Effects of the inclusive dipole-pomeron to exclusive processes

The consequences of the inclusive dipole-Pomeron for the exclusive processes are investigated. In the weak coupling limit a two component picture for the production mechanism is obtained and self-consistency of the inclusive Pomeron dipole is found.     

Cooperative study teams in mathematics classrooms

This article describes a general instructional strategy designed to help students in the learning process from textbooks and to furnish opportunities for practice in critical reading. Students participate in cooperative learning by breaking the class up into small groups—the Study Teams—and providing them with worksheets and reading organizers, which organize the material into small items that reflect the major concepts in the reading material on which the study is focused. Some of the benefits that this type of instruction with Study Teams can produce are described.     

Private labels and retail assortment planning: a differential evolution approach

Despite the longstanding recognition of the importance of product assortment planning (PAP), existing literature has failed to provide satisfactory solutions to a great deal of problems that reside in this area of research. The issue of optimal assortment planning in the retail sector becomes even more important in periods of economic crisis, as retailers must adapt their product portfolios to new evolving patterns of consumer buying behaviour and reduced levels of consumer’s purchasing power. Private labels (PLs) typically experience significant growth in times of recession, due to their low prices, and the reduced disposable income of households. In this direction, the present paper introduces differential evolution to assist retailers in adapting their product portfolios in periods of economic recession and facilitate strategic PAP decisions, related to (a) optimal variety of PL product categories, (b) optimal service level of PL merchandise within a product category, and hence, (c) optimal balance between PLs and National Brands in a retailer’s product portfolio. The interrelated issue of assortment adaptation across different store formats is also considered. Economic recessions contribute to the prolonged upward evolution in PL share, and hence, our mechanism facilitates decisions that are nowadays more important than ever before. The proposed mechanism is illustrated through an implementation to an empirical dataset derived from a random sample of 1928 consumers who participated in a large-scale computer assisted telephone survey during the current economic crisis period.     

Atomistic insights into dislocation-based mechanisms of void growth and coalescence

One of the low-temperature failure mechanisms in ductile metallic alloys is the growth of voids and their coalescence. In the present work we attempt to obtain atomistic insights into the mechanisms underpinning cavitation in a representative metal, namely Aluminum. Often the pre-existing voids in metallic alloys such as Al have complex shapes (e.g. corrosion pits) and the defromation/damage mechanisms exhibit a rich size-dependent behavior across various material length scales. We focus on these two issues in this paper through large-scale calculations on specimens of sizes ranging from 18 thousand to 1.08 million atoms. In addition to the elucidation of the dislocation propagation based void growth mechanism we highlight the observed length scale effect reflected in the effective stress-strain response, stress triaxiality and void fraction evolution. Furthermore, as expected, the conventionally used Gurson's model fails to capture the observed size-effects calling for a mechanistic modification that incorporates the mechanisms observed in our (and other researchers') simulation. Finally, in our multi-void simulations, we find that, the splitting of a big void into a distribution of small ones increases the load-carrying capacity of specimens. However, no obvious dependence of the void fraction evolution on void coalescence is observed.     

Real-time production planning and control system for job-shop manufacturing: A system dynamics analysis

Much attention has been paid to production planning and control (PPC) in job-shop manufacturing systems. However, there is a remaining gap between theory and practice, in the ability of PPC systems to capture the dynamic disturbances in manufacturing process. Since most job-shop manufacturing systems operate in a stochastic environment, the need for sound PPC systems has emerged, to identify the discrepancy between planned and actual activities in real-time and also to provide corrective measures. By integrating production ordering and batch sizing control mechanisms into a dynamic model, we propose a comprehensive real-time PPC system for arbitrary capacitated job-shop manufacturing. We adopt a system dynamics (SD) approach which is proved to be appropriate for studying the dynamic behavior of complex manufacturing systems. We study the system’s response, under different arrival patterns for customer orders and the existence of various types real-time events related to customer orders and machine failures. We determine the near-optimal values of control variables, which improve the shop performance in terms of average backlogged orders, work in process inventories and tardy jobs. The results of extensive numerical investigation are statistically examined by using analysis of variance (ANOVA). The examination reveals an insensitivity of near-optimal values to real-time events and to arrival pattern and variability of customer orders. In addition, it reveals a positive impact of the proposed real-time PPC system on the shop performance. The efficiency of PPC system is further examined by implementing data from a real-world manufacturer.     

Annexin A6 is highly abundant in monocytes of obese and type 2 diabetic individuals and is downregulated by adiponectin in vitro

Adiponectin stimulates cholesterol efflux in macrophages and low adiponectin may in part contribute to disturbed reverse cholesterol transport in type 2 diabetes. Monocytes express high levels of annexin A6 that could inhibit cholesterol efflux and it was investigated whether the atheroprotective effects of adiponectin are accompanied by changes in annexin A6 levels. Adiponectin reduces annexin A6 protein whereas mRNA levels are not affected. Adiponectin-mediated activation of peroxisome proliferator-activated receptor α (PPARα) and AMP-activated protein kinase (AMPK) does not account for reduced annexin A6 expression. Further, fatty acids and lipopolysaccharide that are elevated in obesity do not influence annexin A6 protein levels. Annexin A6 in monocytes from overweight probands or type 2 diabetic patients is significantly elevated compared to monocytes of normal-weight controls. Monocytic annexin A6 positively correlates with body mass index and negatively with systemic adiponectin of the blood donors. Therefore, the current study demonstrates that adiponectin reduces annexin A6 in monocytes and thereby may enhance cholesterol efflux. In agreement with these in vitro finding an increase of monocytic annexin A6 in type 2 diabetes monocytes was observed.