Gravitational Biology Facility on Space Station: Meeting the needs of space biology

The Gravitational Biology Facility (GBF) is a set of generic laboratory equipment needed to conduct research on Space Station Freedom (SSF), focusing on Space Biology Program science (Cell and Developmental Biology and Plant Biology). The GBF will be functional from the earliest utilization flights through the permanent manned phase. Gravitational biology research will also make use of other Life Sciences equipment on the space station as well as existing equipment developed for the space shuttle. The facility equipment will be developed based on requirements derived from experiments proposed by the scientific community to address critical questions in the Space Biology Program. This requires that the facility have the ability to house a wide variety of species, various methods of observation, and numerous methods of sample collection, preservation, and storage. The selection of the equipment will be done by the members of a scientific working group (5 members representing cell biology, 6 developmental biology, and 6 plant biology) who also provide requirements to design engineers to ensure that the equipment will meet scientific needs. All equipment will undergo extensive ground based experimental validation studies by various investigators addressing a variety of experimental questions. Equipment will be designed to be adaptable to other space platforms. The theme of the Gravitational Biology Facility effort is to provide optimal and reliable equipment to answer the critical questions in Space Biology as to the effects of gravity on living systems

A review of nonlinear constitutive models for metals

Over the past two decades a number of thermomechanical constitutive theories have been proposed for viscoplastic metals. These models are in most cases similar in that they utilize a set of internal state variables which provide locally averaged representations of microphysical phenomena such as dislocation rearrangement and grain boundary sliding. The state of development of several of these models is now at the point where accurate theoretical solutions can be obtained for a wide variety of structural problems at elevated temperatures. The fundamentals of viscoplasticity are briefly reviewed and a general framework is outlined. Several of the more prominent models are reviewed, and predictions from models are compared to experimental results

QUANTIFYING GAINS TO RISK DIVERSIFICATION USING CERTAINTY EQUIVALENCE IN A MEAN-VARIANCE MODEL: AN APPLICATION TO FLORIDA CITRUS

The marginal benefit and cost of diversification for Florida orange producers is analyzed using certainty equivalents. Results indicate that for moderate and high levels of risk aversion, diversification into strawberry, grapefruit, or additional orange production is not optimal. However, moderately risk averse Florida orange producers can gain by diversifying into grapefruit production if the annual amortized fixed costs can be reduced by as little as 10 percent.Risk and Uncertainty,

The Effects Of Jaw Clenching, Jaw Alignment Via Performance Mouthpiece, And The Combination Of Both On Power And Force Production

Jaw clenching has been demonstrated to elicit concurrent activation potentiation (CAP), which is the ergogenic advantage of increased prime mover muscular force production during physical activity. Further, jaw aligning mouthpieces have been shown to improve the force production capabilities of individuals with temporomandibular joint disorder (TMD) and are purported to have similar effects on persons without symptoms of TMD. Previous research examining these phenomena has focused solely on jaw alignment via mouthpiece use or jaw clenching as mutually exclusive factors explaining the reported performance benefits. However, these factors do not appear to be mutually exclusive. No previously published investigations have attempted to determine whether observed performance improvements can be attributed exclusively to jaw clenching, jaw alignment via mouthpiece use, or if the combination of clenching and the presence of a mouthpiece further facilitates performance improvement. Therefore, the purpose of this study was to examine the effects of jaw clenching, jaw alignment via mouthpiece use, and the combination of the two on measures of force production and muscle activation. Participants (n=36) were required one familiarization visit and three testing visits to the lab. The familiarization visit consisted of participant prescreening, obtaining informed consent, basic anthropometric measurement, mouthpiece fitting and instruction, and familiarization of the countermovement vertical jump (CMVJ) and isometric mid-thigh clean pull (MTCP) assessments. The testing conditions, counterbalanced for all participants were as follows: performance mouthpiece with jaw clenched (PMP-C), performance mouthpiece with jaw relaxed (PMP), traditional mouthpiece with jaw clenched (MP-C), traditional mouthpiece with jaw relaxed (MP), no mouthpiece with jaw clenched (NoMP-C), and no mouthpiece with jaw relaxed (NoMP). The dependent variables examined were rate of force development (RFD), peak force (PF), relative peak force (nPF), and muscle activation during both CMVJ and MTCP assessments. A 3 x 2 (mouthpiece x clench condition) ANOVA for repeated measures was conducted to analyze each of the dependent performance variables. Post-hoc analysis for multiple comparisons were performed using a Bonferroni correction. Paired samples t-tests were used to further analyze observed interaction significance. Results revealed that clenching significantly improved all measured force production variables during the MTCP (p \u3c 0.05). There was no difference between clench conditions for the CMVJ assessment. There was no difference in any force production variables between mouthpiece conditions for either the CMVJ or the MTCP. Muscle activation, measured via electromyography, was significantly greater under clench conditions during the CMVJ assessment (p \u3c 0.05). Jaw aligning mouthpiece and no mouthpiece conditions lead to greater muscle activation than the traditional mouthpiece condition during the CMVJ assessment as well (p \u3c 0.05). There were no differences in muscle activation between conditions during the MTCP. These results support the use of jaw clenching as a viable strategy for eliciting CAP during isometric muscle actions. Future studies should attempt to identify the mechanisms behind the observed changes in force production, as the current results do not support increased neural drive as the underlying factor

A summary of the published data on host plants and morphology of immature stages of Australian jewel beetles (Coleoptera: Buprestidae) : with additional new records

A summary is given of the published host plant and descriptive immature stage morphology data for 671 species and 11 subspecies in 54 genera of Australian jewel beetles (Coleoptera: Buprestidae). New host data for 155 species and 3 subspecies in 17 genera including the first published data for 75 species are included

A study of near surface elastic-anelastic layers

Wave propagation through layered media is of importance in many disciplines. The near surface layers are of special significance, in that most measurements of waves are made within these layers. The purpose of this investigation was to formulate mathematical models with which to analyze the effects of near surface layering --Introduction, page 1