A Survey of Teacher In-Service Education in Nebraska\u27s Class II Schools

The importance and need for in-service education for educational personnel is high-lighted by the rapid expansion of knowledge. That expansion, coupled with changing methods and developing technology, has created a need for a systematic program that makes provision for professional growth of teachers while in-service

Tillage Research in Ohio A Guide to the Selection of Profitable Tillage Systems

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Purine Transport and Metabolism in Microvascular Endothelial Cells

The microvascular endothelium serves as the barrier between the blood and perfused tissues. Proper function of the endothelium is dependent on the ability of the endothelial cells to produce nitric oxide and form tight junctions between themselves. Dysfunction occurs when stresses overwhelm the endothelial cell, with oxidative stress being a leading cause. Intracellular metabolism of purine nucleosides and nucleobases has been implicated in the production of oxidative stress. Nucleosides (e.g. adenosine) and nucleobases (e.g. hypoxanthine) are moved across cell membranes by a specialized family of proteins called equilibrative nucleoside transporters (ENTs). We characterized primary human cardiac microvascular endothelial cells (MVECs) for expression, function, and regulation of nucleoside and nucleobase transporters. It was discovered that nucleobase transport in these MVECs was mediated by a novel, purine selective transporter that was insensitive to inhibitors of ENTs, which we named equilibrative nucleobase transporter 1 (ENBT1). ENBT1 and the nucleoside selective transporter ENT1 were differentially regulated by a number of intracellular protein kinases, vascular endothelial growth factor, and oxidative stress. The role of nucleoside and nucleobase transport in the physiology of MVECs was also studied, using primary MVECs isolated from wild-type (WT) and ENT1-/- mice. Altered gene expression of adenosine metabolizing enzymes and adenosine signaling was identified and confirmed at the protein level, however, there was no compensatory changes in other nucleoside or nucleobase transporters. Coinciding with the loss of adenosine transport capabilities, ENT1-/- mice had elevated adenosine plasma concentrations compared to WT and lowered blood pressure. Unexpectedly, the ENT1-/- began to develop hind limb paralysis at about 12 months old. Post-mortem analysis revealed abnormal mineralization on the spine leading to spinal cord compression. MicroCT analysis was used to determine a time course of development, with mineralization being apparent as early as 2 months old. The pattern of mineralization resembled the human condition known as diffuse idiopathic skeletal hyperostosis (DISH). Nucleoside and nucleobase transporters are important in the regulation of cardiovascular effects of purines, with special consideration to oxidative stress and blood pressure. We may have also discovered a novel role for ENT1 in the development of DISH

Management of work-relevant upper limb disorders: a review

Background Upper limb disorders (ULDs) are clinically challenging and responsible for considerable work loss. There is a need to determine effective approaches for their management. Aim To determine evidence-based management strategies for work-relevant ULDs and explore whether a biopsychosocial approach is appropriate. Methods Literature review using a best evidence synthesis. Data from articles identified through systematic searching of electronic databases and citation tracking were extracted into evidence tables. The information was synthesized into high-level evidence statements, which were ordered into themes covering classification/diagnosis, epidemiology, associations/risks and management/treatment, focusing on return to work or work retention and taking account of distinctions between non-specific complaints and specific diagnoses. Results Neither biomedical treatment nor ergonomic workplace interventions alone offer an optimal solution; rather, multimodal interventions show considerable promise, particularly for occupational outcomes. Early return to work, or work retention, is an important goal for most cases and may be facilitated, where necessary, by transitional work arrangements. The emergent evidence indicates that successful management strategies require all the players to be onside and acting in a coordinated fashion; this requires engaging employers and workers to participate. Conclusions The biopsychosocial model applies: biological considerations should not be ignored, but psychosocial factors are more influential for occupational outcomes. Implementation of interventions that address the full range of psychosocial issues will require a cultural shift in the way the relationship between upper limb complaints and work is conceived and handled. Dissemination of evidence-based messages can contribute to the needed cultural shift

Power asymmetries and punishment in a prisoner's dilemma with variable cooperative investment

