes empirically to understanding the health care of First Nations patients insofar as triage is a quantifiable, intermediate process by which systemic racism10 may influence patient outcomes. The Canadian Triage Acuity Scale11 is a 5-level scale used to classify the severity of patient symptoms. Triage nurses use a brief assessment, medical history, and presenting signs and symptoms to assign each patient a triage score that determines the priority in which the patient should be seen by a provider. Therefore, accurate triage is important for patient health outcomes.12 In practice, triage is a social interaction where local practice, biases, stereotypes and communication barriers come into play. Studies have found that women receive less acute triage scores than men,13,14 and that racial minority13,15–17 and Indigenous18–20 patients receive less acute triage scores than white or non-Indigenous patients. Indeed, Indigenous patients in Canada have described a perception “of social triaging in the [emergency department], whereby decisions about who is seen first seemed to them [to be] based less on triaged clinical priorities but on the social positioning of the patient.”21 Differential triage scores for minority populations raise health equity concerns.As part of a larger mixed-methods project evaluating the quality of emergency care for First Nations people in Alberta, we sought to evaluate quantitative differences in emergency visit characteristics and outcomes of First Nations and non–First Nations people in Alberta. Specifically, we aimed to estimate the relation between First Nations status and acuity of triage, and to evaluate whether predictors of acuity differ by First Nations status. 相似文献