Dynamics of Surface Roughening with Quenched Disorder

We study the dynamical exponent $z$ for the directed percolation depinning (DPD) class of models for surface roughening in the presence of quenched disorder. We argue that $z$ for $(d+1)$ dimensions is equal to the exponent $d_{\rm min}$ characterizing the shortest path between two sites in an isotropic percolation cluster in $d$ dimensions. To test the argument, we perform simulations and calculate $z$ for DPD, and $d_{\rm min}$ for percolation, from $d = 1$ to $d = 6$.Comment: RevTex manuscript 3 pages + 6 figures (obtained upon request via email [email protected]

Strong Stein neighborhood bases

Let D be a smooth bounded pseudoconvex domain in C^n. We give several characterizations for the closure of D to have a strong Stein neighborhood basis in the sense that D has a defining function r such that {z\in C^n:r(z)<a} is pseudoconvex for sufficiently small a>0. We also show that this condition is invariant under proper holomorphic maps that extend smoothly to the boundary.Comment: 14 pages, fixed same references, to appear in Complex Var. Elliptic Eq

Towards a systematic design of isotropic bulk magnetic metamaterials using the cubic point groups of symmetry

In this paper a systematic approach to the design of bulk isotropic magnetic metamaterials is presented. The role of the symmetries of both the constitutive element and the lattice are analyzed. For this purpose it is assumed that the metamaterial is composed by cubic SRR resonators, arranged in a cubic lattice. The minimum symmetries needed to ensure an isotropic behavior are analyzed, and some particular configurations are proposed. Besides, an equivalent circuit model is proposed for the considered cubic SRR resonators. Experiments are carried out in order to validate the proposed theory. We hope that this analysis will pave the way to the design of bulk metamaterials with strong isotropic magnetic response, including negative permeability and left-handed metamaterials.Comment: Submitted to Physical Review B, 23 page

Spitzer 3.6 micron and 4.5 micron full-orbit lightcurves of WASP-18

We present new lightcurves of the massive hot Jupiter system WASP-18 obtained with the Spitzer spacecraft covering the entire orbit at 3.6 micron and 4.5 micron. These lightcurves are used to measure the amplitude, shape and phase of the thermal phase effect for WASP-18b. We find that our results for the thermal phase effect are limited to an accuracy of about 0.01% by systematic noise sources of unknown origin. At this level of accuracy we find that the thermal phase effect has a peak-to-peak amplitude approximately equal to the secondary eclipse depth, has a sinusoidal shape and that the maximum brightness occurs at the same phase as mid-occultation to within about 5 degrees at 3.6 micron and to within about 10 degrees at 4.5 micron. The shape and amplitude of the thermal phase curve imply very low levels of heat redistribution within the atmosphere of the planet. We also perform a separate analysis to determine the system geometry by fitting a lightcurve model to the data covering the occultation and the transit. The secondary eclipse depths we measure at 3.6 micron and 4.5 micron are in good agreement with previous measurements and imply a very low albedo for WASP-18b. The parameters of the system (masses, radii, etc.) derived from our analysis are in also good agreement with those from previous studies, but with improved precision. We use new high-resolution imaging and published limits on the rate of change of the mean radial velocity to check for the presence of any faint companion stars that may affect our results. We find that there is unlikely to be any significant contribution to the flux at Spitzer wavelengths from a stellar companion to WASP-18. We find that there is no evidence for variations in the times of eclipse from a linear ephemeris greater than about 100 seconds over 3 years.Comment: 17 pages, 10 figures. Accpeted for publication in MNRA

Neural Underpinnings of Distortions in the Experience of Time Across Senses

Auditory signals (A) are perceived as lasting longer than visual signals (V) of the same physical duration when they are compared together. Despite considerable debate about how this illusion arises psychologically, the neural underpinnings have not been studied. We used functional magnetic resonance imaging (fMRI) to investigate the neural bases of audiovisual temporal distortions and more generally, intersensory timing. Adults underwent fMRI while judging the relative duration of successively presented standard interval–comparison interval (CI) pairs, which were unimodal (A–A, V–V) or crossmodal (V–A, A–V). Mechanisms of time dilation and compression were identified by comparing the two crossmodal pairs. Mechanisms of intersensory timing were identified by comparing the unimodal and crossmodal conditions. The behavioral results showed that auditory CIs were perceived as lasting longer than visual CIs. There were three novel fMRI results. First, time dilation and compression were distinguished by differential activation of higher-sensory areas (superior temporal, posterior insula, middle occipital), which typically showed stronger effective connectivity when time was dilated (V–A). Second, when time was compressed (A–V) activation was greater in frontal cognitive-control centers, which guide decision making. These areas did not exhibit effective connectivity. Third, intrasensory timing was distinguished from intersensory timing partly by decreased striatal and increased superior parietal activation. These regions showed stronger connectivity with visual, memory, and cognitive-control centers during intersensory timing. Altogether, the results indicate that time dilation and compression arise from the connectivity strength of higher-sensory systems with other areas. Conversely, more extensive network interactions are needed with core timing (striatum) and attention (superior parietal) centers to integrate time codes for intersensory signals

