Consciousness and choking in visually-guided actions

Choking under pressure describes the phenomenon of people performing well below their expected standard under circumstances where optimal performance is crucial. One of the prevailing explanations for choking is that pressure increases the conscious attention to the underlying processes of the performer's task execution, thereby disrupting what would normally be a relatively automatic process. However, research on choking has focused mainly on the influence of pressure on motor performance, typically overlooking how it might alter the way that vision is controlled when performing these motor actions. In this article we ask whether the visual component of expert motor-skill execution is susceptible to choking much like the motor component is thought to be. To do so, we draw heavily on empirical findings from studies of sporting expertise, in particular focussing on the role of gaze in three types of visually-guided actions: interceptive actions, aiming tasks, and anticipatory skill. For each of these skills we evaluate the nature of the expert advantage, discuss the role of consciousness in their control, examine the potential impact of pressure on task performance, and consider interventions designed to reduce the likelihood of choking when performing these tasks

The 1987 debris flows in Switzerland: documentation and analysis

A great number of debris flows occurred during the flood catastrophes of the summer of 1987 in the Swiss Alps. Aerial photography, field investigations and eyewitness accounts documented and analysed the events. As an example of the reconstructed major events, the large debris flow in the Varuna valley involved an estimated peak discharge between 400 and 800 m3/s and an event magnitude of 200,000 m3. Several single pulses were observed; the duration of each of them appeared to be not more than a few minutes. Apart from incision into weak bedrock, the maximum erosion depth seemed to depend on the channel gradient. Based on approximately 600 events, typical starting zones and rainfall conditions are discussed with regard to the triggering conditions. Existing and new empirical formulae are proposed to estimate the most important flow parameters. These values are compared to debris flow data from Canada and Japan.

Characterization of Chelonus inanitus polydnavirus segments: sequences and analysis, excision site and demonstration of clustering

Polydnaviruses (genera Ichnovirus and Bracovirus) have a segmented genome of circular double-stranded DNA molecules, replicate in the ovary of parasitic wasps and are essential for successful parasitism of the host. Here we show the first detailed analysis of various segments of a bracovirus, the Chelonus inanitus virus (CiV). Four segments were sequenced and two of them, CiV12 and CiV14, were found to be closely related while CiV14.5 and CiV16.8 were unrelated. CiV12, CiV14.5 and CiV16.8 are unique while CiV14 occurs also nested in another larger segment. All four segments are predicted to contain genes and predictions could be substantiated in most cases. Comparison with databases revealed no significant similarities at either the nucleotide or amino acid level. Inverted repeats with identities between 77% and 92% and lengths between 26 bp and 100 bp were found on all segments outside of predicted genes. Hybridization experiments indicate that CiV12 and CiV14 are both flanked by other virus segments, suggesting that proviral CiV segments are clustered in the genome of the wasp. The integration/excision site of CiV14 was analysed and compared to that of CiV12. On both termini of proviral CiV12 and CiV14 as well as in the excised circular molecule and the rejoined DNA a very similar repeat of 14 bp was found. A model to illustrate where the terminal repeats might recombine to yield the circular molecule is presented. Excision of CiV12 and CiV14 is restricted to the female and sets in at a very specific time-point in pupal-adult development.

Transgenerational effects of land use on offspring performance and growth in Trifolium repens

entral European grasslands vary widely in productivity and in mowing and grazing regimes. The resulting differences in competition and heterogeneity among grasslands might have direct effects on plants, but might also affect the growth and morphology of their offspring through maternal effects or adaptive evolution. To test for such transgenerational effects, we grew plants of the clonal herb Trifolium repens from seeds collected in 58 grassland sites differing in productivity and mowing and grazing intensities in different treatments: without competition, with homogeneous competition, and with heterogeneous competition. In the competition-free treatment, T. repens from more productive, less frequently mown, and less intensively grazed sites produced more vegetative offspring, but this was not the case in the other treatments. When grown among or in close proximity to competitors, T. repens plants did not show preferential growth towards open spaces (i.e., no horizontal foraging), but did show strong vertical foraging by petiole elongation. In the homogeneous competition treatment, petiole length increased with the productivity of the parental site, but this was not the case in the heterogeneous competition treatment. Moreover, petiole length increased with mowing frequency and grazing intensity of the parental site in all but the homogeneous competition treatment. In summary, although the expression of differences between plants from sites with different productivities and land-use intensities depended on the experimental treatment, our findings imply that there are transgenerational effects of land use on the morphology and performance of T. repens.

