4,849 research outputs found
The Affect of Temperature on the Fluorescence of Heteromeles arbutifolia (Hollywood) in the Santa Monica Mountains
Presented here is a comparison of the predawn fluorescence of adult Heteromeles arbutifolia growing on the Pepperdine Seaver campus next to the lacrosse field, and adult Heteromeles growing in Tapia canyon. The analysis of the leaf temperature measured by an IR thermometer showed an average of 9.32°C drop when measuring plants in Tapia canyon compared to those growing on the warmer Pepperdine campus. The air temperature measured by the Kestrel and IR thermometer showed Tapia canyon being an average of 7.27°C colder than predawn measurements on Pepperdine campus. Finally, the fluorescence of the plants in both locations was measured using a Pulse-modulated fluorometer, and based on these results it is evident that there is no difference between the fluorescence of Heteromeles arbutifolia grown in a cold climate versus a warm climate
Vascular dysfunction and fibrosis in stroke-prone spontaneously hypertensive rats: the aldosterone-mineralocorticoid receptor-Nox1 Axis
Aims:
We questioned whether aldosterone and oxidative stress play a role in vascular damage in severe hypertension and investigated the role of Nox1 in this process.
Materials and methods:
We studied mesenteric arteries, aortas and vascular smooth muscle cells (VSMC) from WKY and SHRSP rats. Vascular effects of eplerenone or canrenoic acid (CA) (mineralocorticoid receptor (MR) blockers), ML171 (Nox1 inhibitor) and EHT1864 (Rac1/2 inhibitor) were assessed. Nox1-knockout mice were also studied. Vessels and VSMCs were probed for Noxs, reactive oxygen species (ROS) and pro-fibrotic/inflammatory signaling.
Key findings:
Blood pressure and plasma levels of aldosterone and galectin-3 were increased in SHRSP versus WKY. Acetylcholine-induced vasorelaxation was decreased (61% vs 115%) and phenylephrine-induced contraction increased in SHRSP versus WKY (Emax 132.8% vs 96.9%, p < 0.05). Eplerenone, ML171 and EHT1864 attenuated hypercontractility in SHRSP. Vascular expression of collagen, fibronectin, TGFβ, MCP-1, RANTES, MMP2, MMP9 and p66Shc was increased in SHRSP versus WKY. These changes were associated with increased ROS generation, 3-nitrotyrosine expression and Nox1 upregulation. Activation of vascular p66Shc and increased expression of Nox1 and collagen I were prevented by CA in SHRSP. Nox1 expression was increased in aldosterone-stimulated WKY VSMCs, an effect that was amplified in SHRSP VSMCs (5.2vs9.9 fold-increase). ML171 prevented aldosterone-induced VSMC Nox1-ROS production. Aldosterone increased vascular expression of fibronectin and PAI-1 in wild-type mice but not in Nox1-knockout mice.
Significance:
Our findings suggest that aldosterone, which is increased in SHRSP, induces vascular damage through MR-Nox1-p66Shc-mediated processes that modulate pro-fibrotic and pro-inflammatory signaling pathways
Emergency supply of prescription-only medicines to patients by community pharmacists: a mixed methods evaluation incorporating patient, pharmacist and GP perspectives
Objective To evaluate and inform emergency supply of prescription-only medicines by community pharmacists (CPs), including how the service could form an integral component of established healthcare provision to maximise adherence.
Design Mixed methods. 4 phases: prospective audit of emergency supply requests for prescribed medicines (October–November 2012 and April 2013); interviews with CPs (February–April 2013); follow-up interviews with patients (April–May 2013); interactive feedback sessions with general practice teams (October–November 2013).
Setting 22 community pharmacies and 6 general practices in Northwest England.
Participants 27 CPs with experience of dealing with requests for emergency supplies; 25 patients who received an emergency supply of a prescribed medicine; 58 staff at 6 general practices.
Results Clinical audit in 22 pharmacies over two 4-week periods reported that 526 medicines were requested by 450 patients. Requests peaked over a bank holiday and around weekends. A significant number of supplies were made during practice opening hours. Most requests were for older patients and for medicines used in long-term conditions. Difficulty in renewing repeat medication (forgetting to order, or prescription delays) was the major reason for requests. The majority of medicines were ‘loaned’ in advance of a National Health Service (NHS) prescription. Interviews with CPs and patients indicated that continuous supply had a positive impact on medicines adherence, removing the need to access urgent care. General practice staff were surprised and concerned by the extent of emergency supply episodes.
