INTER-TRIAL VARIABILITY IN KINEMATIC DESCRIPTORS OF GAIT

The purpose of this study was to determine the inter-trial variability of kinematic descriptors of human gait. A case study subject with spastic hemiplegic gait following traumatic event was analyzed for kinematic differences pertreatment, 1-week post-treatment and 4-weeks post-treatment. The treatment protocol included a focal dennervation of the spastic gastrocnemius muscle on the affected side of the body. Data was collected via three 60 Hz S-VHS camcorders set at a shutter speed of 11100 second. Each camera was placed at approximately a 30 degree angle with respect to the optical axis of the other two cameras. Ten trials of walking gait at a self-selected pace were recorded for both the affected and unaffected sides for two complete strides. Kinetic data was recorded during a single stance phase simultaneous with the kinematic data. The three views were synchronized using a single pulse from a standard flash unit. The three planer views were transformed to three-dimensional coordinates using a Direct Linear Transformation (DLT) as part of the Ariel Performance Analysis System (APAS). Each joint center location as smoothed individually by selecting the proper cutoff frequency of a double-pass recursive Butterworth filter via an inspection of the joint center's power spectrum. Joint angular displacements of the ankle, knee and hip were compared across the ten trials for each leg individually using a univariate analysis of variance (ANOVA). The pre-treatment and two post-treatment conditions were analyzed separately. Non-significant inter-trial differences were found for each variable and each leg across the data collection periods. Given the proliferation and gait analysis as a clinical tool, as well as a research device for exercise and sport, demonstration of the efficacy and reliability of this analysis is essential

Thin teflon-like films for eliminating adhesion in released polysilicon microstructures

This paper presents a method for depositing thin Teflon-like films using a commercial plasma reactor to eliminate adhesion or stiction in released polysilicon microstructures. A Lam 384T oxide etch system is used in a remote plasma mode with commercially available trifluoromethane (CHF{sub 3}) to deposit thin hydrophobic films around and under released microstructures. Hard, uniform, Teflon-like films which penetrate into undercuts beneath structures have been produced. Thus far, surfaces beneath gears as large as 1600 micron diameter with a gap of 2.0 microns are hydrophobic after being exposed to plasma treatment. These Teflon-like coatings have been shown to reduce the coefficient of friction from 1.0 to 0.07

Prostaglandin D2 generation from human lung mast cells is catalysed exclusively by cyclooxygenase-1

Mast cells are an exceptionally rich source of prostaglandin D2 (PGD2). PGD2 is pro-inflammatory and can cause bronchoconstriction. The enzyme cyclooxygenase (COX) is central to the generation of prostanoids such as PGD2. Non-steroidal anti-inflammatory drugs (NSAIDs) inhibit COX. COX exists as two isoforms, COX-1 and COX-2. The principal aim of this study was to establish whether COX-1 and/or COX-2 mediates PGD2 generation from human lung mast cells. Mast cells were isolated from human lung tissue and purified by flotation over Percoll and immunomagnetic bead separations. The cells were activated with anti-IgE or Stem Cell Factor (SCF). The generation of PGD2 was determined by ELISA. The effects of NSAIDs (aspirin, ibuprofen, diclofenac, naproxen, indomethacin), COX-1 selective (FR122047), and COX-2 selective (celecoxib) inhibitors on PGD2 generation were determined. The expression of COX-1 and COX-2 in mast cells was determined by Western blotting. All the NSAIDs tested abrogated stimulated PGD2 generation from mast cells except aspirin which was only weakly effective. FR122047 was an effective inhibitor of PGD2 generation (EC50 ~25 nM) from mast cells whereas celecoxib was ineffective. Immunoblotting indicated that COX-1 was strongly expressed in all mast cell preparations while COX-2 expression was weak. No induction of COX-2 was observed following activation of mast cells. These findings indicate that COX-1 is the principal isoform involved in generating PGD2 from human lung mast cells. These studies provide insight into the potential behaviour of NSAIDs in the context of respiratory diseases