Production Streamlining through Design, Implementation, and Analysis of Lean Manufacturing Methods

Through the correct implementation of lean manufacturing methods, a company can greatly improve their business. Over a period of three months at TTM Technologies, I utilized my knowledge to fix existing problems ans streamline production. In addition, other trouble areas in their production process were discovered and proper lean methods were used to address them. TTM Technologies saw many changed in the right direction over this time period.

Dielectrophoretic approaches to sample preparation and analysis

Dielectrophoresis (DEP) has been used to manipulate cells in low-conductivity suspending media using AC electrical fields generated on micro-fabricated electrode arrays. This has created the possibility of performing automatically on a micro-scale more sophisticated cell processing than that currently requiring substantial laboratory equipment, reagent volumes, time, and human intervention. In this research the manipulation of aqueous droplets in an immiscible, low-permittivity suspending medium is described to complement previous work on dielectrophoretic cell manipulation. Such droplets can be used as carriers not only for air- and water-borne samples, contaminants, chemical reagents, viral and gene products, and cells, but also the reagents to process and characterize these samples. A long-term goal of this area of research is to perform chemical and biological assays on automated, micro-scaled devices at or near the point-of-care, which will increase the availability of modern medicine to people who do not have ready access to large medical institutions and decrease the cost and delays associated with that lack of access. In this research I present proofs-of-concept for droplet manipulation and droplet-based biochemical analysis using dielectrophoresis as the motive force. Proofs-of-concept developed for the first time in this research include: (1) showing droplet movement on a two-dimensional array of electrodes, (2) achieving controlled dielectric droplet injection, (3) fusing and reacting droplets, and (4) demonstrating a protein fluorescence assay using micro-droplets. ^

The Relationship between AP English Language Performance and College Outcomes

This study focused on the relationship between students’ Advanced Placement (AP) English language performance and their subsequent college success. Targeted students were divided into three groups according to their AP English Language performance. Subsequent college success was measured by students’ first-year college GPA, retention to the second year, and institutional selectivity. The demographic characteristics of the three AP performance groups with regard to gender, ethnicity, and best language spoken are provided. Results indicated that, after controlling for students’ SAT scores as a measure of prior academic performance, AP English Language performance was positively related to all three measures of college success.

The medical malpractice insurance "crises" and federal medical malpractice tort reform: Collection and analysis of bills passed by the United States House of Representatives from 1995--2005

There have been three medical malpractice insurance "crises" in the United States over a time spanning roughly the past three decades (Poisson, 2004, p. 759-760). Each crisis is characterized by a number of common features, including rapidly increasing medical malpractice insurance premiums, cancellation of existing insurance policies, and a decreased willingness of insurers to offer or renew medical malpractice insurance policies (Poisson, 2004, p. 759-760). Given the recurrent "crises," many sources argue that medical malpractice insurance coverage has become too expensive a commodity—one that many physicians simply cannot afford (U.S. Department of Health and Human Services [HHS], 2002, p. 1-2; Physician Insurers Association of America [PIAA], 2003, p. 1; Jackiw, 2004, p. 506; Glassman, 2004, p. 417; Padget, 2003, p. 216). ^ The prohibitively high cost of medical liability insurance is said to limit the geographical areas and medical specializations in which physicians are willing to practice. As a result, the high costs of medical liability insurance are ultimately said to affect whether or not people have access to health care services. ^ In an effort to control the medical liability insurance crises—and to preserve or restore peoples' access to health care—every state in the United States has passed "at least some laws designed to reduce medical malpractice premium rates" (GAO, 2003, p.5-6). More recently, however, the United States has witnessed a push to implement federal reform of the medical malpractice tort system. Accordingly, this project focuses on federal medical malpractice tort reform. This project was designed to investigate the following specific question: Do the federal medical malpractice tort reform bills which passed in the House of Representatives between 1995 and 2005 differ in respect to their principle features? To answer this question, the text of the bills, law review articles, and reports from government and private agencies were analyzed. Further, a matrix was compiled to concisely summarize the principle features of the proposed federal medical malpractice tort reform bills. Insight gleaned from this investigation and matrix compilation informs discussion about the potential ramifications of enacting federal medical malpractice tort reform legislation. ^

