Effects of varying force levels and combinations of force application and release during an isometric pinch force task

Fine motor control is important for the completion of many activities of daily living, such as writing, eating, buttoning a shirt, and texting. All these tasks require a high amount of continuous coordination and regulation of increasing and decreasing forces between multiple digits using sub-maximal force levels to successfully accomplish the task. Thus understanding the coordination of force regulation by the thumb and index finger at these sub-maximal force levels is a relevant topic especially for rehabilitation and instrumentation. This study was designed to investigate how accuracy and smoothness of performance of an isometric pinch force tracking task is affected by changing the level of forces required to perform the task and by different combinations of application and release of force by the thumb and index finger. Twenty two healthy, right handed adult participants between the ages of 18-30 were asked to manipulate a cursor to track a moving target ball counterclockwise around a prescribed path using the thumb and index finger of the right hand only. The goal of the task was to keep the cursor as close as possible to the moving target throughout the entire trial. Each participant was given 50 practice trials: 25 at 24% MVC and 25 at 12% MVC. For the 40 experimental trials, participants returned 24 hours later to complete 10 trials at each of the following force levels: 4%, 8%, 16%, and 32%. RMSE and CVE were calculated for each digit (thumb and index finger) as well as the combined digits and were used as indicators of accuracy and smoothness, respectively. Results showed significant differences in all dependent variables with p-values less than 0.05. Task performance accuracy was found to decrease as force level increased, whereas smoothness was found to decrease as force level decreased for all three. These findings suggest that varying force levels and combinations of force application and force release can change performance of this fine motor task and should be further investigated in order to better understand mechanisms involved and for implementing new designs of equipment and diagnostic tools.Kinesiology and Health Educatio

Natural killer cells as an initial defense against pathogens.

Natural killer (NK) cells serve as a crucial first line of defense against tumors and a diverse range of pathogens. Recognition of infection by NK cells is accomplished by the activation of receptors on the NK cell surface, which initiate NK cell effector functions. Many of the receptors and ligands involved in NK cell antimicrobial activity have been identified, and we are beginning to appreciate how they function during infection. In addition, NK cells are activated by cytokines (e.g. interleukin 12 and type I interferons), which are products of activated macrophages and dendritic cells. In response to these activating stimuli, NK cells secrete cytokines and chemokines and lyse target cells. Recent studies have focused on the mechanisms by which NK cells recognize and respond to viruses, parasites and bacteria, and on the unique role of NK cells in innate immunity to infection

Migratory Waterbird Conservation at the Flyway Level: Distilling the Added Value of AEWA in Relation to the Ramsar Convention

In June 1995, the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA) was adopted, and this instrument remains the only legally binding waterbird Agreement in the CMS Family. However, while AEWA has been lauded as a very promising instrument, the concern has also been raised that the Agreement “has a large potential scope for the duplication of obligations, especially with regard to the protection of wetland habitats, given the operation of the Ramsar Convention”. The existing literature thus recognizes that overlap between AEWA and the Ramsar Convention is potentially problematic. It fails, however, to provide a detailed analysis of the nature of this overlap and the interplay between the provisions of the Agreement and the Convention, or of their respective roles in relation to waterbird conservation. This article’s primary objective is to present such an analysis and, in so doing, draw conclusions about the gaps that AEWA is able to fill in the Ramsar regime. The article’s subsidiary objectives are to make suggestions concerning the lessons that AEWA can draw from the experiences of the Ramsar Convention (and the critiques thereof); as well as the lessons that a comparison of the Convention and the Agreement offer concerning the roles, advantages, and disadvantages of ecosystem-based and species-based treaties more broadly. To provide a framework against which to assess the extent to which the Ramsar Convention currently promotes the conservation of waterbirds and the areas in which AEWA makes – or has the potential to make – a unique contribution in relation to Ramsar, part II of the article outlines priority measures for achieving the effective long-term conservation of migratory waterbirds. Particular detail is provided regarding habitat conservation, since it is in this area that the provisions of the Agreement and the Convention experience the greatest overlap and in respect of which the most intricate analysis is therefore necessary in order to distinguish each treaty’s distinctive role. That AEWA has a more pronounced contribution to make than Ramsar in respect of threats that are unrelated to habitat is fairly obvious; though, as will be illustrated in the course of the article, the Convention’s provisions are also relevant in this regard and establish an important link to the Agreement. Part II, therefore, also briefly outlines the need to address threats that are not habitat-related, as well as to address gaps in knowledge. After an introduction to the Ramsar Convention and AEWA is presented in part III, parts IV to VI assess the manners in which the texts of, and the guidance, procedures, and institutions developed under, these two instruments provide for the measures identified in part II, and suggest various improvements that can be made in this regard. While other multilateral environmental agreements (MEAs) are referred to where relevant, a full assessment of their contribution to waterbird conservation falls beyond the scope of this article. Part VII highlights the need to make accession more appealing to developing countries and considers whether there are any lessons that AEWA can draw from the Ramsar Convention in this regard. Although the article does not attempt to present a comprehensive analysis of the current implementation status of AEWA and the Ramsar Convention, it does comment on the extent to which, and the manner in which, certain provisions are being implemented, as determined by the various monitoring mechanisms that are in place under each treaty. Finally, by unpacking the unique, though complementary, contributions of AEWA and the Ramsar Convention, the article provides a setting within which to reflect on the respective advantages and disadvantages of ecosystem-based and species-based treaties in general. The broader lessons that are offered by this comparison are therefore briefly considered in part VIII before conclusions are presented in part IX

