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991.
992.
Attempts to arrest seagrass loss through numerous rehabilitation methods have traditionally produced inconsistent results. On Australia's southern coast, hessian bags made from biodegradable jute fibers show promise for rehabilitating Amphibolis antarctica by facilitating recruitment of seedlings in situ. Testing ways to improve the performance of bags (i.e. increasing seagrass recruitment and establishment) showed that bags with a coarse outer weave of hessian facilitated greater seedling densities (approximately 1700 individuals/m2) than bags with a fine outer weave, but the content of bags (sand vs. sand and rubble mixture) had little effect. Isolated bags facilitated greater longer term densities than bags grouped together, while similar densities were sampled up to 80 m away from a natural meadow. Lastly, bags that had spent less time in situ initially facilitated more recruits than older bags, but longer term (21–32 months) retention was similar among bag ages. Collectively, the results suggest hessian bags can be a relatively simple, cost‐effective, and environmentally friendly method for rehabilitating Amphibolis seagrass, with few considerations in their use other than their physical architecture and arrangement (e.g. isolated coarse‐weave bags). 相似文献
993.
Jared L. Delahaye Olivia K. Foster Annalise Vine Daniel S. Saxton Thomas P. Curtin Hannah Somhegyi Rebecca Salesky Greg J. Hermann 《Molecular biology of the cell》2014,25(7):1073-1096
As early endosomes mature, the SAND-1/CCZ-1 complex acts as a guanine nucleotide exchange factor (GEF) for RAB-7 to promote the activity of its effector, HOPS, which facilitates late endosome–lysosome fusion and the consumption of AP-3–containing vesicles. We show that CCZ-1 and the HOPS complex are essential for the biogenesis of gut granules, cell type–specific, lysosome-related organelles (LROs) that coexist with conventional lysosomes in Caenorhabditis elegans intestinal cells. The HOPS subunit VPS-18 promotes the trafficking of gut granule proteins away from lysosomes and functions downstream of or in parallel to the AP-3 adaptor. CCZ-1 also acts independently of AP-3, and ccz-1 mutants mistraffic gut granule proteins. Our results indicate that SAND-1 does not participate in the formation of gut granules. In the absence of RAB-7 activity, gut granules are generated; however, their size and protein composition are subtly altered. These observations suggest that CCZ-1 acts in partnership with a protein other than SAND-1 as a GEF for an alternate Rab to promote gut granule biogenesis. Point mutations in GLO-1, a Rab32/38-related protein, predicted to increase spontaneous guanine nucleotide exchange, specifically suppress the loss of gut granules by ccz-1 and glo-3 mutants. GLO-3 is known to be required for gut granule formation and has homology to SAND-1/Mon1–related proteins, suggesting that CCZ-1 functions with GLO-3 upstream of the GLO-1 Rab, possibly as a GLO-1 GEF. These results support LRO formation occurring via processes similar to conventional lysosome biogenesis, albeit with key molecular differences. 相似文献
994.
