4,565 research outputs found
Recommended from our members
Assessing the potential economic benefits to farmers from various GM crops becoming available in the European Union by 2025: results from an expert survey
This paper reports on a study that identified a range of crop-trait combinations that are: agronomically suited to the EU; provide advantages to arable farmers and consumers; and are either already available in international markets, or advancing along the development pipeline and likely to become available by 2025. An expert stakeholder panel was recruited and asked for their views, using the Delphi approach, on the impact of these crop-traits on enterprise competitiveness, through changes to yields, production costs and product prices. In terms of input traits, there was consensus that traits such as herbicide tolerant/insect resistant (HT/IR) maize, HT sugar beet and HT soya bean would provide positive benefits for farmers. Output-side traits such as winter-sown rape with reduced saturated fats, were seen as offering benefits to consumers, but were either likely to be restricted to niche markets, or offer relatively modest price premia to farmers growing them. Our analysis of the financial impact of the adoption of GM crops more widely in the EU, showed that the competitiveness of the agricultural sector could well be improved by this. However, such improvements would be relatively small-scale in that large-scale national natural advantages from either economic or environmental conditions is unlikely to be overturned
Combining amenity with experience: exploring the hidden capital of a winescape experience
© The Author(s) 2016. Industry and government bodies have recommended augmentation of traditional production and marketing techniques as ways of increasing an industry’s profitability. This article values the amenity of the wine industry, a sensory experience that provides an array of opportunities both culturally to the tourist and economically to many regions across the world. Using the wine industry in the Central West region of New South Wales, Australia, we use input–output analysis to assess the economic impacts of this industry and the amenity hidden within. The industry not only provides jobs and commerce supporting local prosperity but also supplies a mixed production and consumption amenity from an agricultural product that meets the tourist’s leisure desire – an amenity that transcends from its origin in the vineyard to its destination at the table
Recommended from our members
Above all, do no harm: Towards more ethical ways of being and acting in psychological formulation
Recent evidence seems to suggest mental health service users can be at risk of persistent harm as a result of psychological interventions. This article analyses ways of addressing harm by using the ‘lenses’ of four ethical theories to view psychological formulation
Identifying and treating high blood pressure in men under 55 years with grade 1 hypertension: the TREAT CASP study and RCT
Background:
There is uncertainty regarding whether or not younger (i.e. aged < 55 years), low-risk patients with grade 1 hypertension (i.e. a clinic blood pressure of 140–159/90–99 mmHg) should be treated with blood pressure-lowering medication. This is a heterogeneous group of patients because of variation in systolic/pulse pressure amplification from the central aorta to the brachial artery. It is hypothesised that within grade 1 hypertension, patients can be divided into those with high central aortic systolic pressure and those with low central aortic systolic pressure.
Objectives:
The aims of this study were to (1) evaluate whether or not non-invasive central aortic systolic pressure measurement can better identify younger patients with grade 1 hypertension, who are more likely to have an increased left ventricular mass index; and (2) determine whether or not blood pressure lowering regresses early cardiac structural change in patients with high central aortic systolic pressure.
Setting:
A university hospital with satellite primary care recruitment sites.
Participants:
A total of 726 men (aged 18 to < 55 years) were screened to identify 162 men with grade 1 hypertension and low or high central aortic systolic pressure. Blood pressure status was classified according to seated clinic blood pressure, central aortic systolic pressure and 24-hour ambulatory blood pressure.
Design:
(1) Evaluating the strength of the correlation between central aortic systolic pressure, clinic blood pressure and 24-hour ambulatory blood pressure with left ventricular mass index in 162 patients; (2) a 12-month randomised controlled trial in patients with grade 1 hypertension and high central aortic systolic pressure (i.e. a central aortic systolic pressure of ≥ 125 mmHg) (n = 105), using a prospective, open, blinded, end-point design; and (3) a 12-month observational study in 57 patients with grade 1 hypertension and low central aortic systolic pressure (i.e. a central aortic systolic pressure of < 125 mmHg).