Impacts of Homestay on Language Acquisition

The aim of this study was to look at differences in language outcome and cultural integration for adult sojourners outside of the university context. 131 participants responded to an online survey; 58% completed a homestay as a part of language and/or culture learning and 42% did not engage in a homestay. When these two groups were compared using an Independent sample t-test, it showed that homestay participants received statistically significant higher scores in final language achievement and final cultural integration. Within the homestay group, there was no statistical difference in these areas, except for those who engaged their homestay after three months of language learning, but before four months of language learning. This group performed worse than all other groups on final cultural integration. This study did not identify an optimal time for a homestay, although the participants recommend a basic level of language before engaging a homestay in order to achieve more language growth while in the homestay

New Ligands for Lanthanides and Transition Metals toward Magnetic Resonance Imaging Contrast Agents

MRI is a non-invasive technique used in medical imaging. Although contrast agents have been used to enhance the image generated by MRI, it still suffers the major shortcoming of low sensitivity. This has led to a thrust to develop contrast agents that improve sensitivity by relaxivity and CEST. This thesis describes attempts made to aid in the development of sensitive MRI contrast agents. Chapter 2 investigated pH dependent reversible binding on CEST effect and relaxivity in DO3AM complexes possessing a lone p-nitrophenol arm. Unfortunately, only the Tb3+complex had a small CEST signal. T1 relaxivity of the Gd3+ complex showed high relaxivity at acidic pH and low relaxivity at basic pH. Chapter 3 discussed rigidification of the DOTAM structure to promote formation of the SAP isomer for CEST signal generation. These ligands were rigidified by at least one cyclohexyl group and were found to be very selective toward transition metals. Regrettably, none of the complexes produced a CEST signal. Chapter 4 examined electronic effects on the amide CEST signal of DOTAM-tetraanilides containing various para-substituents on the aniline ring. Due to the insolubility of the other complexes, only the p-H and p-OMe complexes were evaluated. The X-ray crystal structure of Tm3+-p-OMe showed no metal bound water. The CEST spectrum of this complex also revealed two amide signals. Absence of water exchange allowed these agents to have higher signal to noise ratios because of reduced relaxation. Chapter 5 involved a study that assessed electronic effects of para-substituents on the amide CEST signal and relaxivity of DO3A-monoanilide complexes. CEST spectra of only the Tm3+complexes could be acquired, with CEST effects observed at different pH values. T1 relaxivities of all complexes were low but the Dy3+ complexes had much higher T2 relaxivities as compared to the Tm3+-based ones. Finally, Chapter 6 highlighted the attempt to synthesize analogues of the DOTAM-tetraanilides of the p-H and p-OMe complexes mentioned previously, which would be suitable for in vivo studies. These complexes were to possess a monophosphate group in the para position of one aniline ring. Due to synthetic challenges, the synthesis of these modified complexes is still ongoing

Uberon: towards a comprehensive multi-species anatomy ontology

The lack of a single unified species-neutral ontology covering the anatomy of a variety of metazoans is a hindrance to translating model organism research to human health. We have developed an Uber-anatomy ontology to fill this need, filling the gap between the CARO upper-level ontology and species-specific anatomical ontologies