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Significant Capacity (significant + capacity)
Selected AbstractsNational-scale metacommunity dynamics of carabid beetles in UK farmlandJOURNAL OF ANIMAL ECOLOGY, Issue 2 2008David R. Brooks Summary 1Understanding the wide-scale processes controlling communities across multiple sites is a foremost challenge of modern ecology. Here, data from a nation-wide network of field sites are used to describe the metacommunity dynamics of arable carabid beetles. This is done by modelling how communities are structured at a local level, by changes in the environment of the sampled fields and, at a regional level, by fitting spatial parameters describing latitudinal and longitudinal gradients. 2Local and regional processes demonstrated independent and significant capacities for structuring communities. Within the local environment, crop type was found to be the primary determinant of carabid community composition. The regional component included a strong response to a longitudinal gradient, with significant increases in diversity in an east-to-west direction. 3Carabid metacommunities seem to be structured by a combination of species sorting dynamics, operating at two different, but equally important, spatial scales. At a local scale, species are sorted along a resource gradient determined by crop type. At a wider spatial scale species appear to be sorted along a longitudinal gradient. 4Nation-wide trends in communities coincided with known gradients of increased homogeneity of habitat mosaics and agricultural intensification. However, more work is required to understand fully how communities are controlled by the interaction of crops with changes in landscape structure at different spatial scales. 5We conclude that crop type is a powerful determinant of carabid biodiversity, but that it cannot be considered in isolation from other components of the landscape for optimal conservation policy. [source] Can America Finance Freedom?FOREIGN POLICY ANALYSIS, Issue 4 2009Assessing U.S. Democracy Promotion via Economic Statecraft Recent discourse on U.S. efforts to promote democracy has focused on military activities; especially the strategic and normative perils of democracy promotion at the point of bayonets. This paper explores the United States' use of economic statecraft to foster democratization, with particular attention to democracy incentive and assistance strategies. Incentive approaches attempt to promote democracy from the top-down, by leveraging aid and trade privileges to persuade authoritarian leaders to implement political reform. Assistance approaches aim to induce democratization from the inside, through funding and technical assistance to state institutions, and from the bottom-up, by providing support to civil society and elections. This study finds that while top-down incentive approaches can stimulate democratic change, this strategy tends to work only when aid and trade benefits are conditional; that is, when benefits are withheld until recipient states meet rigorous democratic benchmarks. Washington has historically eschewed democratic conditionality, however, and thus can claim very few aid-induced or trade-induced democratization events. Scant evidence exists to demonstrate that inside approaches,that is, institutional aid,possesses significant capacity to induce democracy. It is the bottom-up approach,empowering the masses to compel democratic change,that has registered the greatest number of democracy promotion successes. [source] Paleosols in Central Illinois as Potential Sources of Ammonium in GroundwaterGROUND WATER MONITORING & REMEDIATION, Issue 4 2009Justin J. G. Glessner Glacially buried paleosols of pre-Holocene age were evaluated as potential sources for anomalously large concentrations of ammonium in groundwater in East Central Illinois. Ammonium has been detected at concentrations that are problematic to water treatment facilities (greater than 2.0 mg/L) in this region. Paleosols characterized for this study were of Quaternary age, specifically Robein Silt samples. Paleosol samples displayed significant capacity to both store and release ammonium through experiments measuring processes of sorption, ion exchange, and weathering. Bacteria and fungi within paleosols may significantly facilitate the leaching of ammonium into groundwater by the processes of assimilation and mineralization. Bacterial genetic material (DNA) was successfully extracted from the Robein Silt, purified, and amplified by polymerase chain reaction to produce 16S rRNA terminal restriction fragment length polymorphism (TRFLP) community analyses. The Robein Silt was found to have established diverse and viable bacterial communities. 16S rRNA TRFLP comparisons to well-known bacterial species yielded possible matches with facultative chemolithotrophs, cellulose consumers, nitrate reducers, and actinomycetes. It was concluded that the Robein Silt is both a source and reservoir for groundwater ammonium. Therefore, the occurrence of relatively large concentrations of ammonium in groundwater monitoring data may not necessarily be an indication of only anthropogenic contamination. The results of this study, however, need to be placed in a hydrological context to better understand whether paleosols can be a significant source of ammonium to drinking water supplies. [source] Lithium-Ion Batteries: Nanostructured Fe3O4/SWNT Electrode: Binder-Free and High-Rate Li-Ion Anode (Adv. Mater.ADVANCED MATERIALS, Issue 20 201020/2010) A flexible carbon nanotube net is employed to demonstrate high capacity/high volume expansion materials for Li-ion battery electrodes, as presented by A. C. Dillon et al. on page E145. An electrode, with well over twice the capacity of the state-of-the-art technology, charges and discharges in 12 minutes without significant capacity fade. These advancements, funded by the US Department of Energy, Office of Vehicle Technologies Program, will help enable next generation electric vehicles. [source] Temperature Effects on Survival and DNA Repair in Four Freshwater Cladoceran Daphnia Species Exposed to UV RadiationPHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 1 2009Sandra J. Connelly The biological responses of four freshwater daphniid species, Daphnia middendorffiana, D. pulicaria, D. pulex and D. parvula, to a single acute dose of ultraviolet B radiation (UVB) were compared. In addition to survival, we compared the induction of DNA damage (i.e. cyclobutane pyrimidine dimers) between species as well as the ability to repair this damage in the presence or absence of photoreactivating light. All four species showed high levels of shielding against DNA damage when compared to damage induced in purified DNA dosimeters at the same time and dose. Significant variation in survival was observed between species depending on temperature and light conditions. Contrary to our expectations, all species showed significantly higher survival and light-dependent DNA damage removal rates at 10°C compared to 20°C, suggesting that the enhanced rate of photoenzymatic repair (PER) at the lower temperature contributed significantly to the recovery of these organisms from UVB. PER was highly effective in promoting survival of three of the four species at 10°C, but at 20°C it was only partially effective in two species, and ineffective in two others. None of the species showed significant dark repair at 20°C and only D. pulicaria showed a significant capacity at 10°C. Two species, D. middendorffiana and D. pulex, showed some short-term survival at 10°C in absence of PER despite their inability to repair any appreciable amount of DNA damage in the dark. All species died rapidly at 20°C in absence of PER, as predicted from complete or near-absence of nucleotide excision repair (NER). Overall, the protective effects of tissue structure and pigmentation were similar in all Daphnia species tested and greatly mitigated the absorption of UVB by DNA and its damaging effects. Surprisingly, the visibly melanotic D. middendorffiana was not better shielded from DNA damage than the three non-melanotic species, and in fact suffered the highest damage rates. Melanin content in this species was not temperature dependent under the experimental growth conditions, and so did not contribute to temperature-dependent responses. It is evident that different species within the same genus have developed diverse biological responses to UVB. Our data strongly suggest that DNA damage is lethal to Daphnia and that photoenzymatic repair is the primary mechanism for removing these lesions. In the absence of light, few species are capable of removing any DNA damage. Surprisingly, the single species in which significant excision repair was detected did so only at reduced temperature. This temperature-dependence of excision repair is striking and may reflect adaptations of certain organisms to stress in a complex and changing environment. [source] Analysis of the membrane proteome of canine pancreatic rough microsomes identifies a novel Hsp40, termed ERj7PROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 13 2009René P. Zahedi Abstract The rough ER (rER) plays a central role in the biogenesis of most extracellular and many organellar proteins in eukaryotic cells. Cells that are specialized in protein secretion, such as pancreatic cells, are particularly rich in rER. In the process of cell homogenization, the rER is converted into ribosome-studded vesicles, the so-called rough microsomes. Here we report on a membrane proteomic analysis of canine pancreatic rough microsomes. Special emphasis was placed on components involved in the various aspects of protein biogenesis, such as protein transport, protein folding, protein modification, and protein degradation. Our results indicate that the Hsp70-chaperone network that is present in the pancreatic ER is even more complex than previously thought, and suggest that the pancreatic rER has a significant capacity for protein degradation. [source] Bacterial translocation in a non-lethal rat model of peritonitisCOLORECTAL DISEASE, Issue 5 2001V. Yao Background Bacterial translocation from the gut may occur under a variety of different clinical circumstances and has been implicated in the development of multiple organ failure. The aim of this study was to determine the distribution of bacterial translocation occurring in a model of chemically induced peritonitis. We also sought to document the degree of the associated immune and inflammatory response. Methods Though a midline laparotomy, rats were injected with 5 mg of zymosan (in 0.2 ml of saline) into the subomental space. After 4, 18, 24, 48 and 96 h, a number of endpoints evaluated: intraperitoneal cellular influx, TNF-, and interleukin-6 concentrations and myeloperoxidase activity. Bacterial cultures were initiated from the free peritoneal fluid, mesenteric lymph nodes, liver, lung, and kidney. Imprints were also made of the peritoneal mesothelial surface to determine its integrity. Results When comparing rats injected with zymosan with the controls, there was evidence of a peritoneal inflammatory response within 4 hours. Facultative gram negative bacteria were found to be growing in the mesenteric lymph nodes and in the peritoneal fluid at 48 h. Anaerobic organisms were also cultured from the peritoneal fluid at 48 h. No organisms were cultured from the liver, lung or kidneys. In addition there was a significant increase in intraperitoneal cell numbers (predominantly neutrophils, P < 0.05), myeloperoxidase activity (P < 0.05) and TNF-, and IL-6 concentrations (P < 0.05). There was extensive loss of the peritoneal mesothelial cells. The peritoneal inflammatory changes and bacterial translocation had resolved by 96 h. Conclusion Bacterial translocation can be induced by the presence of an acute inflammatory focus in the peritoneal cavity. The translocation and inflammatory changes were associated with extensive loss of mesothelial cells. Nonetheless, these changes all resolved, indicating that the peritoneal cavity has a significant capacity to deal with such insults. A clearer understanding of the cellular and molecular events involved in the resolution phase could lead to improvements in the treatment of peritonotis. [source] | ||||||||||