Generalized Poisson difference autoregressive processes

This paper introduces a novel stochastic process with signed integer values. Its autoregressive dynamics effectively captures persistence in conditional moments, rendering it a valuable feature for forecasting applications. The increments follow a Generalized Poisson distribution, capable of accommodating over- and under-dispersion in the conditional distribution, thereby extending standard Poisson difference models. We derive key properties of the process, including stationarity conditions, the stationary distribution, and conditional and unconditional moments, which prove essential for accurate forecasting. We provide a Bayesian inference framework with an efficient posterior approximation based on Markov Chain Monte Carlo. This approach seamlessly incorporates inherent parameter uncertainty into predictive distributions. The effectiveness of the proposed model is demonstrated through applications to benchmark datasets on car accidents and an original dataset on cyber threats, highlighting its superior fitting and forecasting capabilities compared to standard Poisson model

Blood Viscosity in Subjects With Normoglycemia and Prediabetes

OBJECTIVE Blood viscosity (BV) is higher in diabetic patients and might represent a risk factor for the development of insulin resistance and type 2 diabetes. However, data in subjects with normal glucose or prediabetes are missing. In the current study, we evaluated the relationship between BV and blood glucose in subjects with normal glucose or prediabetes. RESEARCH DESIGN AND METHODS Enrolled subjects were divided into three groups according to blood glucose: group A ( n = 74), blood glucose <90 mg/dL; group B ( n = 96), blood glucose ranging from 90 to 99 mg/dL; and group C ( n = 94), blood glucose ranging from 100 to 125 mg/dL. BV was measured at 37°C with a cone-plate viscometer at shear rates ranging from 225 to 22.5 s−1. RESULTS Blood pressure, blood lipids, fibrinogen, and plasma viscosity were similar in the three groups. BMI and waist circumference were significantly increased in group C. Hematocrit ( P < 0.05) and BV ( P between 0.01 and 0.001) were significantly higher in groups B and C compared with group A. Blood glucose was significantly and inversely correlated with HDL cholesterol and directly with BMI, waist, hematocrit ( r = 0.134), and BV (from 225 s−1 to 22.5 s−1; r ranging from 0.162 to 0.131). BV at shear rate 225 s−1 was independently associated with blood glucose. CONCLUSIONS The current study shows a direct relationship between BV and blood glucose in nondiabetic subjects. It also suggests that, even within glucose values considered completely normal, individuals with higher blood glucose levels have increased BV comparable with that observed in subjects with prediabetes

Flexible distributed Bragg reflectors as optical outcouplers for OLEDs based on a polymeric anode

Top-emitting OLEDs (TOLEDs) represent a promising technology for the development of next-generation flexible and rollable displays, thanks to their improved light outcoupling and their compatibility with opaque substrates. Metal thin films are the most used electrodes for the manufacturing of TOLEDs, but they show poor resistance to mechanical deformation, which compromises the long-term durability of flexible devices. This paper reports the exploitation of a dielectric mirror (DBR) based on seven pairs of TiO2 and SiO2 combined with a polymeric electrode as an alternative to the bottom metal electrode in flexible TOLEDs. The DBR showed a maximum reflectivity of 99.9% at about 550 nm, and a stop-band width of about 200 nm. The reflectivity remained unchanged after bending and treatment with water and solvents. Green TOLED devices were fabricated on top of DBRs, and demonstrated good stability in terms of electro-optical and colorimetric characteristics, according to varying viewing angles. These results demonstrate that the combination of the flexible DBR with the polymeric anode is an interesting strategy for improving the durability of flexible TOLEDs for display applications, implemented on different kinds of free-standing ultra-thin substrates

Endothelial dysfunction or dysfunctions? Identification of three different FMD responses in males with type 2 diabetes.

Endothelial function is widely evaluated by vasodilatation of the brachial artery induced by ischemia (flow-mediated vasodilatation, FMD). The function of the endothelium, in this setting, is to sense wall shear stress (WSS) increase and to release vasodilators. Following current guidelines FMD is measured 50-60s after ischemia. It is not known whether this lapse of time is sufficient to observe maximal vasodilatation, especially in diseased subjects. Sixty-six subjects with type 2 diabetes and 30 controls underwent FMD-test. Brachial artery WSS was measured at rest and during the first 15s after ischemia as index of peripheral resistances vessels reactivity, and FMD at 50, 120, 180, and 300s after ischemia as index of conduit vessel function. All controls exhibited increased WSS and peak FMD at 50s. Among subjects with diabetes three groups were identified based on the time at which peak FMD occurred. Twenty subjects with diabetes exhibited peak at 50s (Early FMD), 28 at 2 min (Late FMD), and 18 showed no FMD (Absent FMD). Peak FMD in Late FMD subgroup was comparable to peak in control subjects and significantly higher than peak in other subjects with diabetes. The "Absent FMD" group showed also impaired WSS. The present findings demonstrate that brachial artery response to ischemia is heterogeneous in type 2 diabetes, suggesting different mechanisms responsible for FMD alteration in this condition

Body mass index, metabolic syndrome and carotid atherosclerosis.

