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The relationship between different surrogates of insulin resistance and left ventricular geometry in obese children is still unclear.
We sought to explore the relationship between commonly used measures of insulin sensitivity/resistance (homeostatic model assessment index, serum uric acid, and triglycerides to high-density lipoprotein cholesterol ratio) and left ventricular geometry in normotensive obese children.
In this cross-sectional study, 32 normotensive obese children were examined. Transthoracic echocardiography was used to measure left ventricular mass index and relative wall thickness. Homeostasis model assessment index, serum uric acid level, and a ratio of triglycerides to high-density lipoprotein cholesterol were used as markers of the insulin resistance. Simple and partial correlation analyses (to control for the effects of body mass index) were conducted to explore relationship between studied variables and left ventricular mass index or relative wall thickness as outcome variables.
We found positive correlations between homeostasis model assessment index and relative wall thickness (r = 0.47, p = 0.03) which remained significant after controlling for the effect of body mass index, z-score (r = 0.48, p = 0.03). The cutoff level of homeostasis model assessment index with the optimum sensitivity (Sn) and specificity (Sp) derived from the receiver operating characteristic (ROC) curves for predicting concentric remodelling was ≥5.51 with Sn = 83.33 and Sp = 68.75.
There is a positive relationship between homeostasis model assessment index and relative wall thickness of obese normotensive children which may help to distinguish at risk obese normotensive children for the development of concentric left ventricular remodelling.
Dietary lipids (omega-3 polyunsaturated fatty acids (n-3) PUFAs) and saturated fatty acids (SFA) seem to play an important role in brain health. (n-3) PUFAs have been shown to improve cerebral perfusion and to promote synaptogenesis. In this study, we investigated the relationship between dietary fat composition, cognitive performance and brain morphology in cognitively healthy individuals.
A total of 101 cognitively healthy participants (age: 42.3 ± 21.3 years, 62 females) were included in this study. Verbal memory was assessed using the California Verbal Learning Test (CVLT). Intake of (n-3) PUFA and SFA was calculated from food-frequency questionnaire-derived data (EPIC-FFQ). Magnetic resonance imaging (MRI) data were obtained (Siemens Trio 3T scanner) and grey matter volumes (GMV) were assessed by voxel-based morphometry (VBM/SPM8). We examined the association of SFA/(n-3) PUFA ratio and memory performance as well as GMV using regression models adjusted for age, sex, education, body mass index, apolipoprotein E (APOE) status and alcohol consumption. For VBM data, a multiple regression analysis was performed using the same covariates as mentioned before with intracranial volume as an additional covariate.
A high SFA/(n-3) PUFA ratio was significantly (p < 0.05) correlated with poorer verbal memory performance and with lower GMV in areas of the left prefrontal cortex that support memory processes.
These findings suggest that a diet rich in PUFAs is likely to exert favourable effects on brain morphology in brain areas important for memory and executive functions. This could constitute a possible mechanism for maintaining cognitive health in older age.
Mental health difficulties and mental disorders are common in adolescents living with HIV or who are affected by HIV because of living in HIV-affected households in low- and middle-income (LMICs) countries, but little is known about the interventions that target these individuals and whether they are effective.
This systematic review aims to address these gaps by examining what has worked and what has not worked to support the mental health of adolescents living with HIV or affected by HIV in low- and middle-income contexts (PROSPERO Number: CRD42018103269).
A systematic literature review of online databases from the year 2000 to 2018, using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, included English-language publications of quantitative evaluations of psychosocial interventions aiming to improve mental health among adolescents living with HIV and adolescents from HIV-affected households (aged 10–24 years) in LMICs.
Out of 2956 articles, 16 studies from 8 LMICs met the inclusion criteria. Thirteen studies focused on adolescents affected by HIV and only three studies on adolescents living with HIV. Only five studies included were from Sub-Saharan Africa. Interventions most often used a family-strengthening approach strengthening caregiver–adolescent relationships and communication and some problem-solving in groups or individually. Five studies reported statistically significant changes in adolescent and caregiver mental health or mental well-being, five among adolescents only and two among caregivers only.
Research on what works to improve mental health in adolescents living with HIV in LMIC is in its nascent stages. Family-based interventions and economic strengthening show promise.
Mild cognitive impairment (MCI) often precedes Alzheimer’s Dementia (AD), and in a high proportion of individuals affected by MCI, there are already neuropathological processes ongoing that become more evident when patients progress to AD. Accordingly, there is a need for reliable biomarkers to distinguish between normal aging and incipient AD. Recent research suggests that, in addition to established biomarkers such as CSF Aß42, total tau and hyperphosphorylated tau, resting state connectivity established by functional magnetic resonance imaging might also be a feasible biomarker for prodromal stages of AD. In order to explore this possibility, we investigated resting state functional connectivity as well as cerebrospinal fluid (CSF) biomarker profiles in patients with MCI (n = 30; age 66.43 ± 7.06 years) and cognitively healthy controls (n = 38; age 66.89 ± 7.12 years). CSF Aß42, total tau and hyperphosphorylated tau concentrations were correlated with measures of cognitive performance (immediate and delayed recall, global cognition, processing speed). Moreover, MCI-related alterations in intrinsic functional connectivity within the default mode network were investigated using functional resting state MRI. As expected, MCI patients showed decreased CSF Aß42 and increased total tau concentrations. These alterations were associated with cognitive performance. However, there were no differences between MCI patients and cognitively healthy controls regarding intrinsic functional connectivity. In conclusion, our results indicate that CSF protein profiles seem to be more closely related to cognitive decline than alterations in resting state activity. Thus, resting state connectivity might not be a reliable biomarker for early stages of AD.
