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We conduct a laboratory experiment in Kenya in which we elicit time and risk preference parameters from 494 participants, using convex time budgets and tightly controlling for transaction costs. Using the Kenyan mobile money system M-Pesa to make real-time transfers to subjects’ phones , we vary whether same-day payments are made immediately after the experimental session or at the close of the business day. We find strong evidence of present bias, with estimates of the present bias parameter ranging from 0.902 to 0.924—but only when same-day payments are made immediately after the experiment.
We propose Rényi information generating function (RIGF) and discuss its properties. A connection between the RIGF and the diversity index is proposed for discrete-type random variables. The relation between the RIGF and Shannon entropy of order q > 0 is established and several bounds are obtained. The RIGF of escort distribution is derived. Furthermore, we introduce the Rényi divergence information generating function (RDIGF) and discuss its effect under monotone transformations. We present nonparametric and parametric estimators of the RIGF. A simulation study is carried out and a real data relating to the failure times of electronic components is analyzed. A comparison study between the nonparametric and parametric estimators is made in terms of the standard deviation, absolute bias, and mean square error. We have observed superior performance for the newly proposed estimators. Some applications of the proposed RIGF and RDIGF are provided. For three coherent systems, we calculate the values of the RIGF and other well-established uncertainty measures, and similar behavior of the RIGF is observed. Further, a study regarding the usefulness of the RDIGF and RIGF as model selection criteria is conducted. Finally, three chaotic maps are considered and then used to establish a validation of the proposed information generating function.
A hospital-based cross-sectional study involving children aged 2–15 years attending the obesity clinic of a tertiary care hospital from January 2016 to March 2018 was carried out to study carotid intima media thickness (cIMT) and its association with cardiometabolic risk factors in children with overweight and obesity. Secondary objective was to compare children with elevated (EcIMT) and normal cIMT (NcIMT). Out of 223 patients enrolled for the study, 102 (45·7 %) had EcIMT. Mean cIMT of the study participants was 0·41 (sd 0·13) mm. Median alanine transaminase levels (27 v. 24, P= 0·006) and proportion of patients with fatty liver (63·7 % v. 48·8 %, P= 0·025) and ≥ 3 risk factors (80·4 % v. 66·1 %, P= 0·003) were higher in the EcIMT group compared with NcIMT group. Proportion of patients with hypercholesterolemia (36·4 % v. 16 %, P= 0·024), elevated LDL-cholesterol (38·6 % v. 16 %, P= 0·013), low HDL-cholesterol (40·9 % v. 20 %, P= 0·027) and dyslipidemia (84·1 % v. 58 %, P= 0·006) was higher in the pubertal EcIMT group and those with fatty liver (63·8 % v. 45·1 %, P= 0·034) was higher in the prepubertal EcIMT group compared with pubertal and prepubertal NcIMT groups, respectively. No significant correlations were observed between cIMT and various cardiometabolic parameters. Our finding of EcIMT in nearly half of the study participants including young children is very concerning as these children are at increased risk of atherosclerotic CVD in adulthood. Interventions starting at a young age are important when trajectories are likely to be more malleable and adverse cardiometabolic phenotypes and subclinical atherosclerosis are reversible.
The d-ATS patch was developed as an alternative to oral amphetamine formulations for attention-deficit hyperactivity disorder (ADHD). The US Food & Drug Administration (FDA) recommends evaluating irritation of transdermal patches under intended (rotating application sites) and exaggerated use (repeated application to one site). These studies assessed irritation after d-ATS application.
Methods
Intended Use: In Study 1, adults with ADHD, d-ATS was applied daily (9-hour application) for 4 weeks rotated between 5 sites (left/right: hip, flank, chest, upper arm, upper back), with irritation assessed on Days 1, 7, 14, 27, and 28. In Study 2, children and adolescents with ADHD, d-ATS was applied daily (9 hours) for 5 weeks to the hip (left or right), with irritation assessed daily.
Exaggerated Use: In Study 3, adults with ADHD, d-ATS was applied daily (9 hours) to the hip (repeated application to one site) for 4 weeks, with irritation assessed daily. In Study 4, healthy adults, 1 d-ATS and 1 placebo patch were applied daily (24 hours) for 21 days to the back (repeated application to 1 site), with irritation assessed daily.
Irritation was assessed by a trained evaluator 30-60 min after patch removal using Berger and Bowman Dermal Response (0-7, with 7 being the worst reaction) and Other Effects (0-3, with 3 being the worst reaction) scores. Dermal Response and Other Effects scores were added together for the combined score. A combined score of ≥3 was considered clinically meaningful irritation.
