Resolving the Centipede's Dilemma: external focus distance and expertise in applied, continuous skills.

Research has reliably demonstrated that an external focus of attention during skill production enhances performance, retention, and transfer relative to an internal focus on movement mechanics. The optimisation of external focus points, across a range of contexts and performers, is important for effective skill production. Two studies were conducted evaluating the impact of external focus distance in an applied, continuous sports skill (kayak sprinting) with participants of two different expertise levels. In Study 1, using a within-participants design, recreational kayakers (n = 20) were timed sprinting 75 m in a surf ski under proximal external focus, distal external focus, and control conditions. The distal focus (on the finish) (29.75 s) was significantly faster than both other trials (ps < 0.001). The control condition (30.95 s) was significantly faster than the proximal focus (on the boat) (32.37 s) (p = 0.003). The effect size was large (ηp2 = 0.55). In Study 2, specifically trained racers in sprint kayaks (K1s) (n = 16) were timed in a 100 m K1 sprint under the same three conditions as in Study 1. The control condition (28.96 s) was significantly faster than the proximal focus trial (29.83 s) (p = 0.02). The effect size was large (ηp2 = 0.23). There was no significant difference between the distal focus trial (29.03 s) and the other conditions. These findings suggest that focus distance can play a pivotal role in continuous skills. Whilst recreational performers may benefit immediately from a distal focus, this might not be the case for specifically trained athletes. Further, a proximal focus on fitted, passive equipment may be detrimental to performance.

Strain measurement with multiplexed FBG sensor arrays: An experimental investigation.

In conventional rock mechanics testing, radial strain measuring devices are usually attached to the sample's surface at its mid-height. Although this procedure provides a realistic picture of the lateral deformation undergone by homogeneous samples, however, this assumption may not be accurate if the tested rock has significant heterogeneity. Fibre Bragg Grating (FBG) sensors have recently been introduced to various rock testing applications due to their versatility over conventional strain gauges and radial cantilevers. FBG sensors have small size, multiplexing capability, and immunity to magnetic interference. The main objective of this study is to explore and understand the capabilities of FBG sensing for strain measurement during rock mechanics testing, including under confining. To do so, two limestone plugs (Savonnières limestone) and one acrylic Poly Methyl Methacrylate (PMMA) plug, all of 38 mm diameter, were prepared. The acrylic plug and one of the Savonnières samples plugs were subjected to Unconfined Compressive Strength (UCS) tests. The second Savonnières plug was subjected to a hydrostatic test up to 20 MPa confining at room temperature. FBG sensors of 125 µm cladding diameter with ceramics (Ormocer) coating were glued on the surface of each sample, spreading across the entire sample's height. Strain gauges and cantilever-type radial gauges were used on the samples submitted to UCS for comparison. Results show that radial strain measurements and calculated elastic properties derived from the FBG readings for samples are comparable to readings from the conventional strain gauges and cantilever-type devices. Apparent bulk moduli based on volumetric strain computed from FBG radial strain readings during the hydrostatic test on the Savonnières sample was consistent with benchtop measurements conducted on the Savonnières sample and another plug extracted from the same parental block, as well as published literature data. Moreover, variations in the calculated elastic properties are interpreted as evidence that the FBG sensors detected heterogeneities in the samples' inner structure, which can be seen in the density profiles computed from x-ray CT images. Such observation confirms the potential of the presented FBG sensors configuration for 3D strain mapping in rock mechanics tests.

Integrin activation by Fam38A uses a novel mechanism of R-Ras targeting to the endoplasmic reticulum.

The integrin family of heterodimeric cell-surface receptors are fundamental in cell-cell and cell-matrix adhesion. Changes to either integrin-ligand affinity or integrin gene expression are central to a variety of disease processes, including inflammation, cardiovascular disease and cancer. In screening for novel activators of integrin-ligand affinity we identified the previously uncharacterised multi-transmembrane domain protein Fam38A, located at the endoplasmic reticulum (ER). siRNA knockdown of Fam38A in epithelial cells inactivates endogenous beta1 integrin, reducing cell adhesion. Fam38A mediates integrin activation by recruiting the small GTPase R-Ras to the ER, which activates the calcium-activated protease calpain by increasing Ca(2+) release from cytoplasmic stores. Fam38A-induced integrin activation is blocked by inhibition of either R-Ras or calpain activity, or by siRNA knockdown of talin, a well-described calpain substrate. This highlights a novel mechanism for integrin activation by Fam38A, utilising calpain and R-Ras signalling from the ER. These data represent the first description of a novel spatial regulator of R-Ras, of an alternative integrin activation-suppression pathway based on direct relocalisation of R-Ras to the ER, and of a mechanism linking R-Ras and calpain signalling from the ER with modulation of integrin-ligand affinity.

