164 research outputs found
Assessment of Pesticide Use in Major Vegetables From Farmers\u27 Perception and Knowledge in Dhading District, Nepal
A field study was carried out to assess the pesticide use status in major vegetable crops from farmers\u27 perception and knowledge in Dhading, Nepal in 2019. Field study was carried with 100 commercial farmer\u27s using semi-structure questionnaire by face to face interview. This study was analyzed by categorization of farmers into small holder (51) and large holder (49) groups on the basis of mean area of vegetable cultivation (6.48 ropani). The highest amount of pesticides is needed in tomato in both large holders and small holders according to the farmer\u27s experience. Among the study farmer\u27s, 41% of them spray the pesticides by making a cocktail or mixed method and 56% follow the waiting period of 3-5 days in both of the cases. A significant positive correlation was found at 5% level of significance between the knowledge and practice pattern of waiting period of the pesticides and negative correlation was found between the Personal Protective equipment score and health hazard score. Headache was the major health hazards faced by the farmers which was higher in small holders (66.7%) as compared to the large holders (46.9%). Mask was the most used PPE by the farmer\u27s i.e. by 83% in overall. Fourty three percent of the farmer\u27s throw the pesticide containers in secret place after using of it.The use of PPE was seen lower in small holders as compared to the large holders. This study reveals the necessities of suitable program and policies regarding the knowledge, safe handling and use of pesticide among the farmer\u27s level
An Extended Jahn-Teller Hamiltonian for Large-Amplitude Motion: Application To Vibrational Conical Intersections in CH3SH and CH3OH
An extended Jahn-Teller Hamiltonian is presented for the case where the (slow) nuclear motion extends far from the symmetry point and may be described approximately as motion on a sphere. Rather than the traditional power series expansion in the displacement from the C3v symmetry point, an expansion in the spherical harmonics is employed. Application is made to the vibrational Jahn-Teller effect in CH3XH, with X = S, O, where the equilibrium CXH angles are 83° and 72°, respectively. In addition to the symmetry-required conical intersection (CI) at the C3v symmetry point, ab initio calculations reveal sets of six symmetry-allowed vibrational CIs in each molecule. The CIs for each molecule are arranged differently in the large-amplitude space, and that difference is reflected in the infrared spectra. The CIs in CH3SH are found in both eclipsed and staggered geometries, whereas those for CH3OH are found only in the eclipsed geometry near the torsional saddle point. This difference between the two molecules is reflected in the respective high-resolution spectra in the CH stretch fundamental region
B cell responses to a peptide epitope. VII. Antigen-dependent modulation of the germinal center reaction
Germinal center responses to two analogous peptides, PS1CT3 and G32CT3, that differ in sequence only at one position within the B cell epitopic region were examined. In comparison with peptide PS1CT3, peptide G32CT3 elicited a poor germinal center response. By demonstrating equal facility of immune complexes with IgM and IgG Ab isotypes to seed germinal centers, we excluded differences in isotype profiles of early primary anti-PS1CT3 and anti-G32CT3 Ig as the probable cause. Quantitative differences in germinal center responses to the two peptides were also not due to either qualitative/quantitative differences in T cell priming or variation in the frequency of the early Ag-activated B cells induced. Rather, they resulted from qualitative differences in the nature of B cells primed. Analysis of early primary anti-PS1CT3 and anti-G32CT3 IgMs revealed that the latter population was of a distinctly lower affinity, implying the existence of an Ag affinity threshold that restricts germinal center recruitment of G32CT3-specific B cells. The impediment in anti-G32CT3 germinal center initiation could be overcome by making available an excess of Ag-activated Th cells at the time of immunization. This resulted in the appearance of a higher affinity population of G32CT3-specific B cells that, presumably, are now capable of seeding germinal centers. These data suggest that the strength of a germinal center reaction generated is Ag dependent. At least one regulatory parameter represents the quality of B cells that are initially primed
Multi-time scale control of demand flexibility in smart distribution networks
This paper presents a multi-timescale control strategy to deploy electric vehicle (EV) demand flexibility for simultaneously providing power balancing, grid congestion management, and economic benefits to participating actors. First, an EV charging problem is investigated from consumer, aggregator, and distribution system operator’s perspectives. A hierarchical control architecture (HCA) comprising scheduling, coordinative, and adaptive layers is then designed to realize their coordinative goal. This is realized by integrating multi-time scale controls that work from a day-ahead scheduling up to real-time adaptive control. The performance of the developed method is investigated with high EV penetration in a typical residential distribution grid. The simulation results demonstrate that HCA efficiently utilizes demand flexibility stemming from EVs to solve grid unbalancing and congestions with simultaneous maximization of economic benefits to the participating actors. This is ensured by enabling EV participation in day-ahead, balancing, and regulation markets. For the given network configuration and pricing structure, HCA ensures the EV owners to get paid up to five times the cost they were paying without control
B cell responses to a peptide epitope. VIII. Immune complex-mediated regulation of memory B cell generation within germinal centers
