The Relationship Between Task Cohesion and Competitive State Anxiety

The general purpose of the present study was to determine if perceptions of team cohesion are related to the interpretation athletes attach to their precompetition anxiety. Specifically examined was the association between athlete perceptions of task cohesiveness (Individual Attractions to the Group–Task, ATG-T, and Group Integration–Task, GI-T) and the degree to which perceptions of the intensity of precompetition anxiety symptoms (cognitive and somatic) were viewed as facilitative versus debilitative. Participants were athletes (N = 392) from the sports of soccer, rugby, and field hockey. Each athlete completed the Group Environment Questionnaire (Carron, Widmeyer, & Brawley, 1985) after a practice session. A directionally modified version of the Competitive State Anxiety Inventory-2 (Martens, Burton, Vealey, Bump, & Smith, 1990) was completed just prior to a competition. Results showed that athletes who perceived their cognitive anxiety as facilitative had higher perceptions of both ATG-T and GI-T, χ2 (2, N = 260) = 8.96, p \u3c .05, than athletes who perceived their cognitive anxiety as debilitative. Also, athletes who perceived their somatic anxiety as facilitative had higher perceptions of GI-T, χ2 (2, N = 249) = 5.85, p \u3c .05

Effects Of Coal Fly-Ash Disposal On Water Chemistry in an Intradunal Wetland at Indiana Dunes

An intradunal wetland within the Indiana Dunes National Lakeshore on the south shore of Lake Michigan was flooded for 15 years by seepage from fly-ash settling ponds located adjacent to the park. Studies were undertaken to determine the effects of the seepage on water chemistry in the flooded wetlands. These water chemistry conditions have been correlated to ongoing studies of soil contamination and secondary succession in the wetland basin following cessation of seepage. The seepage increased the concentrations of calcium, potassium, sulfate, aluminum, boron, iron, manganese, molybdenum, nickel, strontium, and zinc in ground water and surface water downgradient from the settling ponds. Chemical interactions with aquifer materials, particularly organic matter, significantly limit the transport of aluminum, iron, nickel, and zinc in this system. The organic soils of the dewatered wetland basin now contain elevated concentrations of aluminum, boron, manganese, and zinc that are potentially phytotoxic under the low pH (\u3c4) conditions that exist. Plant growth and secondary succession were affected by the soil chemistry of the dewatered wetlands

Induction of Immunological Tolerance to Tissue Allografts with Antilymphocyte Serum

Our interest in the problem of tolerance induction is directly concerned with clinical organ transplantation. ALS is highly effective in depressing cellular immunities. Since at least initial allograft rejection is predominantly a cellular phenomenon, one would expect ALS to be highly effective clinically. Our initial observations in this regard support this concept. However, non-specific depression of cellular immunity may also lead to an increased number or viral, fungal, and protozoan infections. Experiments, such as these presented, strongly suggest that a specific state of tolerance to organ grafts in man should be attainable with the aid of ALS followed by introduction of appropriate antigen

Structure and electronic properties of the quasi-one-dimensional Ba₂Co₁₋ₓZnₓS₃ series

This work focuses on the structure and physical properties of the solid solution Ba₂Co₁₋ₓZnₓS₃ (0 ≤ x ≤ 1), a family of quasi-one-dimensional sulfides with end members Ba₂CoS₃ and Ba₂ZnS₃. The structure of selected compounds with increasing Zn²⁺ content has been analysed using, neutron diffraction, TEM and EXAFS and the physical properties via magnetic susceptibility and resistivity measurements. The progressive substitution of the non-magnetic Zn²⁺ cation for Co²⁺ rapidly destroys the antiferromagnetic transition present at 46 K in the quasi one-dimensional Ba₂CoS₃, leading to paramagnetic behaviour down to the lowest investigated temperature (5K) for compounds with x > 0.25. For compounds with x ≥ 0.4, a pure CW regime is recovered around 300 K, yielding effective moments consistent with the g factor of the tetrahedrally coordinated Co²⁺ previously determined for Ba₂CoS₃. The Zn²⁺/Co²⁺ substitution also removes the metallic-like behaviour of Ba₂CoS₃ causing an increase in the value of the resistivity with all the Ba₂Co₁₋ₓZnₓS₃ compounds showing semiconducting behaviour. The negative magnetoresistance of Ba₂CoS₃ is improved by the Zn²⁺/Co²⁺ substitution, with values of – 6% for Ba₂Co₀.₇₅Zn₀.₂₅S₃, – 9% for Ba₂Co₀.₅Zn₀.₅S₃ and – 8% for Ba₂Co₀.₂₅Zn₀.₇₅S₃. However, there does not seem to be a correlation between the values of the resistivity and the magnetoresistance and the content of Zn²⁺, leading to the hypothesis that transport properties may be linked more closely to extrinsic properties

