9,988 research outputs found
On-chip timing measurement architecture with femtosecond resolution
A new timing measurement architecture based on the time-to-digital conversion technique is presented. The architecture occupies a small silicon area (200x185Āµm) in a 0.12Āµm CMOS Process and can achieve tens of femtoseconds timing resolution, which is the highest reported to date
Corporate Boards and Ownership Structure as Antecedents of Corporate Governance Disclosure in Saudi Arabian Publicly Listed Corporations
We investigate whether and to what extent publicly listed corporations voluntarily comply with and disclose recommended good corporate governance (CG) practices, and distinctively examine whether the observed cross-sectional differences in such CG disclosures can be explained by ownership and board mechanisms with specific focus on Saudi Arabia. Our results suggest that corporations with larger boards, a big-four auditor, higher government ownership, a CG committee and higher institutional ownership disclose considerably more than those that are not. By contrast, we find that an increase in block ownership significantly reduces CG disclosure. Our results are generally robust to a number of econometric models that control for different types of disclosure indices, firm-specific characteristics and firm-level fixed-effects. Our results have important implications for policy-makers, practitioners and regulatory authorities, especially those in developing countries across the globe
Transverse Spin Structure of the Nucleon through Target Single Spin Asymmetry in Semi-Inclusive Deep-Inelastic Reaction at Jefferson Lab
Jefferson Lab (JLab) 12 GeV energy upgrade provides a golden opportunity to
perform precision studies of the transverse spin and
transverse-momentum-dependent structure in the valence quark region for both
the proton and the neutron. In this paper, we focus our discussion on a
recently approved experiment on the neutron as an example of the precision
studies planned at JLab. The new experiment will perform precision measurements
of target Single Spin Asymmetries (SSA) from semi-inclusive electro-production
of charged pions from a 40-cm long transversely polarized He target in
Deep-Inelastic-Scattering kinematics using 11 and 8.8 GeV electron beams. This
new coincidence experiment in Hall A will employ a newly proposed solenoid
spectrometer (SoLID). The large acceptance spectrometer and the high polarized
luminosity will provide precise 4-D (, , and ) data on the
Collins, Sivers, and pretzelocity asymmetries for the neutron through the
azimuthal angular dependence. The full 2 azimuthal angular coverage in the
lab is essential in controlling the systematic uncertainties. The results from
this experiment, when combined with the proton Collins asymmetry measurement
and the Collins fragmentation function determined from the ee collision
data, will allow for a quark flavor separation in order to achieve a
determination of the tensor charge of the d quark to a 10% accuracy. The
extracted Sivers and pretzelocity asymmetries will provide important
information to understand the correlations between the quark orbital angular
momentum and the nucleon spin and between the quark spin and nucleon spin.Comment: 23 pages, 13 figures, minor corrections, matches published versio
A Cluster Analysis of Lifestyle and Health Habits of Youth from Two Geographically and Culturally Diverse Countries
Objectives: Obesity is a leading risk factor for global mortality, promoted by poor dietary habits and sedentary behaviour. This study explores the clustering and differences in dietary habits, body mass index (BMI) and physical activity (PA) amongst youth from United Kingdom (UK) and Saudi Arabia (SA). Methods: 2290 males and females aged 15 - 17 years completed a self-report questionnaire and an objective measure of BMI. Results: Youth from SA had a higher prevalence of overweight/obesity and lower levels of PA than youth from the UK. Males were more physically active than females across both countries. Three clusters were identified: a āhigh riskā cluster with least healthy dietary habits, low PA and high BMI; a āmoderate clusterā with moderate healthy dietary habits, PA and BMI; a ālow riskā cluster with healthiest dietary habits, greatest PA and the lowest BMI compared to the other clusters. There were more SA youth in the high and moderate risk clusters compared to UK youth. Conclusions: Exploring cross-cultural and demographic characteristics of youth enables the identification of similarities and differences that might lead to the development of universal intervention strategies
A comparison of machine learning models for the mapping of groundwater spring potential
Groundwater resources are vitally important in arid and semi-arid areas meaning that spatial planning tools are required for their exploration and mapping. Accordingly, this research compared the predictive powers of five machine learning models for groundwater potential spatial mapping in Wadi az-Zarqa watershed in Jordan. The five models were random forest (RF), boosted regression tree (BRT), support vector machine (SVM), mixture discriminant analysis (MDA), and multivariate adaptive regression spline (MARS). These algorithms explored spatial distributions of 12 hydrological-geological-physiographical (HGP) conditioning factors (slope, altitude, profile curvature, plan curvature, slope aspect, slope length (SL), lithology, soil texture, average annual rainfall, topographic wetness index (TWI), distance to drainage network, and distance to faults) that determine where groundwater springs are located. The area under the curve (AUC) of the receiver operating characteristic (ROC) curve was employed to evaluate the prediction accuracies of the five individual models. Here the results were ranked in descending order as MDA (83.2%), RF (80.6%), SVM (80.2%), BRT (78.0%), and MARS (75.5%).The results show good potential for further use of machine learning techniques for mapping groundwater spring potential in other places where the use and management of groundwater resources is essential for sustaining rural or urban life
Paper and electronic versions of HM-PRO, a novel patient-reported outcome measure for hematology: an equivalence study.
