483 research outputs found

    Efficacy of rifampicin combination therapy for the treatment of enterococcal infections assessed in vivo using a Galleria mellonella infection model.

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    Enterococci are a leading cause of healthcare-associated infection worldwide and display increasing levels of resistance to many of the commonly used antimicrobials, making treatment of their infections challenging. Combinations of antibiotics are occasionally employed to treat serious infections, allowing for the possibility of synergistic killing. The aim of this study was to evaluate the effects of different antibacterial combinations against enterococcal isolates using an in vitro approach and an in vivo Galleria mellonella infection model. Five Enterococcus faecalis and three Enterococcus faecium strains were screened by paired combinations of rifampicin, tigecycline, linezolid or vancomycin using the chequerboard dilution method. Antibacterial combinations that displayed synergy were selected for in vivo testing using a G. mellonella larvae infection model. Rifampicin was an effective antibacterial enhancer when used in combination with tigecycline or vancomycin, with minimum inhibitory concentrations (MICs) of each individual antibiotic being reduced by between two and four doubling dilutions, generating fractional inhibitory concentration index (FICI) values between 0.31 and 0.5. Synergy observed with the chequerboard screening assays was subsequently observed in vivo using the G. mellonella model, with combination treatment demonstrating superior protection of larvae post-infection in comparison with antibiotic monotherapy. In particular, rifampicin in combination with tigecycline or vancomycin significantly enhanced larvae survival. Addition of rifampicin to anti-enterococcal treatment regimens warrants further investigation and may prove useful in the treatment of enterococcal infections whilst prolonging the clinically useful life of currently active antibiotics

    Inheritance of parthenocarpy in gynoecious cucumber (Cucumis sativus L.) cultivar PPC-2

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    The gynoecious and parthenocarpic inbred line, Pant Parthenocarpic Cucumber-2 (PPC- 2) was crossed with Indian monoecious and non-parthenocarpic cultivar Pusa Uday to develop F1, F2, B1 and B2 to determine the inheritance of parthenocarpy.The crop was grown under insect proof net house of 40 mesh. The pistillate buds were covered using butter paper bags before anthesis to prevent out-crossing.The observations were recorded separately for the development of early parthenocarpic fruits (i.e.1-7th nodes), late parthenocarpy (8th and above nodes) and non-parthenocarpic fruits. In F1 generation, out of 40 plants screened, 2 plants produced parthenocarpic fruits at lower nodes (1-7th nodes), 37 plants produced parthenocarpic fruits at upper nodes (8th and above), whereas,only 1 plant that did not produced any fruit was considered as non-parthenocarpic. The segregation of F2 population and test crosses for parthenocarpic fruit development suggested that parthenocarpy in gynoecious and parthenocarpic cucumber line PPC-2 is under the control of incomplete dominant gene

    Seed yield and quality as influenced by growing conditions in hybrid seed production of bitter gourd (Momordica charantia L.) cv. Pusa Hybrid-1

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    The present investigation was carried out under insect proof net house (IPN) and open field condition (OFC) at Centre for Protected Cultivation Technology and Seed Testing Laboratory of Division of Seed Science &Technology, IARI, New Delhi in bitter gourd cv. Pusa Hybrid-1 during summer season because under open field condition the seed yield and seed quality of bitter gourd drastically reduced due to viral diseases and fruit fly in kharif and early onset of high temperature, unseasonal rains during summer, which restricts the hybrid seed production of bitter gourd under north Indian condition. The observations on seed yield & quality characters and physical properties of seed were recorded. The quality attributes were evaluated immediately after harvest and after 8 months of ambient storage and their results were compared. The experimental results revealed that total number of seed per fruit (46.7), number of filled seed per fruit (45.3), seed yield per fruit (9.41g), seed yield per plant (27.28g), and seed yield per hectare (232kg) were significantly higher under IPN in comparison to OFC. Among the physical parameters of seed, seed width (0.81cm) & seed coat (0.79g) weight recorded significantly higher in IPN. The seed quality attributes immediately after harvest was also significantly superior under IPN compared to OFC except for germination %. The hybrid seed produced under IPN conditions could maintain their superiority for quality traits even after 8 monthsof its ambient storage. The seed yield and seed quality attributes were comparatively superior under IPN conditions. The seed crop grown under IPN overcomes the threat of insect vectors, viral diseases and unfavourable climatic conditions and helps in attaining the better seed yield and quality

    Farmers, food and climate change: ensuring community-based adaptation is mainstreamed into agricultural programmes

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    Climate change creates widespread risks for food production. As climate impacts are often locally specific, it is imperative that large-scale initiatives to support smallholder farmers consider local priorities and integrate lessons from successful autonomous adaptation efforts. This article explores how large-scale programmes for smallholder adaptation to climate change might link effectively with community-led adaptation initiatives. Drawing on experiences in Bangladesh, Mozambique, Uganda and India, this article identifies key success factors and barriers for considering local priorities, capacities and lessons in large-scale adaptation programmes. It highlights the key roles of extension services and farmers' organizations as mechanisms for linking between national-level and community-level adaptation, and a range of other success factors which include participative and locally driven vulnerability assessments, tailoring of adaptation technologies to local contexts, mapping local institutions and working in partnership across institutions. Barriers include weak governance, gaps in the regulatory and policy environment, high opportunity costs, low literacy and underdeveloped markets. The article concludes that mainstreaming climate adaptation into large-scale agricultural initiatives requires not only integration of lessons from community-based adaptation, but also the building of inclusive governance to ensure smallholders can engage with those policies and processes affecting their vulnerability

