2,550 research outputs found
Phytosanitary practices and evaluation of 17 pesticides residues in tomatoes fruits produced in Foumbot District Western Highland-Cameroon
The involvement of pesticides in agriculture requires the implementation of best phytosanitary practices in order to guarantee the health of populations and preserve the environment. This study focused on the assessment of phytosanitary practices of tomato producers in Foumbot, Western Highlands-Cameroon, and evaluated the residues of 17 pesticides in tomatoes. The methodological approach consisted of field investigations by survey, collection of samples, pesticide residue extraction using QuEChERS method, and their analysis by gas chromatography tandem mass spectrometry (GC-MS). Survey of 100 farmers showed that, they did not comply with the instructions for the use of plant protection products: 56% of farmers interviewed increased the dose of products when they noticed its ineffectiveness; 93% did not the respect pre-harvest intervals; while 77% increased the application frequency at the time of fruiting. All the producers work without personal protective equipment (PPE) and 68% of them use empty packaging for packaging consumable including water, red oil and palm wine. The reuse of empty packaging could expose populations (producers and consumers) to numerous health risks. Regarding pesticides residues, 03 actives ingredients were detected and quantified in the samples, all the samples were contaminated by lambda-cyhalothrin, 86.66% by cypermethrin and 66.66% by acetamiprid. Moreover, residue concentrations above the maximum residue limit (MRL) were found in all the positive samples of lambda-cyhalothrin, and 92.30% of cypermethrin positive samples. This study shows that utilization of plant protection products in Foumbot requires extensive monitoring with producers, in order to reduce risk of consumers exposure
Delirium: assessment and treatment of patients with cancer PART 2
Delirium at the end of life may present significant ethical dilemmas in clinical practice: whether to simply treat it in order to maximise symptom relief, with the resulting side effect being palliative sedation, or to attempt to reverse delirium and risk prolonging suffering. Determining whether the delirium can be reversed involves comprehensive assessment using established tools, which may or may not provide the answer to the question posed. This article examines the evidence surrounding several assessment tools that have been suggested as effective in identifying delirium, and the consequences of various approaches to the management of delirium in a patient with a cancer diagnosis. It also considers the impact delirium may have on the health professional and those close to the patient.N/
The role of mentorship in protege performance
The role of mentorship on protege performance is a matter of importance to
academic, business, and governmental organizations. While the benefits of
mentorship for proteges, mentors and their organizations are apparent, the
extent to which proteges mimic their mentors' career choices and acquire their
mentorship skills is unclear. Here, we investigate one aspect of mentor
emulation by studying mentorship fecundity---the number of proteges a mentor
trains---with data from the Mathematics Genealogy Project, which tracks the
mentorship record of thousands of mathematicians over several centuries. We
demonstrate that fecundity among academic mathematicians is correlated with
other measures of academic success. We also find that the average fecundity of
mentors remains stable over 60 years of recorded mentorship. We further uncover
three significant correlations in mentorship fecundity. First, mentors with
small mentorship fecundity train proteges that go on to have a 37% larger than
expected mentorship fecundity. Second, in the first third of their career,
mentors with large fecundity train proteges that go on to have a 29% larger
than expected fecundity. Finally, in the last third of their career, mentors
with large fecundity train proteges that go on to have a 31% smaller than
expected fecundity.Comment: 23 pages double-spaced, 4 figure
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Users’ experiences of lighting controls: a case-study
The aim of this paper is to elucidate how occupants perceive their lit environments in a university setting and how they interact with lighting controls using qualitative methods. Semi-structured interviews were carried out with academic teaching and research staff. Thematic analysis identified four main themes: control and choice, connection with the outdoors, concentration, and comfort. Participants were largely able to control and adapt their lighting using small power lighting in office spaces and they perceived this as beneficial to comfort and concentration. Participants expressed frustration with the light switches in classrooms, a lack of consistency in lighting controls across the university buildings was particularly notable. Installers should consider how piecemeal upgrades on large estates affect the perception of buildings where occupiers face multiple control systems. The management of the lighting in classroom spaces including the type and location of blinds, lack of regular window cleaning in some buildings and difficulty in minimising light on projection screens in upgraded classrooms were cited as areas for improvement. Wider implications for lighting control and management highlighted by this study include most notably that a lack of end users consultation has serious consequences on their perception of lighting upgrades and their willingness to employ “workarounds”
The Na+/H+ Exchanger Controls Deoxycholic Acid-Induced Apoptosis by a H+-Activated, Na+-Dependent Ionic Shift in Esophageal Cells
