On the formal neighborhood of a degenerate arc

We prove a result describing the structure of the formal neighborhoods of certain arcs in the arc space of an algebraic variety which are completely contained in the singular locus. In particular, we provide a precise formulation of the intuitive statement that constant arcs centered in the singular locus are the most singular points of the arc space.Comment: 10 pages; comments are welcom

Observations of cyclone-induced storm surge in coastal Bangladesh

Water level measurements from 15 tide gauges in the coastal zone of Bangladesh are analyzed in conjunction with cyclone tracks and wind speed data for 54 cyclones between 1977 and 2010. Storm surge magnitude is inferred from residual water levels computed by subtracting modeled astronomical tides from observed water levels at each station. Observed residual water levels are generally smaller than reported storm surge levels for cyclones where both are available, and many cyclones produce no obvious residual at all. Both maximum and minimum residual water levels are higher for west-landing cyclones producing onshore winds and generally diminish for cyclones making landfall on the Bangladesh coast or eastward producing offshore winds. Water levels observed during cyclones are generally more strongly influenced by tidal phase and amplitude than by storm surge alone. In only 7 of the 15 stations does the highest plausible observed water level coincide with a cyclone. While cyclone-coincident residual water level maxima occur at a wide range of tidal phases, very few coincide with high spring tides. Comparisons of cyclone-related casualties with maximum wind speed, hour of landfall, population density and residual water level (inferred storm surge) show no significant correlations for any single characteristic. Cyclones with high casualties are often extreme in one or more of these characteristics but there appears to be no single extreme characteristic shared by all high casualty cyclones.Comment: 23 pages, 7 figure

Enhancement of Surgical Training Practice with the Spring Tensor Heuristic Model

The enhancement of surgical simulation tools is an important research study, to assist in the assessment and feedback of medical training practice. In this research, the Spring Tensor Model (STEM) has been used for laparoscopic end-effector navigation through obstacles and high-risk areas. The modelling of the surgical trainer as part of the laparoscopic simulator seeks to emulate the physical environment as a virtualised representation in the integrated infrastructure. Combining sensor network framework paradigms to a surgical knowledge-based construct demonstrates how STEMcan enhance medical practice. The architectural hybridisation of the training framework has enabled the adaptation of STEM modelling techniques for a simulated laparoscopic training methodology. The primary benefit of the architecture is that this integration strategy has resulted in a seamless transition of the heuristic framework to be applied to surgical training

Higher derivations of modules and the Hasse-Schmidt module

In this paper we revisit Ribenboim's notion of higher derivations of modules and relate it to the recent work of De Fernex and Docampo on the sheaf of differentials of the arc space. In particular, we derive their formula for the K\"ahler differentials of the Hasse-Schmidt algebra as a consequence of the fact that the Hasse-Schmidt algebra functors commute.Comment: 13 page

Incorporating Sampling Weights Into The Generalizability Theory For Large-Scale Analyses

Large scale studies frequently use complex sampling procedures, disproportionate sampling weights, and adjustment techniques to account for potential bias due to nonresponses and to ensure that results from the sample can be generalized to a larger population. Survey researchers are concerned about measurement error and the use of weights in developing models. Consequently, multiple weighting factors are used and these weighting factors are manifested as a final survey (composite) weight available for analysis. We developed a method to incorporate an external weighting factor like this for analyses of measurement errors in the theory of generalizability to provide researchers with a tool to evaluate the measurement error components of survey quality and undesirable error components of large-scale assessment programs such as national and state assessments

Epistasis from functional dependence of fitness on underlying traits

Epistasis between mutations in two genes is thought to reflect an interdependence of their functions. While sometimes epistasis is predictable using mechanistic models, its roots seem, in general, hidden in the complex architecture of biological networks. Here, we ask how epistasis can be quantified based on the mathematical dependence of a system-level trait (e.g. fitness) on lower-level traits (e.g. molecular or cellular properties). We first focus on a model in which fitness is the difference between a benefit and a cost trait, both pleiotropically affected by mutations. We show that despite its simplicity, this model can be used to analytically predict certain properties of the ensuing distribution of epistasis, such as a global negative bias, resulting in antagonism between beneficial mutations, and synergism between deleterious ones. We next extend these ideas to derive a general expression for epistasis given an arbitrary functional dependence of fitness on other traits. This expression demonstrates how epistasis relative to fitness can emerge despite the absence of epistasis relative to lower level traits, leading to a formalization of the concept of independence between biological processes. Our results suggest that epistasis may be largely shaped by the pervasiveness of pleiotropic effects and modular organization in biological networks.Organismic and Evolutionary Biolog

