105 research outputs found

    Coping with Drought in Rice Farming in Asia: Insights from a Cross-Country Comparative Study

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    Drought is a major constraint affecting rice production especially in rainfed areas of Asia. Despite its importance in rice growing areas, the magnitude of economic losses arising from drought, its impact on farm households and farmers' drought coping mechanisms are poorly understood. This paper provides insights into these aspects of drought based on a cross-country comparative analysis of rainfed rice growing areas in China, India and Thailand. The economic cost of drought is found to be substantially higher in eastern India than in the other two countries. Higher probability and greater spatial covariance of drought and less diversified farming systems with rice accounting for a large r share of household income are likely to be the main reasons for this higher cost of drought in eastern India. Farmers deploy various coping mechanisms but such mechanisms are largely unable to prevent a reduction in income and consumption, especially in eastern India. As a result, welfare consequences on poor farmers are substantial with a large number of people falling back into poverty during drought years. The overall implications for technology design and for policy improvements for drought mitigation and drought relief are discussed in the light of the empirical findings of the study.Drought, Economic cost, Coping mechanisms, Poverty, Crop Production/Industries, D1, I3, Q1,

    Emission Spectroscopic Measurements in the Plenum Region of the NASA IHF Arc Jet Facility

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    A newly designed segment with optical access was installed in the plenum chamber of the 60 MW Interaction Heating arcjet Facility at NASA Ames Research Center. This special segment has ports located off axis, and the optical fibers can be inserted into these ports. The special segment allows for optical examination of the arc-heated flow as it enters the plenum, and thus assists in determining estimates of the thermodynamic state of the inflow to the convergent section of the nozzle. In the present work, optical emission measurements have been made in VIS-NIR region (wavelengths between 500 nm to 900 nm) for two settings of the arc heater - a 6000 A condition (high condition) with the minimum amount of radial injection of cold air in the plenum, and a 3300 A condition (low condition) with significant amount of cold air injection to reduce the enthalpy of the arc-heated stream. The results presented here were obtained using an Acton SP300i spectrometer coupled to a Princeton Instruments PI-max intensified camera. In addition to the optical emission measurements, computations were performed for the flow in the plenum and radiation along lines of sight corresponding to the optical ports. Along the centerline, i.e., the longest line of sight across the plenum cross-section, there is good agreement between computations and measurements for the high enthalpy condition, although the off-axis radial profiles show some differences. For the low enthalpy condition, there are significant differences between computations and measurements. The current working hypothesis is that the computational model does not capture details of the mixing process in the plenum

    Molecular diversity and pathogenic variability in Colletotrichum capsici of chilli (Capsicum annuum) in Haryana

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    The fruit rot of chilli (Capsicum annuum L.), caused by Colletotrichum capsici, is the most serious disease of chilli in India. Fourteen isolates of C. capsici collected from different locations in Haryana state were investigated for molecular variations along with their virulence pattern. Different levels of virulence were expressed dividing isolates into four groups. Out of 33 primers, 22 exhibited DNA polymorphism producing a total of 108 bands with an average of 4.90 bands per primer. At an arbitrary cut-off at 45% similarity level of dendrogram, the isolates were clustered into two main clusters. The grouping of the isolates based on RAPDs was in general neither in agreement with their pathogenicity on different host cultivars nor with the geographical location of the isolate. The information may be helpful in improving chilli fruit rot resistance and varietal deployment strategies essential for effective disease management

    Monitoring Temperature in High Enthalpy Arc-heated Plasma Flows using Tunable Diode Laser Absorption Spectroscopy

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    A tunable diode laser sensor was designed for in situ monitoring of temperature in the arc heater of the NASA Ames IHF arcjet facility (60 MW). An external cavity diode laser was used to generate light at 777.2 nm and laser absorption used to monitor the population of electronically excited oxygen atoms in an air plasma flow. Under the assumption of thermochemical equilibrium, time-resolved temperature measurements were obtained on four lines-of-sight, which enabled evaluation of the temperature uniformity in the plasma column for different arcjet operating conditions

    Clinical Study Evaluation of Diabetic Patients with Breast Cancer Treated with Metformin during Adjuvant Radiotherapy

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    . Purpose. The purpose of this study was to evaluate acute locoregional toxicity in patients with breast cancer receiving concurrent metformin plus radiation therapy. Methods and Materials. Diabetic breast cancer patients receiving concurrent metformin and radiation therapy were matched with nondiabetic patients and diabetic patients using an alternative diabetes medication. Primary endpoints included the presence of a treatment break and development of dry or moist desquamation. Results. There was a statistically significant increase in treatment breaks for diabetic patients receiving concurrent metformin when compared to the nondiabetic patients ( value = 0.02) and a trend toward significance when compared to diabetic patients receiving an alternate diabetes medication ( value = 0.08). Multiple logistic regression analysis demonstrated concurrent metformin use as being associated with a trend toward the predictive value of determining the incidence of developing desquamation in diabetic patients receiving radiation therapy compared to diabetic patients receiving an alternate diabetes medication ( value = 0.06). Conclusions. Diabetic patients treated with concurrent metformin and radiation therapy developed increased acute locoregional toxicity in comparison with diabetic patients receiving an alternate diabetes medication and nondiabetic patients. Further clinical investigation should be conducted to determine the therapeutic ratio of metformin in combination with radiation therapy