Results
Intended Use: In Study 1 (N=15), meaningful irritation after patch removal was reported in 9/15 subjects (60%). The mean (SD) combined score was 1.05 (0.21), with no treatment-emergent adverse events at the application site. In Study 2 (N=110), all combined irritation scores were ≤3 for d-ATS, with a combined score of 3 reported by 2% of patients. There were no discontinuations due to dermal reactions in either study.
Exaggerated Use: In Study 3 (N=20), meaningful irritation was reported in 19/20 subjects (95%). The mean (SD) combined score was 1.63 (0.78). In Study 4, mean (SD) combined scores were 2.1 (0.73) for d-ATS and 1.3 (0.69) for placebo (N=206 for both), with no discontinuations due to dermal reactions.
Conclusions
These results support previous findings that d-ATS is safe and well tolerated for ADHD. After intended use, irritation was minimal and did not cause study discontinuations.
The dextroamphetamine transdermal system (d-ATS) was developed as an alternative to current oral formulations of amphetamine, which is a first-line treatment for ADHD. In a randomized controlled trial of d-ATS in children and adolescents with ADHD, the primary endpoint (SKAMP total score) and secondary endpoints were met. This analysis evaluated the efficacy of d-ATS using SKAMP total score by optimized dose, gender, age group, ADHD type, and baseline ADHD severity.
Methods
This study comprised a 5-week, open-label dose-optimization period (DOP) followed by a 2-week, randomized, cross-over double-blind treatment period (DBP). All eligible patients received d-ATS 5 mg/9hr, with weekly evaluation for dose increase to 10 mg/9hr, 15 mg/9hr, and 20 mg/9hr. Once reached, the optimal dose was maintained for the DOP and used during the DBP. Preplanned subgroup analyses of mean SKAMP total score by optimized dose, gender, age group, ADHD type, and baseline ADHD severity were conducted. Efficacy was assessed by difference (d-ATS vs placebo) in least-squares (LS) mean SKAMP total score from a mixed-model repeated-measures (MMRM) analysis and is reported throughout as LS mean (95% confidence interval [CI]).
Results
In total, 110 patients were enrolled in the DOP, and 106 patients were randomized in the DBP. During the DOP, three patients reported 3 TEAEs that led to study discontinuation (irritability, appetite loss, abdominal pain). The difference (d-ATS vs placebo) in LS mean SKAMP total score was -5.9 (-6.8, -5.0), with differences in attention, deportment, and quality of work sub-scores of -1.4 (-1.7, -1.1), -1.9 (-2.2, -1.5), and -1.3 (-1.5, -1.0), respectively. Patients receiving d-ATS at each optimized dose demonstrated improvements vs placebo in LS mean SKAMP total score (-7.3 [-10.8, -3.7], -4.5 [-6.0, -3.0], -5.9 [-7.4, -4.5], -7.6 [-9.6, -5.6] at 5, 10, 15, and 20 mg/9hr, respectively). Both male and female patients experienced improvements vs placebo in SKAMP total score. The observed difference was greater in males (-6.3 [-7.3, -5.2]) vs females (-5.0 [-6.6, -3.4]). Similarly, improvements vs placebo were seen in patients with combined type ADHD and in those with predominantly inattentive type ADHD, with an observed LS mean difference of -8.0 (-9.2, -6.8) for the combined type and -3.3 (-4.6, -2.1) for the inattentive type. In addition, patients demonstrated improvement during the DBP regardless of baseline ADHD severity. The difference in LS mean SKAMP total score was -4.5 (-5.9, -3.1) for patients with a baseline SKAMP total score of 0-36 and -6.7 (-7.9, -5.6) for those with a baseline SKAMP score of 37-54.
Conclusions
d-ATS was effective and generally well-tolerated in treating ADHD in children and adolescents regardless of optimized dose, gender, age group, ADHD type, or baseline ADHD severity.
In this article, some additive models of behavioral measures are defined, and distributional tests of them are proposed. Major theoretical results include (a) conditions for additivity of components to predict the highest level of dominance in a model-free stochastic dominance hierarchy, (b) methods of identifying the shape of the hazard rate function of an added component from certain relationships among the observable density and distribution functions, and (c) effects of stochastic dependence between components on the distributional tests. Feasibility and usefulness of the methods are demonstrated by application to choice RT and ratings experiments.
