Neural Correlate of Filtering of Irrelevant Information from Visual Working Memory

In a dynamic environment stimulus task relevancy could be altered through time and it is not always possible to dissociate relevant and irrelevant objects from the very first moment they come to our sight. In such conditions, subjects need to retain maximum possible information in their WM until it is clear which items should be eliminated from WM to free attention and memory resources. Here, we examined the neural basis of irrelevant information filtering from WM by recording human ERP during a visual change detection task in which the stimulus irrelevancy was revealed in a later stage of the task forcing the subjects to keep all of the information in WM until test object set was presented. Assessing subjects' behaviour we found that subjects' RT was highly correlated with the number of irrelevant objects and not the relevant one, pointing to the notion that filtering, and not selection, process was used to handle the distracting effect of irrelevant objects. In addition we found that frontal N150 and parietal N200 peak latencies increased systematically as the amount of irrelevancy load increased. Interestingly, the peak latency of parietal N200, and not frontal N150, better correlated with subjects' RT. The difference between frontal N150 and parietal N200 peak latencies varied with the amount of irrelevancy load suggesting that functional connectivity between modules underlying fronto-parietal potentials vary concomitant with the irrelevancy load. These findings suggest the existence of two neural modules, responsible for irrelevant objects elimination, whose activity latency and functional connectivity depend on the number of irrelevant object

Eccentric exercise versus Usual-care with older cancer survivors: The impact on muscle and mobility- an exploratory pilot study

<p>Abstract</p> <p>Background</p> <p>Resistance exercise programs with high compliance are needed to counter impaired muscle and mobility in older cancer survivors. To date outcomes have focused on older prostate cancer survivors, though more heterogeneous groups of older survivors are in-need. The purpose of this exploratory pilot study is to examine whether resistance exercise via negative eccentrically-induced work (RENEW) improves muscle and mobility in a diverse sample of older cancer survivors.</p> <p>Methods</p> <p>A total of 40 individuals (25 female, 15 male) with a mean age of 74 (± 6) years who have survived (8.4 ± 8 years) since their cancer diagnosis (breast, prostate, colorectal and lymphoma) were assigned to a RENEW group or a non-exercise Usual-care group. RENEW was performed for 12 weeks and measures of muscle size, strength, power and mobility were made pre and post training.</p> <p>Results</p> <p>RENEW induced increases in quadriceps lean tissue average cross sectional area (Pre: 43.2 ± 10.8 cm²; Post: 44.9 ± 10.9 cm²), knee extension peak strength (Pre: 248.3 ± 10.8 N; Post: 275.4 ± 10.9 N), leg extension muscle power (Pre: 198.2 ± 74.7 W; Post 255.5 ± 87.3 W), six minute walk distance (Pre: 417.2 ± 127.1 m; Post 466.9 ± 125.1 m) and a decrease on the time to safely descend stairs (Pre: 6.8 ± 4.5 s; Post 5.4 ± 2.5 s). A significant (P < 0.05) group x time interaction was noted for the muscle size and mobility improvements.</p> <p>Conclusions</p> <p>This exploration of RENEW in a heterogeneous cohort of older cancer survivors demonstrates increases in muscle size, strength and power along with improved mobility. The efficacy of a high-force, low perceived exertion exercise suggests RENEW may be suited to older individuals who are survivors of cancer.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov Identifier: <a href="http://www.clinicaltrials.gov/ct2/show/NCT00335491">NCT00335491</a></p

Increased methylation of glucocorticoid receptor gene (NR3C1) in adults with a history of childhood maltreatment: a link with the severity and type of trauma

Childhood maltreatment, through epigenetic modification of the glucocorticoid receptor gene (NR3C1), influences the hypothalamic–pituitary–adrenal axis (HPA axis). We investigated whether childhood maltreatment and its severity were associated with increased methylation of the exon 1F NR3C1 promoter, in 101 borderline personality disorder (BPD) and 99 major depressive disorder (MDD) subjects with, respectively, a high and low rate of childhood maltreatment, and 15 MDD subjects with comorbid post-traumatic stress disorder (PTSD). Childhood sexual abuse, its severity and the number of type of maltreatments positively correlated with NR3C1 methylation (P=6.16 × 10−8, 5.18 × 10−7 and 1.25 × 10−9, respectively). In BPD, repetition of abuses and sexual abuse with penetration correlated with a higher methylation percentage. Peripheral blood might therefore serve as a proxy for environmental effects on epigenetic processes. These findings suggest that early life events may permanently impact on the HPA axis though epigenetic modifications of the NR3C1. This is a mechanism by which childhood maltreatment may lead to adulthood psychopathology

Active learning and optimal climate policy

This paper develops a climate-economy model with uncertainty, irreversibility, and active learning. Whereas previous papers assume learning from one observation per period, or experiment with control variables to gain additional information, this paper considers active learning from investment in monitoring, specifically in improved observations of the global mean temperature. We find that the decision maker invests a significant amount of money in climate research, far more than the current level, in order to increase the rate of learning about climate change. This helps the decision maker make improved decisions. The level of uncertainty decreases more rapidly in the active learning model than in the passive learning model with only temperature observations. As the uncertainty about climate change is smaller, active learning reduces the optimal carbon tax. The greater the risk, the larger is the effect of learning. The method proposed here is applicable to any dynamic control problem where the quality of monitoring is a choice variable, for instance, the precision at which we observe GDP, unemployment, or the quality of education

