University of Kansas

About: University of Kansas is a education organization based out in Lawrence, Kansas, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 38183 authors who have published 81381 publications receiving 2986312 citations. The organization is also known as: KU & Univ of Kansas.

Empirical perspectives on species borders: from traditional biogeography to global change

Abstract: In this paper we will outline several empirical approaches to developing and testing hypotheses about the determinants of species borders. We highlight environmental change as an important opportunity - arguing that these unplanned, large-scale manipulations can be used to study mechanisms which limit species distributions. Our discussion will emphasize three main ideas. First, we review the traditional biogeographic approach. We show how modern analytical and computer techniques have improved this approach and generated important new hypotheses concerning species' range determinants. However, abilities to test those hypotheses continue to be limited. Next we look at how the additions of temporal data, field and lab experimentation, biological details and replication, when applied to systems that have been the subject of classical biogeographic studies, have been used to support or refute hypotheses on range determinants. Such a multi-faceted approach adds rigor, consistency and plausible mechanisms to the study of species ranges, and has been especially fruitful in the study of climate and species' ranges. Lastly, we present an alternative avenue for exploration of range-limiting mechanisms which has been under-utilized. We argue that carefully designed comparisons and contrasts between groups of species or systems provide a powerful tool for examining hypotheses on species' borders. The seasonality hypothesis as an explanation for Rapoport's rule serves as a model of this approach. A test is constructed by comparing patterns of seasonality and range size among marine and terrestrial systems. The seasonality hypothesis is not supported.

Nanoparticles for biomedical imaging

Abstract: Background: Synthetic nanoparticles are emerging as versatile tools in biomedical applications, particularly in the area of biomedical imaging. Nanoparticles 1 – 100 nm in diameter have dimensions comparable to biological functional units. Diverse surface chemistries, unique magnetic properties, tunable absorption and emission properties, and recent advances in the synthesis and engineering of various nanoparticles suggest their potential as probes for early detection of diseases such as cancer. Surface functionalization has expanded further the potential of nanoparticles as probes for molecular imaging. Objective: To summarize emerging research of nanoparticles for biomedical imaging with increased selectivity and reduced nonspecific uptake with increased spatial resolution containing stabilizers conjugated with targeting ligands. Methods: This review summarizes recent technological advances in the synthesis of various nanoparticle probes, and surveys methods to improve the targeting of nanoparticles for...

Adaptive plasticity in motor cortex: implications for rehabilitation after brain injury.

Abstract: It is now widely recognized that the cerebral cortex of adult human and non-human mammals is capable of widespread functional and structural plasticity. During the learning of new skills, cortical regions associated with sensorimotor function of the body parts most utilized for the skilled task come to be represented over larger cortical territories. More recent studies have shown that functional and structural changes take place in the cerebral cortex after injury, such as occurs after stroke or trauma. These two modulators of cortical function, sensorimotor learning and cortical injury, interact. Thus, after cortical injury, the structure and function of undamaged parts of the brain are remodeled during recovery, shaped by the sensorimotor experiences of the individual in the weeks to months following injury. These recent neuroscientific findings suggest that new rehabilitative interventions, both physiotherapeutic and pharmacotherapeutic, may have benefit via modulation of neuroplastic mechanisms.

Alternative Origins to Interorganizational Trust: An Interdependence Perspective on the Shadow of the Past and the Shadow of the Future

Abstract: Despite the widespread acceptance of trust as an informal governance institution, our understanding of its origins is nascent. Our review of the literature identified two distinct explanations: Trust emerges from either a shadow of the past (i.e., prior history) or a shadow of the future (i.e., expectations of continuity). In this paper we develop and empirically examine a third perspective: The potential interdependence of these two explanations. Our results strongly endorse this third perspective. We find that prior history does not directly affect trust; instead, the observed positive relationship between the two is mediated by expectations of continuity. Consistent with this result, analyses further show that a longer prior history makes the effect of continuity on trust much stronger than a shorter prior history. We interpret these findings as suggesting: (1) the criticality and centrality of a shadow of the future (i.e., a forward-looking calculus) in generating trust in interorganizational exchanges and (2) that a shadow of the past plays a facilitating, albeit indirect, role in trust building. Our conceptual model also extends the conventional use of the transaction cost logic to show how reciprocal investments in asset specificity and uncertainty drive expectations of continuity, and consequently, interorganizational trust. Our results also show, unexpectedly, that prior history has a direct negative effect on trust after specifying the mediating path of continuity. Our moderation analysis indicates when this effect occurs: When weak expectations of continuity exist, trust is lower for exchanges characterized by a longer prior history, suggesting a potential darkside of overembedded ties.