2,451 research outputs found
Enhanced Neural Responses to Imagined Primary Rewards Predict Reduced Monetary Temporal Discounting
The pervasive tendency to discount the value of future rewards varies considerably across individuals and has important implications for health and well-being. Here, we used fMRI with human participants to examine whether an individual's neural representation of an imagined primary reward predicts the degree to which the value of delayed monetary payments is discounted. Because future rewards can never be experienced at the time of choice, imagining or simulating the benefits of a future reward may play a critical role in decisions between alternatives with either immediate or delayed benefits. We found that enhanced ventromedial prefrontal cortex response during imagined primary reward receipt was correlated with reduced discounting in a separate monetary intertemporal choice task. Furthermore, activity in enhanced ventromedial prefrontal cortex during reward imagination predicted temporal discounting behavior both between- and within-individual decision makers with 62% and 73% mean balanced accuracy, respectively. These results suggest that the quality of reward imagination may impact the degree to which future outcomes are discounted.
SIGNIFICANCE STATEMENT We report a novel test of the hypothesis that an important factor influencing the discount rate for future rewards is the quality with which they are imagined or estimated in the present. Previous work has shown that temporal discounting is linked to individual characteristics ranging from general intelligence to the propensity for addiction. We demonstrate that individual differences in a neurobiological measure of primary reward imagination are significantly correlated with discounting rates for future monetary payments. Moreover, our neurobiological measure of imagination can be used to accurately predict choice behavior both between and within individuals. These results suggest that improving reward imagination may be a useful therapeutic target for individuals whose high discount rates promote detrimental behaviors
Serum Hsp70 antigen: Early diagnosis marker in perinatal asphyxia
BACKGROUND:
Perinatal asphyxia is an important cause of mortality and permanent neurological and developmental deficit. Early and accurate diagnosis would help to establish the likely prognosis and may also help in determining the most appropriate treatment. Studies in experimental animal models suggest that a protein called Hsp70 may be a good and potentially useful marker of cellular stress that may be clinically useful in determining the presence of neonatal asphyxia.
OBJECTIVES:
Regarding the importance of early and accurate diagnosis of asphyxia, we conducted this study, which is the first investigation of the comparison of the serum Hsp70 antigen level between asphyxiated and healthy infants.
PATIENTS AND METHODS:
In this observational study, the serum concentrations of Hsp70 antigen were compared between neonates suffering from perinatal asphyxia (n = 50) and normal neonates (n = 51). The inclusion criteria for the cases were neonates who had reached term and had at least two clinical criteria of asphyxia. Exclusion criteria were babies with gestational age < 37 weeks, infants with congenital abnormalities or positive blood culture. Exclusion criteria in this group were the requirement to hospital stay during first week of the life or babies whose mothers had difficulties during pregnancy or delivery. Term neonates without major anomalies who had asphyxia during delivery were enrolled in the first six hours after delivery, and control group consisted of healthy term neonates without problems and normal delivery process in the first week of life. The cord blood was taken during labor to measure Hsp70 antigen level by using an in-house ELISA (The enzyme-linked immunosorbent assay).
RESULTS:
The median values of serum anti Hsp70 titers were significantly higher in asphyxiated neonates compared with non-asphyxiated neonates (0.36 [0.04 - 1.14] vs 0.24 [0.01 - 0.63]). At cutoff point = 0.3125 ng/mL, sensitivity was 58% and specificity 76% based on ROC curve.
