198 research outputs found

    Identifying Water Stress in Potatoes Using Leaf Reflectance as an Indicator of Soil Water Content

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    Soil water content must be monitored and maintained at adequate level for optimal productivity. Accuracy of traditional sensors used to monitor soil water content depends on the installation technique and proper contact between soil and sensor, which is difficult to achieve in light textured sandy soils. Non-contact sensing technique does not have the limitation of contact with soil and can monitor plant status continuously. In this study, hyperspectral imaging was used as a non-contact technique for detecting changes in spectral reflectance of Umatilla Russet potato plants grown under varying soil water content. An experiment was carried out in a greenhouse to subject potato plants at different levels of soil water content from extreme stress to surplus. Yield data was also collected, which showed that maximum yield for Umatilla Russet potato can be achieved at 18% to 21% soil moisture content. Various spectral indices were calculated using spectral reflectance data at different water stress levels. Principal component analysis was used to identify indices that represented maximum variability in the data. Simple Ratio Index and Modified Red Edge Simple Ratio Index were identified as the two most relevant indices for differentiating soil water content. K-Means clustering with these two indices resulted in an accuracy of 75% in identifying highly stressed plants and 92% accuracy in identifying stressed plants (that included both high and low stress levels). These results showed a promise for development of a non-contact sensor for detecting plant water stress in potatoes, which may lead to an automated irrigation system for maintaining optimal soil water content during potato growing season

    Time for global scale-up, not randomized trials, of uterine balloon tamponade for postpartum hemorrhage.

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    Maternal death is the greatest health disparity globally, with postpartum hemorrhage the most common cause. As senior leaders in obstetrics and maternal health from Bolivia, Canada, Colombia, Côte d'Ivoire, Honduras, India, Kenya, Nepal, Niger, Norway, Peru, Tanzania, the UK, the USA, and Zambia, we are deeply disturbed by recent calls for randomized controlled trials (RCTs) of uterine balloon tamponade (UBT) in women with uncontrolled postpartum hemorrhage (PPH). Our collective experience, in combination with mounting evidence, unequivocally supports the effectiveness of commercial and condom UBTs in averting death and disability from PPH associated with atonic uterus. We believe it would be highly unethical to embark on an RCT of UBT, now or in the future, unless compared with a proven equivalent intervention. This article is protected by copyright. All rights reserved

    The globalizability of temporal discounting

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    Economic inequality is associated with preferences for smaller, immediate gains over larger, delayed ones. Such temporal discounting may feed into rising global inequality, yet it is unclear whether it is a function of choice preferences or norms, or rather the absence of sufficient resources for immediate needs. It is also not clear whether these reflect true differences in choice patterns between income groups. We tested temporal discounting and five intertemporal choice anomalies using local currencies and value standards in 61 countries (N = 13,629). Across a diverse sample, we found consistent, robust rates of choice anomalies. Lower-income groups were not significantly different, but economic inequality and broader financial circumstances were clearly correlated with population choice patterns

    Post-implementation Review of the Himalaya Home Care Project for Home Isolated COVID-19 Patients in Nepal

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    Background: The emergence of coronavirus disease 2019 (COVID-19) has resulted in a pandemic that has significantly impacted healthcare systems at a global level. Health care facilities in Nepal, as in other low- and middle-income countries, have limited resources for the treatment and management of COVID-19 patients. Only critical cases are admitted to the hospital resulting in most patients in home isolation. Methods: Himalaya Home Care (HHC) was initiated to monitor and provide counseling to home isolated COVID-19 patients for disease prevention, control, and treatment. Counselors included one physician and four nurses. Lists of patients were obtained from district and municipal health facilities. HHC counselors called patients to provide basic counseling services. A follow-up check-in phone call was conducted 10 days later. During this second call, patients were asked about their perceptions of the HHC program. Project objects were: (1) To support treatment of home isolated persons with mild to moderate COVID-19, decrease burden of hospitalizations, and decrease risks for disease transmission; and, (2) To improve the health status of marginalized, remote, and vulnerable populations in Nepal during the COVID-19 pandemic. Results: Data from 5823 and 3988 patients from May 2021-February 2022 were entered in initial and follow-up forms on a REDCap database. The majority of patients who received counseling were satisfied. At follow-up, 98.4% of respondents reported that HHC prevented hospitalization, 76.5% reported they could manage their symptoms at home, and 69.5% reported that counseling helped to limit the spread of COVID-19 in their household. Conclusions: Telehealth can be an essential strategy for providing services while keeping patients and health providers safe during the COVID-19 pandemic

    Primary mediastinal atypical meningioma: Report of a case and literature review

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    Meningiomas are common neoplasms arising from the central nervous system meninges. On the other hand, primary ectopic meningiomas are extremely rare and usually limited to the head and neck region or to the paravertebral soft tissues. Their occurrence in the mediastinum is even rarer. Until now, only 4 cases of primary mediastinal meningioma have been reported in the literature searched on Medline. Because of its rarity and intriguing pathogenesis, we report here a case of primary mediastinal meningioma that was treated by surgical resection. The clinical features, treatment, pathological findings, and prognosis are analyzed, and the literature on ectopic meningioma is reviewed

    Resonant Thermoelectric Nanophotonics

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    Photodetectors are typically based either on photocurrent generation from electron–hole pairs in semiconductor structures or on bolometry for wavelengths that are below bandgap absorption. In both cases, resonant plasmonic and nanophotonic structures have been successfully used to enhance performance. Here, we show subwavelength thermoelectric nanostructures designed for resonant spectrally selective absorption, which creates large localized temperature gradients even with unfocused, spatially uniform illumination to generate a thermoelectric voltage. We show that such structures are tunable and are capable of wavelength-specific detection, with an input power responsivity of up to 38 V W^(–1), referenced to incident illumination, and bandwidth of nearly 3 kHz. This is obtained by combining resonant absorption and thermoelectric junctions within a single suspended membrane nanostructure, yielding a bandgap-independent photodetection mechanism. We report results for both bismuth telluride/antimony telluride and chromel/alumel structures as examples of a potentially broader class of resonant nanophotonic thermoelectric materials for optoelectronic applications such as non-bandgap-limited hyperspectral and broadband photodetectors

    Cultural Diversity and Saccade Similarities: Culture Does Not Explain Saccade Latency Differences between Chinese and Caucasian Participants

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    A central claim of cultural neuroscience is that the culture to which an individual belongs plays a key role in shaping basic cognitive processes and behaviours, including eye movement behaviour. We previously reported a robust difference in saccade behaviour between Chinese and Caucasian participants; Chinese participants are much more likely to execute low latency express saccades, in circumstances in which these are normally discouraged. To assess the extent to which this is the product of culture we compared a group of 70 Chinese overseas students (whose primary cultural exposure was that of mainland China), a group of 45 participants whose parents were Chinese but who themselves were brought up in the UK (whose primary cultural exposure was western European) and a group of 70 Caucasian participants. Results from the Schwartz Value Survey confirmed that the UK-Chinese group were culturally similar to the Caucasian group. However, their patterns of saccade latency were identical to the mainland Chinese group, and different to the Caucasian group. We conclude that at least for the relatively simple reflexive saccade behaviour we have investigated, culture cannot explain the observed differences in behaviour
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