Effect of Abutments Design on Wear of Locator Attachments in Implant Retained Mandibular Overdenture.

Purpose: The aim of this study is to compare the effect of abutments design on wear behavior of Locator attachments in implant-retained mandibular overdenture. Materials and Methods: Two epoxy models representing an edentulous mandible were used, two implants were placed in each model. Twenty-four locator attachments were used (twelve in each study group). Cycles of Insertion and removal were performed using a universal testing machine resembling 3 years of clinical use, then each abutment was scanned by scanning electron microscope (SEM) before and after insertion and removal cycles. Data were compared qualitatively using a specialized computer software Results: There was a statistically significant difference in wear between the two studied locator groups P=0000*. Locator F-TX showed 29±1.704 % of surface change. PEEKLOC. Locator showed 21±2.090 %of surface change. Conclusions: PEEKLoc. abutment design showed more wear resistance than the recently introduced Locator F-TX

Bayesian Online Learning of the Hazard Rate in Change-Point Problems

Change-point models are generative models of time-varying data in which the underlying generative parameters undergo discontinuous changes at different points in time known as change points. Changepoints often represent important events in the underlying processes, like a change in brain state reflected in EEG data or a change in the value of a company reflected in its stock price. However, change-points can be difficult to identify in noisy data streams. Previous attempts to identify change-points online using Bayesian inference relied on specifying in advance the rate at which they occur, called the hazard rate (h). This approach leads to predictions that can depend strongly on the choice of h and is unable to deal optimally with systems in which h is not constant in time. In this letter, we overcome these limitations by developing a hierarchical extension to earlier models. This approach allows h itself to be inferred from the data, which in turn helps to identify when change-points occur. We show that our approach can effectively identify change-points in both toy and real data sets with complex hazard rates and how it can be used as an ideal-observermodel for human and animal behavior when faced with rapidly changing inputs

Magnetism and Piezoelectricity in Stable Transition Metal Silicate Monolayers

Two-dimensional van der Waals (2D vdW) materials that display ferromagnetism and piezoelectricity have received increased attention. Despite numerous 2D materials have so far been reported as ferromagnetic, developing an air stable and transferable vdW material that is multiferroic has been challenging. To address this problem, we report our work on layered transition metal silicates that are derivatives of kaolinites and lizardites with transition metal substituting on Al$^{3+}$ and Mg$^{2+}$ sites using ab-initio calculations. Using Density Functional Theory (DFT), we show that these compounds are stable under varying O$_2$ partial pressure and can be synthesized using a surface assisted method. We show that these materials have finite out-of-plane piezoelectric response thanks to the lack of inversion symmetry and also they can be tailored to be ferrimagnetic with a non-zero net moment

Functionally Dissociable Influences on Learning Rate in a Dynamic Environment

Maintaining accurate beliefs in a changing environment requires dynamically adapting the rate at which one learns from new experiences. Beliefs should be stable in the face of noisy data but malleable in periods of change or uncertainty. Here we used computational modeling, psychophysics, and fMRI to show that adaptive learning is not a unitary phenomenon in the brain. Rather, it can be decomposed into three computationally and neuroanatomically distinct factors that were evident in human subjects performing a spatial-prediction task: (1) surprise-driven belief updating, related to BOLD activity in visual cortex; (2) uncertainty-driven belief updating, related to anterior prefrontal and parietal activity; and (3) reward-driven belief updating, a context-inappropriate behavioral tendency related to activity in ventral striatum. These distinct factors converged in a core system governing adaptive learning. This system, which included dorsomedial frontal cortex, responded to all three factors and predicted belief updating both across trials and across individuals

Role of expression of atrial natriuretic peptide gene in essential hypertension among Egyptian patients

Introduction: Essential Hypertension has been a great burden on public health services for a long time, with many life-threatening complications. Therefore, we decided to study Atrial Natriuretic peptide (ANP) gene expression as one of the most important blood pressure controlling genes, in order to use ANP gene as a potential diagnostic or therapeutic marker in the near future.Methods: One hundred essential hypertensive patients and 100 normotensive controls were included. Study Subjects were subjected to ANP gene expression analysis, together with blood pressure measurement, Lab investigations, and BMI analysis.Results: There was a statistical difference between ANP gene expression and blood pressure, with lower ANP gene expression level (median of 0.3) being present among hypertensive patients and higher ANP gene expression level (median of 1.6) among normotensive controls (p < 0.001).Discussion: We proved that ANP gene expression to be low in essential hypertension patients compared with normotensive individuals

Age differences in learning emerge from an insufficient representation of uncertainty in older adults

Healthy aging can lead to impairments in learning that affect many laboratory and real-life tasks. These tasks often involve the acquisition of dynamic contingencies, which requires adjusting the rate of learning to environmental statistics. For example, learning rate should increase when expectations are uncertain (uncertainty), outcomes are surprising (surprise) or contingencies are more likely to change (hazard rate). In this study, we combine computational modelling with an age-comparative behavioural study to test whether age-related learning deficits emerge from a failure to optimize learning according to the three factors mentioned above. Our results suggest that learning deficits observed in healthy older adults are driven by a diminished capacity to represent and use uncertainty to guide learning. These findings provide insight into age-related cognitive changes and demonstrate how learning deficits can emerge from a failure to accurately assess how much should be learned

Knowledge, Beliefs, and Decisions of Pregnant Australian Women Concerning Donation and Storage of Umbilical Cord Blood: A Population‐Based Survey

Background: Many women giving birth in Australian hospitals can choose to donate their child’s umbilical cord blood to a public cord blood bank or pay to store it privately. We conducted a survey to determine the proportion and characteristics of pregnant women who are aware of umbilical cord blood (UCB) banking and who have considered and decided about this option. The survey also sought to ascertain information sources, knowledge and beliefs about UCB banking, and the effect of basic information about UCB on decisions. Methods: Researchers and/or hospital maternity staff distributed a survey with basic information about UCB banking to 1,873 women of at least 24 weeks gestation who were attending antenatal classes and hospital clinics in 14 Public and private maternity hospitals in New South Wales. Results: Most respondents (70.7%) were aware of UCB banking. Their main information sources were leaflets from hospital clinics, print media, antenatal classes, TV, radio, friends and relatives. Knowledge about UCB banking was patchy, and respondents overestimated the likelihood their child would need or benefit from UCB. Women who were undecided about UCB banking were younger, less educated or from ethnic or rural backgrounds. After providing basic information about UCB banking, the proportion of respondents who indicated they had decided whether or not to donate or store UCB more than doubled from 30.0% to 67.7%. Conclusions: Basic information for parents about UCB banking can affect planned decisions about UCB banking. Information should be accurate and balanced, should counter misconceptions, and should target specific groups. Keywords: Antenatal care; Health information; Blood banks; New South Wales, AustraliaNational Health and Medical Research Council of Australia. Grant Number: 51241