An approximate analytical solution is derived for a certain class of stochastic differential equations with constant diffusion, but nonlinear drift coefficients. Specifically, a closed form expression is derived for the response process transition probability density function (PDF) based on the concept of the Wiener path integral and on a Cauchy–Schwarz inequality treatment. This is done in conjunction with formulating and solving an error minimisation problem by relying on the associated Fokker–Planck equation operator. The developed technique, which requires minimal computational cost for the determination of the response process PDF, exhibits satisfactory accuracy and is capable of capturing the salient features of the PDF as demonstrated by comparisons with pertinent Monte Carlo simulation data. In addition to the mathematical merit of the approximate analytical solution, the derived PDF can be used also as a benchmark for assessing the accuracy of alternative, more computationally demanding, numerical solution techniques. Several examples are provided for assessing the reliability of the proposed approximation.
The use of assessment tools has been shown to improve the inter-rater reliability of capacity assessments. However, instrument-based capacity assessments of people with dementia face challenges. In dementia research, measuring capacity with instruments like the MacArthur Competence Assessment Tool for Treatment (MacCAT-T) mostly employ hypothetical treatment vignettes that can overwhelm the abstraction capabilities of people with dementia and are thus not always suitable for this target group. The primary aim of this study was to provide a standardized real informed consent paradigm that enables the dementia-specific properties of capacity to consent to treatment in people with dementia to be identified in a real informed consent process that is both externally valid and ethically justifiable.
The sample consisted of 53 people with mild to moderate dementia and a group of 133 people without cognitive impairment. Rather than using a hypothetical treatment vignette, we used a standardized version of the MacCAT-T to assess capacity to consent to treatment with cholinesterase inhibitors in people with dementia. Inter-rater reliability, item statistics, and psychometric properties were also investigated.
Intraclass correlations (ICCs) (0.951–0.990) indicated high inter-rater reliability of the standardized real informed consent paradigm. In the dementia group, performance on different items of the MacCAT-T varied. Most people with dementia were able to express a treatment choice, and were aware of the need to take a tablet. Further information on the course of the disorder and the benefits and risks of the treatment were less understood, as was comparative reasoning regarding treatment alternatives.
The standardized real informed consent paradigm enabled us to detect dementia-specific characteristics of patients’ capacity to consent to treatment with cholinesterase inhibitors. In order to determine suitable enhanced consent procedures for this treatment, we recommend the consideration of MacCAT-T results on an item level. People with dementia seem to understand only basic information. Our data indicate that one useful strategy to enhance capacity to consent is to reduce attention and memory demands as far as possible.
In the global insurance market, the number of product-specific policies from different companies has increased significantly, and strong market competition has boosted the demand for a competitive premium. Thus, in the present paper, by considering the competition between each pair of insurers, an N-player game is formulated to investigate the optimal pricing strategy by calculating the Nash equilibrium in an insurance market. Under that framework, each insurer is assumed to maximise its utility of wealth over the unit time interval. With the purpose of solving a game of N-players, the best-response potential game with non-linear aggregation is implemented. The existence of a Nash equilibrium is proved by finding a potential function of all insurers' payoff functions. A 12-player insurance game illustrates the theoretical findings under the framework in which the best-response selection premium strategies always provide the global maximum value of the corresponding payoff function.
The calculation of a fair premium is always a challenging topic in the real-world insurance applications. In this paper, a non-linear premium-reserve (P-R) model is presented and the premium is derived by minimising a quadratic performance criterion. The reserve is a stochastic equation, which includes an additive random non-linear function of the state, premium and not necessarily Gaussian noise, which is, however, independently distributed in time, provided only that the mean value and the covariance of the random function is 0 and a quadratic function of the state, premium and other parameters, respectively. In this quadratic representation of the covariance function, new parameters are implemented and enriched further by the previous linear models, such as the income insurance elasticity of demand, the number of insured and the inflation in addition to the company’s reputation. The quadratic utility function concerns the present value of the reserve. Interestingly, for the very first time, the derived optimal premium in a competitive market environment is also dependent on the company’s reserve among the other parameters. Finally, a numerical application illustrates the main findings of the paper.
