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91.
Justin M. Gaudon Laurel J. Haavik Chris J. K. MacQuarrie Sandy M. Smith Jeremy D. Allison 《Journal of Insect Behavior》2016,29(3):301-314
Sirex noctilio F. (Hymenoptera: Siricidae) is a woodwasp of pine trees that has recently invaded and established in North American forests. Although S. noctilio has had a limited impact in North America to date, there is some concern that it could have a significant impact on pine plantations, especially in the southeastern U.S.A. Moreover, there are few data on the flight capacity of male S. noctilio. We found no association between parasitism by D. siricidicola and whether or not S. noctilio initiated flight on the flight mill. Male wasps that were parasitized by nematodes were heavier than non-parasitized males, but there was no significant difference in mass between parasitized and non-parasitized females. We also examined the flight capacity of male and female S. noctilio in relation to nematode parasitism, body mass, temperature (for only males), and diel period. Body mass, temperature, and diel period affected flight in S. noctilio such that wasps were generally observed to fly faster, farther, and more frequently if they were heavier, flying at warmer temperatures, and flying during the photoperiod. The fact that nematode-parasitized male wasps were found to fly farther than the non-parasitized males is consistent with the hypothesis that nematode parasitism does not negatively affect the flight capacity of S. noctilio. 相似文献
92.
Thomas J. Lisney Karyn Stecyk Jeffrey Kolominsky Brian K. Schmidt Jeremy R. Corfield Andrew N. Iwaniuk Douglas R. Wylie 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》2013,199(5):385-402
Despite the large body of literature on ecomorphological adaptations to foraging in waterfowl, little attention has been paid to their sensory systems, especially vision. Here, we compare eye shape and retinal topography across 12 species representing 4 different foraging modes. Eye shape was significantly different among foraging modes, with diving and pursuit-diving species having relatively smaller corneal diameters compared to non-diving species. This may be associated with differences in ambient light intensity while foraging or an ability to tightly constrict the pupil in divers in order to facilitate underwater vision. Retinal topography was similar across all species, consisting of an oblique visual streak, a central area of peak cell density, and no discernible fovea. Because the bill faces downwards when the head is held in the normal posture in waterfowl, the visual streak will be held horizontally, allowing the horizon to be sampled with higher visual acuity. Estimates of spatial resolving power were similar among species with only the Canada goose having a higher spatial resolution. Overall, we found no evidence of ecomorphological adaptations to different foraging modes in the retinal ganglion cell layer in waterfowl. Rather, retinal topography in these birds seems to reflect the ‘openness’ of their habitats. 相似文献
93.
Dan M. Berger Nancy Torres Minu Dutia Dennis Powell Greg Ciszewski Ariamala Gopalsamy Jeremy I. Levin Kyung-Hee Kim Weixin Xu James Wilhelm YongBo Hu Karen Collins Larry Feldberg Steven Kim Eileen Frommer Donald Wojciechowicz Robert Mallon 《Bioorganic & medicinal chemistry letters》2009,19(23):6519-6523
As part of our research effort to discover B-Raf kinase inhibitors, we prepared a series of C-3 substituted N-(3-(pyrazolo[1,5-a]pyrimidin-7-yl)phenyl)-3-(trifluoromethyl)benzamides. X-ray crystallography studies revealed that one of the more potent inhibitors (10n) bound to B-Raf kinase without forming a hinge-binding hydrogen bond. With basic amine residues appended to C-3 aryl residues, cellular activity and solubility were enhanced over previously described compounds of this class. 相似文献
94.
Timothy M. Smith Jeremy S. Hindell Greg P. Jenkins Rod M. Connolly 《The Journal of animal ecology》2010,79(1):275-281
1. Patch area and proximity of patch edge can influence ecological processes across patchy landscapes and may interact with each other. Different patch sizes have different amounts of core habitat, potentially affecting animal abundances at the edge and middle of patches. In this study, we tested if edge effects varied with patch size.