Several neural networks have been proposed in the general literature for pattern recognition and clustering, but little empirical comparison with traditional methods has been done. The results reported here compare neural networks using Kohonen learning with a traditional clustering method (K-means) in an experimental design using simulated data with known cluster solutions. Two types of neural networks were examined, both of which used unsupervised learning to perform the clustering. One used Kohonen learning with a conscience and the other used Kohonen learning without a conscience mechanism. The performance of these nets was examined with respect to changes in the number of attributes, the number of clusters, and the amount of error in the data. Generally, the K-means procedure had fewer points misclassified while the classification accuracy of neural networks worsened as the number of clusters in the data increased from two to five.
Aortic arch obstruction and/or coarctation of aorta is uncommon (5–20%) in balanced atrioventricular septal defects. Although technically challenging, prenatal diagnosis of aortic arch obstruction in atrioventricular septal defect is critical for delivery planning and improves prenatal counselling regarding the timing of cardiac surgery. We sought to identify prenatal predictors of coarctation of aorta in atrioventricular septal defect.
Methods:
Retrospective review of patients prenatally diagnosed with atrioventricular septal defect at two institutions.
Results:
Ninety-five fetuses with atrioventricular septal defect were identified and sufficient outcome data and diagnostic acoustic windows were available in 62. Six patients (10%) had coarctation of aorta after birth. Among the 38 patients with Trisomy 21, four (11%) had coarctation of aorta. On multivariable analysis, the proximal transverse aortic arch z score and ratio of left:right atrioventricular valve were independent predictors of coarctation of aorta with good interobserver reproducibility. Either proximal transverse aortic arch z score < −2, or ratio of left:right atrioventricular valve <0.7, predicted aortic arch obstruction with 100% sensitivity and 89% specificity.
Conclusion:
Proximal transverse aortic arch z score and lower ratio of left:right atrioventricular valve diameter are independent predictors of postnatal coarctation of aorta in fetal patients with atrioventricular septal defect. The next step is the prospective application of these parameters to create an algorithm directing fetal counselling in terms of delivery location, and expected timing of surgical interventions.
Low-intensity psychological interventions are effective for children and young people (CYP) with mental health difficulties and can help bridge the demand–capacity gap. Despite increasing awareness, training and use of low-intensity psychological interventions, it is not yet understood what is being implemented in clinical practice in the UK and the associated evidence base.
Method:
This paper presents two studies; first, a national survey (n=102) of practitioners to identify low-intensity psychological interventions currently delivered in practice and second, an exploration of the availability and the strength of empirical support (characterised as ‘gold’, ‘silver’ and ‘bronze’) of low-intensity CBT interventions for CYP.
Results:
The first study found a wide variety of interventions being used across different services; 101/102 respondents reported using routine outcome measures. The second study identified 44 different low-intensity interventions, 28 of which were rated as having gold empirical support. However, only 13 of the gold interventions were considered accessible for practitioners and only two were reported being used in routine practice.
Conclusion:
These findings highlight that these interventions have been developed and empirically tested, but many are not easily accessible, highlighting the ‘research–practice’ gap in the provision of low-intensity interventions. There is a need for an increase in standardisation of care and accessibility of gold interventions. This paper hopes to begin the process of creating a hub of low-intensity interventions that are accessible and empirically supported to improve equity of access and outcomes of low-intensity psychological interventions for CYP.
In Singapore, the Critically Endangered Sunda pangolin Manis javanica is threatened by habitat loss and fragmentation, and road traffic collisions. To mitigate these threats, an understanding of its spatiotemporal distribution is needed, as identified in the National Conservation Strategy and Action Plan for the species. However, Sunda pangolin occurrence data are held in multiple separate databases, are typically collected using non-standardized methods, and often lack accurate location details. To compile a complete georeferenced database of Sunda pangolin records in Singapore, we consolidated occurrence data from heterogeneous databases and mainstream and social media, and converted locality descriptions into geographical coordinates. We demonstrate the use of this database to analyse data on rescued pangolins and those killed on roads, to aid conservation efforts in Singapore, and describe other potential applications. We georeferenced 482 records of pangolin sightings, rescues and roadkill for 1996–2021, finding an increase in all three over the study period. Roadkill and rescues occurred mostly in central and western Singapore, close to forested areas, and were predominantly of subadults and adult males. The data can be used to inform threat mitigation strategies, post-rescue release plans and further research. The database has already been used in practice, contributing to environmental impact assessments and conservation recommendations. Overall, this georeferenced database demonstrates the value of citizen science and collating wildlife data from multiple sources, and the methods used can be applied to other taxa to aid conservation strategies.