The premium pricing process and the medium- and long-term stability of the reserve policy under conditions of uncertainty present very challenging issues in relation to the insurance world. Over the last two decades, applications of Markovian regime switching models to finance and macroeconomics have received strong attention from researchers, and particularly market practitioners. However, relatively little research has so far been carried out in relation to insurance. This paper attempts to consider how a linear Markovian regime switching system in discrete-time could be applied to model the medium- and long-term reserves and the premiums (abbreviated here as the P-R process) for an insurer. Some recently developed techniques from linear robust control theory are applied to explore the stability, stabilisation and robust H∞-control of a P-R system, and the potential effects of abrupt structural changes in the economic fundamentals, as well as the insurer's strategy over a finite time period. Sufficient linear matrix inequality conditions are derived for solving the proposed sub-problems. Finally, a numerical example is presented to illustrate the applicability of the theoretical results.
Focusing on material culture, this article considers a range of issues concerning the cultural policies, ideologies, and identities that have underlain Serbian development since the Middle Ages, and tests some widely held yet previously uncontested views. In particular it questions the Serbs' perceived affiliation with the Byzantine Empire and challenges the view that this affiliation was so pervasive that it influenced Serbian development and national formation in the modern age. It is argued that Byzantium had little if any role in the Serbs' cultural development - neither in historical memories nor in surviving traditions. Serbia's Byzantine culture is largely a myth developed in the 1930s by the Serbian clergy as a corollary of the Russian-inspired Svetosavlje ideology. This myth was meant to dislocate Serbia's cultural identity from its secular European sources and reposition it closer to Orthodox Russia.
In this work we reported low and high repetition frequency femtosecond laser-induced modifications of tungsten-based thin film. The tungsten-titanium (WTi) thin film, thickness of 190 nm, was deposited by sputtering on single crystal Si (100) wafer. Irradiations were performed in air by linearly polarized and focused femtosecond laser beams with following parameters: (1) pulse duration 160 fs, wavelength 800 nm, laser repetition frequency (LRF) 75 MHz — high LRF, and (2) duration 40 fs, wavelength 800 nm, LRF of 1 kHz — low LRF. The results of femtosecond lasers processing of the WTi thin film revealed laser induced periodical surface structures (LIPSS) in the case of low LRF regime. LIPSSs were formed with different periodicity and different orientation to the laser polarization at the surface: micro-scale LIPSSs with orientation perpendicular to the laser polarization and nano-scale LIPSSs parallel and perpendicular to the laser polarization. After processing of the WTi/Si system in high LRF regime ablation and nano-particles formation were registered.
One of the pricing strategies for Bonus–Malus (BM) systems relies on the decomposition of the claims’ randomness into one part accounting for claims’ frequency and the other part for claims’ severity. By mixing an exponential with a Lévy distribution, we focus on modelling the claim severity component as a Weibull distribution. For a Negative Binomial number of claims, we employ the Bayesian approach to derive the BM premiums for Weibull severities. We then conclude by comparing our explicit formulas and numerical results with those for Pareto severities that were introduced by Frangos & Vrontos.
In this paper, we propose a model for the optimal premium pricing policy of an insurance company into a competitive environment using Dynamic Programming into a stochastic, discrete-time framework when the company is expected to drop part of the market. In our approach, the volume of business which is related to the past year experience, the average premium of the market, the company's premium which is a control function and a linear stochastic disturbance, have been considered. Consequently, maximizing the total expected linear discounted utility of the wealth over a finite time horizon, the optimal premium strategy is defined analytically and endogenously. Finally, considering two different strategies for the average premium of the market, the optimal premium policy for a company with an expected decreasing volume of business is derived and fully investigated. The results of this paper are further evaluated by using data from the Greek Automobile Insurance Industry.
Early spread of tumor cells is usually undetected even by high-resolution imaging technologies, preventing potentially effective early intervention. However, sensitive immunocytochemical and molecular assays now enable the specific detection of “occult” metastatic tumor cells even at the single-cell stage. These technologies provide the potential to track systemic tumor cell dissemination in the blood and the bone marrow (BM) as one of the first crucial steps in the metastatic cascade.
In colorectal cancer, approximately 50 percent of patients undergoing a curative resection (R0) die from metastatic disease within five years. Even among lymph node–negative (N0) patients, the relapse rate is 30 percent [1, 2]. In lung cancer, the prognosis is even worse, with 60 percent of R0 and 40 percent of N0 patients dying of the disease . Whereas in breast and prostate cancer the overall survival today is relatively high (5 years, 80%–90%; 10 years, 70%–80%), a considerable fraction of node-negative patients still relapse (25%–30% and 15%–50%, respectively) and this can often take place many years (>10 years) after the removal of the primary tumor [4–6].
Various clinical studies have provided evidence for an association between the presence of disseminated tumor cells (DTCs) detected at the time of initial tumor resection and postoperative metastatic relapse in patients with cancers of the breast, prostate, lung, and gastrointestinal tract . This work paved the way for the introduction of DTCs in international tumor staging systems [8, 9], and in 2007 DTCs and CTCs (circulating tumor cells) were mentioned for the first time in the American Society of Clinical Oncology (ASCO) recommendations on tumor markers .