310 research outputs found

    Potential of the system of rice intensification for systemic improvement in rice production and water use: the case of Andhra Pradesh, India

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    As opportunities to enhance the irrigation base for raising food production in the country are dwindling, India needs a more concerted effort to increase the efficiency and productivity of its irrigation systems. This study, based on an analysis of experience from the state of Andhra Pradesh, addresses the potential of the System of Rice Intensification (SRI) to contribute to systemic corrections in present paddy cultivation, both with regard to agronomic productivity and irrigation water use efficiency. This study points to the considerable increase in rice productivity and farmer incomes, which is being achieved in Andhra Pradesh with substantial reduction in irrigation water application, labor, and seed costs through utilization of SRI methods. Potential public savings on water and power costs could be drawn upon not only for promoting SRI but also to effect systemic corrections in the irrigation sector, to mutual advantage

    Instantaneous Antarctic ice-sheet mass loss driven by thinning ice shelves

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    Abstract Recent observations show that the rate at which the Antarctic Ice Sheet (AIS) is contributing to sea level rise is increasing. Increasing ice-ocean heat exchange has the potential to induce substantial mass loss through the melting of its ice shelves. Lack of data and limitations in modelling, however, have made it challenging to quantify the importance of ocean-induced changes in ice-shelf thickness as a driver for ongoing mass loss. Here, we use a numerical ice-sheet model in combination with satellite observations of ice-shelf thinning from 1994 to 2017 to quantify instantaneous changes in ice flow across all AIS grounding lines, resulting from changes in ice-shelf buttressing alone. Our process-based predictions are in good agreement with observed spatial patterns of ice loss, providing support for the notion that a significant portion of the current ice loss of the AIS is ocean driven and caused by a reduction in ice-shelf buttressing

    Esophageal Cancer Recurrence Patterns and Implications for Surveillance

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    Introduction:After definitive treatment of esophageal cancer, patients are at high risk for recurrence. Consistent follow-up is important for detection and treatment of recurrence. The optimal surveillance regimen remains undefined. We investigated posttreatment recurrence patterns and methods of detection in survivors of esophageal cancer.Methods:We retrospectively studied a cohort of patients who had undergone surgical resection for esophageal cancer at our institution between 1996 and 2010. Routine computed tomography scan and upper endoscopy were performed for surveillance.Results:In total, 1147 patients with resected esophageal adenocarcinoma or squamous cell carcinoma were included (median follow-up, 46 months). Of these, 723 patients (63%) had received neoadjuvant therapy before surgery. During follow-up, there were 595 deaths (52%) and 435 recurrences (38%) (distant [55%], locoregional [28%], or both [17%]). Half of recurrences were detected as a result of symptoms (n = 217), 45% by routine chest and abdominal computed tomography scan (n = 194), and 1% by surveillance upper endoscopy (n = 6). The recurrence rate decreased from 27 per 100 person-years in posttreatment year 1 to 4 per 100 person-years in year 6. In the first 2 years, the rate of recurrence was higher among patients who had received neoadjuvant therapy (35 per 100 person-years) than among those who had not (14 per 100 person-years) (p < 0.001).Conclusions:The incidence of recurrence is high after esophagectomy for cancer. Surveillance endoscopy has limited value for detection of asymptomatic local recurrence. The yield from follow-up scans diminishes significantly after the sixth year; surveillance scans after that point are likely unnecessary

    Differential Timing and Coordination of Neurogenesis and Astrogenesis in Developing Mouse Hippocampal Subregions

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    Funding Information: Funding: This research was funded by the National Institutes of Health, grant number R35NS097370 to G.-l.M. and grant number R35NS116843 to H.S.Peer reviewedPublisher PD

    Predictive Value of Initial PET-SUVmax in Patients with Locally Advanced Esophageal and Gastroesophageal Junction Adenocarcinoma

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    Introduction:We have previously shown that in early clinical stage esophageal adenocarcinoma, a positron emission tomography standardized uptake values (PET SUVmax) of <4.5 is associated with earlier pathologic stage and predicts better survival. In this study, we analyze the impact of the pretreatment PET SUVmax in patients with locally advanced esophageal adenocarcinoma who undergo preoperative chemoradiotherapy.Methods:We performed a retrospective analysis, selecting patients with adenocarcinoma of the esophagus who had a pretreatment PET scan and who received chemoradiotherapy before esophagectomy. Data recorded included demographics, PET SUVmax, treatment details, pathologic details, and survival data. Comparison of categorical variables was done by χ2 analysis, continuous variables by t test, survival analysis by the Kaplan-Meier method, and comparisons of survival using the log-rank test.Results:Between January 1996 and September 2007, 189 patients were appropriate for this analysis. The initial PET SUVmax was <4.5 in 28 patients and ≥4.5 in 161 patients. The two groups were similar with regards to demographics and treatment details. Patients in the low SUV group were less likely to show evidence of treatment response after chemoradiotherapy, including a higher likelihood of residual nodal disease and a lower likelihood of a pathologic complete response and estimated treatment response. However, both groups had similar survival.Conclusions:Although the initial PET SUVmax does not predict survival in patients with locally advanced esophageal adenocarcinoma who receive preoperative chemoradiotherapy, patients with a high initial SUVmax respond better to preoperative therapy. These results can be used to better select esophageal cancer patients for combined modality treatment

    Intraoperative localization of lymph node metastases with a replication-competent herpes simplex virus

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    ObjectivesLymph node status is the most important prognostic factor determining recurrence and survival in patients with mesothelioma and other thoracic malignancies. Accurate localization of lymph node metastases is therefore necessary to improve selection of resectable and curable patients for surgical intervention. This study investigates the potential to identify lymph node metastases intraoperatively by using herpes-guided cancer cell–specific expression of green fluorescent protein.MethodsAfter infection with NV1066, a herpes simplex virus carrying green fluorescent protein transgene, human mesothelioma cancer cell lines were assessed for cancer cell–specific infection, green fluorescent protein expression, viral replication, and cytotoxicity. Murine models of lymphatic metastasis were established by means of surgical implantation of cancer cells into the preauricular (drainage to cervical lymph nodes) and pleural (mediastinal and retroperitoneal lymph nodes) spaces of athymic mice. Fluorescent thoracoscopy, laparoscopy, and stereomicroscopy were used to localize lymph node metastases that were confirmed by means of immunohistochemistry.ResultsIn vitro NV1066 infected, replicated (5- to 17,000-fold), and expressed green fluorescent protein in all cancer cells, even when infected at a low ratio of one viral plaque-forming unit per 100 tumor cells. In vivo NV1066 injected into primary tumors was able to locate and infect lymph node metastases producing green fluorescent protein that was visualized by means of fluorescent imaging. Histology confirmed lymphatic metastases, and immunohistochemistry confirmed viral presence in regions that expressed green fluorescent protein.ConclusionsHerpes virus–guided cancer cell–specific production of green fluorescent protein can facilitate accurate localization of lymph node metastases. Fluorescent filters that detect green fluorescent protein can be incorporated into operative scopes to precisely localize and biopsy lymph node metastases
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