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121.
122.
Phyto-beneficial effects of rhizobacteria specifically Enterobacter species were evaluated on maize seedling health and growth. Out of the 19 isolates examined, two were remarkable in their phosphate solubilization efficiency (PSE > 70%), chitinase enzyme activity (CEA > 85%) and antifungal activity with evidence of no or low disease expression in maize seedling. The selected isolates (OSR7 and IGGR11) were identified and 16S rDNA revealed both isolates as Enterobacter species. Re-evaluation of both isolates ascertains that their combined effects are more effective on maize seedling than their individual effects. Their combinations completely suppressed pathogenic activity of Fusarium verticillioides on maize seedling with evidence of no disease symptoms. Other treatments significantly (p < 0.05) expressed varied maize seedling diseases such as leaf curl and stem rot. Apart from treatment T2 (maize + pathogen), other treatments most especially their combinations significantly (p < 0.05) enhanced seedling height, stem girth, leaf area, nitrogen and potassium contents. The phyto-beneficial effects of these Enterobacter species suggest that they could be employed as bio-inoculant for maize seedling health and growth. 相似文献
123.
Patrice A. Mawa Gyaviira Nkurunungi Moses Egesa Emily L. Webb Steven G. Smith Robert Kizindo Mirriam Akello Swaib A. Lule Moses Muwanga Hazel M. Dockrell Stephen Cose Alison M. Elliott 《Philosophical transactions of the Royal Society of London. Series B, Biological sciences》2015,370(1671)
Bacille Calmette–Guérin (BCG) immunization provides variable protection against tuberculosis. Prenatal antigen exposure may have lifelong effects on responses to related antigens and pathogens. We therefore hypothesized that maternal latent Mycobacterium tuberculosis infection (LTBI) influences infant responses to BCG immunization at birth. We measured antibody (n = 53) and cellular (n = 31) responses to M. tuberculosis purified protein derivative (PPD) in infants of mothers with and without LTBI, in cord blood and at one and six weeks after BCG. The concentrations of PPD-specific antibodies declined between birth (median [interquartile range (IQR)]) 5600 ng ml−1 [3300–11 050] in cord blood) and six weeks (0.00 ng ml−1 [0–288]). Frequencies of PPD-specific IFN-γ-expressing CD4+T cells increased at one week and declined between one and six weeks (p = 0.031). Frequencies of IL-2- and TNF-α-expressing PPD-specific CD4+T cells increased between one and six weeks (p = 0.019, p = 0.009, respectively). At one week, the frequency of PPD-specific CD4+T cells expressing any of the three cytokines, combined, was lower among infants of mothers with LTBI, in crude analyses (p = 0.002) and after adjusting for confounders (mean difference, 95% CI −0.041% (−0.082, −0.001)). In conclusion, maternal LTBI was associated with lower infant anti-mycobacterial T-cell responses immediately following BCG immunization. These findings are being explored further in a larger study. 相似文献
124.
Liver sinusoid on a chip: Long‐term layered co‐culture of primary rat hepatocytes and endothelial cells in microfluidic platforms
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125.
Documented information on the ecology of larval habitats in Botswana is lacking but is critical for larval control programs. Therefore, this study determined the characteristics of these habitats and the influences of biotic and abiotic factors in Tubu village, Botswana. Eight water bodies were sampled between January and December, 2013. The aquatic vegetation and invertebrate species present were characterized. Water parameters measured were turbidity (NTU), conductivity (μS/cm), oxygen (mg/l), and pH. Larval densities of Anopheles arabiensis mosquitoes and their correlation with abiotic factors were determined. Larval breeding was associated with ‘short’ aquatic vegetation, a variety of habitats fed by both rainfall and flood waters and sites with predators and competitors. The monthly mean (± SEmean) larval density was 8.16±1.33. The monthly mean (±SEmean) pH, conductivity, oxygen, and turbidity were 7.65±0.13, 1152.834±69.171, 5.59±1.33, and 323.421±33.801, respectively. There was a significant negative correlation between larval density and conductivity (r = ‐0.839; p < 0.01), while a significant positive correlation occurred between turbidity and larval density (r = 0.685; p < 0.05). Oxygen (r = 0.140; p > 0.05) and pH (r = 0.252; p > 0.05) were not correlated with larval density. Floods and diversified breeding sites contributed to prolonged and prolific larval breeding. ‘Short’ aquatic vegetation and predator‐infested waters offered suitable environments for larval breeding. Turbidity and conductivity were good indicators for potential breeding places and can be used as early warning indices for predicting larval production levels. 相似文献
126.