Identification and analysis of novel mitotic inhibitors of the Caenorhabditis elegans Aurora B kinase

Proper execution of mitosis requires the accurate segregation of replicated DNA into each daughter cell. The highly conserved mitotic kinase AIR-2/Aurora B is a dynamic protein that interacts with subsets of cofactors and substrates to coordinate chromosome segregation and cytokinesis in Caenorhabdiris elegans. To identify components of the AIR-2 regulatory pathway, a genome-wide RNAi-based screen for suppressors of air-2 temperature-sensitive mutant lethality was conducted. Here, I present evidence that two classes of suppressors identified in this screen are bona fide regulators of the AIR-2 kinase. The strongest suppressor cdc-48.3, encodes an Afg2/Spaf-related Cdc48-like AAA+ ATPase that regulates AIR-2 kinase activity and stability during C. elegans embryogenesis. Loss of CDC-48.3 suppresses the lethality of air-2 mutant embryos, marked by the restoration of the dynamic behavior of AIR-2 and rescue of chromosome segregation and cytokinesis defects. Loss of CDC-48.3 leads to mitotic delays and abnormal accumulation of AIR-2 during late telophase/mitotic exit. In addition, AIR-2 kinase activity is significantly upregulated from metaphase through mitotic exit in CDC-48.3 depleted embryos. Inhibition of the AIR-2 kinase is dependent on (1) a direct physical interaction between CDC-48.3 and AIR-2, and (2) CDC-48.3 ATPase activity. Importantly, the increase in AIR-2 kinase activity does not correlate with the stabilization of AIR-2 in late mitosis. Hence, CDC-48.3 is a bi-functional inhibitor of AIR-2 that is likely to act via distinct mechanisms. The second class of suppressors consists of psy-2/smk-1 and pph-4.1, which encode two components of the conserved PP4 phosphatase complex that is essential for spindle assembly, chromosome segregation, and overall mitotic progression. AIR-2 and its substrates are likely to be targets of this complex since mitotic AIR-2 kinase activity is significantly increased during mitosis when either PSY-2/SMK-1 or PPH-4.l is depleted. Altogether, this study demonstrates that during the C. elegans embryonic cell cycle, regulators including the CDC-48.3 ATPase and PP4 phosphatase complex interact with and control the kinase activity, targeting behavior and protein stability of the Aurora B kinase to ensure accurate and timely progression of mitosis. ^

AN EPIDEMIOLOGIC DESCRIPTION AND ANALYSIS OF LOST WORKDAY OCCUPATIONAL BURN INJURIES

Background research consisted of a hospital case series of all adult burn patients (n = 162) admitted to John Sealy Hospital's burn unit from January 1978 to June 1979. Comparisons between occupationally and nonoccupationally burned adults demonstrated that occupationally burned adults were significantly more likely to have been active in the burn injury event and to have changed jobs during the prior year. They were significantly less likely to have physical or mental problems which contributed to sustaining the burn injury. Comparisons between occupational and nonoccupational burn injury events concluded that occupational burn injury events were significantly more likely to involve multiple sources of energy, sparks as the source of ignition and gases as the source of combustion. Other salient characteristics of occupational burn injuries indicated that subsequent research should focus upon lost workday occupational burns and other injuries sustained by blue-collar petrochemical workers employed in Galveston County, Texas.^ Subsequent research consisted of a historical cohort study of occupational injuries sustained in 1979 by a cohort of blue-collar petrochemical workers (n = 1771) who belonged to O.C.A.W. Local 4-449 in Texas City, Texas. Specific cohort injury rates included 15.08 occupational injuries per 100 person work-years, 11.98 lost workday occupational injuries per 100 person work-years, and 1.64 lost workday occupational burn injuries per 100 person work-years. Salient results from this study indicate that burn injuries are a very important type (in terms of both frequency and severity) of occupational injury sustained by blue-collar petrochemical workers, pipefitters are at greatest risk of lost workday injuries and lost workday burn injuries, company-specific experiences are comparable for lost workday occupational injuries, differences among company-specific nonlost workday occupational injury experiences may not be "safety-related", and minimal job-specific experience may not place employees at greater risk of lost workday burn injuries.^

