JURNAL AGROTEKNOLOGI
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Bias and consistency in three-way gravity models
No full textWe study the incidental parameter problem for the “three-way” Poisson Pseudo-Maximum Likelihood (“PPML”) estimator recently recommended for identifying the effects of trade policies and in other panel data gravity settings. Despite the number and variety of fixed effects involved, we confirm PPML is consistent for fixed T and we show it is in fact the only estimator among a wide range of PML gravity estimators that is generally consistent in this context when T is fixed. At the same time, asymptotic confidence intervals in fixed-T panels are not correctly centered at the true point estimates, and cluster-robust variance estimates used to construct standard errors are generally biased as well. We characterize each of these biases analytically and show both numerically and empirically that they are salient even for real-data settings with a large number of countries. We also offer practical remedies that can be used to obtain more reliable inferences of the effects of trade policies and other time-varying gravity variables, which we make available via an accompanying Stata package called ppml_fe_bias
The structural basis of fatty acid elongation by the ELOVL elongases
No full textVery long chain fatty acids (VLCFAs) are essential building blocks for the synthesis of ceramides and sphingolipids. The first step in the fatty acid elongation cycle is catalyzed by the 3-keto acyl-coenzyme A (CoA) synthases (in mammals, ELOVL elongases). Although ELOVLs are implicated in common diseases, including insulin resistance, hepatic steatosis and Parkinson’s, their underlying molecular mechanisms are unknown. Here we report the structure of the human ELOVL7 elongase, which comprises an inverted transmembrane barrel surrounding a 35-Å long tunnel containing a covalently attached product analogue. The structure reveals the substrate-binding sites in the narrow tunnel and an active site deep in the membrane. We demonstrate that chain elongation proceeds via an acyl-enzyme intermediate involving the second histidine in the canonical HxxHH motif. The unusual substrate-binding arrangement and chemistry suggest mechanisms for selective ELOVL inhibition, relevant for diseases where VLCFAs accumulate, such as X-linked adrenoleukodystrophy
Detection of asymptomatic carotid stenosis in patients with lower extremity arterial disease: development and external validations of a risk score
No full textBackground: Recommendations for screening patients with lower extremity arterial disease (LEAD) to detect asymptomatic carotid stenosis (ACS) are conflicting. Prediction models might identify patients at high risk of ACS, possibly allowing targeted screening to improve preventive therapy and compliance.
Methods: We conducted aA systematic search for prediction models for ≥50% ACS in patients with LEAD was conducted. A prediction model in screened patients from the United States with anklebrachial index (ABI) of ≤0.9 was subsequently developed and . We assessed for discrimination and calibration. Finally, external validation in two independent cohorts, comprising 5400 cases from the
United Kingdom and 1536 cases from the Netherlands.
Results: After screening 4721 studies, no previously published prediction models were found. For
development of our new model, data of 112,117 cases were used, of whom 6354 (5.7%) had ≥50% and 2801 (2.5%) had ≥70% ACS. Age, sex, smoking status, history of hypercholesterolemia, stroke/TIA, CHD and measured SBP were predictors of ACS. The model discriminated well, with an area under receiver operator characteristic (AUROC) curve of 0.71 (95%CI, 0.71-0.72) for ≥50% and 0.73 (95%CI,
0.72-0.74) for ≥70% ACS. Screening the 20% cases at highest risk detected 13.1% with ≥50% [number needed to screen (NNS: 8)], and 5.8% with ≥70% ACS (NNS: 17). This yielded 44.2% and 46.9% of cases with ≥50% and ≥70% ACS, respectively. External validation showed reliable discrimination and adequate calibration.
Conclusion: The present risk score can predict significant ACS in LEAD cases reliably. This approach
can be used to inform targeted screening of high-risk individuals to enhance detection of ACS.