Using an in vivo reconstitution assay, we examine here the role of immune complexes in both formation of germinal centers (GC) and processes that occur subsequently within. The presence of Ag, as immune complexes, was found not to constitute a limiting requirement for the initiation of GC formation. No detrimental effect either on numbers or sizes of the resulting GC was observed when Ag-containing immune complexes were omitted during reconstitution. Thus, both recruitment and proliferation of Ag-activated B cells within GC appear not to be limited by Ag concentrations. In contrast, the presence of immune complexes was observed to be obligatory for the generation of Ag-specific memory B cells. This optimally required immune complexes to be constituted by IgG-class Abs with epitope specificities that were homologous to those of the GC B cells. The GC reaction was also found to be characterized by an enhancement of Ab specificity for the homologous epitope. Although some improvement in specificity was noted in recall responses from immune complex-deficient GC, the presence of appropriate immune complexes served to further optimize the outcome. Here again, isotype and epitope-specificity of the Ab constituent in immune complexes proved to be important
B cell responses to a peptide epitope. V. Kinetic regulation of repertoire discrimination and antibody optimization for epitope
The influence of imposing various conformational constraints on immune responses to a model epitope within a synthetic peptide immunogen was examined in mice. Although overall immunogenicity was affected, the model epitope (sequence DPAF) remained the predominant recognition site regardless of the conformation in which it was presented. A comparison of anti-DPAF mAbs obtained in response to two analogue peptides, PS1CT3 and CysCT3, in which the DPAF segment was either unconstrained or held within a cyclic loop, respectively, revealed a significant homology in the paratope composition. At one level a subset of anti-PS1CT3 and anti-CysCT3 mAbs was found to share a common heavy chain variable region. In addition, nucleotide sequence homology comparisons of both heavy and light chain variable regions identified the presence of anti-PS1CT3 and anti-CysCT3 mAbs that collectively appeared to derive from a common progenitor, but with nonidentical somatic mutations. Interestingly, however, no bias toward homologous Ag could be discerned on measurement of relative affinities of the mAbs for the two peptides. In contrast, mAb binding on-rates clearly discriminated between peptides representing the homologous vs the heterologous confomer of the DPAF epitope. Thus, it would appear that the kinetics of Ag recognition dominate over equilibrium binding criteria both in epitope-driven repertoire selection and Ab maturation in a humoral response
DGAT1 and ABCG2 polymorphism in Indian cattle (Bos indicus) and buffalo (Bubalus bubalis) breeds
BACKGROUND: Indian cattle (Bos indicus) and riverine buffalo (Bubalus bubalis) give a poor yield of milk but it has a high fat and protein percentage compared to taurine cattle. The identification of QTLs (Quantitative Trait Loci) on BTA14 and BTA6 and its subsequent fine mapping has led to identification of two non conservative mutations affecting milk production and composition. Our objective was to estimate the frequency of K232A (DGAT1 – diacylglycerol – acyltransferase 1) and Y581S (ABCG2 – ATP binding cassette sub family G member 2) polymorphisms in diverse cattle and buffalo breeds of India having large variation in terms of milk production. RESULTS: We screened the reported missense mutations in six cattle and five buffalo breeds. The DGAT1(K )and ABCG2(Y )alleles were found to be fixed in Indian cattle and buffalo breeds studied. CONCLUSION: This study provides an indirect evidence that all the Indian cattle and buffalo breeds have fixed alleles with respect to DGAT1 and ABCG2 genes reported to be responsible for higher milk fat yield, higher fat and protein percent
Epitope recognition by diverse antibodies suggests conformational convergence in an antibody response
Crystal structures of distinct mAbs that recognize a common epitope of a peptide Ag have been determined and analyzed in the unbound and bound forms. These Abs display dissimilar binding site structures in the absence of the Ag. The dissimilarity is primarily expressed in the conformations of complementarity-determining region H3, which is responsible for defining the epitope specificity. Interestingly, however, the three Abs exhibit similar complementarity-determining region conformations in the Ag binding site while recognizing the common epitope, indicating that different pathways of binding are used for Ag recognition. The epitope also exhibits conformational similarity when bound to each of these Abs, although the peptide Ag was otherwise flexible. The observed conformational convergence in the epitope and the Ag binding site was facilitated by the plasticity in the nature of interactions
Fabrication of Rare Earth-Doped Transparent Glass Ceramic Optical Fibers by Modified Chemical Vapor Deposition
Rare earth (RE) doped silica-based optical fibers with transparent glass
ceramic (TGC) core was fabricated through the well-known modified chemical
vapor deposition (MCVD) process without going through the commonly used stage
of post-ceramming. The main characteristics of the RE-doped oxyde nanoparticles
namely, their density and mean diameter in the fibers are dictated by the
concentration of alkaline earth element used as phase separating agent.
Magnesium and erbium co-doped fibers were fabricated. Optical transmission in
term of loss due to scattering as well as some spectroscopic characteristics of
the erbium ions was studied. For low Mg content, nano-scale particles could be
grown with and relatively low scattering losses were obtained, whereas large
Mg-content causes the growth of larger particles resulting in much higher loss.
However in the latter case, certain interesting alteration of the spectroscopic
properties of the erbium ions were observed. These initial studies should be
useful in incorporating new doped materials in order to realize active optical
fibers for constructing lasers and amplifiers
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