On-line control of grasping actions: object-specific motor facilitation requires sustained visual input

Dorsal stream visual processing is generally considered to underlie visually driven action, but when subjects grasp an object from memory, as visual information is not available, ventral stream characteristics emerge. In this study we use paired-pulse transcranial magnetic stimulation (TMS) to investigate the importance of the current visual input during visuomotor grasp. Previously, the amplitude of the paired-pulse motor evoked potentials (MEPs) in hand muscles before movement onset have been shown to predict the subsequent pattern of muscle activity during grasp. Specific facilitation of paired-pulse MEPs may reflect premotor–motor (PMC–M1) cortex connectivity. Here we investigate the paired-pulse MEPs evoked under memory-cued and visually driven conditions before grasping one of two possible target objects (a handle or a disc). All trials began with a delay period of 1200 ms. Then, a TMS pulse served as the cue to reach, grasp and hold the target object for 0.5 s. Total trial length was 5 s. Both objects were continually visible in both conditions, but the way in which the target object was designated differed between conditions. In the memory-cued condition, the target object was illuminated for the first 200 ms of the trial only. In the visually driven condition, the target object was illuminated throughout the 5 s trial. Thus, the conditions differed in whether or not the object to be grasped was designated at the time of movement initiation. We found that the pattern of paired-pulse MEP facilitation matched the pattern of object-specific muscle activity only for the visually driven condition. The results suggest that PMC–M1 connectivity contributes to action selection only when immediate sensory information specifies which action to make

Asymmetrical booster ascent guidance and control system design study. Volume 2: SSFS math models - Ascent

The engineering equations and mathematical models developed for use in the space shuttle functional simulator (SSFS) are presented, and include extensive revisions and additions to earlier documentation. Definitions of coordinate systems used by the SSFS models and coordinate tranformations are given, along with documentation of the flexible body mathematical models. The models were incorporated in the SSFS and are in the checkout stage

Comparison of the energy cost of selected fire fighting tasks.

Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1975 .L35. Source: Masters Abstracts International, Volume: 40-07, page: . Thesis (M.H.K.)--University of Windsor (Canada), 1975

redstarts (Setophaga ruticilla)

Breeding dispersions and site fidelity of America

A Review and Case Study of Strategic Carbon Management in the UK Higher Education Sector.

Climate change is arguably one of the greatest environmental challenges facing the world today, bringing organisations under increasing pressure from government, shareholders and stakeholders to reduce carbon emissions. The Higher Education (HE) sector has a significant social and economic impact and is not exempt from challenging carbon reduction targets, in fact, it is argued, should be demonstrating leadership in the field. The term ‘carbon management’ is popular in the literature but strategic carbon management (SCM) is an under-developed and under-researched area as it is an applied concept, especially within the HE sector. Scope 1 and 2 emissions reduction initiatives have received more attention than scope 3 thereby missing a significant opportunity for fully effective carbon reduction. These gaps have been identified through analysis of the academic and practitioner literature, reports, and websites. The study proposed in this paper will look into the gaps and possible future research direction of SCM in the HE sector through a case study of De Montfort University (DMU). It will explore how carbon emissions can be reduced strategically and develop a systematic and comprehensive strategic management approach to doing so. Finally this paper makes some provisional principles for transferable best practices for the HE sector

Class A scavenger receptor 1 (MSR1) restricts hepatitis C virus replication by mediating toll-like receptor 3 recognition of viral RNAs produced in neighboring cells

Persistent infections with hepatitis C virus (HCV) may result in life-threatening liver disease, including cirrhosis and cancer, and impose an important burden on human health. Understanding how the virus is capable of achieving persistence in the majority of those infected is thus an important goal. Although HCV has evolved multiple mechanisms to disrupt and block cellular signaling pathways involved in the induction of interferon (IFN) responses, IFN-stimulated gene (ISG) expression is typically prominent in the HCV-infected liver. Here, we show that Toll-like receptor 3 (TLR3) expressed within uninfected hepatocytes is capable of sensing infection in adjacent cells, initiating a local antiviral response that partially restricts HCV replication. We demonstrate that this is dependent upon the expression of class A scavenger receptor type 1 (MSR1). MSR1 binds extracellular dsRNA, mediating its endocytosis and transport toward the endosome where it is engaged by TLR3, thereby triggering IFN responses in both infected and uninfected cells. RNAi-mediated knockdown of MSR1 expression blocks TLR3 sensing of HCV in infected hepatocyte cultures, leading to increased cellular permissiveness to virus infection. Exogenous expression of Myc-MSR1 restores TLR3 signaling in MSR1-depleted cells with subsequent induction of an antiviral state. A series of conserved basic residues within the carboxy-terminus of the collagen superfamily domain of MSR1 are required for binding and transport of dsRNA, and likely facilitate acidification-dependent release of dsRNA at the site of TLR3 expression in the endosome. Our findings reveal MSR1 to be a critical component of a TLR3-mediated pattern recognition receptor response that exerts an antiviral state in both infected and uninfected hepatocytes, thereby limiting the impact of HCV proteins that disrupt IFN signaling in infected cells and restricting the spread of HCV within the liver