2. Fish were sampled in 10 various-sized seagrass patches (114–5934 m2 ) using a small (0·5 m2 ) push net in three positions within each patch: the seagrass edge, 2 m into a patch and in the middle of a patch.
3. The two most common species showed an interaction between patch size and the edge–interior difference in abundance. In the smallest patches, pipefish ( Stigmatopora nigra ) were at similar densities at the edge and interior, but with increasing patch size, the density at the edge habitat increased. For gobies ( Nesogobius maccullochi ), the pattern was exactly the opposite.
4. This is the first example from a marine system of how patch size can influence the magnitude and pattern of edge effects.
5. Both patch area and edge effects need to be considered in the development of conservation and management strategies for seagrass habitats. 相似文献
2. Fish were sampled in 10 various-sized seagrass patches (114–5934 m
3. The two most common species showed an interaction between patch size and the edge–interior difference in abundance. In the smallest patches, pipefish ( Stigmatopora nigra ) were at similar densities at the edge and interior, but with increasing patch size, the density at the edge habitat increased. For gobies ( Nesogobius maccullochi ), the pattern was exactly the opposite.
4. This is the first example from a marine system of how patch size can influence the magnitude and pattern of edge effects.
5. Both patch area and edge effects need to be considered in the development of conservation and management strategies for seagrass habitats. 相似文献
95.
Differential Mechanisms of Shedding of the Glycosylphosphatidylinositol (GPI)-anchored NKG2D Ligands 总被引:1,自引:0,他引:1
Lola Fern��ndez-Messina Omodele Ashiru Philippe Boutet Sonia Ag��era-Gonz��lez Jeremy N. Skepper Hugh T. Reyburn Mar Val��s-G��mez 《The Journal of biological chemistry》2010,285(12):8543-8551
Tumor cells release NKG2D ligands to evade NKG2D-mediated immune surveillance. The purpose of our investigation was to explore the cellular mechanisms of release used by various members of the ULBP family. Using biochemical and cellular approaches in both transfectant systems and tumor cell lines, this paper shows that ULBP1, ULBP2, and ULBP3 are released from cells with different kinetics and by distinct mechanisms. Whereas ULBP2 is mainly shed by metalloproteases, ULBP3 is abundantly released as part of membrane vesicles known as exosomes. Interestingly, exosomal ULBP3 protein is much more potent for down-modulation of the NKG2D receptor than soluble ULBP2 protein. This is the first report showing functionally relevant differences in the biochemistry of the three members of the ULBP family and confirms that in depth study of the biochemical features of individual NKG2D ligands will be necessary to understand and manipulate the biology of these proteins for therapy. 相似文献
96.
Newman SL Gootee L Hilty J Morris RE 《Journal of immunology (Baltimore, Md. : 1950)》2006,176(3):1806-1813
Histoplasma capsulatum (Hc) is a facultative intracellular fungus that modulates the intraphagosomal environment to survive within macrophages (Mphi). In the present study, we sought to quantify the intraphagosomal pH under conditions in which Hc yeasts replicated or were killed. Human Mphi that had ingested both viable and heat-killed or fixed yeasts maintained an intraphagosomal pH of approximately 6.4-6.5 over a period of several hours. These results were obtained using a fluorescent ratio technique and by electron microscopy using the 3-(2,4-dinitroanilo)-3'-amino-N-methyldipropylamine reagent. Mphi that had ingested Saccharomyces cerevisae, a nonpathogenic yeast that is rapidly killed and degraded by Mphi, also maintained an intraphagosomal pH of approximately 6.5 over a period of several hours. Stimulation of human Mphi fungicidal activity by coculture with chloroquine or by adherence to type 1 collagen matrices was not reversed by bafilomycin, an inhibitor of the vacuolar ATPase. Human Mphi cultured in the presence of bafilomycin also completely degraded heat-killed Hc yeasts, whereas mouse peritoneal Mphi digestion of yeasts was completely reversed in the presence of bafilomycin. However, bafilomycin did not inhibit mouse Mphi fungistatic activity induced by IFN-gamma. Thus, human Mphi do not require phagosomal acidification to kill and degrade Hc yeasts, whereas mouse Mphi do require acidification for fungicidal but not fungistatic activity. 相似文献
97.