Forward thinking: When a distal external focus makes you faster.

Studies have demonstrated a benefit to performance and learning of a distal relative to a proximal external focus of attention. That is, focusing on a movement effect that occurs at a greater distance from the body has been found to be more effective than concentrating on a movement effect closer to the body. The present study examined the distance effect in skilled kayakers performing an open, continuous skill. Participants (n = 27) performed a wild water racing sprint of 100 m on Class 2 water. Using a within-participants design, a distal external focus ("Focus on the finish") was compared to a proximal external focus ("Focus on the paddle") as well as to a control condition. The distal focus condition (30.63 s, SD = 3.21) resulted in significantly shorter sprint times than did the proximal (32.07 s, SD = 3.27) and the control (31.96 s, SD = 3.58) conditions (ps < 0.001). The effect size was large (ηp2 = 0.53). There was no significant difference between the proximal and control condition (p = 1.00). The findings demonstrate the importance of adopting a distal, rather than proximal, external focus for skilled athletes performing open, continuous skills under time pressure.

The Classification of Violence Risk.

(Reprinted with permission from Behav. Sci. Law 24: 721-730, 2006).

The role of endorectal coil MRI in patient selection and treatment planning for prostate seed implants.

PURPOSE: To assess the role of endorectal coil magnetic resonance imaging (MRI) staging for patients undergoing seed implantation (SI) with or without external beam radiotherapy (EBRT). MATERIALS AND METHODS: Between October 1994 and December 1998, 390 patients underwent prostate SI (98% Pd-103, 2% I-125). Seventy-six percent of patients had a prostate serum antigen (PSA) < 10, 17% had PSA of 10-20, and 7% of patients had PSA of > 20. Ten percent of patients had a Gleason score (GS) of 4-5, 54% had GS 6, 29% had GS 7, and 7% had GS >/= 8. Monotherapy was employed in 46% of patients, and the remaining 54% received combined EBRT and SI. Three hundred twenty-seven were staged by high-resolution phased array pelvic coil, or in most cases, an endorectal coil MRI. The MRI findings were used to guide stage-appropriate treatment recommendations, and to assist in the preplanning and optimization of seed distributions. The criteria utilized to determine MRI-based stage were founded on the reported literature from the University of Pennsylvania. All MRI studies were reviewed by C.A., D.B., or W.H., who were unaware of clinical stage at the time of their review. The biopsy report was available to them as the only clinical correlate. RESULTS: Of the 327 patients staged by MRI, 70% were upstaged from the digital rectal examination-based clinical stage; 26% of T(1), T(2) patients were upstaged to T(3). Perineural invasion and the percentage of positive cores predicted for T(3) MRI stage (p < 0.0001 for both variables). MRI findings changed the overall treatment recommendation in 60/327 (18%) patients. The majority of these patients were advised to receive combined therapy instead of monotherapy after the MRI documented more extensive disease. The seed distribution was modified in 183/327 (56%) patients, mostly related to preplanned extracapsular coverage of bulky or extraprostatic disease seen on MRI. With a mean follow-up of 38 months (range 3-72), PSA freedom from progression (FFP) was 94% at 5 years. Cox regression analysis showed that only the percentage of positive cores (p = 0.001) and failure to have MRI staging (p = 0.0008) predicted for failure. Pretreatment PSA level, Gleason score, perineural invasion, and external beam radiotherapy did not significantly predict for PSA failure. We compared our MRI T(3) intermediate-risk group patients treated by combined therapy with a previous study of T(3) intermediate-risk group treated by radical prostatectomy (RP) at the University of Pennsylvania. Our 36-month PSA FFP was 94% compared with 21% for the previous study's RP patients. CONCLUSION: MRI is a valuable staging procedure for prostate cancer patients treated by SI. PSA FFP results appear to be improved by MRI staging. MRI T(3) disease can be treated more effectively by SI + EBRT than by RP.

A new F131V mutation in Chlamydomonas phytoene desaturase locates a cluster of norflurazon resistance mutations near the FAD-binding site in 3D protein models.