CONCLUSIONS:
A significant difference between the serum concentrations of Hsp70 of the control and patient group was observed in this study. It is inferred serum concentrations of Hsp70 antigen may be a useful marker for the early diagnosis of that prenatal hypoxia
An anisotropic viscoplasticity model for shale based on layered microstructure homogenization
Viscoplastic deformation of shale is frequently observed in many subsurface
applications. Many studies have suggested that this viscoplastic behavior is
anisotropic---specifically, transversely isotropic---and closely linked to the
layered composite structure at the microscale. In this work, we develop a
two-scale constitutive model for shale in which anisotropic viscoplastic
behavior naturally emerges from semi-analytical homogenization of a bi-layer
microstructure. The microstructure is modeled as a composite of soft layers,
representing a ductile matrix formed by clay and organics, and hard layers,
corresponding to a brittle matrix composed of stiff minerals. This layered
microstructure renders the macroscopic behavior anisotropic, even when the
individual layers are modeled with isotropic constitutive laws. Using a common
correlation between clay and organic content and magnitude of creep, we apply a
viscoplastic Modified Cam-Clay plasticity model to the soft layers, while
treating the hard layers as a linear elastic material to minimize the number of
calibration parameters. We then describe the implementation of the proposed
model in a standard material update subroutine. The model is validated with
laboratory creep data on samples from three gas shale formations. We also
demonstrate the computational behavior of the proposed model through simulation
of time-dependent borehole closure in a shale formation with different bedding
plane directions
The Natural Selection Game: Incorporating Active Learning in Evolution Curricula for General Biology
Teaching evolution in high school and in entry-level college courses can be challenging due to the inherent misinformation, misunderstanding, and biases with which students approach the topic. In this setting, it is critical to both teach the basic concepts and address common student misconceptions about evolution. We present two paired activities that allow students to (1) explore the processes of natural selection in a direct and experiential way and (2) address common misconceptions in evolutionary theory. The first activity, the “Natural Selection Game,” has students simulate a bird population and experience shifts in phenotype frequency as a result of selective pressures. Following the end of the game, students discuss the outcomes and connect them to real-life examples. The second activity encourages students to actively research common misconceptions with the use of personal technology in order to distinguish between scientifically supported data and poor information online. Both activities can be incorporated in high school and university-level general biology curricula. They will allow students to connect their firsthand experiences to lecture-based instruction and, as a result, develop a stronger understanding of the mechanisms of evolution
A car - like mobile manipulator with an n - link Prismatic Arm
In this research, the Lyapunov based Control Scheme (LbCS) is used to solve the motion planning and control problem of a car-like mobile robot with a long extendible prismatic arm comprising n∈N links. The prismatic arm consists of a base revolute joint and n∈N translational joints, and is mounted on the wheeled car-like mobile platform. The kinematic model of the manipulator is developed, and velocity based algorithms are utilized to firstly, move the car-like base from an initial position to its pseudo-target and secondly, maneuver the end-effector to its designated target, taking into account the restrictions and limitations of the prismatic links and the steering control laws of the system. Computer simulations are presented to illustrate the effectiveness of the proposed control laws
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Socioeconomic Mediators of Racial and Ethnic Disparities in Congenital Heart Disease Outcomes: A Population-Based Study in California.
Background Racial/ethnic and socioeconomic disparities exist in outcomes for children with congenital heart disease. We sought to determine the influence of race/ethnicity and mediating socioeconomic factors on 1-year outcomes for live-born infants with hypoplastic left heart syndrome and dextro-Transposition of the great arteries. Methods and Results The authors performed a population-based cohort study using the California Office of Statewide Health Planning and Development database. Live-born infants without chromosomal anomalies were included. The outcome was a composite measure of mortality or unexpected hospital readmissions within the first year of life defined as >3 (hypoplastic left heart syndrome) or >1 readmissions (dextro-Transposition of the great arteries). Hispanic ethnicity was compared with non-Hispanic white ethnicity. Mediation analyses determined the percent contribution to outcome for each mediator on the pathway between race/ethnicity and outcome. A total of 1796 patients comprised the cohort (n=964 [hypoplastic left heart syndrome], n=832 [dextro-Transposition of the great arteries]) and 1315 were included in the analysis (n=477 non-Hispanic white, n=838 Hispanic). Hispanic ethnicity was associated with a poor outcome (crude odds ratio, 1.72; 95% confidence interval [CI], 1.37-2.17). Higher maternal education (crude odds ratio 0.5; 95% CI , 0.38-0.65) and private insurance (crude odds ratio, 0.65; 95% CI , 0.45-0.71) were protective. In the mediation analysis, maternal education and insurance status explained 33.2% (95% CI , 7-66.4) and 27.6% (95% CI , 6.5-63.1) of the relationship between race/ethnicity and poor outcome, while infant characteristics played a minimal role. Conclusions Socioeconomic factors explain a significant portion of the association between Hispanic ethnicity and poor outcome in neonates with critical congenital heart disease. These findings identify vulnerable populations that would benefit from resources to lessen health disparities
A novel mobile web application for an integrated medical and emergency model
The current situation of medical, healthcare and emergency related system in Malaysia shows that it is
mostly separated and not fully computerized. The fully computerizing and combining of medical
healthcare and emergency systems will lead to produce a Novel Integrated Medical and Emergency
system. This integrated system is being divided into three main parts which is the web based medical and
emergency system, intelligent agent, and mobility. The system contains a database that will communicate
and cooperated with intelligent agent and mobility. The main drawbacks for the current medical,
healthcare, and emergency systems in Malaysia include: Difficulty in searching and reviewing up to date
records for patient, doctor, hospital, drug, etc since many of such records are still kept in filing cabinet
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