Levelling up taxation, funding and education
No full textIn this piece Professor Danny Dorling FAcSS explores some of the complexities and nuances of inequality in the UK. He shines a light on some compelling evidence which makes the case for progressive taxation and reforming education funding as essential ingredients of effective levelling up
Strain sensing metacomposites of polyaniline/silver nanoparticles/carbon foam
No full textMetacomposites have received extensive attention due to their unique electromagnetic properties and excellent structural designability. Although altering composition content is a mature way to change electromagnetic performance, some inherent defects (e.g.: fixed and narrow application frequency, poor environmental adaptability, etc.) caused by this passive adjustment method indeed restrict their further development. Herein, a strain sensing polyaniline/silver nanoparticles/carbon foam (PANI/Ag NPs/CF) metacomposites have been fabricated as an innovative example to tune electromagnetic parameters via strain regulation. Negative permittivity and negative permeability can be effectively adjusted within broad microwave frequency range. Moreover, the mathematical relationship between electromagnetic parameters and deformation degree has further been established to precisely control the metamaterial properties. This strain sensing PANI/Ag NPs/CF metacompsoites break the limitation of fixed working frequency of shaped metacomposites and propose a convenient method to achieve precise adjustment of metacomposite properties, which is very significant for implementing the intelligent adjustable metamaterial applications
Understanding community health worker incentive preferences in Uganda using a discrete choice experiment
No full textBackground
Community health workers (CHWs) play a critical role in supporting health systems, and in improving the availability and accessibility to health care. However, CHW programs globally continue to face challenges with poor performance and high levels of CHW attrition. CHW programs are often underfunded and poorly planned, which can lead to loss of motivation by CHWs. The study aims to determine preferences of CHWs for job incentives with the goal of furthering their motivation and success.
Methods
Relevant incentive attributes were identified through focus group discussions and in-depth interviews with CHWs, non-governmental organization CHWs, CHW supervisors, and policy-level stakeholders. Based on seven attributes (eg, training, workload, stipend) we developed a discrete choice experiment (DCE) that was administered to 399 CHWs across eight districts in Uganda. We used conditional and mixed multinomial logit models to estimate the utility of each job attribute. We calculated the marginal willingness to accept as the trade-off the CHWs were willing to make for a change in salary.
Results
CHWs preferred higher salaries, though salary was not the most important attribute. There was a preference for reliable transportation, such as a bicycle (β = 1.86, 95% CI = 1.06, 2.67), motorcycle (β = 1.81, 95% CI = 1.27, 2.34) or transport allowance (β = 1.37, 95% CI = 0.65, 2.10) to no transport. Formal identification including identity badges (β = 1.61, 95% CI = 0.72, 2.49), branded uniforms (β = 1.04, 95% CI = 0.45, 1.63) and protective branded gear (β = 0.76, 95% CI = 0.32, 1.21) were preferred compared to no identification. CHWs also preferred more regular refresher trainings, the use of mobile phones as job-aids and a lesser workload. The relative importance estimates suggested that transport was the most important attribute, followed by identification, refresher training, salary, workload, recognition, and availability of tools. CHWs were willing to accept a decrease in salary of USH 31 240 (US23) for branded uniforms to no identification.
