6,300 research outputs found
Assessing the climate impacts of Chinese dietary choices using a telecoupled global food trade and local land use framework
Global emissions trajectories developed to meet the 2⁰C temperature target are likely to rely on the widespread deployment of negative emissions technologies and/or the implementation of substantial terrestrial carbon sinks. Such technologies include afforestation, carbon capture and storage (CCS) and bioenergy with carbon capture and storage (BECCS), but mitigation options for agriculture appear limited. For example, using the Global Calculator tool (http://www.globalcalculator.org/), under a 2⁰C pathway, the ‘forests and other land use’ sector is projected to become a major carbon sink, reaching -15 GtCO2e yr-1 by 2050, compared to fossil emissions of 21 GtCO2e yr-1. At the same time, rates of agricultural emissions remain static at about 6 GtCO2e yr-1, despite increasing demands for crop and livestock production to meet the forecast dietary demands of the growing and increasingly wealthy global population. Emissions in the Global Calculator are sensitive to the assumed global diet, and particularly to the level and type of meat consumption, which in turn drive global land use patterns and agricultural emissions. Here we assess the potential to use a modified down-scaled Global Calculator methodology embedded within the telecoupled global food trade framework, to estimate the agricultural emissions and terrestrial carbon stock impacts in China and Brazil, arising from a plausible range of dietary choices in China. These dietary choices are linked via telecoupling mechanisms to Brazilian crop production (e.g. Brazilian soy for Chinese animal feed provision) and drive land and global market dynamics. ‘Spill-over’ impacts will also be assessed using the EU and Malawi as case studies
Rapamycin induces transactivation of the EGFR and increases cell survival.
The mammalian target of rapamycin (mTOR) signaling network regulates cell growth, proliferation and cell survival. Deregulated activation of this pathway is a common event in diverse human diseases such as cancers, cardiac hypertrophy, vascular restenosis and nephrotic hypertrophy. Although mTOR inhibitor, rapamycin, has been widely used to inhibit the aberrant signaling due to mTOR activation that plays a major role in hyperproliferative diseases, in some cases rapamycin does not attenuate the cell proliferation and survival. Thus, we studied the mechanism(s) by which cells may confer resistance to rapamycin. Our data show that in a variety of cell types the mTOR inhibitor rapamycin activates extracellularly regulated kinases (Erk1/2) signaling. Rapamycin-mediated activation of the Erk1/2 signaling requires (a) the epidermal growth factor receptor (EGFR), (b) its tyrosine kinase activity and (c) intact autophosphorylation sites on the receptor. Rapamycin treatment increases tyrosine phosphorylation of EGFR without the addition of growth factor and this transactivation of receptor involves activation of c-Src. We also show that rapamycin treatment triggers activation of cell survival signaling pathway by activating the prosurvival kinases Erk1/2 and p90RSK. These studies provide a novel paradigm by which cells escape the apoptotic actions of rapamycin and its derivatives that inhibit the mTOR pathway
Introduction of structured oral examination in formative assessment of pharmacology for 2nd professional MBBS students
Background: Conventional Oral Examination (COE) is criticized for being too subjective and being influenced by academic and non-academic factors. Another pitfall of COE is unequal distribution of time. Different examiners use a different set of questions with varying difficulty levels. Student related factors include gender, accent, vocabulary used and ability to pick nonverbal cues. These factors make COE less reliable and valid assessment tool. To overcome the limitations of this useful tool, SOE can be implement instead of COE.Methods: It is a prospective and non-randomized study comprising 79 students of pharmacology appeared for two forms of viva i.e. COE and SOE. Three sets of questionnaires - Must know, should know and nice to know were prepared, each having 15 items with increasing difficulty levels and were validated by subject experts and pretested. Ten minutes were allotted for each student for each form of viva. Feedback of students about the novel method was obtained by using semi-structured questionnaire comprising of 19 closed ended questions and one open-ended question.Results: Structured oral examination (SOE) yielded significantly higher marks as compared to COE. There were significant inter-examiner variations in marks awarded in SOE and COE. Other factors influencing implementation were difficulty in structuring viva, rigid time limits, lack of flexibility in knowledge content, monotony and fatigue. The students perceived this format not different from COE but felt that it required in depth preparation of topic.Conclusions: Conducting SOE is a resource-intensive exercise. Despite structuring, inter-examiner variability was not completely eliminated. The student’s performance was depended on factors related to examiners such as teaching experience, vernacular language used, and lack of training. Orientation and training of examiners in assessment strategies is necessary. Standardization of questionnaire is necessary before the implementation of SOE for summative assessment
Aspects of mutually unbiased bases in odd prime power dimensions
We rephrase the Wootters-Fields construction [Ann. Phys., {\bf 191}, 363
(1989)] of a full set of mutually unbiased bases in a complex vector space of
dimensions , where is an odd prime, in terms of the character
vectors of the cyclic group of order . This form may be useful in
explicitly writing down mutually unbiased bases for .Comment: 3 pages, latex, no figure
Quantum phase space distributions in thermofield dynamics
It is shown that the the quantum phase space distributions corresponding to a
density operator can be expressed, in thermofield dynamics, as overlaps
between the state and "thermal" coherent states. The usefulness
of this approach is brought out in the context of a master equation describing
a nonlinear oscillator for which exact expressions for the quantum phase
distributions for an arbitrary initial condition are derived.Comment: 17 pages, revtex, no figures. number of pages were incorrectly stated
as 3 instead of 17. No other correction
How varying CD4 criteria for treatment initiation was associated with mortality of HIV-patients? A retrospective analysis of electronic health records from Andhra Pradesh, India
Background HIV treatment and care services were scaled up in 2007 in India with objective to increase HIV-care coverage. CD4 count based criteria was mainly used for treatment initiation with increasing threshold in later years. Therefore, this paper aimed to evaluate the survival by varying CD4 criteria for antiretroviral treatment (ART) initiation among of HIV-positive patients, and independent factors associated with the mortality. Methods This retrospective cohort study included 127 949 HIV-positive patients aged ≥15 years, who initiated ART between 2007 and 2013 in Andhra Pradesh state, India. The patient’s demographic and clinical characteristics were extracted from the patient’s health records from electronic Computerized Management Information System Software (CMIS). Incidence of mortality/100 person-years was calculated for CD4 and treatment initiation categories. Kaplan-Meier and multivariable Cox-regression analyses were used to explore the association. Results Median CD4 count was 172 (inter-quartile range (IQR) = 102-240) at the time of treatment initiation, and 19.3% of them had ≤ 100 CD4 count. Incidence of mortality for the period 2007-08 (CD4 ≤ 200 cells/mm3) was 8.5/100 person-years compared to 6.4/100 person-years at risk for the period 2012 onwards (CD4 ≤ 350 cells/mm3). Earlier thresholds for treatment initiation showed higher risk of mortality (2007-08 (CD4 ≤ 200 cells/mm3), adjusted hazard ratio (HR): 1.86, 95% confidence interval (CI): 1.68-2.07; 2009-11 (CD4 ≤ 250 cells/mm3), HR = 1.67, 95% CI = 1.51-1.85) compared to 2012 onwards (CD4 ≤ 350 cells/mm3) criteria for treatment initiation. Conclusions Increasing CD4 threshold for treatment initiation over time was independently associated with lower risk of mortality. More efforts are required to detect and treat early, monitoring of follow-ups, promote health education to improve ART adherence, and provide supportive environment that encourages HIV-infected patients to disclose their HIV status in confidence
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