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31.
Hem Bahadur Katuwal Narendra Man Babu Pradhan Jyotendra Jyu Thakuri Krishna Prasad Bhusal Prakash Chandra Aryal Ishana Thapa 《Proceedings of the Zoological Society》2018,71(2):103-113
Kathmandu Valley, Nepal is undergoing rapid urbanization but its effects on the bird communities have not been reported till date. Kathmandu Valley was categorized into urban, sub-urban and rural to study the impact of urbanization in bird communities. By mobilizing volunteers, we monitored 24 transects each with one km long in summer and winter seasons of 2016. A total of 13,749 individuals of birds belonging to 102 species were recorded. Species richness and diversity of all birds declined from rural to urban areas and showed significant variation along urban–rural gradients. Insectivore was the most species-rich guild while nectarivore the least. The richness of insectivore, frugivore and carnivore guilds showed significant variations along the urban–rural gradients and higher preference towards the rural areas. Similarly, species richness of all birds and richness of insectivore and carnivore guilds showed significant seasonal variation and were higher in the winter season. Our results indicate that richness, diversity and feeding guilds of birds show different response towards the urbanization gradients and seasons. Sub-urban areas can function as bird refugia, however, habitat enrichments (like increasing green spaces, setting up new parks and gardens, plantation of native fruiting trees etc.) are utmost necessary to support the bird communities in urban areas of Kathmandu Valley. 相似文献
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Wai‐Lok Yau Pascale Pescher Andrea MacDonald Sonia Hem Dorothea Zander Silke Retzlaff Thierry Blisnick Brice Rotureau Heidi Rosenqvist Martin Wiese Philippe Bastin Joachim Clos Gerald F. Späth 《Molecular microbiology》2014,93(1):80-97
During its life cycle, the protozoan pathogen Leishmania donovani is exposed to contrasting environments inside insect vector and vertebrate host, to which the parasite must adapt for extra‐ and intracellular survival. Combining null mutant analysis with phosphorylation site‐specific mutagenesis and functional complementation we genetically tested the requirement of the L. donovani chaperone cyclophilin 40 (LdCyP40) for infection. Targeted replacement of LdCyP40 had no effect on parasite viability, axenic amastigote differentiation, and resistance to various forms of environmental stress in culture, suggesting important functional redundancy to other parasite chaperones. However, ultrastructural analyses and video microscopy of cyp40?/? promastigotes uncovered important defects in cell shape, organization of the subpellicular tubulin network and motility at stationary growth phase. More importantly, cyp40?/? parasites were unable to establish intracellular infection in murine macrophages and were eliminated during the first 24 h post infection. Surprisingly, cyp40?/? infectivity was restored in complemented parasites expressing a CyP40 mutant of the unique S274 phosphorylation site. Together our data reveal non‐redundant CyP40 functions in parasite cytoskeletal remodelling relevant for the development of infectious parasites in vitro independent of its phosphorylation status, and provide a framework for the genetic analysis of Leishmania‐specific phosphorylation sites and their role in regulating parasite protein function. 相似文献
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Hem S. Bhandari Dennis W. Walker Joseph H. Bouton Malay C. Saha 《Global Change Biology Bioenergy》2014,6(1):26-34
Switchgrass (Panicum virgatum L.) is a C4 grass with high biomass yield potential and is now a model species for the Bioenergy Feedstock Development Program. Two distinct ecotypes (e.g., upland and lowland) and a range of plant morphotypes (e.g., leafy and stemmy) have been observed in switchgrass. The objective of this study was to determine the influence of ecotype and morphotype on biomass feedstock quality. Leaf and stem tissues of leafy and stemmy morphotypes from both lowland and upland ecotypes were analyzed for key feedstock traits. The leaf : stem ratio of leafy morphotype was more than 40% higher than the stemmy morphotype in both upland and lowland ecotypes. Therefore, the stemmy morphotype has significant advantages over leafy morphotype during harvesting, storage, transportation and finally the feedstock quality. Remarkable differences in feedstock