白马雪山国家级自然保护区典型森林生态系统服务 总被引:1,自引:0,他引:1
生态系统服务是近年来生态学研究的热点领域,对关键区域生态系统服务的研究具有重要意义.云南省白马雪山国家级自然保护区地处青藏高原南延部分,拥有独特的地理位置,是生物多样性保护的热点区域.本文对该保护区森林生态系统的生物量与生产力、水源涵养、营养物质循环等3项服务的功能量进行了评估.结果表明:保护区森林总生物量2215.86×104t,生产力171.84×104t·a-1;水源涵养量11964.56×104m3;N、P、K年吸收量分别为26025.94t、2638.57t、12016.85 t.研究表明,保护区森林生态效益显著,对于维持当地以及周边地区的生态安全具有重要意义. 相似文献
127.
128.
Yu T Calvo L Anta B López-Benito S Southon E Chao MV Tessarollo L Arévalo JC 《Traffic (Copenhagen, Denmark)》2011,12(4):521-534
Upon activation by nerve growth factor (NGF), TrkA is internalized, trafficked and sorted through different endosomal compartments. Proper TrkA trafficking and sorting are crucial events as alteration of these processes hinders NGF-mediated functions. However, it is not fully known which proteins are involved in the trafficking and sorting of TrkA. Here we report that Nedd4-2 regulates the trafficking of TrkA and NGF functions in sensory neurons. Depletion of Nedd4-2 disrupts the correct sorting of activated TrkA at the early and late endosome stages, resulting in an accumulation of TrkA in these compartments and, as a result of the reduced trafficking to the degradative pathway, TrkA is either reverted to the cell surface through the recycling pathway or retrogradely transported to the cell body. In addition, Nedd4-2 depletion enhances TrkA signaling and the survival of NGF-dependent dorsal root ganglion neurons, but not those of brain-derived neurotrophic factor-dependent neurons. Furthermore, neurons from a knock-in mouse expressing a TrkA mutant that does not bind Nedd4-2 protein exhibit increased NGF-mediated signaling and cell survival. Our data indicate that TrkA trafficking and sorting are regulated by Nedd4-2 protein. 相似文献
129.
Chen DS Barry AE Leliwa-Sytek A Smith TA Peterson I Brown SM Migot-Nabias F Deloron P Kortok MM Marsh K Daily JP Ndiaye D Sarr O Mboup S Day KP 《PloS one》2011,6(2):e16629
Background
The reservoir of Plasmodium infection in humans has traditionally been defined by blood slide positivity. This study was designed to characterize the local reservoir of infection in relation to the diverse var genes that encode the major surface antigen of Plasmodium falciparum blood stages and underlie the parasite''s ability to establish chronic infection and transmit from human to mosquito.Methodology/Principal Findings
We investigated the molecular epidemiology of the var multigene family at local sites in Gabon, Senegal and Kenya which differ in parasite prevalence and transmission intensity. 1839 distinct var gene types were defined by sequencing DBLα domains in the three sites. Only 76 (4.1%) var types were found in more than one population indicating spatial heterogeneity in var types across the African continent. The majority of var types appeared only once in the population sample. Non-parametric statistical estimators predict in each population at minimum five to seven thousand distinct var types. Similar diversity of var types was seen in sites with different parasite prevalences.Conclusions/Significance
Var population genomics provides new insights into the epidemiology of P. falciparum in Africa where malaria has never been conquered. In particular, we have described the extensive reservoir of infection in local African sites and discovered a unique var population structure that can facilitate superinfection through minimal overlap in var repertoires among parasite genomes. Our findings show that var typing as a molecular surveillance system defines the extent of genetic complexity in the reservoir of infection to complement measures of malaria prevalence. The observed small scale spatial diversity of var genes suggests that var genetics could greatly inform current malaria mapping approaches and predict complex malaria population dynamics due to the import of var types to areas where no widespread pre-existing immunity in the population exists. 相似文献130.
Roess AA Monroe BP Kinzoni EA Gallagher S Ibata SR Badinga N Molouania TM Mabola FS Mombouli JV Carroll DS MacNeil A Benzekri NA Moses C Damon IK Reynolds MG 《PLoS neglected tropical diseases》2011,5(10):e1356