226 research outputs found

    The Effect of Light, Soil Temperature, and Soil Moisture on High-Lime Chlorosis

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    Chlorosis of plants from a lack of available iron is one of the most common plant nutrient problems of the calcareous soils of the west. The disease is characterized by a yellowing of the plant leaves and is accompanied, in severe cases, by a partial root death and premature defoliation (3). In addition to reducing growth, the disease greatly reduces the quality and yield of plants. Many types of plants are affected by iron chlorosis. In Hawaii and Porto Rico rice, sugar cane and pineapple are susceptible, while in California and Arizona, citrus trees are seriously affected. In Utah apples, peaches, plums, prunes, apricots, pears, grapes, raspberries and many ornamental plants are affected (27). The problem of iron chlorosis, therefore, is of great importance to agriculture in the west. Chlorosis has been studied for more than one hundred and fifty years, but until recently, little progress has been made toward finding the solution to the problem. Although these past studies have not solved the problem of iron chlorosis, they have shown many factors to be closely related to the occurrence of the disease. These factors include an unbalanced ratio of available manganese to iron in the growth medium (9, 23, 29); chlorotic leaves are high in potassium, nitrogen in the form of ammonia (21), and in ferric iron and are low in total calcium and ferrous iron in comparison with green leaves (12, 13, 14, 17, 25, 26). The climatic factors of light, soil temperature and soil moisture also appear to be of fundamental importance in chlorosis. It is a common observation that fruit trees are more chlorotic during the early spring when the temperature of the soil is low and the moisture level high. Many investigators have noted that chlorosis tends to be most severe in the poorly drained portions of fruit orchards when water tends to accumulate. However, the work on the affect of climatic conditions on chlorosis has been limited largely to observations. The purpose of this investigation was to study, under controlled conditions, the effect of light, soil temperature and soil moisture on a lime-induced chlorosis

    Does functionalisation enhance CO2 uptake in interpenetrated MOFs? An examination of the IRMOF-9 series

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    The effect of pore functionalisation (-I, -OH, -OCH3) on a series of topologically equivalent, interpenetrated metal-organic frameworks (MOFs) was assessed by both simulation and experiment. Counter-intuitively, a decreased affinity for CO2 was observed in the functionalised materials, compared to the non-functionalised material. This result highlights the importance of considering the combined effects of network topology and chemical functionality in the design of MOFs for enhanced CO2 adsorptionRavichandar Babarao, Campbell J. Coghlan, Damien Rankine, Witold M. Bloch, Gemma K. Gransbury, Hiroshi Sato, Susumu Kitagawa, Christopher J. Sumby, Matthew R. Hill and Christian J. Doona

    Biochemical and histopathological correlation in liver transplant: The first 180 days

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    It is not known whether the histopathology of the liver allograft can be predicted from biochemical measurements in serum with the same confidence as in the native liver. To answer this question we compared the histopathological diagnoses in 170 biopsy specimens from 70 adult transplant recipients obtained during the first 180 days, with the concentrations of the serum bilirubin and the activities of AST, ALT and alkaline phosphatase measured at the same time. The most frequent diagnosis was cholestasis (n = 45), which was mild, moderate or severe and which may have been complicated by rejection (n = 28) or ischemia (n = 14). Hepatitis (n = 14), ischemia with rejection (n = 6) and spotty focal necrosis (n = 6) were diagnosed less frequently. Fifteen biopsy specimens were reported as histopathologically normal. In general, biochemical measurements discriminated poorly between different histopathological diagnoses. The histopathologically normal liver often showed an abnormal pattern of enzymes and an increase in the serum bilirubin level. As a result histopathologically normal biopsy specimens were indistinguishable biochemically from those with hepatitis. When two pathological conditions were found to coexist (e.g., cholestasis with either rejection or ischemic necrosis, or ischemic necrosis with rejection), the effect on the serum biochemistry was usually not additive and in some instances returned the biochemical abnormalities toward normal. With the exception of the serum bilirubin level, which increased with the severity of uncomplicated cholestasis, we could not identify a specific pattern of biochemical changes corresponding to a given histopathological diagnosis. We suggest that until more specific noninvasive methods of monitoring the transplanted liver are developed protocol liver biopsies offer the best means of identifying significant pathological conditions in liver allografts. (H EPATOLOGY 1992;16:688–693.)Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/38382/1/1840160312_ftp.pd

