Quark-Antiquark Energy Density Function applied to Di-Gauge Boson Production at the LHC

In view of the start up of the 14 TeV pp Large Hadron Collider the quark anti-quark reactions leading to the final states W^+W^-, W^+-Z^0 and Z^0Z^0 are studied, in the frame workn of the Standard Model (SM), using helicity amplitudes. The differential and total cross sections are first evaluated in the parton-parton center of mass system. They are then transformed to their expected behavior in pp collisions through the parton-parton Energy Density Functions which are here derived from the known Parton Density Functions of the proton. In particular the single and joint longitudinal polarizations of the final state di-bosons are calculated. The effect on these reactions from the presence of s-channel heavy vector bosons, like the W' and Z', are evaluated to explore the possibility to utilize the gauge boson pair production as a probe for these 'Beyond the SM' phenomena.Comment: 15 pages and 8 figures

Can the implementation of an interdisciplinary retrieval practice in science facilitate students' motivation and perception about cross-curricular concepts?

This study explores the effects on online educational games as a retrieval practice on students’ retention and understanding of the cross curricular concepts between sciences and between sciences and mathematics. The implementation of an online cross-science retrieval practice was introduced to investigate whether it can facilitate students’ understanding of the interrelation of sciences and mathematics, as well as students’ motivation/ participation. It also aimed to explore teachers’ perspectives on a cross-science retrieval approach. Questionnaires were completed before and after the implementation of the intervention with 43 KS4 students and 5 science teachers participating. Based on the findings of this study, it could be suggested that there is evidence, although not at a statistically significant level, to support that applying retrieval practice with online educational games could improve students’ motivation and perception about cross-curricular concepts

The Association of Late-Life Depression, Cognitive Functioning, and Sleep Disorder in Aging

The continuing growth in the demographic of aging individuals in the United States creates concern for diseases of aging that are chronic, notably unipolar depressive disorders. The high rates of depression in the aging population are a concern because of the strong association between late-life depression and cognitive impairment. Poor cognitive functioning is a hallmark of aging related neurological disorders, the most prevalent being Alzheimer’s Disease (AD). Sleep disorder is a core symptom of depression, and is definitively associated with the development of mild cognitive impairment (MCI), the prodrome of AD. MCI is also characterized by similar types of sleep disturbance including sleep fragmentation, which consists of excessive awakenings during the night that leads to atypical suppression of night-time full awakenings and chronic sleep debt that impairs daytime attention and cognition as a consequence of poor sleep quality. The main hypothesis of this study is that current or historical depression in older adults will be associated with poor sleep quality and cognitive impairment. Participants (N=50) from 65-85 years were assessed to determine the impact of depression status on sleep disturbance and cognitive variables. Individuals endorsing current depression (n=9), history of diagnosed depression but no current depression (n=7), or no current depression (n=34) were tested for 7 nights using wrist actigraphy and self-report sleep diaries to assess various sleep parameters used to identify sleep disturbance. Memory consolidation was probed surrounding one night of sleep using a simple procedural memory task and one-month follow-up assessment was used to assess a variety of neurocognitive domains including immediate and delayed recall, visuospatial abilities, etc. Results from this study revealed that individuals with current depression showed poorer sleep quality (i.e. shorter sleep time, lower mean sleep efficiency, longer sleep latency, etc.) and self-reported more sleep disturbances and greater daytime dysfunction when compared with individuals with no current depression or depressive history (p’s \u3c .05). Results of impairment on cognitive tasks from participants with current depression or a history of diagnosed depression were not found. These results provide evidence of an association between sleep disturbance and late-life depression. Cognitive performance of depressed older adults warrant further exploration

Inventory control of spare parts using a Bayesian approach: a case study

This paper presents a case study of applying a Bayesian approach to forecast demand and subsequently determine the appropriate parameter S of an (S-1,S) inventory system for controlling spare parts of electronic equipment. First, the problem and the current policy are described. Then, the basic elements of the Bayesian approach are introduced and the procedure for calculating the appropriate parameter S is illustrated. Finally, we present the results of applying the Bayesian approach in an innovative way to determine the stock levels of three types of circuit packs at several locations. According to the proposed method, a lower base stock than the one currently used is sufficient to achieve the desired service level.inventory control;spare parts;case study;Bayesian analysis

Dominant Role of PI3K p110α over p110β in Insulin and β-Adrenergic Receptor Signalling

Attribution of specific roles to the two ubiquitously expressed PI 3-kinase (PI3K) isoforms p110α and p110β in biological functions they have been implicated, such as in insulin signalling, has been challenging. While p110α has been demonstrated to be the principal isoform activated downstream of the insulin receptor, several studies have provided evidence for a role of p110β. Here we have used isoform-selective inhibitors to estimate the relative contribution of each of these isoforms in insulin signalling in adipocytes, which are a cell type with essential roles in regulation of metabolism at the systemic level. Consistent with previous genetic and pharmacological studies, we found that p110α is the principal isoform activated downstream of the insulin receptor under physiological conditions. p110α interaction with Ras enhanced the strength of p110α activation by insulin. However, this interaction did not account for the selectivity for p110α over p110β in insulin signalling. We also demonstrate that p110α is the principal isoform activated downstream of the β-adrenergic receptor (β-AR), another important signalling pathway in metabolic regulation, through a mechanism involving activation of the cAMP effector molecule EPAC1. This study offers further insights in the role of PI3K isoforms in the regulation of energy metabolism with implications for the therapeutic application of selective inhibitors of these isoforms

Inventory control of spare parts using a Bayesian approach: a case study

This paper presents a case study of applying a Bayesian approach to forecast demand and subsequently determine the appropriate parameter S of an (S-1,S) inventory system for controlling spare parts of electronic equipment. First, the problem and the current policy are described. Then, the basic elements of the Bayesian approach are introduced and the procedure for calculating the appropriate parameter S is illustrated. Finally, we present the results of applying the Bayesian approach in an innovative way to determine the stock levels of three types of circuit packs at several locations. According to the proposed method, a lower base stock than the one currently used is sufficient to achieve the desired service level