ENTREPRENEURS' ATTITUDES, STRATEGY CHOICES, AND FIRM PERFORMANCE

This paper focuses on how attitudes affect entrepreneur’s strategy selection at the organizational level. It also attempts to discover if contingencies exist in this relationship that may account for differences in firm performance. The model developed, based on the existing literature, is tested using a sample of 60 wineries, still operated by their founding entrepreneurs. The results indicate that entrepreneurs used different approaches to impart their values and beliefs to their firms. While we show that this affects the eventual strategy choice, the data indicates that firms can be equally profitable with multiple sets of attitude and strategy combinations.entrepreneurial strategy, beliefs, attitudes, firm performance, emergent strategy, deliberate strategy

Passive Tracking System and Method

System and methods are disclosed for passively determining the location of a moveable transmitter utilizing a pair of phase shifts at a receiver for extracting a direction vector from a receiver to the transmitter. In a preferred embodiment, a phase difference between the transmitter and receiver is extracted utilizing a noncoherent demodulator in the receiver. The receiver includes antenna array with three antenna elements, which preferably are patch antenna elements placed apart by one-half wavelength. Three receiver channels are preferably utilized for simultaneously processing the received signal from each of the three antenna elements. Multipath transmission paths for each of the three receiver channels are indexed so that comparisons of the same multipath component are made for each of the three receiver channels. The phase difference for each received signal is determined by comparing only the magnitudes of received and stored modulation signals to determine a winning modulation symbol

Als3 is a Candida albicans invasin that binds to cadherins and induces endocytosis by host cells.

Candida albicans is the most common cause of hematogenously disseminated and oropharyngeal candidiasis. Both of these diseases are characterized by fungal invasion of host cells. Previously, we have found that C. albicans hyphae invade endothelial cells and oral epithelial cells in vitro by inducing their own endocytosis. Therefore, we set out to identify the fungal surface protein and host cell receptors that mediate this process. We found that the C. albicans Als3 is required for the organism to be endocytosed by human umbilical vein endothelial cells and two different human oral epithelial lines. Affinity purification experiments with wild-type and an als3delta/als3delta mutant strain of C. albicans demonstrated that Als3 was required for C. albicans to bind to multiple host cell surface proteins, including N-cadherin on endothelial cells and E-cadherin on oral epithelial cells. Furthermore, latex beads coated with the recombinant N-terminal portion of Als3 were endocytosed by Chinese hamster ovary cells expressing human N-cadherin or E-cadherin, whereas control beads coated with bovine serum albumin were not. Molecular modeling of the interactions of the N-terminal region of Als3 with the ectodomains of N-cadherin and E-cadherin indicated that the binding parameters of Als3 to either cadherin are similar to those of cadherin-cadherin binding. Therefore, Als3 is a fungal invasin that mimics host cell cadherins and induces endocytosis by binding to N-cadherin on endothelial cells and E-cadherin on oral epithelial cells. These results uncover the first known fungal invasin and provide evidence that C. albicans Als3 is a molecular mimic of human cadherins

Seasonal Shifts in Jumping Patterns: A Study of Countermovement Jump Strategies in High School Football Athletes

Modern sporting trends have begun to adopt sport science and load monitoring to identify in-season trends with the goal of improving performance and reducing injury. Although these resources have become increasingly common in professional and collegiate sports, many high school athletic programs have yet to adopt such technologies. While previous research has demonstrated season-long changes in jump performance, no research has investigated the impact of in-season demands on the changes in jump strategy in male high school football athletes. PURPOSE: The purpose of this study was to examine changes in jump strategy in high school football players over a single football season. METHODS: Sixty-nine male high school football athletes, including 25 offensive skill, 23 linemen, 12 linebackers, 7 defensive backs, and 2 special teams players were tested for maximal jump performance at the beginning and end of a high school football season. Testing was conducted using three attempts of a maximal hands-on-hips countermovement jump on portable force plates, with the average of the three jumps used for analysis. A minimum of 10-weeks between sessions accounted for the time between pre- and post-testing. A dependent-samples t-test was performed to calculate differences between the two time points. RESULTS: Significant reductions were observed across all phases of the jump movement revealed significant differences from pre- to post- testing. The largest reduction was seen during the unweighting phase (0.40 to 0.36s), followed by braking phase (0.22 to 0.19s), and finally propulsive phase (0.30 to 0.28s). Resulting in a total time to takeoff decrease of 0.92 seconds to 0.83 seconds, resulting in an increase in mean jump height (14.15 to 14.89 inches). Jump strategy differences were also significantly different between time points for modified reactive strength index (0.40 to 0.47 and stiffness metrics (-4996.86 to -5622.46N/m). No differences were seen for countermovement depth (t(68) = 0.44, p=0.663) between the two time points. CONCLUSION: At the end of a competitive season, high school football athletes increased their speed at all phases of the jumping motion. Despite the increased speed during the movement, there were no changes in the countermovement depth prior to takeoff. Our research indicates that football athletes become faster and more efficient with their CMJ strategy to achieve increased performance as measured by Jump Height. Future studies may benefit from collecting follow-up data collection to examine the detraining effect that can occur post-competition, and to incorporate differences between double and single leg jumping strategy. Doing so has the potential to identify injury risk and asymmetries throughout the season

