STUDY OF J/PSI THREE-BODY DECAYS INVOLVING BARYONS

The $J/\Psi$ decay into a baryon pair and a pseudoscalar meson is computed, for some channels, in lowest order in perturbative QCD, modeling the baryon with a quark-diquark system. We use a set of parameters that has been proposed by some authors in order to fit the proton magnetic form factor $G^{p}_{M}$, the angular distribution of protons in the process $\gamma \gamma \to p \bar{p}$ and the width of $\eta_{c} \to \gamma \gamma$.Comment: Plain Latex file, 10 pages; 1 figure appended as a uuencoded file; Keywords : Charmonium, Baryons, Paiar production, Particle Structure

Long term outcome of minimally invasive treatment for superficial venous insufficiency of the lower limb

BackgroundVenous insufficiency is estimated to affect up to half of the adult population and is associated with significant quality of life (QoL) impairment. Minimally invasive techniques, such as Endovenous Laser Ablation (EVLA) aim to treat superficial venous insufficiency (SVI) by using thermal energy to destroy the incompetent venous axis. Numerous studies have reported that the EVLA method is superior to Conventional surgery, a previously standard technique, which uses ligation and stripping of the incompetent axis to remove venous reflux associated with SVI. In the short term, EVLA is associated with fewer complications and enhanced QoL recovery compared to conventional surgery, but the long term outcomes remain uncertain.ObjectivesThe aim of this study was to investigate the five year outcomes of EVLA and conventional surgery in the treatment of SVI. The HELP-1 trial directly compared the clinical and technical outcomes of conventional surgery and EVLA. The EVLTAP trial compared the long term consequences of a policy of concomitant or sequential phlebectomy with EVLA. Due to advantageous size of the HELP-1 study, a comparison of the long term outcomes of patients with different severities of SVI was also explored. A cost effective analysis was also undertaken. Finally, investigation of the importance of different EVLA settings and techniques was investigated.MethodsThe HELP-1 and EVLTAP studies were both randomised clinical trials. All patients had primary, symptomatic, unilateral venous insufficiency, with isolated Sapheno-femoral junction (SFJ) incompetence, leading to reflux into the great saphenous vein (GSV). In the HELP-1 study, 280 patients were equally randomised into two groups of either conventional surgery or EVLA. In the EVLAP trial, 50 patients were equally randomised into two groups of either concomitant phlebectomy or sequential phlebectomy. Both groups were offered sequential phlebectomy of any symptomatic residual venous tributaries present after six weeks. Outcomes were generic QoL (Short form 36 (SF-36), EuroQoL 5 Dimension (EQ5D), Disease specific QoL (Aberdeen Varicose Vein Questionnaire AVVQ), Utility Index QoL (SF6D), Objective clinical assessment of venous disease (VCSS), Cosmetic and overall satisfaction, clinical recurrence, symptomatic recurrence and requirement of additional procedures. Assessments were at 1, 6, 12, 52, 104, 260 weeks.The further study of EVLA settings and technique used linear and logistic regression modelling to investigate the effects of Watt power (12W or 14W) and concomitant phlebectomy on QoL (SF-36, EQ5D and AVVQ), clinical outcomes and recurrence. For the economic analysis, costs were calculated using prospective data estimated from the actual resource requirement in each case over five years. Health utility index from the EQ5D or SF6D was used to calculate quality adjusted life years (QALYs) over five years using Area under the Curve (AUC). The Cost per QALY increase was calculated to produce a cost effective ratio (ICER) to determine cost effectiveness at various economic limits. Sensitivity analysis explored parameter uncertainty. For EVLTAP a Monte Carlo simulation was developed to explore the additional costs of various thresholds for sequential phlebectomy.ResultsOver five years, the HELP-1 trial detected early deterioration in the SF-36 QoL domains of Physical function (PF), Role physical (RF), Bodily pain (BP), Social function (SF) and Role emotional (RE) after conventional surgery After EVLA only the domains of PF and RP were impacted. Beyond one year, improvement in the domains of