In many two-player games, players that invest in punishment finish with lower payoffs than those who abstain from punishing. These results question the effectiveness of punishment at promoting cooperation, especially when retaliation is possible. It has been suggested that these findings may stem from the unrealistic assumption that all players are equal in terms of power. However, a previous empirical study which incorporated power asymmetries into an iterated prisoner's dilemma (IPD) game failed to show that power asymmetries stabilize cooperation when punishment is possible. Instead, players cooperated in response to their partner cooperating, and punishment did not yield any additional increase in tendency to cooperate. Nevertheless, this previous study only allowed an all-or-nothing–rather than a variable–cooperation investment. It is possible that power asymmetries increase the effectiveness of punishment from strong players only when players are able to vary their investment in cooperation. We tested this hypothesis using a modified IPD game which allowed players to vary their investment in cooperation in response to being punished. As in the previous study, punishment from strong players did not increase cooperation under any circumstances. Thus, in two-player games with symmetric strategy sets, punishment does not appear to increase cooperation

Modeling Changes in the In-Migration Patterns of Northern Saskatchewan Communities : a Log-Linear Approach

Les auteurs examinent les changements dans les types historiques de migrations au sein des petites communautés frontières du nord de la Saskatchewan durant les périodes 1927-1960, 1961-1970 et 1971-1976. Des problèmes apparaissent lorsqu'on tente de formuler des modèles d'interaction spatiale dans les régions frontières, ou en voie de développement, en particulier le faible volume de migration et le fait que certains termes agglomérés sont impropres lorsqu'utilisés comme mesures de degré d'attraction et de répulsion des communautés. Comme procédure alternative, on utilise une méthode log-linéaire, laquelle identifie, par une analyse à dimensions multiples d'une matrice de données classifiées, les composantes dans les processus d'interaction spatiale. Les résultats initiaux montrent que le sexe de l'immigrant n'a pas d'effet sur la tendance à immigrer, et que les types spatiaux d'immigration n'ont pas changé d'une période à l'autre.This paper examines changes in the historical pattern of in-migration to small frontier communities in northern Saskatchewan in three time periods: 1927-1960, 1961-1970 and 1971-1976. The problems associated with spatial interaction modeling in a developing or frontier region are noted, particularly the low volume of in-migration and the inappropriateness of mass terms as surrogate measures of nodal attractiveness and propulsiveness. As an alternative, a log-linear approach is adopted, whereby multidimensional contingency-table analysis of categorical data reveals structural components in the spatial-interaction process. Initial results indicate that the gender of the migrant has no effect on the propensity to migrate and that spatial patterns of in-migration have not changed over time

Performance Evaluation of Road Traffic Control Using a Fuzzy Cellular Model

In this paper a method is proposed for performance evaluation of road traffic control systems. The method is designed to be implemented in an on-line simulation environment, which enables optimisation of adaptive traffic control strategies. Performance measures are computed using a fuzzy cellular traffic model, formulated as a hybrid system combining cellular automata and fuzzy calculus. Experimental results show that the introduced method allows the performance to be evaluated using imprecise traffic measurements. Moreover, the fuzzy definitions of performance measures are convenient for uncertainty determination in traffic control decisions.Comment: The final publication is available at http://www.springerlink.co

Human osteoblast growth and maturation in response to metformin and the thienopyridone, A769662

Metformin (Met) is a biguanide drug widely used in the treatment and management of non insulin-dependent diabetes mellitus. In recent years it has emerged that Met, by stimulating adenosine monophosphate-activated protein kinase (AMPK), can promote the maturation of osteoblasts, albeit cells sourced from rodent and murine calvaria. Finding novel uses for existing drugs is especially appealing, primarily from the fiscal and time constraints posed in developing new products. Identifying agents capable of supporting human osteoblast growth and differentiation are attractive in a bone regenerative context. Since studies using Met are invariably restricted to rodent and murine osteoblasts we sought to investigate whether this biguanide might have a positive influence upon human osteoblast growth and maturation. To this end we examined the effect of Met on two osteoblast-like cell lines, MG63 and Saos-2, and compared the responses to primary human osteoblasts and their bone marrow-derived stem cell progeny. Furthermore we examined the effect of a cell permeable Met surrogate, A769662, which is a potent and far more selective activator of AMPK. Herein we report that Met is without influence on cell growth. Furthermore the application of Met, albeit in the millimolar range, actually inhibited osteoblast maturation. Conversely A769662 was toxic to the osteosarcoma-derived cell lines, MG63 and Saos-2, but without effect on the growth of primary cells or their stem cell progenitors. Since the cell lines are known to be p53 deficient we propose that activation of AMPK by A769662 could form part of the arsenal in the fight against osteosarcoma