Conclusions CPs regularly provide emergency supplies to patients who run out of their repeat medication, including during practice opening hours. This may aid adherence. There is currently no feedback loop, however, to general practice. Patient care and interprofessional communication may be better served by the introduction of a formally structured and funded NHS emergency supply service from community pharmacies, with ongoing optimisation of repeat prescribing
Higgs Discovery through Top-Partners using Jet Substructure
Top-partners -- vector-like quarks which mix predominantly with the top quark
-- are simple extensions of the standard model present in many theories of new
physics such as little Higgs models, topcolor models, and extra dimensions.
Through renormalizable mixing with the top quark, these top-partners inherit
couplings to the Higgs boson. Higgs bosons produced from the decay of
top-partners are often highly boosted and ideal candidates for analyses based
on jet substructure. Using substructure methods, we show that light Higgs
bosons decaying to b b-bar can be discovered at the 14 TeV LHC with less than
10 inverse fb for top-partner masses up to 1 TeV.Comment: 11 pages, 7 figure
Recommended from our members
Pesticide spraying for West Nile virus control and emergency department asthma visits in New York City, 2000
Pyrethroid pesticides were applied via ground spraying to residential neighborhoods in New York City during July–September 2000 to control mosquito vectors of West Nile virus (WNV). Case reports link pyrethroid exposure to asthma exacerbations, but population-level effects on asthma from large-scale mosquito control programs have not been assessed. We conducted this analysis to determine whether widespread urban pyrethroid pesticide use was associated with increased rates of emergency department (ED) visits for asthma. We recorded the dates and locations of pyrethroid spraying during the 2000 WNV season in New York City and tabulated all ED visits for asthma to public hospitals from October 1999 through November 2000 by date and ZIP code of patients’ residences. The association between pesticide application and asthma-related emergency visits was evaluated across date and ZIP code, adjusting for season, day of week, and daily temperature, precipitation, particulate, and ozone levels. There were 62,827 ED visits for asthma during the 14-month study period, across 162 ZIP codes. The number of asthma visits was similar in the 3-day periods before and after spraying (510 vs. 501, p = 0.78). In multivariate analyses, daily rates of asthma visits were not associated with pesticide spraying (rate ratio = 0.92; 95% confidence interval, 0.80–1.07). Secondary analyses among children and for chronic obstructive pulmonary disease yielded similar null results. This analysis shows that spraying pyrethroids for WNV control in New York City was not followed by population-level increases in public hospital ED visit rates for asthma
Review of soil water models with respect to savanna hydrology
Effective management leading towards sustainable rangeland production in arid and semi-arid regions will stem from effective soil water management and comprehension of the hydrological properties of the soil in relation to pastoralism. However, in such areas, there is great complexity of interaction between the soil, climate and vegetation. Highly variable climates can give rise to extended dry periods in which the majority of rain that does fall is lost to surface evaporation.
Soil water dynamics are a function of soil physical processes and the competition between plant species and individuals for soil water and space. Spatial distribution of canopy and rooting patterns dictate the outcome of this competition, and the subsequent stability of the vegetation structure, although soil nutrients may be more important in determining vegetation composition. However, rainfall infiltration and the spatial redistribution of runoff water are the predominant factors determining patterns in semi-arid vegetation, with grazing impacts and fire also contributing to the generation and maintenance of spatial heterogeneity.
Despite soil water content being the net result of climatic input, soil surface and subterranean characteristics, the extraction of water by plants and it’s return to the atmosphere, the integrated approach needed to comprehend the complete cycle is rarely adopted. Systems models assist us in identifying the gaps in our knowledge by integrating mathematical representations of processes operating at local scales in order to simulate larger scale natural phenomena. However, because of the differences between scientific disciplines, and the bias on investigation that different interests support, true fusion of knowledge is hard to achieve. Hydrologists and ecologists are historically ingrained in their view of soil water dynamics.
It is difficult to make comparisons between the approaches taken by hydrologists and ecologists, as they are so dissimilar, despite their mutual aim to predict the water content of the soil profile. This review aims to present these different approaches and identifies the similarities that actually harmonizes them beyond expectation
- …