PF, BP and Mental health (MH) were maintained after conventional surgery, as were the domains of PF and BP after EVLA. At five years, all SF-36 domains in both groups had returned to baseline, aside from Social Function (SF) which was worse in both groups. Beyond one year, no differences in SF-36 domains were detected between the groups at any time point. Improvement in AVVQ and EQ5D was sustained in both groups, as was objective measure of venous disease (VCSS), with no differences detected between the two treatments. Overall satisfaction and cosmesis remained high. Over five years, clinical recurrence was detected in 56.4% and 44.4% of conventional surgery and EVLA patients respectively (P=0.078). Estimated freedom from clinical recurrence was higher after EVLA (P=0.031). Over five years, symptomatic recurrence was detected in 18 and 19 conventional surgery and EVLA patients respectively (P=0.862) and likelihood of symptomatic recurrence development was similar between both groups (P=0.983). The proportion of those requiring additional procedures were similar between both groups over five years (P=1.000).Over five years, the EVLTAP trial detected an early improvement in AVVQ at six weeks among those receiving concomitant phlebectomy (P=0.008). At 12 weeks both groups reported an improvement in AVVQ (EVLA alone P=0.018, EVLTAP P<0.001). Compared to sequential phlebectomy, concomitant phlebectomy had lower (better) AVVQ scores at 6 weeks (P=0.008) and 12 weeks (P=0.015). Beyond one year both groups reported significantly improved with no intergroup differences detected. Sequential phlebectomy was required in 66.7% of those in the EVLA alone group, and 4% of those in the EVLTAP group. The requirement for additional intervention after one year was however similar between the two groups.From the HELP-1 trial data, more severe baseline disease (CEAP 3-4) was associated with worse long term outcomes compared to those with uncomplicated venous disease (C2). Clinical recurrence arose in 70% of those with C3-4 disease and 43% of those with C2 disease. Symptomatic recurrence was also higher in those with complicated disease, at 27% and 12% in C3-4 and C2 groups respectively. Whereas QoL improvement was maintained to five years in the domains of RP, RP, Vit and RE among those with C2 disease, those with C3-4 disease did not manage to sustain any improvement in any SF-36 QoL domain. However, over five years both groups did improve in disease specific measures of VCSS and AVVQ. Additional treatments were also more prevalent amongst those with C3-4 disease.Economic analysis suggested that the initial treatment costs of EVLA were less than conventional surgery, but after one year costs were broadly the same. QALYs were also similar between both treatments. Cost effectiveness over five years was similar between both treatments, with marginal improvement of QALY but more cost among conventional surgery. Significant costs associated with the long term treatment of those with C3-4 disease and worse QoL outcomes suggested that treatment of C2 disease was much more cost effective overall. Performing EVLA without concomitant phlebectomy is both quicker and cheaper, but additional costs of sequential phlebectomy by one year inflate the overall costs to beyond that of the concomitant group. Costs beyond one year are similar. Monte Carlo modelling suggests that sequential phlebectomy is highly unlikely to be more cost effective at any threshold of further intervention.Investigation into the effects of EVLA setting and technique found that at 12 weeks, PF, Vit and MH were enhanced in those receiving the 14W continuously delivered EVLA versus those receiving the 12W pulse delivered EVLA. Early benefit in PF and AVVQ was also detected in those receiving concomitant phlebectomy. Beyond 12 weeks there was no significant difference in QoL detected, nor did the treatment ultimately effect the clinical outcomes or recurrence.ConclusionEVLA and conventional surgery are both highly effective long term treatments for SVI. In considering the early benefits, this study supports the recent NICE guidance that EVLA should be preferred over conventional surgery. Concomitant phlebectomy during EVLA appears to be the optimum treatment, and treating those with SVI earlier, appears to produce better long term outcomes