IDENTIFICATION AND ANALYSIS OF A NOVEL ROLE FOR THE TOUSLED-LIKE KINASE IN REGULATING MITOTIC SPINDLE DYNAMICS

Deregulation of kinase activity is one example of how cells become cancerous by evading evolutionary constraints. The Tousled kinase (Tsl) was initially identified in Arabidopsis thaliana as a developmentally important kinase. There are two mammalian orthologues of Tsl and one orthologue in C. elegans, TLK-1, which is essential for embryonic viability and germ cell development. Depletion of TLK-1 leads to embryonic arrest large, distended nuclei, and ultimately embryonic lethality. Prior to terminal arrest, TLK-1-depleted embryos undergo aberrant mitoses characterized by poor metaphase chromosome alignment, delayed mitotic progression, lagging chromosomes, and supernumerary centrosomes. I discovered an unanticipated requirement for TLK-1 in mitotic spindle assembly and positioning. Normally, in the newly-fertilized zygote (P0) the maternal pronucleus migrates toward the paternal pronucleus at the posterior end of the embryo. After pronuclear meeting, the pronuclear-centrosome complex rotates 90° during centration to align on the anteroposterior axis followed by nuclear envelope breakdown (NEBD). However, in TLK-1-depleted P0 embryos, the centrosome-pronuclear complex rotation is significantly delayed with respect to NEBD and chromosome congression, Additionally, centrosome positions over time in tlk-1(RNAi) early embryos revealed a defect in posterior centrosome positioning during spindle-pronuclear centration, and 4D analysis of centrosome positions and movement in newly fertilized embryos showed aberrant centrosome dynamics in TLK-1-depleted embryos. Several mechanisms contribute to spindle rotation, one of which is the anchoring of astral microtubules to the cell cortex. Attachment of these microtubules to the cortices is thought to confer the necessary stability and forces in order to rotate the centrosome-pronuclear complex in a timely fashion. Analysis of a microtubule end-binding protein revealed that TLK-1-depleted embryos exhibit a more stochastic distribution of microtubule growth toward the cell cortices, and the types of microtubule attachments appear to differ from wild-type embryos. Additionally, fewer astral microtubules are in the vicinity of the cell cortex, thus suggesting that the delayed spindle rotation could be in part due to a lack of appropriate microtubule attachments to the cell cortex. Together with recently published biochemical data revealing the Tousled-like kinases associate with components of the dynein microtubule motor complex in humans, these data suggest that Tousled-like kinases play an important role in mitotic spindle assembly and positioning.

A systematic review and analysis of the association between endometriosis and ovarian cancer

Ovarian cancer is the most lethal of the gynecologic malignancies. The development of endometriosis has been shown to increase one's risk of ovarian cancer. Numerous studies have investigated this association, yet none have synthesized the available data. In a pooled analysis of cohort and case-control studies, the association between endometriosis and ovarian cancer was strengthened. Women who developed endometriosis-associated ovarian cancer were more likely to develop an early stage clear cell or endometrioid ovarian cancer histotypes and were more likely to have a better overall prognosis. The prognostic differences between endometriosis-associated ovarian cancer and ovarian cancer without an associated endometriosis may indicate genetic and environmental differences between groups.^