Information generating functions (IGFs) have been of great interest to researchers due to their ability to generate various information measures. The IGF of an absolutely continuous random variable (see Golomb, S. (1966). The information generating function of a probability distribution. IEEE Transactions in Information Theory, 12(1), 75–77) depends on its density function. But, there are several models with intractable cumulative distribution functions, but do have explicit quantile functions. For this reason, in this work, we propose quantile version of the IGF, and then explore some of its properties. Effect of increasing transformations on it is then studied. Bounds are also obtained. The proposed generating function is studied especially for escort and generalized escort distributions. Some connections between the quantile-based IGF (Q-IGF) order and well-known stochastic orders are established. Finally, the proposed Q-IGF is extended for residual and past lifetimes as well. Several examples are presented through out to illustrate the theoretical results established here. An inferential application of the proposed methodology is also discussed
In this work, we consider two sets of dependent variables $\{X_{1},\ldots,X_{n}\}$ and $\{Y_{1},\ldots,Y_{n}\}$, where $X_{i}\sim EW(\alpha_{i},\lambda_{i},k_{i})$ and $Y_{i}\sim EW(\beta_{i},\mu_{i},l_{i})$, for $i=1,\ldots, n$, which are coupled by Archimedean copulas having different generators. We then establish different inequalities between two extremes, namely, $X_{1:n}$ and $Y_{1:n}$ and $X_{n:n}$ and $Y_{n:n}$, in terms of the usual stochastic, star, Lorenz, hazard rate, reversed hazard rate and dispersive orders. Several examples and counterexamples are presented for illustrating all the results established here. Some of the results here extend the existing results of [5] (Barmalzan, G., Ayat, S.M., Balakrishnan, N., & Roozegar, R. (2020). Stochastic comparisons of series and parallel systems with dependent heterogeneous extended exponential components under Archimedean copula. Journal of Computational and Applied Mathematics380: Article No. 112965).
We establish here an integral inequality for real log-concave functions, which can be viewed as an average monotone likelihood property. This inequality is then applied to examine the monotonicity of failure rates.
To describe a method of reducing the risk of sternal wound infection after sternotomy in children with a pre-existing tracheostomy. To report our outcomes using this method from 1 January, 2013 to 31 August, 2023.
Methods:
We describe a method for temporarily occluding the tracheal stoma with a removable implant with the primary goal of reducing the risk of sternotomy wound infection by preventing soilage due to tracheostomal secretions. We then performed a retrospective review of all children who underwent temporary tracheostomal occlusion between 1 January, 2013 and 31 August, 2023 at our quaternary care children’s hospital. Clinical variables were extracted from the hospital medical records. The rates of antibiotic use and minor and major complications during the period when the stoma plug was in place were recorded.
Results:
Totally, 19 patients underwent tracheal stoma plugging prior to sternotomy and were included in our analysis. There were two cases of sternal wound infection; one case occurred while the stoma plug was in place, and one developed four days following plug removal. There was one minor complication, with one patient requiring stoma revision via serial dilation at bedside at the time of recannulation. There were no deaths.
Conclusion:
Temporary occlusion of the tracheal stoma with an impermeable plug is a viable option for reducing the risk of sternal wound infection in children with a pre-existing tracheostomy who are undergoing sternotomy.
This is the first study to report on the impact of race on differences in the prevalence of echocardiographic left ventricular hypertrophy and left ventricular adaptation at the time of diagnosis of essential hypertension in children.
Methods:
This cross-sectional, single-centre study included patients aged 3–18 years who had newly diagnosed essential hypertension. Echocardiography was used to assess left ventricular mass index and left ventricular relative wall thickness. An left ventricular mass index > the 95th percentile for age and gender, and an left ventricular relative wall thickness > 0.42, were used to diagnose left ventricular hypertrophy and concentric adaptation. Various echocardiographic parameters were compared between African Americans and Caucasians.