A Study of the effect of oil added to Toray driographic ink on toning in the non-image areas of Toray company\u27s negative working driographic plates

Several studies and investigations have been conducted to test the new Toray plate. The studies revealed that the new plate eliminated many of the problems that used to hinder the progress and development of the driographic plate system. The two major problems with this plate were short run lengths and toning in the non-image areas. This study investigates toning problems in negative working Toray plates. Toning is a term that refers to the non-image areas of the driographic plate that are accepting ink. Previous studies have shown that ink tack and flow do not affect toning in any way. However, printing speed, nip pressure, printing density and ink temperature were found to have some effect on toning. To investigate the effect that different percentages of oil in the ink has on toning in the non-image areas of Toray negative working plates, this study uses five ink samples, each containing a different percentage of oil, and measures with a densitometer the density of toning in the non-image areas. The hypothesis tested in this study states that the amount of toning in the non-image areas of negative Toray plates increases as the amount of oil contained in the ink increases. Upon analyzing the data collected, it was found that when using the special driographic ink no scumming occured. However, the hypothesis proved to stand true because it was found that a strong positive relationship exists between the amount of oil contained in the driographic ink and the amount of toning in the non-image areas of negative Toray plates

Reproductive Life Histories of Mammoths

The end of the Pleistocene saw the extinction of many large vertebrate species, including mammoths (genus Mammuthus). Despite many decades of work by various researchers, the cause(s) of mammoth extinction are still heavily debated, with climate change and human hunting being the two primary hypothesized agents of extinction. One major problem with identifying the cause of this extinction is the fact that changing climates and movement of human hunters into ecosystems containing mammoths are both broadly associated with the time of extinction, making it difficult to decouple one potential cause from the other using only temporal data. This study bypasses the strictly chronological approach of many previous studies and instead investigates the cause of the end-Pleistocene extinction using information about reproductive life history. The age of first conception and the average time between conceptions are both expected to change predictably and divergently under the hypotheses of climate-driven extinction and hunting-driven extinction, so assessment of changes in these aspects of life history approaching the time of extinction could provide a test for cause of extinction. I use the record of growth within tusk dentin to identify patterns associated with reproductive life history in mammoths. Thin sections and serial isotope analyses document the periodicity of X-ray density features observed in microCT sections of tusks. These attenuation features form annually in both Columbian and woolly mammoths (Mammuthus columbi and Mammuthus primigenius, respectively), but form semiannually in a gomphothere from South America. MicroCT scans of entire tusks are employed to provide a record of multiple decades of growth for ten Siberian woolly mammoths. In eight of these specimens, all of them adult females, we observe a repeated 3- to 6-year-long cyclical pattern of regularly varying growth rate. This pattern was absent in both adult males and juveniles. We interpret this pattern as a record of calving in females, and its onset is observed in several individuals to occur at an age approximating that of sexual maturation in extant elephants. Our dataset shows a minor decrease in age of maturation and average calving interval near the end of the Pleistocene. This is predicted by a hunting-driven model of extinction but is not expected for extinction driven by climate change. This work contributes to our knowledge of the reproductive life history of mammoths, which we argue is key to understanding the cause of their extinction.PHDEarth and Environmental SciencesUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttps://deepblue.lib.umich.edu/bitstream/2027.42/143902/1/jeladli_1.pd

Designing a robust production system for erratic demand environments.

Production systems must have the right type of material in the right quantities when required for production. They must minimize the work in progress while ensuring no stock-outstock-out occurs. While these twin opposing goals are achievable when demand is stable, they are difficult to realize under an erratic demand pattern. This dissertation aims to develop a production system that can meet erratic demands with minimal costs or errors. After a detailed introduction to the problem considered, we review the relevant literature. We then conduct a numerical analysis of current production systems, identify their deficiencies, and then present our solution to address these deficiencies via the ARK (Automated Replenishment System) technique. This technique is applied to a real-world problem at Methode Engineering ©. We conclude by detailing the scientific benefit of our technique and proposing ideas for future research

Intraspecific variability modulates interspecific variability in animal organismal stoichiometry.

Interspecific differences in organismal stoichiometry (OS) have been documented in a wide range of animal taxa and are of significant interest for understanding evolutionary patterns in OS. In contrast, intraspecific variation in animal OS has generally been treated as analytical noise or random variation, even though available data suggest intraspecific variability in OS is widespread. Here, we assess how intraspecific variation in OS affects inferences about interspecific OS differences using two co-occurring Neotropical fishes: Poecilia reticulata and Rivulus hartii. A wide range of OS has been observed within both species and has been attributed to environmental differences among stream systems. We assess the contributions of species identity, stream system, and the interactions between stream and species to variability in N:P, C:P, and C:N. Because predation pressure can impact the foraging ecology and life-history traits of fishes, we compare predictors of OS between communities that include predators, and communities where predators are absent. We find that species identity is the strongest predictor of N:P, while stream or the interaction of stream and species contribute more to the overall variation in C:P and C:N. Interspecific differences in N:P, C:P, and C:N are therefore not consistent among streams. The relative contribution of stream or species to OS qualitatively changes between the two predation communities, but these differences do not have appreciable effects in interspecific patterns. We conclude that although species identity is a significant predictor of OS, intraspecific OS is sometimes sufficient to overwhelm or obfuscate interspecific differences in OS

Microglial Scavenger Receptors and Their Roles in the Pathogenesis of Alzheimer's Disease

Alzheimer's disease (AD) is increasing in prevalence with the aging population. Deposition of amyloid-β (Aβ) in the brain of AD patients is a hallmark of the disease and is associated with increased microglial numbers and activation state. The interaction of microglia with Aβ appears to play a dichotomous role in AD pathogenesis. On one hand, microglia can phagocytose and clear Aβ, but binding of microglia to Aβ also increases their ability to produce inflammatory cytokines, chemokines, and neurotoxic reactive oxygen species (ROS). Scavenger receptors, a group of evolutionally conserved proteins expressed on the surface of microglia act as receptors for Aβ. Of particular interest are SCARA-1 (scavenger receptor A-1), CD36, and RAGE (receptor for advanced glycation end products). SCARA-1 appears to be involved in the clearance of Aβ, while CD36 and RAGE are involved in activation of microglia by Aβ. In this review, we discuss the roles of various scavenger receptors in the interaction of microglia with Aβ and propose that these receptors play complementary, nonredundant functions in the development of AD pathology. We also discuss potential therapeutic applications for these receptors in AD