Ā© 2019 Goswami, Oliva, Ionova et al.Aim:To determine measurement equivalence of paper and electronic application of the hematologi-cal malignancy-patient-reported outcome (HM-PRO), a specific measure for the evaluation of patient-reported outcomes in HMs.Patients & methods:Following International Society of Pharmacoeconomicsand Outcomes Research ePRO Good Research Practice Task Force guidelines, a total of 193 adult patientswith different HMs were recruited into a multicenter prospective study. The paper and the electronic ver-sion of the instrument were completed in the outpatient clinics in a randomized crossover design with a30-min time interval to minimize the learning effect. Those who completed the paper version first, com-pleted the electronic version after 30 min and vice versa. Instrument version and order effects were testedon total score of the two parts of the HM-PRO (Part A: quality of life and Part B: signs & symptoms) in atwo-way ANOVA with patients as random effects. Intraclass correlation coefficients (95% CI) and Spear-manās rank correlation coefficients were used to evaluate testāretest reliability and reproducibility. Theeffects of instrument version and order were tested on total score of the two parts of HM-PRO.Results:The questionnaire version and administration order effects were not significant at the 5% level. Therewere no interactions found between these two factors for HM-PRO (Part A [quality of life]; p=0.95); and(part B [signs and symptoms]; p=0.72]. Spearmanās rank correlation coefficients were greater than 0.9, andintraclass correlation coefficients ranged from 0.94 to 0.98; furthermore, the scores were not statisticallydifferent between the two versions, showing acceptable reliability indexes. Noteworthy, the differencebetween the completion time for both paper (mean=6:38 min) and electronic version (mean=7:29 min)was not statistically significant (n=100; p=0.11). Patients did not report any difficulty in completing theelectronic version during cognitive interviews and were able to understand and respond spontaneously.Conclusion:Measurement equivalence has been demonstrated for the paper and electronic applicationof the HM-PRO.Peer reviewe
Use of the Haddon matrix as a tool for assessing risk factors for sharps injury in emergency departments in the United Arab Emirates
We investigated the epidemiology and prevention of sharps injuries in the United Arab Emirates. Among 82 emergency nurses and 38 doctors who responded to our questionnaire, risk factors for sharp device injuries identified using the Haddon matrix included personal factors (for the preāevent phase, a lack of infection control training, a lack of immunization, and recapping needles, and for the postevent phase, underreporting of sharps injuries) and equipmentārelated factors (for the preāevent phase, failure to use safe devices; for the event phase, failure to use gloves in all appropriate situations). Nearly all injuries to doctors were caused by suture needles, and among nurses more than 50% of injuries were caused by hollowābore needles
Accelerating Post-Harvest Food Loss Reduction in Nigeria Through the Development of a Pilot-Scale Vacuum Cooling and Storage System
The problem of the loss of food after harvest has drawn worldwide attention in the latest decades. The Food and Agriculture Organization (FAO) and other national and international organizations had estimated that one-third of all foods produced and half of all fruit and vegetables are lost or wasted between harvest and use. In September 2015, the United Nations (UN) announced its objective of decreasing global food waste and significantly decreasing global food loss by 2030, as part of its Sustainable Development Goals (SDG). The post-harvest loss of food is a major challenge in sub-Saharan African nations for farmers and growers, with spoilt foods leading to up to 50% of harvested food that does not reach the marketplace. This is not only a problem for farmers themselves, who are suffering from decreased incomes and loss of commercial opportunities, but it is also a problem for the environment and resources as far as unnecessary emissions of greenhouse gas are concerned. This paper examines the opportunities that a vacuum storage system presents in reducing food losses after harvest and highlights the challenges in Nigeria to adopt this technology. The equally encapsulated the design, fabrication and testing of vacuum cooling machine Keywords: Postharvest, Food Loss, Nigeria, Storage, Vacuum-Cooling DOI: 10.7176/JBAH/11-20-03 Publication date:October 31st 202
Space-for-time substitutions in climate change ecology and evolution
In an epoch of rapid environmental change, understanding and predicting how biodiversity will respond to a changing climate is an urgent challenge. Since we seldom have sufficient long-term biological data to use the past to anticipate the future, spatial climateābiotic relationships are often used as a proxy for predicting biotic responses to climate change over time. These āspace-for-time substitutionsā (SFTS) have become near ubiquitous in global change biology, but with different subfields largely developing methods in isolation. We review how climate-focussed SFTS are used in four subfields of ecology and evolution, each focussed on a different type of biotic variable ā population phenotypes, population genotypes, species' distributions, and ecological communities. We then examine the similarities and differences between subfields in terms of methods, limitations and opportunities. While SFTS are used for a wide range of applications, two main approaches are applied across the four subfields: spatial in situ gradient methods and transplant experiments. We find that SFTS methods share common limitations relating to (i) the causality of identified spatial climateābiotic relationships and (ii) the transferability of these relationships, i.e. whether climateābiotic relationships observed over space are equivalent to those occurring over time. Moreover, despite widespread application of SFTS in climate change research, key assumptions remain largely untested. We highlight opportunities to enhance the robustness of SFTS by addressing key assumptions and limitations, with a particular emphasis on where approaches could be shared between the four subfields
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