Interventions:
Randomised controlled trial – patients with high central aortic systolic pressure randomised to blood pressure lowering medication (50–100 mg of losartan ± 5–10 mg of amlodipine once daily) versus usual care (no treatment) for 12 months.
Main outcomes:
Randomised controlled trial primary end point – change in left ventricular mass index as measured by cardiac magnetic resonance imaging, comparing treatment with no treatment.
Results:
(1) At baseline, left ventricular mass index was higher in men with high central aortic systolic pressure than in those with low central aortic systolic pressure (mean ± standard deviation 67.9 ± 8.8 g/m2 vs. 64.0 ± 8.5 g/m2; difference 4.0 g/m2, 95% confidence interval 1.1 to 6.9 g/m2; p < 0.01). Central aortic systolic pressure was not superior to clinic blood pressure as a determinant of left ventricular mass index. Univariate analysis, regression coefficients and slopes for left ventricular mass index were similar for clinic systolic blood pressure, ambulatory systolic blood pressure and central aortic systolic pressure. (2) In the randomised controlled trial, blood pressure-lowering treatment reduced central aortic systolic pressure (–21.1 mmHg, 95% confidence interval – 24.4 to –17.9 mmHg; p < 0.001) and clinic systolic blood pressure (–20.0  mmHg, 95% confidence interval – 23.3 to –16.6 mmHg; p < 0.001) versus no treatment. Treatment was well tolerated and associated with a greater change (i.e. from baseline to study closeout) in left ventricular mass index versus no treatment [–3.3 g/m2 (95% confidence interval –4.5 to –2.2 g/m2) vs. –0.9 g/m2 (95% confidence interval –1.7 to –0.2 g/m2); p < 0.01], with a medium-to-large effect size (Cohen’s d statistic –0.74). (3) Patients with low central aortic systolic pressure had no significant change in left ventricular mass index after 12 months (mean change –0.5 g/m2, 95% confidence interval –1.2 to 0.2 g/m2; p = 0.18).
Conclusions:
Men with grade 1 hypertension and high central aortic systolic pressure tended to have higher clinic blood pressure and more hypertension-mediated cardiac structural change than those with low central aortic systolic pressure. Central aortic systolic pressure was not superior to clinic blood pressure or ambulatory blood pressure at stratifying risk of increased left ventricular mass index. Blood pressure-lowering treatment led to a regression of left ventricular mass index in men with grade 1 hypertension and high central aortic systolic pressure compared with no treatment.
Limitations:
The study was limited to a moderate sample of men and there was a low prevalence of very high amplification
Pulse Wave Calibration and Implications for Blood Pressure Measurement: Systematic Review and Meta-Analysis
Central aortic systolic pressure (CASP) can be estimated via filtering of the peripheral pulse wave (PPW) following calibration to brachial blood pressure. Recent studies suggest PPW calibration to mean arterial pressure (MAP) and diastolic BP (DBP) provides more accurate CASP estimates (CASPMD) versus conventional calibration to systolic BP (SBP) and DBP (CASPSD). However, the peak of the MAP-DBP calibrated PPW, that is, SBPMD, is rarely reported or used for BP amplification calculations, despite CASPMD being derived from it. We aimed to calculate the unreported SBPMD from studies using MAP-DBP calibration for estimation of CASPMD and compared it with oscillometric brachial SBP (brSBP). Medline database was searched to March 18, 2020. Meta-analysis includes studies reporting noninvasive CASPSD, CASPMD, brSBP, and brachial DBP. SBPMD was calculated using linear function equations. Data from 21 studies used 8 different BP monitors (13 460 participants, mean age: 54±10 years, 57% female, brachial blood pressure: 130±14/79±9 mm Hg). Weighted mean difference between SBPMD and brSBP was 10 mm Hg (range, -2 to 17 mm Hg) and appeared device specific. Calibration of brachial versus radial PPWs to brachial blood pressure showed a greater disparity between SBPMD and brSBP (14 versus 2 mm Hg). BP amplification was similar comparing SBP-DBP versus MAP-DBP calibrations (brSBP-CASPSD versus SBPMD-CASPMD: 9 versus 11 mm Hg), with no instances of reverse BP amplification. PPWs calibrated to MAP-DBP to derive CASPMD generates SBPMD that differs markedly from brSBP with some oscillometric BP monitors. These findings have important implications for BP monitor accuracy, BP amplification, PPW calibration recommendations, and studies of associations between CASP versus SBP and outcomes