quality and mineral composition were observed in switchgrass genotypes with distinct ecotypic origins and variable plant morphotypes. Lignin, hemicelluloses and cellulose concentrations were higher in stems than in the leaves, while ash content was notably high in leaves. A higher concentration of potassium was found in the stems compared to the leaves. In contrast, calcium was higher and magnesium was generally higher in the leaves compared to stems. The upland genotypes demonstrated considerably higher lignin (14.4%) compared with lowland genotypes (12.4%), while hemicellulose was higher in lowland compared with upland. The stemmy type demonstrated slightly higher lignin compared with leafy types (P < 0.1). Differences between the ecotypes and morphotypes for key quality traits demonstrated the potential for improving feedstock composition of switchgrass through selection in breeding programs. 相似文献
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Morin V Prieto S Melines S Hem S Rossignol M Lorca T Espeut J Morin N Abrieu A 《Current biology : CB》2012,22(4):289-295
Accurate chromosome segregation relies upon a mitotic checkpoint that monitors kinetochore attachment toward opposite spindle poles before enabling chromosome disjunction [1]. The MPS1/TTK protein kinase is a core component of the mitotic checkpoint that lies upstream of MAD2 and BubR1 both at the kinetochore and in the cytoplasm [2, 3]. To gain insight into the mechanisms underlying the regulation of MPS1 kinase, we undertook the identification of Xenopus MPS1 phosphorylation sites by mass spectrometry. We mapped several phosphorylation sites onto MPS1 and we show that phosphorylation of S283 in the noncatalytic region of MPS1 is required for full kinase activity. This phosphorylation potentiates MPS1 catalytic efficiency without impairing its affinity for the substrates. By using Xenopus egg extracts depleted of endogenous MPS1 and reconstituted with single point mutants, we show that phosphorylation of S283 is essential to activate the mitotic checkpoint. This phosphorylation does not regulate the localization of MPS1 to the kinetochore but is required for the recruitment of MAD1/MAD2, demonstrating its role at the kinetochore. Constitutive phosphorylation of S283 lowers the number of kinetochores required to hold the checkpoint, which suggests that CDK-dependent phosphorylation of MPS1 is essential to sustain the mitotic checkpoint when few kinetochores remain unattached. 相似文献
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Background
Minimizing fishery bycatch threats might involve trade-offs between maintaining viable populations and economic benefits. Understanding these trade-offs can help managers reconcile conflicting goals. An example is a set of bycatch reduction measures for the Critically Endangered vaquita porpoise (Phocoena sinus), in the Northern Gulf of California, Mexico. The vaquita is an endemic species threatened with extinction by artisanal net bycatch within its limited range; in this area fisheries are the chief source of economic productivity.Methodology/Principal Findings
We analyze trade-offs between conservation of the vaquita and fisheries, using an end-to-end Atlantis ecosystem model for the Northern Gulf of California. Atlantis is a spatially-explicit model intended as a strategic tool to test alternative management strategies. We simulated increasingly restrictive fisheries regulations contained in the vaquita conservation plan: implementing progressively larger spatial management areas that exclude gillnets, shrimp driftnets and introduce a fishing gear that has no vaquita bycatch. We found that only the most extensive spatial management scenarios recovered the vaquita population above the threshold necessary to downlist the species from Critically Endangered. The scenario that excludes existing net gear from the 2008 area of vaquita distribution led to moderate decrease in net present value (US$ 42 million) relative to the best-performing scenario and a two-fold increase in the abundance of adult vaquita over the course of 30 years.Conclusions/Significance
Extended spatial management resulted in the highest recovery of the vaquita population. The economic cost of proposed management actions was unequally divided between fishing fleets; the loss of value from finfish gillnet fisheries was never recovered. Our analysis shows that managers will have to confront difficult trade-offs between management scenarios for vaquita conservation. 相似文献37.