Mathematical modelling of tissue-engineering angiogenesis

We present a mathematical model for the vascularisation of a porous scaffold following implantation in vivo. The model is given as a set of coupled non-linear ordinary differential equations (ODEs) which describe the evolution in time of the amounts of the different tissue constituents inside the scaffold. Bifurcation analyses reveal how the extent of scaffold vascularisation changes as a function of the parameter values. For example, it is shown how the loss of seeded cells arising from slow infiltration of vascular tissue can be overcome using a prevascularisation strategy consisting of seeding the scaffold with vascular cells. Using certain assumptions it is shown how the system can be simplified to one which is partially tractable and for which some analysis is given. Limited comparison is also given of the model solutions with experimental data from the chick chorioallantoic membrane (CAM) assay

Asymmetrical booster guidance and control system design study. Volume 3: Space shuttle vehicle SRB actuator failure study

The investigation of single actuator failures on the space shuttle solid rocket booster required the analysis of both square pattern and diamond pattern actuator configurations. It was determined that for failures occuring near or prior to the region of maximum dynamic pressure, control gain adjustments can be used to achieve virtually nominal mid-boost vehicle behavior. A distinct worst case failure condition was established near staging that could significantly delay staging. It is recommended that the square pattern be retained as a viable alternative to the baseline diamond pattern because the staging transient is better controlled resulting in earlier staging

On Edge: the impact of race-related vigilance on obesity status in African-Americans

OBJECTIVE: Nearly half of African-Americans are classified as obese. Perceived racism has been associated with obesity, yet the internal experiences of racism have received little attention. African Americans who face racism may ready themselves to cope through survival strategies, including race-related vigilance. This study explores the association between race-related vigilance and obesity in African Americans. DESIGN AND METHODS: The Reactions to Race module of the Behavioral Risk Factor Surveillance Survey (years 2002-2010) was used. Our sample size consisted of 12,214 African-Americans. Race-related vigilance was assessed as: How often do you think about your race? and classified as: never, \u3c daily, daily, and \u3e daily. Obesity was dichotomized as body mass index (BMI) \u3e /=30 kg/m2 vs. \u3c 30 kg/m2 using self-reported weight and height. Multivariable logistic models assessed the association between race-related vigilance and obesity. RESULTS: Seventeen percent of respondents reported thinking about their race \u3e daily; 14% daily; 31% \u3c daily, and 39% reported never thinking about their race. Compared to those who reported never thinking about their race, the adjusted odds of obesity were 0.91, 95% CI: 0.72-1.15 among those thinking about their race \u3c daily, 1.09, 95%CI: 0.81-1.46 among those thinking about their race daily, and 1.37, 95% CI: 1.07-1.76 among those thinking about their race \u3e daily. CONCLUSIONS: Frequently thinking about one\u27s race was a risk factor for obesity in African-Americans in this study. Internalized impacts of racism captured through race-related vigilance may be particularly detrimental to African-Americans, driving their risk for obesity

Memories of a Wall in Old Montreal – Reassembling the Puzzle of the Past

An existing five storey building in Old Montreal has an exposed wall revealing a remarkable history of contributions from at least five building states, the earliest of which was constructed in the eighteenth century. Using the framework of semiotics as proposed by Charles Saunders Peirce (1839-1914) and Jacques Derrida’s (1930-2004) exploration of the parergon, this thesis examines aspects of the wall relative to its history, in relation to the presentation of official narratives and national identity, as well as to the experience of an Anglophone Montrealer’s personal history and identity. Archival sources such as those of the City of Montreal, Adhémar and the Ministère des Resources naturelles et Faunes, along with the Bibliothèque national and ArchivesCanadaFrance.org, provide the historical basis for the reconstruction of the development of this site, a wall that only in its latest form is exposed in such as way as to inspire this research. Works by Andreas Huyssen, Alain Gordon, M. Christine Boyer, and Pierre Nora form the basis of the question regarding the building of national narratives as they relate to the quarter of Old Montreal. This thesis culminates in a better understanding of my own experience as a fifth-generation, bilingual English Montrealer in a predominantly Francophone city