Apoptosis resistance is a hallmark of cancer cells. Typically, bile acids induce apoptosis. However during gastrointestinal (GI) tumorigenesis the cancer cells develop resistance to bile acid-induced cell death. To understand how bile acids induce apoptosis resistance we first need to identify the molecular pathways that initiate apoptosis in response to bile acid exposure. In this study we examined the mechanism of deoxycholic acid (DCA)-induced apoptosis, specifically the role of Na+/H+ exchanger (NHE) and Na+ influx in esophageal cells. In vitro studies revealed that the exposure of esophageal cells (JH-EsoAd1, CP-A) to DCA (0.2 mM -0.5 mM) caused lysosomal membrane perturbation and transient cytoplasmic acidification. Fluorescence microscopy in conjunction with atomic absorption spectrophotometry demonstrated that this effect on lysosomes correlated with influx of Na+, subsequent loss of intracellular K+, an increase of Ca2+ and apoptosis. However, ethylisopropyl-amiloride (EIPA), a selective inhibitor of NHE, prevented Na+, K+ and Ca2+ changes and caspase 3/7 activation induced by DCA. Ouabain and amphotericin B, two drugs that increase intracellular Na+ levels, induced similar changes as DCA (ion imbalance, caspase3/7 activation). On the contrary, DCA-induced cell death was inhibited by medium with low a Na+ concentrations. In the same experiments, we exposed rat ileum ex-vivo to DCA with or without EIPA. Severe tissue damage and caspase-3 activation was observed after DCA treatment, but EIPA almost fully prevented this response. In summary, NHE-mediated Na+ influx is a critical step leading to DCA-induced apoptosis. Cells tolerate acidification but evade DCA-induced apoptosis if NHE is inhibited. Our data suggests that suppression of NHE by endogenous or exogenous inhibitors may lead to apoptosis resistance during GI tumorigenesis
Mycobacterium tuberculosis Responds to Chloride and pH as Synergistic Cues to the Immune Status of its Host Cell
PubMed ID: 23592993This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Phytosanitary Practices And Evaluation Of 17 Pesticides Residues In Tomatoes Fruits Produced In Foumbot District Western Highland-Cameroon
The involvement of pesticides in agriculture requires the implementation of best phytosanitary practices in order to guarantee the health of populations and preserve the environment. This study focused on the assessment of phytosanitary practices of tomato producers in Foumbot, European Scientific Journal, ESJ ISSN: 1857-7881 (Print) e - ISSN 1857-7431 January 2021 edition Vol.17, No.3 www.eujournal.org 31 Western Highlands-Cameroon, and evaluated the residues of 17 pesticides in tomatoes. The methodological approach consisted of field investigations by survey, collection of samples, pesticide residue extraction using QuEChERS method, and their analysis by gas chromatography tandem mass spectrometry (GC-MS). Survey of 100 farmers showed that, they did not comply with the instructions for the use of plant protection products: 56% of farmers interviewed increased the dose of products when they noticed its ineffectiveness; 93% did not the respect pre-harvest intervals; while 77% increased the application frequency at the time of fruiting. All the producers work without personal protective equipment (PPE) and 68% of them use empty packaging for packaging consumable including water, red oil and palm wine. The reuse of empty packaging could expose populations (producers and consumers) to numerous health risks. Regarding pesticides residues, 03 actives ingredients were detected and quantified in the samples, all the samples were contaminated by lambda-cyhalothrin, 86.66% by cypermethrin and 66.66% by acetamiprid. Moreover, residue concentrations above the maximum residue limit (MRL) were found in all the positive samples of lambda-cyhalothrin, and 92.30% of cypermethrin positive samples. This study shows that utilization of plant protection products in Foumbot requires extensive monitoring with producers, in order to reduce risk of consumers exposure
A Unique Resource Mutualism between the Giant Bornean Pitcher Plant, Nepenthes rajah, and Members of a Small Mammal Community
The carnivorous pitcher plant genus Nepenthes grows in nutrient-deficient substrates and produce jug-shaped leaf organs (pitchers) that trap arthropods as a source of N and P. A number of Bornean Nepenthes demonstrate novel nutrient acquisition strategies. Notably, three giant montane species are engaged in a mutualistic association with the mountain treeshrew, Tupaia montana, in which the treeshrew defecates into the pitchers while visiting them to feed on nectar secretions on the pitchers' lids
The labour supply effect of Education Maintenance Allowance and its implications for parental altruism
Education Maintenance Allowance (EMA) was a UK government cash transfer paid directly to children aged 16–18, in the first 2 years of post-compulsory full-time education. This paper uses the labour supply effect of EMA to infer the magnitude of the transfer response made by the parent, and so test for the presence of an ‘effectively altruistic’ head-of-household, who redistributes resources among household members so as to maximise overall welfare. Using data from the Longitudinal Study of Young People in England, an EMA payment of £30 per week is found to reduce teenagers’ labour supply by 3 h per week and probability of employment by 13 % points from a base of 43 %. We conclude that parents withdraw cash and in-kind transfers from their children to a value of between 22 and 86 % of what the child receives in EMA. This means we reject the hypothesis of an effectively altruistic head-of-household, and argue that making this cash transfer directly to the child produces higher child welfare than if the equivalent transfer were made to parents
IFN-γ Rα Is a Key Determinant of CD8+ T Cell-Mediated Tumor Elimination or Tumor Escape and Relapse in FVB Mouse
During the past decade, the dual function of the immune system in tumor inhibition and tumor progression has become appreciated. We have previously reported that neu-specific T cells can induce rejection of neu positive mouse mammary carcinoma (MMC) and also facilitate tumor relapse by inducing neu antigen loss and epithelial to mesenchymal transition (EMT). Here, we sought to determine the mechanism by which CD8+ T cells either eliminate the tumor, or maintain tumor cells in a dormant state and eventually facilitate tumor relapse. We show that tumor cells that express high levels of IFN-γ Rα are eliminated by CD8+ T cells. In contrast, tumor cells that express low levels of IFN-γ Rα do not die but remain dormant and quiescent in the presence of IFN-γ producing CD8+ T cells until they hide themselves from the adaptive immune system by losing the tumor antigen, neu. Relapsed tumor cells show CD44+CD24- phenotype with higher rates of tumorigenesis, in vivo. Acquisition of CD44+CD24- phenotype in relapsed tumors was not solely due to Darwinian selection. Our data suggest that tumor cells control the outcome of tumor immune surveillance through modulation of the expression of IFN-γ Rα
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