Analyses of risks associated with radiation exposure from past major solar particle events

Radiation exposures and cancer induction/mortality risks were investigated for several major solar particle events (SPE's). The SPE's included are: February 1956, November 1960, August 1972, October 1989, and the September, August, and October 1989 events combined. The three 1989 events were treated as one since all three could affect a single lunar or Mars mission. A baryon transport code was used to propagate particles through aluminum and tissue shield materials. A free space environment was utilized for all calculations. Results show the 30-day blood forming organs (BFO) limit of 25 rem was surpassed by all five events using 10 g/sq cm of shielding. The BFO limit is based on a depth dose of 5 cm of tissue, while a more detailed shield distribution of the BFO's was utilized. A comparison between the 5 cm depth dose and the dose found using the BFO shield distribution shows that the 5 cm depth value slightly higher than the BFO dose. The annual limit of 50 rem was exceeded by the August 1972, October 1989, and the three combined 1989 events with 5 g/sq cm of shielding. Cancer mortality risks ranged from 1.5 to 17 percent at 1 g/sq cm and 0.5 to 1.1 percent behind 10 g/sq cm of shielding for five events. These ranges correspond to those for a 45 year old male. It is shown that secondary particles comprise about 1/3 of the total risk at 10 g/sq cm of shielding. Utilizing a computerized Space Shuttle shielding model to represent a typical spacecraft configuration in free space at the August 1972 SPE, average crew doses exceeded the BFO dose limit

The Relationship Between Task Cohesion and Competitive State Anxiety

The general purpose of the present study was to determine if perceptions of team cohesion are related to the interpretation athletes attach to their precompetition anxiety. Specifically examined was the association between athlete perceptions of task cohesiveness (Individual Attractions to the Group–Task, ATG-T, and Group Integration–Task, GI-T) and the degree to which perceptions of the intensity of precompetition anxiety symptoms (cognitive and somatic) were viewed as facilitative versus debilitative. Participants were athletes (N = 392) from the sports of soccer, rugby, and field hockey. Each athlete completed the Group Environment Questionnaire (Carron, Widmeyer, & Brawley, 1985) after a practice session. A directionally modified version of the Competitive State Anxiety Inventory-2 (Martens, Burton, Vealey, Bump, & Smith, 1990) was completed just prior to a competition. Results showed that athletes who perceived their cognitive anxiety as facilitative had higher perceptions of both ATG-T and GI-T, χ2 (2, N = 260) = 8.96, p \u3c .05, than athletes who perceived their cognitive anxiety as debilitative. Also, athletes who perceived their somatic anxiety as facilitative had higher perceptions of GI-T, χ2 (2, N = 249) = 5.85, p \u3c .05

Natural products that reduce rotavirus infectivity identified by a cell-based moderate-throughput screening assay