The effect of antinociceptive doses of oxotremorine on the steady-state level and turnover rate of acetylcholine (ACh) was investigated in male Swiss-Webster mice. Oxotremorine produced dose-related increases in ACh levels which attained statistical significance (p ≥ 95; Dunnett's T) with the ED84 antinociceptive dose in two sacrifice methods. The increased steady-state level of ACh was temporally correlated with the peak antinociceptive effect of oxotremorine. ACh turnover rate decreased with increasing doses of oxotremorine. The ACh turnover rate decreased from 11.06 ± 1.62 nmol/g/min to 5.38 ± 0.71 nmol/g/min by decapitation method and 30.20 ± 1.8 nmol/g/min to 19.99 ± 1.6 nmol/g/min by the microwave irradiation method (Ed84 oxotremorine doses). The decrease in turnover rate of ACh produced by antinociceptive doses of oxotremorine is of a lesser magnitude than that produced by tremorogenic doses (1,2). 相似文献
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Arne H. Eide Hasheem Mannan Mustafa Khogali Gert van Rooy Leslie Swartz Alister Munthali Karl-Gerhard Hem Malcolm MacLachlan Karin Dyrstad 《PloS one》2015,10(5)
There is an increasing awareness among researchers and others that marginalized and vulnerable groups face problems in accessing health care. Access problems in particular in low-income countries may jeopardize the targets set by the United Nations through the Millennium Development Goals. Thus, identifying barriers for individuals with disability in accessing health services is a research priority. The current study aimed at identifying the magnitude of specific barriers, and to estimate the impact of disability on barriers for accessing health care in general. A population based household survey was carried out in Sudan, Namibia, Malawi, and South Africa, including a total of 9307 individuals. The sampling strategy was a two-stage cluster sampling within selected geographical areas in each country. A listing procedure to identify households with disabled members using the Washington Group six screening question was followed by administering household questionnaires in households with and without disabled members, and questionnaires for individuals with and without disability. The study shows that lack of transport, availability of services, inadequate drugs or equipment, and costs, are the four major barriers for access. The study also showed substantial variation in perceived barriers, reflecting largely socio-economic differences between the participating countries. Urbanity, socio-economic status, and severity of activity limitations are important predictors for barriers, while there is no gender difference. It is suggested that education reduces barriers to health services only to the extent that it reduces poverty. Persons with disability face additional and particular barriers to health services. Addressing these barriers requires an approach to health that stresses equity over equality. 相似文献
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Background
Early HIV diagnosis and enrolment in care is needed to achieve early antiretroviral treatment (ART) initiation. Studies on HIV disease stage at enrolment in care from Asian countries are limited. We evaluated trends in and factors associated with late HIV disease presentation over a ten-year period in the largest ART center in Cambodia.Methods
We conducted a retrospective analysis of program data including all ARV-naïve adults (> 18 years old) enrolling into HIV care from March 2003-December 2013 in a non-governmental hospital in Phnom Penh, Cambodia. We calculated the proportion presenting with advanced stage HIV disease (WHO clinical stage IV or CD4 cell count <100 cells/μL) and the probability of ART initiation by six months after enrolment. Factors associated with late presentation were determined using multivariate logistic regression.Results
From 2003–2013, a total of 5642 HIV-infected patients enrolled in HIV care. The proportion of late presenters decreased from 67% in 2003 to 44% in 2009 and 41% in 2013; a temporary increase to 52% occurred in 2011 coinciding with logistical/budgetary constraints at the national program level. Median CD4 counts increased from 32 cells/μL (IQR 11–127) in 2003 to 239 cells/μL (IQR 63–291) in 2013. Older age and male sex were associated with late presentation across the ten-year period. The probability of ART initiation by six months after enrolment increased from 22.6% in 2003–2006 to 79.9% in 2011–2013.Conclusion
Although a gradual improvement was observed over time, a large proportion of patients still enroll late, particularly older or male patients. Interventions to achieve early HIV testing and efficient linkage to care are warranted. 相似文献40.
Mohammad R. Alavi Hem D. Shukla Brent Whitaker Jill Arnold Manoucher Shahamat 《World journal of microbiology & biotechnology》2007,23(1):93-101
Properties of attachment of Mycobacterium marinum to hydrophobic surfaces and subsequent␣biofilm formation were investigated. Binding of M. marinum to polypropylene occured under aerobic and anaerobic/microaerophilic conditions. However, aerobic conditions were necessary
for biofilms to persist. Highly non-polar organic solvents were found to efficiently remove attached bacteria from the polypropylene
surface, indicating strong hydrophobic interactions between the M. marinum cell wall and the surface. Increased capsular material, occurring during stationary phase, correlated with a decrease in
attachment of cells to polypropylene. A protein of approximately 40 kDa appears to be present in increased amounts during
the stationary phase. The protein has been identified by LC MS/MS analysis as alanine dehydrogenase. 相似文献