To characterize the repair pathways of chromosome double-strand breaks (DSBs), one approach involves monitoring the repair of site-specific DSBs generated by rare-cutting endonucleases, such as I-SceI. Using this method, we first describe the roles of Ercc1, Msh2, Nbs1, Xrcc4, and Brca1 in a set of distinct repair events. Subsequently, we considered that the outcome of such assays could be influenced by the persistent nature of I-SceI-induced DSBs, in that end-joining (EJ) products that restore the I-SceI site are prone to repeated cutting. To address this aspect of repair, we modified I-SceI-induced DSBs by co-expressing I-SceI with a non-processive 3′ exonuclease, Trex2, which we predicted would cause partial degradation of I-SceI 3′ overhangs. We find that Trex2 expression facilitates the formation of I-SceI-resistant EJ products, which reduces the potential for repeated cutting by I-SceI and, hence, limits the persistence of I-SceI-induced DSBs. Using this approach, we find that Trex2 expression causes a significant reduction in the frequency of repair pathways that result in substantial deletion mutations: EJ between distal ends of two tandem DSBs, single-strand annealing, and alternative-NHEJ. In contrast, Trex2 expression does not inhibit homology-directed repair. These results indicate that limiting the persistence of a DSB causes a reduction in the frequency of repair pathways that lead to significant genetic loss. Furthermore, we find that individual genetic factors play distinct roles during repair of non-cohesive DSB ends that are generated via co-expression of I-SceI with Trex2. 相似文献
98.
Inuit in Canada’s Arctic conceptualize both human hunters and their polar bear prey as active participants in the hunt and
as part of a larger socio-economic system requiring the involvement of both humans and animals. Although often treated through
the lens of common-pool resource theory, the Inuit viewpoint conflicts with Western wildlife management systems that typically
treat animals, and nature in general, as passive. When polar bears are understood as active participants in the hunt, the
rights associated with common property regimes and assumptions about collective-choice decisions in common-pool resource management
require significant revision. In this paper we argue that common-pool resource theories which assume natural resources are
inherently passive cannot adequately account for the system of active relationships operating among Inuit in Arctic Canada.
The co-management system of Nunavut Territory, Canada, uses a flexible quota approach, which, while following conservation
guidelines, allows some space for the traditional Inuit-polar bear system to operate. This example shows how common-pool resources
may be managed sustainably without the attendant assumption that natural resources exist passively outside of common-pool
resource regimes. 相似文献
99.
100.
Aaron E. Carnes Jeremy M. Luke Justin M. Vincent Angela Schukar Sheryl Anderson Clague P. Hodgson James A. Williams 《Biotechnology and bioengineering》2011,108(2):354-363
Industrial plasmid DNA manufacturing processes are needed to meet the quality, economy, and scale requirements projected for future commercial products. We report development of a modified plasmid fermentation copy number induction profile that increases gene vaccination/therapy vector yields up to 2,600 mg/L. We determined that, in contrast to recombinant protein production, secretion of the metabolic byproduct acetate into the media had only a minor negative effect on plasmid replication. We also investigated the impact of differences in epigenetic dcm methylase‐directed cytosine methylation on plasmid production, transgene expression, and immunogenicity. While Escherichia coli plasmid production yield and quality are unaffected, dcm− versions of CMV and CMV‐HTLV‐I R promoter plasmids had increased transgene expression in human cells. Surprisingly, despite improved expression, dcm− plasmid is less immunogenic. Our results demonstrate that it is critical to lock the plasmid methylation pattern (i.e., production strain) early in product development and that dcm− strains may be superior for gene therapy applications wherein reduced immunogenicity is desirable and for in vitro transient transfection applications such as AAV production where improved expression is beneficial. Biotechnol. Bioeng. 2011;108: 354–363. © 2010 Wiley Periodicals, Inc. 相似文献