Countermovement Jump Performance Trends in High School Football Players Throughout a Competitive Season

Football is the largest participation sport amongst male high school athletes in the country with over one million participants. Previous research has demonstrated that countermovement jump (CMJ) performance is negatively affected by in-season fatigue in contact sports such as rugby and hockey. However, little data are available to describe how CMJ performance and force metrics change in high school athletes throughout a competitive football season. PURPOSE: The purpose of this study was to examine the changes in strength and power metrics in high school football players over a single football season. METHODS: Sixty-nine male high school football athletes comprised of 25 offensive skill players, 23 linemen, 12 linebackers 7 defensive backs, and 2 special teams players were tested for maximal lower body force output at the beginning and end of a high school football season. Testing was conducted using three attempts of a maximal hands-on-hips countermovement jump on portable force plates, with the average of the three jumps used for analysis. Pre-testing occurred prior to the first game of the season, and post-test was conducted after the final game of the season with a minimum of 10-weeks between sessions accounted for the time between pre- and post-testing. A dependent-samples t-test was performed to calculate differences between the two time points. RESULTS: Significant improvements in jump height (14.15 to 14.89 inches), relative force at minimum displacement (220.36 to 235.77% body weight), peak relative braking force (220.72 to 236.39% body weight), peak relative propulsive force (238.07 to 248.02% body weight), peak braking velocity (-1.17 to -1.30m/s), and takeoff velocity (2.64 to 2.71m/s). No significant differences were seen in relative peak landing force (t(68) = 0.53, p=0.600). CONCLUSION: At the end of a competitive season, high school football athletes produced more force and increased their movement velocity, resulting in improvements in jump height compared to the beginning of the season. However, there were no significant differences in landing metrics indicating no changes in force absorption capacity. These increases in jump performance do not reflect results previously reported in contact sports such as rugby and hockey where jump performance typically decreased over the course of a season. Future studies may benefit from collecting additional performance data to assess the impact seasonal fatigue has on other body systems separate to lower body power production, and the effect to which practice and strength and conditioning programming impact force metrics. Without appropriate monitoring strategies, coaches are leaving the assessment of load management to chance, which can potentially lead to decreased performance and an increased chance of injury

Ultra-Wideband Angle-of-Arrival Tracking Systems

Systems that measure the angles of arrival of ultra-wideband (UWB) radio signals and perform triangulation by use of those angles in order to locate the sources of those signals are undergoing development. These systems were originally intended for use in tracking UWB-transmitter-equipped astronauts and mobile robots on the surfaces of remote planets during early stages of exploration, before satellite-based navigation systems become operational. On Earth, these systems could be adapted to such uses as tracking UWB-transmitter-equipped firefighters inside buildings or in outdoor wildfire areas obscured by smoke. The same characteristics that have made UWB radio advantageous for fine resolution ranging, covert communication, and ground-penetrating radar applications in military and law-enforcement settings also contribute to its attractiveness for the present tracking applications. In particular, the waveform shape and the short duration of UWB pulses make it possible to attain the high temporal resolution (of the order of picoseconds) needed to measure angles of arrival with sufficient precision, and the low power spectral density of UWB pulses enables UWB radio communication systems to operate in proximity to other radio communication systems with little or no perceptible mutual interference