Al2O3-based nanofluids: a review

Ultrahigh performance cooling is one of the important needs of many industries. However, low thermal conductivity is a primary limitation in developing energy-efficient heat transfer fluids that are required for cooling purposes. Nanofluids are engineered by suspending nanoparticles with average sizes below 100 nm in heat transfer fluids such as water, oil, diesel, ethylene glycol, etc. Innovative heat transfer fluids are produced by suspending metallic or nonmetallic nanometer-sized solid particles. Experiments have shown that nanofluids have substantial higher thermal conductivities compared to the base fluids. These suspended nanoparticles can change the transport and thermal properties of the base fluid. As can be seen from the literature, extensive research has been carried out in alumina-water and CuO-water systems besides few reports in Cu-water-, TiO2-, zirconia-, diamond-, SiC-, Fe3O4-, Ag-, Au-, and CNT-based systems. The aim of this review is to summarize recent developments in research on the stability of nanofluids, enhancement of thermal conductivities, viscosity, and heat transfer characteristics of alumina (Al2O3)-based nanofluids. The Al2O3 nanoparticles varied in the range of 13 to 302 nm to prepare nanofluids, and the observed enhancement in the thermal conductivity is 2% to 36%

Uncertainty Compensation in Human Attention: Evidence from Response Times and Fixation Durations

BACKGROUND: Uncertainty and predictability have remained at the center of the study of human attention. Yet, studies have only examined whether response times (RT) or fixations were longer or shorter under levels of stimulus uncertainty. To date, no study has examined patterns of stimuli and responses through a unifying framework of uncertainty. METHODOLOGY/PRINCIPAL FINDINGS: We asked 29 college students to generate repeated responses to a continuous series of visual stimuli presented on a computer monitor. Subjects produced these responses by pressing on a keypad as soon a target was detected (regardless of position) while the durations of their visual fixations were recorded. We manipulated the level of stimulus uncertainty in space and time by changing the number of potential stimulus locations and time intervals between stimulus presentations. To allow the analyses to be conducted using uncertainty as common description of stimulus and response we calculated the entropy of the RT and fixation durations. We tested the hypothesis of uncertainty compensation across space and time by fitting the RT and fixation duration entropy values to a quadratic surface. The quadratic surface accounted for 80% of the variance in the entropy values of both RT and fixation durations. RT entropy increased as a function of spatial and temporal uncertainty of the stimulus, alongside a symmetric, compensatory decrease in the entropy of fixation durations as the level of spatial and temporal uncertainty of the stimuli was increased. CONCLUSIONS/SIGNIFICANCE: Our results demonstrate that greater uncertainty in the stimulus leads to greater uncertainty in the response, and that the effects of spatial and temporal uncertainties are compensatory. We also observed compensatory relationship across the entropies of fixation duration and RT, suggesting that a more predictable visual search strategy leads to more uncertain response patterns and vice versa

The big five personality traits, perfectionism and their association with mental health among UK students on professional degree programmes

Background In view of heightened rates of suicide and evidence of poor mental health among healthcare occupational groups, such as veterinarians, doctors, pharmacists and dentists, there has been increasing focus on the students aiming for careers in these fields. It is often proposed that a high proportion of these students may possess personality traits which render them vulnerable to mental ill-health. Aim To explore the relationship between the big five personality traits, perfectionism and mental health in UK students undertaking undergraduate degrees in veterinary medicine, medicine, pharmacy, dentistry and law. Methods A total of 1744 students studying veterinary medicine, medicine, dentistry, pharmacy and law in the UK completed an online questionnaire, which collected data on the big five personality traits (NEO-FFI), perfectionism (Frost Multidimensional Perfectionism Scale), wellbeing (Warwick-Edinburgh Mental Well-being Scale), psychological distress (General Health Questionnaire-12), depression (Beck Depression Inventory-II) and suicidal ideation and attempts. Results Veterinary, medical and dentistry students were significantly more agreeable than law students, while veterinary students had the lowest perfectionism scores of the five groups studied. High levels of neuroticism and low conscientiousness were predictive of increased mental ill-health in each of the student populations. Conclusions The study highlights that the prevailing anecdotal view of professional students possessing maladaptive personality traits that negatively impact on their mental health may be misplaced

Effective Rheology of Bubbles Moving in a Capillary Tube

We calculate the average volumetric flux versus pressure drop of bubbles moving in a single capillary tube with varying diameter, finding a square-root relation from mapping the flow equations onto that of a driven overdamped pendulum. The calculation is based on a derivation of the equation of motion of a bubble train from considering the capillary forces and the entropy production associated with the viscous flow. We also calculate the configurational probability of the positions of the bubbles.Comment: 4 pages, 1 figur

Does neurocognitive training have the potential to improve dietary self-care in type 2 diabetes? Study protocol of a double blind randomised controlled trial

Dietary self-care is a key element of self-management in type 2 diabetes. It is also the most difficult aspect of diabetes self-management. Adhering to long-term dietary goals and resisting immediate food desires requires top-down inhibitory control over subcortical impulsive and emotional responses to food. Practising simple neurocognitive tasks can improve inhibitory control and health behaviours that depend on inhibitory control, such as resisting alcohol consumption. It is yet to be investigated, however, whether neurocognitive training can improve dietary self-care in people with type 2 diabetes. The aim of this randomised controlled trial is to investigate whether web-based neurocognitive training can improve the ability of people with type 2 diabetes to resist tempting foods and better adhere to a healthy dietary regime