Business Process Re-engineering in Saudi Arabia: A Survey of Understanding and Attitudes

This survey was conducted in the Kingdom of Saudi Arabia (KSA) to investigate the level of awareness of BPR. Respondents (customers, employees, and Managers) had different educational backgrounds and were from private and public sectors. Findings of the study indicate a general awareness of BPR in KS

Randomized control trial of computer-based rehabilitation of spatial neglect syndrome: the RESPONSE trial protocol

Background: Spatial neglect is a frequent and debilitating consequence of acquired brain injury and currently has no widely accepted standard of care. While previous interventions for spatial neglect have targeted patients’ overt spatial deficits (e.g., reduced contralesional visual scanning), far fewer have directly targeted patients’ non-spatial deficits (e.g., sustained attention deficits). Considering that non-spatial deficits have shown to be highly predictive of long-term disability, we developed a novel computer based training program that targets both sustained (tonic) and moment-to-moment (phasic) aspects of non-spatial attention (Tonic and Phasic Alertness Training, TAPAT). Preliminary studies demonstrate that TAPAT is safe and effective in improving both spatial and non-spatial attention deficits in the post-acute recovery phase in neglect patients. The purpose of the current trial (referred to as the REmediation of SPatial Neglect or RESPONSE trial) is to compare TAPAT to an active control training condition, include a larger sample of patients, and assess both cognitive and functional outcomes. Methods/Design We will employ a multi-site, longitudinal, blinded randomized controlled trial (RCT) design with a target sample of 114 patients with spatial neglect. Patients will either perform, at their home, the experimental TAPAT training program or an active control computer games condition for thirty minutes/day, five days a week, over three months. Patients will be assessed on a battery of cognitive and functional outcomes on three occasions: a) immediately before training, b) within forty-eight hours post completion of total training, and c) after a three-month no-contact period post completion of total training, to assess the longevity of potential training effects. Discussion The strengths of this protocol are that it tests an innovative, in-home administered treatment that targets a fundamental deficit in neglect, employs highly sensitive computer-based assessments of cognition as well as functional outcomes, and incorporates a large sample size (relative to other neglect treatment studies) in an RCT design. Trial registration ClinicalTrials.gov identifier, NCT0196595

Reactive Video: Movement Sonification as Auditory Feedback for Supporting Physical Activity

This paper provides initial efforts in developing and evaluating a real-time movement sonification framework for physical activity practice and learning. Reactive Video provides an interactive, vision-based, adaptive video playback with auditory feedback on users' performance to better support when learning and practicing new physical skills. We implement the sonification for auditory feedback design by extending the Web Audio API framework. The current application focuses on Tai-Chi performance and provides two main audio cues to users for several Tai Chi exercises. We provide our design approach, implementation, and sound generation and mapping, specifically for interactive systems with direct video manipulation. Our observations reveal the relationship between the movement-to-sound mapping and characteristics of the physical activity

Reversal of aging-induced increases in aortic stiffness by targeting cytoskeletal protein-protein interfaces

BACKGROUND: The proximal aorta normally functions as a critical shock absorber that protects small downstream vessels from damage by pressure and flow pulsatility generated by the heart during systole. This shock absorber function is impaired with age because of aortic stiffening. METHODS AND RESULTS: We examined the contribution of common genetic variation to aortic stiffness in humans by interrogating results from the AortaGen Consortium genome‐wide association study of carotid‐femoral pulse wave velocity. Common genetic variation in the N‐WASP (WASL) locus is associated with carotid‐femoral pulse wave velocity (rs600420, P=0.0051). Thus, we tested the hypothesis that decoy proteins designed to disrupt the interaction of cytoskeletal proteins such as N‐WASP with its binding partners in the vascular smooth muscle cytoskeleton could decrease ex vivo stiffness of aortas from a mouse model of aging. A synthetic decoy peptide construct of N‐WASP significantly reduced activated stiffness in ex vivo aortas of aged mice. Two other cytoskeletal constructs targeted to VASP and talin‐vinculin interfaces similarly decreased aging‐induced ex vivo active stiffness by on‐target specific actions. Furthermore, packaging these decoy peptides into microbubbles enables the peptides to be ultrasound‐targeted to the wall of the proximal aorta to attenuate ex vivo active stiffness. CONCLUSIONS: We conclude that decoy peptides targeted to vascular smooth muscle cytoskeletal protein‐protein interfaces and microbubble packaged can decrease aortic stiffness ex vivo. Our results provide proof of concept at the ex vivo level that decoy peptides targeted to cytoskeletal protein‐protein interfaces may lead to substantive dynamic modulation of aortic stiffness.Published versio