Coulomb interactions in single, charged self-assembled quantum dots: radiative lifetime and recombination energy
We present results on the charge dependence of the radiative recombination
lifetime, Tau, and the emission energy of excitons confined to single
self-assembled InGaAs quantum dots. There are significant dot-to-dot
fluctuations in the lifetimes for a particular emission energy. To reach
general conclusions, we present the statistical behavior by analyzing data
recorded on a large number of individual quantum dots. Exciton charge is
controlled with extremely high fidelity through an n-type field effect
structure, providing access to the neutral exciton (X0), the biexciton (2X0)
and the positively (X1+) and negatively (X1-) charged excitons. We find
significant differences in the recombination lifetime of each exciton such
that, on average, Tau(X1-) / Tau(X0) = 1.25, Tau(X1+) / Tau(X0) = 1.58 and
Tau(2X0) / Tau(X0) = 0.65. We attribute the change in lifetime to significant
changes in the single particle hole wave function on charging the dot, an
effect more pronounced on charging X0 with a single hole than with a single
electron. We verify this interpretation by recasting the experimental data on
exciton energies in terms of Coulomb energies. We show directly that the
electron-hole Coulomb energy is charge dependent, reducing in value by 5-10% in
the presence of an additional electron, and that the electron-electron and
hole-hole Coulomb energies are almost equal.Comment: 8 pages, 7 figures, submitted to Phys. Rev.
The Plasmodium berghei Ca(2+)/H(+) exchanger, PbCAX, is essential for tolerance to environmental Ca(2+) during sexual development.
Ca(2+) contributes to a myriad of important cellular processes in all organisms, including the apicomplexans, Plasmodium and Toxoplasma. Due to its varied and essential roles, free Ca(2+) is tightly regulated by complex mechanisms. These mechanisms are therefore of interest as putative drug targets. One pathway in Ca(2+) homeostatic control in apicomplexans uses a Ca(2+)/H(+) exchanger (a member of the cation exchanger family, CAX). The P. falciparum CAX (PfCAX) has recently been characterised in asexual blood stage parasites. To determine the physiological importance of apicomplexan CAXs, tagging and knock-out strategies were undertaken in the genetically tractable T. gondii and P. berghei parasites. In addition, a yeast heterologous expression system was used to study the function of apicomplexan CAXs. Tagging of T. gondii and P. berghei CAXs (TgCAX and PbCAX) under control of their endogenous promoters could not demonstrate measureable expression of either CAX in tachyzoites and asexual blood stages, respectively. These results were consistent with the ability of parasites to tolerate knock-outs of the genes for TgCAX and PbCAX at these developmental stages. In contrast, PbCAX expression was detectable during sexual stages of development in female gametocytes/gametes, zygotes and ookinetes, where it was dispersed in membranous networks within the cytosol (with minimal mitochondrial localisation). Furthermore, genetically disrupted parasites failed to develop further from "round" form zygotes, suggesting that PbCAX is essential for ookinete development and differentiation. This impeded phenotype could be rescued by removal of extracellular Ca(2+). Therefore, PbCAX provides a mechanism for free living parasites to multiply within the ionic microenvironment of the mosquito midgut. Ca(2+) homeostasis mediated by PbCAX is critical and suggests plasmodial CAXs may be targeted in approaches designed to block parasite transmission
- …