    Assessing Order Effects in Online Community-based Health Forums

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    Measuring the quality of health content in online health forums is a challenging task. The majority of the existing measures are based on evaluations of forum users and may not be reliable. We employed machine learning techniques, text mining methods, and Big Data platforms to construct four measures of textual quality to automatically determine the similarity of a given answer to professional answers. We then used them to assess the quality of 66,888 answers posted on Yahoo! Answers Health section. All four measures of textual quality revealed a higher quality for asker-selected best answers indicating that askers, to some extent, have a proper judgment to select the best answers. We also studied the presence of order effects in online health forums. Our results suggest that the textual quality of the first answer positively influences the mean textual quality of the subsequent answers and negatively influences the quantity of subsequent answers

    Tuneable nature of metal organic frameworks as heterogeneous solid catalysts for alcohol oxidation

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    [EN] Selective benzyl alcohol oxidation (BA) to benzaldehyde has been frequently used as a benchmark reaction to evaluate the catalytic activity of metal organic frameworks (MOFs) as oxidation catalysts. Substituted BAs, and aliphatic and allylic alcohols have also been often used as substrates in these studies. In the present review, the current state of the art of MOFs as heterogeneous catalysts for the oxidation of BA and other alcohols is described, grouping the reports according to the nature of the active sites present on the MOFs. Thus, MOFs in which the catalytic centres are located at the ligands, at metallic nodes, or at metal nanoparticles (MNPs) incorporated within the MOF pores and photoassisted oxidations have been commented on. The aim of this review is to stress the current limitations encountered in the use of MOFs, particularly with respect to MOF stability and activity and propose new targets in the area.AD thanks the University Grants Commission (UGC), New Delhi, for the award of an Assistant Professorship under its Faculty Recharge Programme. AD also thanks the Department of Science and Technology, India, for the financial support through Extra Mural Research Funding (EMR/2016/006500). Financial support from the Spanish Ministry of Economy and Competitiveness (Severo Ochoa and CTQ2015-69153-CO2-1) is gratefully acknowledged.Dhakshinamoorthy, A.; Asiri, AM.; García Gómez, H. (2017). Tuneable nature of metal organic frameworks as heterogeneous solid catalysts for alcohol oxidation. Chemical Communications. 53(79):10851-10869. https://doi.org/10.1039/c7cc05927bS1085110869537

    Advances in Social Media Research:Past, Present and Future

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    Social media comprises communication websites that facilitate relationship forming between users from diverse backgrounds, resulting in a rich social structure. User generated content encourages inquiry and decision-making. Given the relevance of social media to various stakeholders, it has received significant attention from researchers of various fields, including information systems. There exists no comprehensive review that integrates and synthesises the findings of literature on social media. This study discusses the findings of 132 papers (in selected IS journals) on social media and social networking published between 1997 and 2017. Most papers reviewed here examine the behavioural side of social media, investigate the aspect of reviews and recommendations, and study its integration for organizational purposes. Furthermore, many studies have investigated the viability of online communities/social media as a marketing medium, while others have explored various aspects of social media, including the risks associated with its use, the value that it creates, and the negative stigma attached to it within workplaces. The use of social media for information sharing during critical events as well as for seeking and/or rendering help has also been investigated in prior research. Other contexts include political and public administration, and the comparison between traditional and social media. Overall, our study identifies multiple emergent themes in the existing corpus, thereby furthering our understanding of advances in social media research. The integrated view of the extant literature that our study presents can help avoid duplication by future researchers, whilst offering fruitful lines of enquiry to help shape research for this emerging field
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