Long-Wavelength Instability in Surface-Tension-Driven Benard Convection

Laboratory studies reveal a deformational instability that leads to a drained region (dry spot) in an initially flat liquid layer (with a free upper surface) heated uniformly from below. This long-wavelength instability supplants hexagonal convection cells as the primary instability in viscous liquid layers that are sufficiently thin or are in microgravity. The instability occurs at a temperature gradient 34% smaller than predicted by linear stability theory. Numerical simulations show a drained region qualitatively similar to that seen in the experiment.Comment: 4 pages. The RevTeX file has a macro allowing various styles. The appropriate style is "mypprint" which is the defaul

A Review of Controlling Motivational Strategies from a Self-Determination Theory Perspective: Implications for Sports Coaches

The aim of this paper is to present a preliminary taxonomy of six controlling strategies, primarily based on the parental and educational literatures, which we believe are employed by coaches in sport contexts. Research in the sport and physical education literature has primarily focused on coaches’ autonomysupportive behaviours. Surprisingly, there has been very little research on the use of controlling strategies. A brief overview of the research which delineates each proposed strategy is presented, as are examples of the potential manifestation of the behaviours associated with each strategy in the context of sports coaching. In line with self-determination theory (Deci & Ryan, 1985; Ryan & Deci, 2002), we propose that coach behaviours employed to pressure or control athletes have the potential to thwart athletes’ feelings of autonomy, competence,and relatedness, which, in turn, undermine athletes’ self-determined motivation and contribute to the development of controlled motives. When athletes feel pressured to behave in a certain way, a variety of negative consequences are expected to ensue which are to the detriment of the athletes’ well-being. The purpose of this paper is to raise awareness and interest in the darker side of sport participation and to offer suggestions for future research in this area

Birthing practices of traditional birth attendants in South Asia in the context of training programmes

Traditional Birth Attendants (TBA) training has been an important component of public health policy interventions to improve maternal and child health in developing countries since the 1970s. More recently, since the 1990s, the TBA training strategy has been increasingly seen as irrelevant, ineffective or, on the whole, a failure due to evidence that the maternal mortality rate (MMR) in developing countries had not reduced. Although, worldwide data show that, by choice or out of necessity, 47 percent of births in the developing world are assisted by TBAs and/or family members, funding for TBA training has been reduced and moved to providing skilled birth attendants for all births. Any shift in policy needs to be supported by appropriate evidence on TBA roles in providing maternal and infant health care service and effectiveness of the training programmes. This article reviews literature on the characteristics and role of TBAs in South Asia with an emphasis on India. The aim was to assess the contribution of TBAs in providing maternal and infant health care service at different stages of pregnancy and after-delivery and birthing practices adopted in home births. The review of role revealed that apart from TBAs, there are various other people in the community also involved in making decisions about the welfare and health of the birthing mother and new born baby. However, TBAs have changing, localised but nonetheless significant roles in delivery, postnatal and infant care in India. Certain traditional birthing practices such as bathing babies immediately after birth, not weighing babies after birth and not feeding with colostrum are adopted in home births as well as health institutions in India. There is therefore a thin precarious balance between the application of biomedical and traditional knowledge. Customary rituals and perceptions essentially affect practices in home and institutional births and hence training of TBAs need to be implemented in conjunction with community awareness programmes

The effect of twisted magnetic field on the resonant absorption of MHD waves in coronal loops