BACKGROUND: There is widespread interest in the use of innate immune modulators as a defense strategy against infectious pathogens. Using rotavirus as a model system, we developed a cell-based, moderate-throughput screening (MTS) assay to identify compounds that reduce rotavirus infectivity in vitro, toward a long-term goal of discovering immunomodulatory agents that enhance innate responses to viral infection. RESULTS: A natural product library consisting of 280 compounds was screened in the assay and 15 compounds that significantly reduced infectivity without cytotoxicity were identified. Time course analysis of four compounds with previously characterized effects on inflammatory gene expression inhibited replication with pre-treatment times as minimal as 2 hours. Two of these four compounds, α-mangostin and 18-β-glycyrrhetinic acid, activated NFκB and induced IL-8 secretion. The assay is adaptable to other virus systems, and amenable to full automation and adaptation to a high-throughput format. CONCLUSION: Identification of several compounds with known effects on inflammatory and antiviral gene expression that confer resistance to rotavirus infection in vitro suggests the assay is an appropriate platform for discovery of compounds with potential to amplify innate antiviral responses

Multi-Wavelength Variability of the Synchrotron Self-Compton Model for Blazar Emission

Motivated by recent reports of strongly correlated radio and X-ray variability in 3C279 (Grandi, etal 1995), we have computed the relative amplitudes of variations in the synchrotron flux at $\nu$ and the self-Compton X-ray flux at 1 keV ($R(\nu)$) for a homogeneous sphere of relativistic electrons orbiting in a tangled magnetic field. Relative to synchrotron self-Compton scattering without induced Compton scattering, stimulated scattering reduces the amplitude of $R(\nu)$ by as much as an order of magnitude when \tau_T \gtwid 1. When $\tau_T$ varies in a fixed magnetic field, $R_{\tau}$ increases monotonically from 0.01 at $\nu_o$, the self-absorption turnover frequency, to $0.5$ at $100 \nu_o$. The relative amplitudes of the correlated fluctuations in the radio-mm and X-ray fluxes from 3C279 are consistent with the synchrotron self-Compton model if $\tau_T$ varies in a fixed magnetic field and induced Compton scattering is the dominant source of radio opacity. The variation amplitudes are are too small to be produced by the passage of a shock through the synchrotron emission region unless the magnetic field is perpendicular to the shock front.Comment: 21 pages, 4 fig

Functional immunoglobulin transgenes guide ordered B-cell differentiation in Rag-1-deficient mice

We have examined the regulatory role of the individual components of the immunoglobulin antigen receptor in B-cell development by transgenic complementation of Rag-1 deficient (Rag-1⁻) mice. Complementation with a membrane µ heavy chain (µHC) gene allows progression of developmentally arrested Rag-1⁻ pro-B-cells to the small pre-B cell stage, whereas the introduction of independently integrated µHC and κ light chain (κLC) transgenes promotes the appearance of peripheral lymphocytes which, however, remain unresponsive to external stimuli. Complete reconstitution of the B-cell lineage and the emergence of functionally nature Rag-1⁻ peripheral B cells is achieved by the introduction of cointegrated heavy and light chain transgenes encoding an anti-H-2^k antibody. This experimental system demonstrates the competence of the µHC and κLC to direct and regulate the sequential stages of B-cell differentiation, defines the time at which negative selection of self-reactive B cells occurs, and shows that elimination of these cells occurs equally well in the absence of Rag-1 as in its presence. These data also support the hypothesis that Rag-1 directly participates in the V(D)J recombination process

Optimal manipulations with qubits: Universal quantum entanglers

We analyze various scenarios for entangling two initially unentangled qubits. In particular, we propose an optimal universal entangler which entangles a qubit in unknown state $|\Psi>$ with a qubit in a reference (known) state $|0>$. That is, our entangler generates the output state which is as close as possible to the pure (symmetrized) state $(|\Psi>|0> +|0>|\Psi>)$. The most attractive feature of this entangling machine, is that the fidelity of its performance (i.e. the distance between the output and the ideally entangled -- symmetrized state) does not depend on the input and takes the constant value $F= (9+3\sqrt{2})/14\simeq 0.946$. We also analyze how to optimally generate from a single qubit initially prepared in an unknown state |\Psi\r a two qubit entangled system which is as close as possible to a Bell state $(|\Psi\r|\Psi^\perp\r+|\Psi^\perp\r|\Psi\r)$, where \l\Psi|\Psi^\perp\r =0.Comment: 11 pages, 3 eps figures, accepted for publication in Phys. Rev.