The green alga Chlamydomonas reinhardtii provides a tractable genetic model to study herbicide mode of action using forward genetics. The herbicide norflurazon inhibits phytoene desaturase, which is required for carotenoid synthesis. Locating amino acid substitutions in mutant phytoene desaturases conferring norflurazon resistance provides a genetic approach to map the herbicide binding site. We isolated a UV-induced mutant able to grow in very high concentrations of norflurazon (150 µM). The phytoene desaturase gene in the mutant strain contained the first resistance mutation to be localised to the dinucleotide-binding Rossmann-likedomain. A highly conserved phenylalanine amino acid at position 131 of the 564 amino acid precursor protein was changed to a valine in the mutant protein. F131, and two other amino acids whose substitution confers norflurazon resistance in homologous phytoene desaturase proteins, map to distant regions in the primary sequence of the C. reinhardtii protein (V472, L505) but in tertiary models these residues cluster together to a region close to the predicted FAD binding site. The mutant gene allowed direct 5 µM norflurazon based selection of transformants, which were tolerant to other bleaching herbicides including fluridone, flurtamone, and diflufenican but were more sensitive to beflubutamid than wild type cells. Norflurazon resistance and beflubutamid sensitivity allow either positive or negative selection against transformants expressing the mutant phytoene desaturase gene.

Expression of cohesin and condensin genes during zebrafish development supports a non-proliferative role for cohesin.

Cohesin and condensin are similar, but distinct multi-subunit protein complexes that have well-described roles in sister chromatid cohesion and chromosome condensation, respectively. Recently it has emerged that cohesin, and proteins that regulate cohesin function have additional developmental roles. To further understand the role of cohesin in development, we analyzed the expression of genes encoding cohesin and condensin subunits in developing zebrafish embryos and juvenile brain. We found that cohesin subunits are expressed in a pattern that is similar (but not quite identical) to the expression of condensin subunits. Cohesin genes smc1a, rad21, pds5b and smc3 were expressed in the forebrain ventricular zone, the tectum, the mid-hindbrain boundary, the fourth ventricle, branchial arches, the otic vesicle, the eye and faintly in the developing pectoral fins. Condensin genes smc2 and smc4 were expressed in the forebrain ventricular zone, the tectum, the mid-hindbrain boundary, the fourth ventricle, branchial arches, eye and pectoral fins. Condensin genes were additionally expressed in the hindbrain proliferative zone, an area in which cohesin genes were not detected. A comparison with pcna expression and BrdU incorporation revealed that the expression of cohesins and condensins closely overlap with zones of proliferation. Interestingly, cohesin genes were expressed in non-proliferating cells flanking rhombomere boundaries in the developing brain. In mature brain and eye, cohesin was expressed in both proliferating cells and in broad zones of post-mitotic cells. The distribution of cohesin and condensin mRNAs supports existing evidence for a non-cell cycle role for cohesin in the developing brain.

The classification of violence risk.

The Classification of Violence Risk (COVR) is an interactive software program designed to estimate the risk that a person hospitalized for mental disorder will be violent to others. The software leads the evaluator through a chart review and a brief interview with the patient. At the end of this interview, the software generates a report that contains a statistically valid estimate of the patient's violence risk-ranging from a 1% to a 76% likelihood of violence-including the confidence interval for that estimate, and a list of the risk factors that the program took into account to produce the estimate. In this article, the development of the COVR software is described and several issues that arise in its administration are discussed.

Impact of a mild scrotal heat stress on DNA integrity in murine spermatozoa.

An increase in scrotal temperature can lead to the production of poor quality spermatozoa and infertility. In the present study we have used mice to examine the impact of mild, scrotal heat stress (42 degrees C for 30 min) on numbers of spermatozoa as well as on the integrity of their DNA. Spermatozoa recovered from the epididymides hours (1 to 24) or days (7 to 32) after treatment were analysed using COMET and sperm chromatin structure (SCSA) assays. The treatment induced a stress response in both the testis and the epididymis that was associated with reduced expression of the cold inducible RNA binding protein (Cirp) and an increase in germ cell apoptosis (Apotag positive cells). Although spermatozoa present in the epididymis at the time of heating contained correctly packaged DNA, its integrity was compromised by heat stress. In addition, although some germ cells, which were present within the testis at the time of heat stress, were removed by apoptosis, many germ cells completed their development and were recovered as motile spermatozoa with damaged DNA. In conclusion, these data demonstrate that scrotal heat stress can compromise the DNA integrity of spermatozoa and this may have clinical implications for patients undergoing IVF and intra-cytoplasmic sperm injection (ICSI).