University of Connecticut

About: University of Connecticut is a education organization based out in Storrs, Connecticut, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 35297 authors who have published 81224 publications receiving 2952682 citations. The organization is also known as: UConn & Storrs Agricultural School.

Prokaryotic Evolution in Light of Gene Transfer

Abstract: Accumulating prokaryotic gene and genome sequences reveal that the exchange of genetic information through both homology-dependent recombination and horizontal (lateral) gene transfer (HGT) is far more important, in quantity and quality, than hitherto imagined. The traditional view, that prokaryotic evolution can be understood primarily in terms of clonal divergence and periodic selection, must be augmented to embrace gene exchange as a creative force, itself responsible for much of the pattern of similarities and differences we see between prokaryotic microbes. Rather than replacing periodic selection on genetic diversity, gene loss, and other chromosomal alterations as important players in adaptive evolution, gene exchange acts in concert with these processes to provide a rich explanatory paradigm-some of whose implications we explore here. In particular, we discuss (1) the role of recombination and HGT in giving phenotypic "coherence" to prokaryotic taxa at all levels of inclusiveness, (2) the implications of these processes for the reconstruction and meaning of "phylogeny," and (3) new views of prokaryotic adaptation and diversification based on gene acquisition and exchange.

Clarifying conditions and decision points for mediational type inferences in Organizational Behavior

Abstract: Although mediational designs and analyses are quite popular in Organizational Behavior research, there is much confusion surrounding the basis of causal inferences. We review theoretical, research design, and construct validity issues that are important for drawing inferences from mediational analyses. We then distinguish between indirect effects, and partial and full mediational hypotheses and outline decision points for drawing inferences of each type. An empirical illustration is provided using structural equation modeling (SEM) techniques, and we discuss extensions and directions for future research. Copyright © 2006 John Wiley & Sons, Ltd.

A Promising Approach for Expanding and Sustaining School-Wide Positive Behavior Support.

Abstract: Educators and psychologists are concerned about problem behavior. Fortunately, effective interventions and practices have been documented for addressing this problem behavior. However, sustained an...

The SLAC wrist : Scapholunate advanced collapse pattern of degenerative arthritis

Abstract: Four thousand wrist x-ray films were reviewed to establish the pattern of sequential changes in degenerative arthritis of the wrist. After eliminating all other arthritides, we studied 210 cases of degenerative arthritis. The most common pattern (57%) was arthritis between the scaphoid, lunate, and radius; 27% of cases occurred between the scaphoid, trapezium, and trapezoid; a combination of these two patterns occurred in 15%. Twenty operations were performed on 19 patients with the scapholunate advanced collapse pattern. Eighteen of 19 patients had less pain postoperatively and none required pain medication. Flexion-extension and radial-ulnar deviation motions showed considerable improvement after the operation.

Role of osteoblasts in hormonal control of bone resorption - a hypothesis

Abstract: The following hypothesis attempts to explain the puzzling fact that osteoblasts--the bone-forming cells--seem to be the target cells of parathyroid hormone (PTH), the prostaglandins, and 1,25-dihydroxyvitamin D3 (1,25(OH)2D3), the bone-resorbing hormones. This hypothesis combines some old and new physiological, biochemical, and morphological data, and ascribes to the osteoblasts a pivotal role in bone resorption. PTH has been shown to have a large number of effects on osteoblasts or \"osteoblast-like\" cells including: (a) stimulation of adenylate cyclase activity resulting in a cyclic AMP (cAMP) surge [1, 2]; (b) rapid activation of cyclic AMP-dependent protein kinase [3]; (c) inhibition of collagen synthesis [4]; (d) inhibition of alkaline phosphatase activity [1, 5]; (e) stimulation of calcium uptake [6, 7]; and (f) production of cell shape changes resulting in less tight packing of the cells, observed both in calvaria and in culture [8, 9]. On the other hand, there is little evidence so far that osteoclasts possess PTH receptors or respond to PTH directly. There is accumulating evidence that circulating mononuclear cells (monocytes) are osteoclast precursors and can resorb devitalized bone in culture [10, 12], but PTH has no effect on the chemotactic migration or the resorbing activity of these cells. Moreover, PTH does not seem tO be essential for normal osteoclastic activity and bone remodeling since these functions are retained in parathyroidectomized newborn rats [13]. Furthermore, no PTH-related defect can be implicated in osteoclast malfunctions associated with osteopetrosis [14]. Other bone-resorbing humoral factors have osteoblasts as their targets. Prostaglandins stimulate cyclic AMP accumulation in osteoblast-like cells, and there is a remarkably close correlation between