OBJECTIVE: Body fatness and fat distribution are widely accepted as coronary heart disease risk factors. In this study, we have evaluated the contribution of generalized adiposity, assessed by body mass index (BMI), to carotid atherosclerosis, in participants with or without metabolic syndrome (MetS). METHODS: We have analysed 840 female and 1002 male participants in a regional Cardiovascular Disease Prevention Campaign. Blood glucose and lipids were analysed by standard methods. According to BMI, calculated as weight (in kilograms)/height (in square metres), participants were divided into normal weight (BMI <25 kg/m2), overweight (BMI between 25 and 29.9 kg/m2) and obese (BMI>29.9 kg/m2). Carotid atherosclerosis was evaluated by echo Doppler. RESULTS: Blood pressure, waist circumference, triglycerides and glucose were significantly higher, and high-density lipoprotein was lower, in overweight and obese participants, compared with normal weight. MetS was more frequent among obese and overweight than normal-weight participants (51.7 vs. 21.5 vs. 9.8%, respectively). The prevalence of carotid atherosclerosis was 45.29% in participants with MetS, significantly higher than in participants without MetS (33.04%, P<0.0001), but it was similar across the three weight categories. Furthermore, in multiple regression analyses BMI was not significantly associated with carotid atherosclerosis. CONCLUSION: The present findings suggest that increasing body weight favours the clustering of coronary heart disease risk factors. Overweight and obesity, however, do not independently associate with carotid atherosclerosis

Components of the metabolic syndrome and carotid atherosclerosis: role of elevated blood pressure.

Elevated blood pressure is among the factors that contribute to the metabolic syndrome (MetS). It is not known whether subjects with MetS and elevated blood pressure are at the same cardiovascular risk as subjects with MetS but without elevated blood pressure. To clarify this point, we have evaluated the prevalence of carotid atherosclerosis in subjects with MetS with or without elevated blood pressure. A large population was examined (842 women and 1011 men). Blood pressure, lipids, glucose, and waist were measured by routine methods. Carotid atherosclerosis was evaluated by echo Doppler examination. The prevalence of MetS was 24.4% in women and 28.7% in men. The prevalence of carotid atherosclerosis was 35.1% in women and 37.3% in men (p=NS), and increased with increasing number of MetS components. Age, smoking, and systolic blood pressure (SBP) were associated with the presence of carotid atherosclerosis (logistic model), whereas age, high-density lipoprotein cholesterol, and SBP were associated with the extent of atherosclerosis (linear model). When comparing subjects with an equal number of MetS components, the prevalence of carotid atherosclerosis was significantly higher in subjects with elevated blood pressure than in those without. No difference in carotid atherosclerosis prevalence was found in subjects bearing or not bearing components of the syndrome other than elevated blood pressure. The present findings demonstrate that subjects with MetS and elevated blood pressure have increased carotid atherosclerosis compared with subjects with MetS but without elevated blood pressure. The diagnosis of MetS per se might not adequately identify subjects at elevated cardiovascular risk

Components of the metabolic syndrome and carotid atherosclerosis role of elevated blood pressure

Elevated blood pressure is among the factors that contribute to the metabolic syndrome (MetS). It is not known whether subjects with MetS and elevated blood pressure are at the same cardiovascular risk as subjects with MetS but without elevated blood pressure. To clarify this point, we have evaluated the prevalence of carotid atherosclerosis in subjects with MetS with or without elevated blood pressure. A large population was examined ( 842 women and 1011 men). Blood pressure, lipids, glucose, and waist were measured by routine methods. Carotid atherosclerosis was evaluated by echo Doppler examination. The prevalence of MetS was 24.4% in women and 28.7% in men. The prevalence of carotid atherosclerosis was 35.1% in women and 37.3% in men (p=NS), and increased with increasing number of MetS components. Age, smoking, and systolic blood pressure (SBP) were associated with the presence of carotid atherosclerosis ( logistic model), whereas age, high-density lipoprotein cholesterol, and SBP were associated with the extent of atherosclerosis ( linear model). When comparing subjects with an equal number of MetS components, the prevalence of carotid atherosclerosis was significantly higher in subjects with elevated blood pressure than in those without. No difference in carotid atherosclerosis prevalence was found in subjects bearing or not bearing components of the syndrome other than elevated blood pressure. The present findings demonstrate that subjects with MetS and elevated blood pressure have increased carotid atherosclerosis compared with subjects with MetS but without elevated blood pressure. The diagnosis of MetS per se might not adequately identify subjects at elevated cardiovascular risk