    Racial Disparities in Patients with Stage IIIC Endometrial Cancer

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    Purpose/Objective(s): To report the impact of race on clinical outcomes in patients with stage IIIC endometrial carcinoma (EC). Materials/Methods: A retrospective multi-institutional cohort study was conducted across 13 Northern American academic centers and included patients with stage IIIC endometrial carcinoma (EC) who received both chemotherapy and radiation in an adjuvant setting. Overall survival (OS) and recurrence-free survival (RFS) were calculated by Kaplan-Meier method. Univariable and multivariable analysis were performed by Cox proportional hazard models for RFS/OS. Propensity score matching was used to estimate the effect of race on survival outcomes. Statistical analyses were conducted using statistical software. Results: A total of 90 Black and 568 non-Black patients (83%) were identified with a median age at diagnosis of 62 (Interquartile Range (IQR) 55-70). Median follow-up was 45.3 months (IQR 24-71 months). Black patients were significantly older (p\u3c0.0001), had significantly more non-endometrioid histology (p\u3c0.0001), grade 3 tumors (p\u3c0.0001) and were more likely to have \u3e1 positive paraaortic lymph nodes (PALN) compared to non-black patients. The presence of lymphovascular space invasion (LVSI), depth of myometrial involvement, number of total nodes involved, adnexal and cervical involvement and stage were not correlated with race (all p\u3e0.1). As for treatment type, chemoradiotherapy sequencing approach was not correlated with race and no difference in number of chemotherapy cycles between Black and non-Black patients (p=0.32) was observed. Black patients were more often treated with external beam radiation therapy (EBRT) (43.3% and 24%, respectively) while a higher proportion of non-black patients received both EBRT and vaginal cuff brachytherapy (VBT) (65% vs. 38 %) (P\u3c0.0001) despite similar cervical involvement. The 5-year estimated OS and RFS rates were 45% and 47% compared to 77% and 68% for Black patients vs. non-black patients, respectively (p\u3c0.001). After propensity score matching, the 2 groups were well balanced for most of the covariates (age, histology, stage, grade, number of positive PALN, adnexal and cervical involvement) except for depth of myometrial invasion and radiation type. The estimated hazard ratios (HRs) of Black vs. non-Black patients were 1.613 (95% CI = (1.01, 2.575), p-value = 0.045) for OS and 1.487 (95% CI = (0.906, 2.440), p-value = 0.116) for RFS, indicating that Black patients have significantly worse OS. RFS differences did not reach statistical significance. Conclusion: Compared to non-Black patients, Black patients have higher rates of non-endometrioid histology, grade 3 tumors and number of PALNs. After propensity score matching, Black patients had worse OS but no statistically significant difference in RFS. Racial disparities could be mitigated by better access to care, equitable inclusion on randomized trials, and identification of genomic/molecular differences to better tailor adjuvant treatment

    Early Cardiac Effects of Contemporary Radiation Therapy in Patients With Breast Cancer

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    Purpose To characterize the early changes in echocardiographically derived measures of cardiac function with contemporary radiation therapy (RT) in breast cancer and to determine the associations with radiation dose-volume metrics, including mean heart dose (MHD). Methods and Materials In a prospective longitudinal cohort study of 86 patients with breast cancer treated with photon or proton thoracic RT, clinical and echocardiographic data were assessed at 3 time points: within 4 weeks before RT initiation (T0), within 3 days before 6 weeks after the end of RT (T1), and 5 to 9 months after RT completion (T2). Associations between MHD and echocardiographically derived measures of cardiac function were assessed using generalized estimating equations to define the acute (T0 to T1) and subacute (T0 to T2) changes in cardiac function. Results The median estimates of MHD were 139 cGy (interquartile range, 99-249 cGy). In evaluating the acute changes in left ventricular ejection fraction (LVEF) from T0 to T1, and accounting for the time from RT, age, race, preexisting cardiovascular disease, and an interaction term with anthracycline or trastuzumab exposure and MHD, there was a modest decrease in LVEF of borderline significance (0.22%; 95% confidence interval [CI], –0.44% to 0.01%; P = .06) per 30-day interval for every 100 cGy increase of MHD. Similarly, there was a modest worsening in longitudinal strain (0.19%; 95% CI, –0.01% to 0.39%; P = .06) per 30-day interval for each 100 cGy increase in MHD. We did not find significant associations between MHD and changes in circumferential strain or diastolic function. Conclusions With modern radiation planning techniques, there are modest subclinical changes in measures of cardiac function in the short-term. Longer-term follow-up studies are needed to determine whether these early changes are associated with the development of overt cardiac disease

    Chromosomal instability drives metastasis through a cytosolic DNA response

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    Chromosomal instability is a hallmark of cancer that results from ongoing errors in chromosome segregation during mitosis. Although chromosomal instability is a major driver of tumour evolution, its role in metastasis has not been established. Here we show that chromosomal instability promotes metastasis by sustaining a tumour cell-autonomous response to cytosolic DNA. Errors in chromosome segregation create a preponderance of micronuclei whose rupture spills genomic DNA into the cytosol. This leads to the activation of the cGAS-STING (cyclic GMP-AMP synthase-stimulator of interferon genes) cytosolic DNA-sensing pathway and downstream noncanonical NF-ÎşB signalling. Genetic suppression of chromosomal instability markedly delays metastasis even in highly aneuploid tumour models, whereas continuous chromosome segregation errors promote cellular invasion and metastasis in a STING-dependent manner. By subverting lethal epithelial responses to cytosolic DNA, chromosomally unstable tumour cells co-opt chronic activation of innate immune pathways to spread to distant organs
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