    Characterization of Murine Thymic Stromal-Cell Lines Immortalized by Temperature-Sensitive Simian Virus 40 Large T or Adenovirus 5 E1a

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    The heterogeneity of thymic stromal cells is probably related to their role in providing different microenvironments where T cells can develop. We have immortalized thymic stromal elements using recombinant retroviral constructs containing a temperature-sensitive simian virus 40 (SV40tsA58) large-T antigen gene or the adenovirus 5 E1a region linked to the gene coding for resistance to G418. Cell lines containing the thermolabile large T antigen encoded by SV40 proliferate at the permissive temperature of 33°C and arrest growth when transferred to the nonpermissive temperature of 39°C. At the nonpermissive temperature, ts-derived cell lines are shown to alter their phenotype but remain metabolically active, as indicated by the inducible expression of class I and class II MHC antigens. Here we describe the generation of a total of 84 thymic stromal-cell lines, many of which show distinct morphologic, phenotypic, and functional properties consistent with fibroblastoid, epithelial, or monocytoid origins. Several E1a and SV40tsA58-derived cell lines generated exhibit the epithelial characteristic of desmosome formation and, in addition, two of these lines (15.5 and 15.18) form multicellular complexes (rosettes) when incubated with unfractionated thymocytes from syngeneic mice. A single line (14.5) displays very strong nonspecific esterase activity, suggesting it may represent a macrophagelike cell type. We describe the generation of stromal cell lines with different properties, which is consistent with the heterogeneity found in the thymic microenvironment. In addition to documenting this diversity, these cell lines may be useful tools for studying T-cell development in vitro and give access to model systems in which stromal-thymocyte interactions can be examined

    Rapid cell-surface prion protein conversion revealed using a novel cell system

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    Prion diseases are fatal neurodegenerative disorders with unique transmissible properties. The infectious and pathological agent is thought to be a misfolded conformer of the prion protein. Little is known about the initial events in prion infection because the infecting prion source has been immunologically indistinguishable from normal cellular prion protein (PrPC). Here we develop a unique cell system in which epitope-tagged PrPC is expressed in a PrP knockdown (KD) neuroblastoma cell line. The tagged PrPC, when expressed in our PrP-KD cells, supports prion replication with the production of bona fide epitope-tagged infectious misfolded PrP (PrPSc). Using this epitope-tagged PrPSc, we study the earliest events in cellular prion infection and PrP misfolding. We show that prion infection of cells is extremely rapid occurring within 1 min of prion exposure, and we demonstrate that the plasma membrane is the primary site of prion conversion

    Strategic selection of white maize inbred lines for tropical adaptation and their utilization in developing stable, medium to long duration maize hybrids

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    White maize plays an important role in human diet, especially in traditional crop growing regions of northern hill region, north-eastern states and central-western parts of India. Breeding efforts to enhance the genetic potential of white maize was not so prominent as compared to yellow maize in the country. As a result, genetic base of the material utilized in white maize breeding program in India is very narrow and majorly contains indigenous germplasm and few introductions. Hence, efforts were made to use 365 white maize inbred lines from CIMMYT, Mexico, for breeding program. These new inbred lines were grown at winter nursery center, Indian Institute of Maize Research, New Delhi for its tropical adaptation. After preliminary evaluation, a total 47 inbred lines were selected and evaluated in randomized complete block design with two replications at Regional Maize Research and Seed Production Centre, Begusarai, Bihar, during rabi 2014. Out of this top performing 12 inbred lines viz, CML 47, CML 95, CML 314, CML 319, CML 377, CML 488, CML 494, CML 504, CML 517, CML 522, CML 531 and CML 538 were selected and were crossed in diallel manner to obtain 66 medium to long duration experimental hybrids. Stability analysis using AMMI model was done to identify adaptive hybrids with high yielding potentiality. According to the ASVi value obtained, the hybrid G38 appeared to be stable followed by G50 and G44. On the other hand, the hybrid G25 appeared as location specific hybrid suitable for high input conditions

    Microbiological and enzymatic properties of diverse Jaivik Krishi inputs used in organic farming