Results:
The study included 422 patients (289 African Americans and 133 Caucasians) diagnosed with essential hypertension at a median age of 14.6 (interquartile range; 12.1–16.3) years. Eighty-eight patients (20.9%) had left ventricular hypertrophy. There was no statistically significant difference in the prevalence of left ventricular hypertrophy between African Americans and Caucasians (22.5% versus 17.3%, p=0.22). The median left ventricular relative wall thickness was 0.35 (0.29–0.43), and 114 patients (27.0%) had an left ventricular relative wall thickness > 0.42. The presence of an left ventricular relative wall thickness > 0.42 was significantly higher among African Americans compared to Caucasians (30.1% versus 20.3%, p = 0.04). The African American race was a strong predictor for an left ventricular relative wall thickness > 0.42 (odds ratio 1.7, p = 0.04), but not for left ventricular mass index > the 95th percentile (p = 0.22). Overweight/obesity was a strong predictor for an left ventricular mass index > the 95th percentile.
Conclusions:
There was no difference in the prevalence of left ventricular hypertrophy in children with essential hypertension of different races. Obesity, rather than being African American, is associated with left ventricular hypertrophy.
Inaccuracy and information measures based on cumulative residual entropy are quite useful and have received considerable attention in many fields, such as statistics, probability, and reliability theory. In particular, many authors have studied cumulative residual inaccuracy between coherent systems based on system lifetimes. In a previous paper (Bueno and Balakrishnan, Prob. Eng. Inf. Sci.36, 2022), we discussed a cumulative residual inaccuracy measure for coherent systems at component level, that is, based on the common, stochastically dependent component lifetimes observed under a non-homogeneous Poisson process. In this paper, using a point process martingale approach, we extend this concept to a cumulative residual inaccuracy measure between non-explosive point processes and then specialize the results to Markov occurrence times. If the processes satisfy the proportional risk hazard process property, then the measure determines the Markov chain uniquely. Several examples are presented, including birth-and-death processes and pure birth process, and then the results are applied to coherent systems at component level subject to Markov failure and repair processes.
The purpose of this paper is twofold. The first part is to introduce relative-$\chi_{\alpha}^{2}$, Jensen-$\chi_{\alpha}^{2}$ and (p, w)-Jensen-$\chi_{\alpha}^2$ divergence measures and then examine their properties. In addition, we also explore possible connections between these divergence measures and Jensen–Shannon entropy measure. In the second part, we introduce $(p,\eta)$-mixture model and then show it to be an optimal solution to three different optimization problems based on $\chi_{\alpha}^{2}$ divergence measure. We further study the relative-$\chi_{\alpha}^{2}$ divergence measure for escort and arithmetic mixture densities. We also provide some results associated with relative-$\chi_{\alpha}^{2}$ divergence measure of mixed reliability systems. Finally, to demonstrate the usefulness of the Jensen-$\chi_{\alpha}^{2}$ divergence measure, we apply it to a real example in image processing and present some numerical results. Our findings in this regard show that the Jensen-$\chi_{\alpha}^{2}$ is an effective criteria for quantifying the similarity between two images.
The coronavirus disease (COVID-19) pandemic has necessitated e-learning strategies in academic emergency medicine (EM) programs. A study was conducted during the COVID-19 pandemic to understand e-learning in the Indian EM context.
Methods:
After IEC/IRB approval, we conducted a multicenter national survey validated by experts and underwent multiple reviews by the research team. The final survey was converted into Google Forms for dissemination via email to National Medical Commission (NMC) approved EM residency program as of 2020–2021. Data were exported into Excel format and analyzed.
Results:
Residents and faculty comprised 41.5% and 58.5% of 94 respondents. The COVID-19 pandemic’s second wave in India significantly impacted response rates. Internet connectivity was cited as a significant barrier to e-learning, while flexible timings and better engagement were facilitators identified by the survey. The attitude among residents and faculty toward e-learning was also evaluated.
Conclusion:
This survey reveals a significant positive shift in medical education from conventional teaching strategies toward e-learning, specifically during the pandemic. It also shows the need for all stakeholders (learners/educators) to better understand e-learning and adapt to its requirements. We need more data on the efficacy of e-learning compared to traditional methods. Until then, innovative hybrid/blended strategies would be the way forward.
In this paper, several linear two-dimensional consecutive k-type systems are studied, which include the linear connected-(k, r)-out-of-$(m,n)\colon\! F$ system and the linear l-connected-(k, r)-out-of-$(m,n)\colon\! F$ system without/with overlapping. Reliabilities of these systems are studied via the finite Markov chain imbedding approach (FMCIA) in a novel way. Some numerical examples are provided to illustrate the theoretical results established here and also to demonstrate the efficiency of the developed method. Finally, some possible applications and generalizations of the developed results are pointed out.