The standing quasi modes in a cylindrical incompressible flux tube with magnetic twist that undergoes a radial density structuring is considered in ideal magnetohydrodynamics (MHD). The radial structuring is assumed to be a linearly varying density profile. Using the relevant connection formulae, the dispersion relation for the MHD waves is derived and solved numerically to obtain both the frequencies and damping rates of the fundamental and first-overtone modes of both the kink (m=1) and fluting (m=2,3) waves. It was found that a magnetic twist will increase the frequencies, damping rates and the ratio of the oscillation frequency to the damping rate of these modes. The period ratio P_1/P_2 of the fundamental and its first-overtone surface waves for kink (m=1) and fluting (m=2,3) modes is lower than 2 (the value for an untwisted loop) in the presence of twisted magnetic field. For the kink modes, particularly, the magnetic twists B_{\phi}/B_z=0.0065 and 0.0255 can achieve deviations from 2 of the same order of magnitude as in the observations. Furthermore, for the fundamental kink body waves, the frequency bandwidth increases with increasing the magnetic twist.Comment: 18 pages, 9 figure

Local recurrences in western low rectal cancer patients treated with or without lateral lymph node dissection after neoadjuvant (chemo) radiotherapy: An international multi-centre comparative study

Background: In the West, low rectal cancer patients with abnormal lateral lymph nodes (LLNs) are commonly treated with neoadjuvant (chemo)radiotherapy (nCRT) followed by total mesorectal excision (TME). Additionally, some perform a lateral lymph node dissection (LLND). To date, no comparative data (nCRT vs. nCRT + LLND) are available in Western patients. Methods: An international multi-centre cohort study was conducted at six centres from the Netherlands, US and Australia. Patients with low rectal cancers from the Netherlands and Australia with abnormal LLNs (≥5 mm short-axis in the obturator, internal iliac, external iliac and/or common iliac basin) who underwent nCRT and TME (LLND-group) were compared to similarly staged patients from the US who underwent a LLND in addition to nCRT and TME (LLND + group). Results: LLND + patients (n = 44) were younger with higher ASA-classifications and ypN-stages compared to LLND-patients (n = 115). LLND + patients had larger median LLNs short-axes and received more adjuvant chemotherapy (100 vs. 30%; p < 0.0001). Between groups, the local recurrence rate (LRR) was 3% for LLND + vs. 11% for LLND- (p = 0.13). Disease-free survival (DFS, p = 0.94) and overall survival (OS, p = 0.42) were similar. On multivariable analysis, LLND was an independent significant factor for local recurrences (p = 0.01). Sub-analysis of patients who underwent long-course nCRT and had adjuvant chemotherapy (LLND-n = 30, LLND + n = 44) demonstrated a lower LRR for LLND + patients (3% vs. 16% for LLND-; p = 0.04). DFS (p = 0.10) and OS (p = 0.11) were similar between groups. Conclusion: A LLND in addition to nCRT may improve loco-regional control in Western patients with low rectal cancer and abnormal LLNs. Larger studies in Western patients are required to evaluate its contribution

Shape Space Methods for Quantum Cosmological Triangleland

With toy modelling of conceptual aspects of quantum cosmology and the problem of time in quantum gravity in mind, I study the classical and quantum dynamics of the pure-shape (i.e. scale-free) triangle formed by 3 particles in 2-d. I do so by importing techniques to the triangle model from the corresponding 4 particles in 1-d model, using the fact that both have 2-spheres for shape spaces, though the latter has a trivial realization whilst the former has a more involved Hopf (or Dragt) type realization. I furthermore interpret the ensuing Dragt-type coordinates as shape quantities: a measure of anisoscelesness, the ellipticity of the base and apex's moments of inertia, and a quantity proportional to the area of the triangle. I promote these quantities at the quantum level to operators whose expectation and spread are then useful in understanding the quantum states of the system. Additionally, I tessellate the 2-sphere by its physical interpretation as the shape space of triangles, and then use this as a back-cloth from which to read off the interpretation of dynamical trajectories, potentials and wavefunctions. I include applications to timeless approaches to the problem of time and to the role of uniform states in quantum cosmological modelling.Comment: A shorter version, as per the first stage in the refereeing process, and containing some new reference

A Comparison of 37-Ca(p,n) Cross Sections to 37-Ca β-Decay

This research was sponsored by the National Science Foundation Grant NSF PHY-931478