Understanding older adults’ perceptions of and attitudes towards exergames

Purpose Maintaining physical activity is a key component of successful aging and has benefits for both physical and cognitive functioning in the older adult population. One promising method for engaging in physical activity is through exergames, which are video games designed to promote exercise. Exergames have the potential to be used by a wide range of people, including older adults, in a variety of settings, such as at home, in community living environments, or senior centers. However, exergames have not been designed for older adults (e.g., with respect to their attitudes, needs). Thus, older adults may not adopt these systems if they perceive them as not useful or relevant to them. Method Twenty older adults (aged 60-79) interacted with two exergames, and were then interviewed about their perceptions of the system’s ease of use and usefulness, as well as their general attitudes towards the system. Results Participants identified the potential for exergames’ usefulness for various goals, such as to increase their physical activity. However, they also reported negative attitudes concerning the system, including perceiving barriers to system use. Overall, participants said they would use the system in the future and recommend it to other people at their age for improving health, despite these use challenges. Conclusion The older adults were open to adopting exergames, which could provide opportunities to increase physical activity. Given the participants’ overall positive perceptions of the usefulness of exergames, designers must address the perceived challenges of using these systems. Understanding barriers and facilitators for older adults’ use of exergames can guide design, training, and adoption of these systems

Calorons and localization of quark eigenvectors in lattice QCD

We analyze the localization properties for eigenvectors of the Dirac operator in quenched lattice QCD in the vicinity of the deconfinement phase transition. Studying the characteristic differences between the Z_3 sectors above the critical temperature T_c, we find indications for the presence of calorons.Comment: 4 pages, 4 figure

Phase 2 - Parametric study of flight-induced pulmonary pathology Final report

Pulmonary pathological response data on four subjects after breathing conditioned atmosphere and being centrifuge

What are the barriers to care integration for those at the advanced stages of dementia living in care homes in the UK? Health care professional perspective

People with advanced dementia are frequently bed-bound, doubly incontinent and able to speak only a few words. Many reside in care homes and may often have complex needs requiring efficient and timely response by knowledgeable and compassionate staff. The aim of this study is to improve our understanding of health care professionals' attitudes and knowledge of the barriers to integrated care for people with advanced dementia. In-depth, interactive interviews conducted with 14 health care professionals including commissioners, care home managers, nurses and health care assistants in the UK. Barriers to care for people with advanced dementia are influenced by governmental and societal factors which contribute to challenging environments in care homes, poor morale amongst care staff and a fragmentation of health and social care at the end of life. Quality of care for people with dementia as they approach death may be improved by developing collaborative networks to foster improved relationships between health and social care services

An ethnographic study of strategies to support discussions with family members on end-of-life care for people with advanced dementia in nursing homes

BACKGROUND: Most people with advanced dementia die in nursing homes where families may have to make decisions as death approaches. Discussions about end-of-life care between families and nursing home staff are uncommon, despite a range of potential benefits. In this study we aimed to examine practices relating to end-of-life discussions with family members of people with advanced dementia residing in nursing homes and to explore strategies for improving practice. METHODS: An ethnographic study in two nursing homes where the Compassion Intervention was delivered. The Compassion Intervention provides a model of end-of-life care engaging an Interdisciplinary Care Leader to promote integrated care, educate staff, support holistic assessments and discuss end of life with families. We used a framework approach, undertaking a thematic analysis of fieldwork notes and observations recorded in a reflective diary kept by the Interdisciplinary Care Leader, and data from in-depth interviews with 23 informants: family members, GPs, nursing home staff, and external healthcare professionals. RESULTS: Four major themes described strategies for improving practice: (i) educating families and staff about dementia progression and end-of-life care; (ii) appreciating the greater value of in-depth end-of-life discussions compared with simple documentation of care preferences; (iii) providing time and space for sensitive discussions; and (iv) having an independent healthcare professional or team with responsibility for end-of-life discussions. CONCLUSIONS: The Interdisciplinary Care Leader role offers a promising method for supporting and improving end-of-life care discussions between families of people with advanced dementia and nursing home staff. These strategies warrant further evaluation in nursing home settings