Amit K Mittal Nagendra K Chaturvedi Karan J Rai Christine E Gilling-Cutucache Tara M Nordgren Margaret Moragues Runqing Lu Rene Opavsky Greg R Bociek Dennis D Weisenburger Javeed Iqbal Shantaram S Joshi 《Molecular medicine (Cambridge, Mass.)》2014,20(1):290-301
Chronic lymphocytic leukemia (CLL) cells survive longer in vivo than in vitro, suggesting that the tissue microenvironment provides prosurvival signals to tumor cells. Primary and secondary lymphoid tissues are involved in the pathogenesis of CLL, and the role of these tissue microenvironments has not been explored completely. To elucidate host–tumor interactions, we performed gene expression profiling (GEP) of purified CLL cells from peripheral blood (PB; n = 20), bone marrow (BM; n = 18), and lymph node (LN; n = 15) and validated key pathway genes by real-time polymerase chain reaction, immunohistochemistry and/or TCL1 trans-genic mice. Gene signatures representing several pathways critical for survival and activation of B cells were altered in CLL cells from different tissue compartments. Molecules associated with the B-cell receptor (BCR), B cell–activating factor/a proliferation-inducing ligand (BAFF/APRIL), nuclear factor (NF)-κB pathway and immune suppression signature were enriched in LN-CLL, suggesting LNs as the primary site for tumor growth. Immune suppression genes may help LN-CLL cells to modulate antigen-presenting and T-cell behavior to suppress antitumor activity. PB CLL cells overexpressed chemokine receptors, and their cognate ligands were enriched in LN and BM, suggesting that a chemokine gradient instructs B cells to migrate toward LN or BM. Of several chemokine ligands, the expression of CCL3 was associated with poor prognostic factors. The BM gene signature was enriched with antiapoptotic, cytoskeleton and adhesion molecules. Interestingly, PB cells from lymphadenopathy patients shared GEP with LN cells. In Eμ-TCL1 transgenic mice (the mouse model of the disease), a high percentage of leukemic cells from the lymphoid compartment express key BCR and NF-κB molecules. Together, our findings demonstrate that the lymphoid microenvironment promotes survival, proliferation and progression of CLL cells via chronic activation of BCR, BAFF/APRIL and NF-κB activation while suppressing the immune response. 相似文献
995.
996.
Ian A. N. Stringer G. Richard Parrish Greg H. Sherley Darryl I. MacKenzie 《Molluscan research.》2014,34(3):155-175
The large land snail Placostylus ambagiosus (Pulmonata: Bulimulidae) was studied in northernmost New Zealand from 1988 to 2004. At Cape Maria van Diemen (CMvD), more juveniles than adults were found, although estimates showed adults as the most abundant. A cohort, hatched after rodent control commenced in 1990, began maturing in 1995, but 89% died by 1997 (partly through competition with garden snails, Cornu aspersum), before numbers partially recovered by 2003. At Surville Cliffs, adults were estimated to be more abundant than juveniles but few juveniles were observed. Numbers under 12 food plants fluctuated between 425 and 657. Many snails dispersed after horses (Equus caballus) partially defoliated their food plants but returned once these recovered. A translocated population increased after rodent control commenced in 1999, but declined when rodent control ceased in 2002. Another translocated population declined when rodents were present and never recovered even after rodent control commenced in 2002. Snails took 2.8–11.7 years to mature from half-grown juveniles depending on location. Estimated adult life expectancies were 5.2 years at CMvD and 10.0 years at Surville Cliffs. Small juvenile snails experienced the highest mortality, and snails that moved between food plants experienced increased mortality. These results are discussed in relation to conservation management. 相似文献
997.
998.
999.
Milka P. Podder Laura Rogers Peter K. Daley Greg P. Keefe Hugh G. Whitney Kapil Tahlan 《PloS one》2014,9(9)
Klebsiella spp. is a common cause of bovine mastitis, but information regarding its molecular epidemiology is lacking from many parts of the world. On using mass spectrometry and partial sequencing of the rpoB gene, it was found that over a one year study, K. variicola and Enterobacter cloacae were misidentified as K. pneumoniae in a small number of clinical mastitis (CM) cases from Newfoundland. Results suggest that the currently used standard biochemical/phenotypic tests lack the sensitivity required to accurately discriminate among the three mentioned Gram negative bacteria. In addition, a single strain of K. variicola was associated with CM from one farm in the study as demonstrated by Random Amplified Polymorphic DNA (RAPD) PCR. To the best of our knowledge, K. variicola, which is normally found in the environment, has not been isolated previously from milk obtained from cows with CM. Therefore, it is possible that K. variicola was not detected in milk samples in the past due to the inability of standard tests to discriminate it from other Klebsiella species. 相似文献
1000.
Jaime L. Taylor Greg D. Zimet Kelly L. Donahue Andreia B. Alexander Marcia L. Shew Nathan W. Stupiansky 《PloS one》2014,9(12)