Conclusions
This study utilized CHW and policymaker perspectives to identify realistic and pragmatic incentives to improve CHW working conditions, which is instrumental in improving their retention. Non-monetary incentives (eg, identification, transportation) are crucial motivators for CHWs and should be considered as part of the compensation package to facilitate improved performance of CHW programs
Personalized exercise prescription in the prevention and treatment of arterial hypertension: a Consensus Document from the European Association of Preventive Cardiology (EAPC) and the ESC Council on Hypertension
No full textTreatment of hypertension and its complications remains a major ongoing health care challenge. Around 25% of heart attacks in Europe are already attributed to hypertension and by 2025 up to 60% of the population will have hypertension. Physical inactivity has contributed to the rising prevalence of hypertension, but patients who exercise or engage in physical activity reduce their risk of stroke, myocardial infarction, and cardiovascular mortality. Hence, current international guidelines on cardiovascular disease prevention provide generic advice to increase aerobic activity, but physiological responses differ with blood pressure (BP) level, and greater reductions in BP across a population may be achievable with more personalized advice. We performed a systematic review of meta-analyses to determine whether there was sufficient evidence for a scientific Consensus Document reporting how exercise prescription could be personalized for BP control. The document discusses the findings of 34 meta-analyses on BP-lowering effects of aerobic endurance training, dynamic resistance training as well as isometric resistance training in patients with hypertension, high-normal, and individuals with normal BP. As a main finding, there was sufficient evidence from the meta-review, based on the estimated range of exercise-induced BP reduction, the number of randomized controlled trials, and the quality score, to propose that type of exercise can be prescribed according to initial BP level, although considerable research gaps remain. Therefore, this evidence-based Consensus Document proposes further work to encourage and develop more frequent use of personalized exercise prescription to optimize lifestyle interventions for the prevention and treatment of hypertension
Instrumental requirements for the study of Venus’ cloud top using the UV imaging spectrometer VeSUV
No full textUltraviolet spectral imaging has been a powerful tool to investigate the cloud top of Venus, allowing for measurement of several minor gases (especially SO2, SO, O3), of cloud top aerosol’s microphysical properties and of atmospheric dynamics through tracking of the unevenly distributed UV absorber. After a brief review of recent UV instruments that orbited around Venus, we present the results of a state-of-the-art radiative transfer model from Marcq et al. (2020) to derive the spectral resolution and Signal-to-Noise ratio (SNR) required to derive abundances of these gases, retrieve optical properties of the aerosols beyond our current knowledge. This leads us to propose a two-channel UV hyperspectral push-broom imager called VeSUV (standing for Venusian Spectroscopy in UV) whose technical characteristics will improve on existing measurements by a factor of at least 2, and which is well suited to the integration into the payload of future low Venus orbit platforms such as the proposed EnVision mission to ESA M5 call
Protocol for the co-design and development of a primary school-based pathway for child anxiety screening and intervention delivery: A mixed-methods feasibility study
No full textIntroduction Anxiety difficulties are among the most common mental health problems in childhood. Despite this, few children access evidence-based interventions, and school may be an ideal setting to improve children’s access to treatment. This article describes the design, methods and expected data collection of the Identifying Child Anxiety Through Schools – Identification to Intervention (iCATS i2i) study, which aims to develop acceptable school-based procedures to identify and support child anxiety difficulties.
Methods and analysis iCATS i2i will use a mixed-methods approach to codesign and deliver a set of procedures—or ‘pathway’—to improve access to evidence-based intervention for child anxiety difficulties through primary schools in England. The study will consist of four stages, initially involving in-depth interviews with parents, children, school staff and stakeholders (stage 1) to inform the development of the pathway. The pathway will then be administered in two primary schools, including screening, feedback to parents and the offer of treatment where indicated (stage 2), with participating children, parents and school staff invited to provide feedback on their experience (stages 3 and 4). Data will be analysed using Template Analysis.
Ethics and dissemination The iCATS i2i study was approved by the University of Oxford’s Research Ethics Committee (REF R64620/RE001). It is expected that this codesign study will lead on to a future feasibility study and, if indicated, a randomised controlled trial. The findings will be disseminated in several ways, including via lay summary report, publication in academic journals and presentation at conferences. By providing information on child, parent, school staff and other stakeholder’s experiences, we anticipate that the findings will inform the development of an acceptable evidence-based pathway for identification and intervention for children with anxiety difficulties in primary schools and may also inform broader approaches to screening for and treating youth mental health problems outside of clinics
Remote versus face-to-face ambulatory blood pressure monitoring: de-identified blood pressure data from 65 participants of the Screening for Hypertension in the Inpatient Environment (SHINE) study
No full textThe two files within this dataset contain ambulatory blood pressure data for 65 participants collected between 2020 and 2021. Ten participants had their ambulatory blood pressure monitors fitted and decommissioned via face-to-face clinic appointments (prior to the UK COVID-19 epidemic) and fifty-five participants had their ambulatory blood pressure monitors distributed to their chosen community location by courier and fitted via remote video appointments and decommissioned via telephone call (during the UK COVID-19 epidemic).
The files were created in Excel and data analysis was performed in Excel for the manuscript pertaining to this data. The files have been converted to CSV for sharing to ensure accessibility and ease of use for others