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    237-243Jaivik Krishi is a system of production and natural agriculture free from all fertilizers, pesticides, herbicides and synthetic harmful substances. Organic Farming is a method which forbids the application of synthetic inputs (such as chemical fertilizers, pesticides, feed additives, hormones, etc.) Jaivik krishi products (organic inputs) are organic formulations that boost the biological productivity of crops and the nutritional quality of vegetables and fruits. The use of Javik Krishi inputs helped in sustaining crop yields in organic nutrient management system. In the present study, various organic formulations were prepared from the various indigenous cow-products and plant based waste materials. Microbial count viz., total bacteria, fungus and actinomycetes count, and enzymatic activities viz., acid phosphatase, alkaline phosphatase and dehydrogenase were also evaluated in different organic liquid formulations. The average microbial count of Panchgavya (14.9x108, 5.8x105, 8x105 cfu/mL for total bacteria, fungus and actinomycetes count respectively) was highest among various Javik Krishi inputs studied followed by Dasparni. In present study, enzymatic activities of Javik Krishi inputs was directly related and corresponded to the microbial count. The enzyme activities of Panchgavya was highest (29.97, 52.10 and 66.64 µg/mL for acid phosphatase, alkaline phosphatase and dehydrogenase respectively) followed by Dasparni. These Javik Krishi inputs will benefit in enhancing the soil carbon content of soil and improving the soil fertility and micro-fauna

    Evaluating Climate Change Mitigation and Adaptation Potential of Conservation Agriculture in Semi-arid Tropics of Southern India

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    Aims: As climate change related rainfall and temperature variability is being increasingly experienced in the SAT regions, we assessed climate change mitigation and adaptation potential of Conservation Agriculture (CA) by studying effects of minimum tillage (MT) and residue management practices on rain water use efficiency (RWUE), soil moisture, runoff, energy use and carbon dioxide emission in two maize-legume cropping systems. Study Design: The experiment was laid out in split-split plot design with four replications. Place and Duration of Study: The study was conducted at the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) farm, Patancheru, Telangana, India during 2010-11 and 2011-12. Methodology: RWUE was calculated as maize equivalent yield divided by rainfall received during the crop season. Integrated digital runoff and soil loss monitoring unit (IDRSMU) was used to measure runoff. Soil moisture content was measured using the gravimetric method (0-30 cm depth) and neutron probe (60-90 cm depth). The soil organic carbon was analyzed following the Walkley-Black method [1]. The diesel consumption in MT and conventional tillage (CT) was estimated following Downs and Hansen (http://www.ext.colostate.edu/pubs) and emission of CO2 was estimated according to EPA, 2009 [2]. Results: Tillage and residue management practices did not show significant effect on RWUE except; CT having significantly higher RWUE over MT during 2011-12. Effect of cropping systems on RWUE was significant but variable during the two years of study. MT-RT (minimum tillage- residue retained) reduced total seasonal runoff by 28.62% and 80.22% compared to CT-RR (conventional tillage- residue removed) in 2010-11 and 2011-12, respectively. Similarly, MT-RT reduced rainwater loss and peak rate of runoff compared to CT-RR in both the years of study. During 2010, MT-RT had higher total soil moisture (v/v) in the 0-90 cm soil depth in sole as well as intercropped maize compared to CT-RR, however, during 2011 MT-RT had higher total soil moisture in sole maize only. As compared to CT, even though, MT improved SOC in 0-15 cm depth but lowered slightly in 15-30 cm depth. RT (residue retained) improved SOC in 0-15 and 15-30 cm depths compared to residue removal (RR). MT-RT had higher or equal SOC in 0-15 and 15-30 cm soil depths compared to CT-RR in both the maize-legume cropping systems. MT saved energy corresponding to 41.49 l of diesel per hectare annually compared to CT. Similarly, MT emitted 110.79 kg less CO2 annually on per hectare basis compared to CT due to reduced diesel use. Conclusion: CA, when adopted by following good agricultural practices and refined to suit the local conditions, could emerge as sustainable production system for climate change mitigation and adaptation of dryland cropping systems in semi-arid tropics of southern India

    Climate Change Mitigation and Adaptation Potential of Conservation Agriculture: Effects on Rainwater Use Efficiency, Runoff, Soil Moisture, Soil Organic Carbon and Energy Use

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    As climate change will likely have adverse effects on agricultural productivity and food security in much of the semi-arid tropics ((SAT, IPCC, 2007), there is need to develop and disseminate production technologies that provide a layer of resilience against such climate change effects on food security. A long-term experiment was initiated at the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) farm in Patancheru, India in 2009 rainy season to assess the potential of conservation agriculture (CA) as an alternative and resilient production technology for sustainable crop intensification under rainfed situations in the SAT of southern India. Two tillage treatments -- , normal tillage (NT) minimum tillage (MT), and residue management practices -- residue removal (RR) and residue retention (RT) were tested in maize-chickpea sequence and maize/pigeonpea intercropping systems with four replications. The soil of experimental field was Vertic Inceptisol, which according to USDA is classified as a member of the fine, montmorillonite, isohyperthermic family of paralithic Vertic Ustopepts (Vertic cambisol as per FAO classification); slightly alkaline (pH 7.91) with EC 0.22, medium in organic C (0.42 %) and available P (10.61 kgha-1). Here we present effects of tillage and residue management practices on rainwater use efficiency (RWUE), runoff, soil moisture content and soil organic carbon (SOC) during 2010-11 and 2011-12 seasons. Data from integrated digital runoff and soil loss monitoring unit (IDRSMU, Pathak et al., 2011) were analyzed to estimate runoff in different treatment plots in maize-chickpea system. Soil moisture content was measured using the neutron probe (Troxler model 4302) calibrated under same soil
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