Cyclic-AMP regulates postnatal development of neural and behavioral responses to NaCl in rats

During postnatal development rats demonstrate an age-dependent increase in NaCl chorda tympani (CT) responses and the number of functional apical amiloride-sensitive epithelial Na+channels (ENaCs) in salt sensing fungiform (FF) taste receptor cells (TRCs). Currently, the intracellular signals that regulate the postnatal development of salt taste have not been identified. We investigated the effect of cAMP, a downstream signal for arginine vasopressin (AVP) action, on the postnatal development of NaCl responses in 19–23 day old rats. ENaC-dependent NaCl CT responses were monitored after lingual application of 8-chlorophenylthio-cAMP (8-CPT-cAMP) under open-circuit conditions and under ±60 mV lingual voltage clamp. Behavioral responses were tested using 2 bottle/24h NaCl preference tests. The effect of [deamino-Cys1, D-Arg8]-vasopressin (dDAVP, a specific V2R agonist) was investigated on ENaC subunit trafficking in rat FF TRCs and on cAMP generation in cultured adult human FF taste cells (HBO cells). Our results show that in 19–23 day old rats, the ENaC-dependent maximum NaCl CT response was a saturating sigmoidal function of 8-CPT-cAMP concentration. 8-CPT-cAMP increased the voltage-sensitivity of the NaCl CT response and the apical Na+ response conductance. Intravenous injections of dDAVP increased ENaC expression and γ-ENaC trafficking from cytosolic compartment to the apical compartment in rat FF TRCs. In HBO cells dDAVP increased intracellular cAMP and cAMP increased trafficking of γ- and δ-ENaC from cytosolic compartment to the apical compartment 10 min post-cAMP treatment. Control 19–23 day old rats were indifferent to NaCl, but showed clear preference for appetitive NaCl concentrations after 8-CPT-cAMP treatment. Relative to adult rats, 14 day old rats demonstrated significantly less V2R antibody binding in circumvallate TRCs. We conclude that an age-dependent increase in V2R expression produces an AVP-induced incremental increase in cAMP that modulates the postnatal increase in TRC ENaC and the neural and behavioral responses to NaCl

caCORRECT2: Improving the accuracy and reliability of microarray data in the presence of artifacts

© 2011 Moffitt et al.; licensee BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.DOI: 10.1186/1471-2105-12-383Background. In previous work, we reported the development of caCORRECT, a novel microarray quality control system built to identify and correct spatial artifacts commonly found on Affymetrix arrays. We have made recent improvements to caCORRECT, including the development of a model-based data-replacement strategy and integration with typical microarray workflows via caCORRECT's web portal and caBIG grid services. In this report, we demonstrate that caCORRECT improves the reproducibility and reliability of experimental results across several common Affymetrix microarray platforms. caCORRECT represents an advance over state-of-art quality control methods such as Harshlighting, and acts to improve gene expression calculation techniques such as PLIER, RMA and MAS5.0, because it incorporates spatial information into outlier detection as well as outlier information into probe normalization. The ability of caCORRECT to recover accurate gene expressions from low quality probe intensity data is assessed using a combination of real and synthetic artifacts with PCR follow-up confirmation and the affycomp spike in data. The caCORRECT tool can be accessed at the website: http://cacorrect.bme.gatech.edu webcite. Results. We demonstrate that (1) caCORRECT's artifact-aware normalization avoids the undesirable global data warping that happens when any damaged chips are processed without caCORRECT; (2) When used upstream of RMA, PLIER, or MAS5.0, the data imputation of caCORRECT generally improves the accuracy of microarray gene expression in the presence of artifacts more than using Harshlighting or not using any quality control; (3) Biomarkers selected from artifactual microarray data which have undergone the quality control procedures of caCORRECT are more likely to be reliable, as shown by both spike in and PCR validation experiments. Finally, we present a case study of the use of caCORRECT to reliably identify biomarkers for renal cell carcinoma, yielding two diagnostic biomarkers with potential clinical utility, PRKAB1 and NNMT. Conclusions. caCORRECT is shown to improve the accuracy of gene expression, and the reproducibility of experimental results in clinical application. This study suggests that caCORRECT will be useful to clean up possible artifacts in new as well as archived microarray data