Steve Irwin's Influence on Wildlife Conservation

The present study assesses audience involvement with popular television personality Steve Irwin, who died tragically at the peak of his career. A survey of 1,800 media consumers revealed that Irwin was perceived to be a hero and role model for wildlife conservation. News of his death spread quickly and globally, promoting interpersonal dialoguing and Internet searching. Those more highly involved with Irwin talked with more people and longer about his death, and, as hypothesized, were more likely to increase their support of wildlife conservation. The effects of involvement with Irwin spanned age groups, educational levels, ethnic groups, and gender. Implications of these findings on the international influence of popular celebrities are discussed.     

Fluid circulation and heat extraction from engineered geothermal reservoirs

A large amount of fluid circulation and heat extraction (i.e., thermal power production) research and testing has been conducted on engineered geothermal reservoirs in the past 15 years. In confined reservoirs, which best represent the original Hot Dry Rock concept, the flow distribution at any given time is primarily determined by three parameters: (1) the nature of the interconnected network of pressure-stimulated joints and open fractures within the flow-accessible reservoir region, (2) the mean pressure in the reservoir, and (3) the cumulative amount of fluid circulation—and therefore reservoir cooling—that has occurred. For an initial reservoir rock temperature distribution and mean fluid outlet temperature, the rate of heat extraction (i.e., thermal power) is at first only a function of the production flow rate, since the production temperature can be expected to remain essentially constant for some time (months, or even years). However, as reservoir circulation proceeds, the production temperature will eventually start to decline, as determined by the mean effective joint spacing and the total flow-accessible (i.e., heat-transfer) volume of the reservoir. The rate of heat extraction, which depends on the production flow rate, can also vary with time as a result of continuing changes in the flow distribution arising from reservoir cooling.The thermal power of engineered reservoirs can most readily be increased by increasing the production flow rate, as long as this does not lead to premature cooldown, the development of short-circuit flow paths, or excessive water losses. Generally, an increase in flow rate can be accomplished by increasing the injection pressure within limits. This strategy increases the driving pressure drop across the reservoir and the mean reservoir pressure, which in turn reduces the reservoir flow impedance by increasing the amount of joint dilation. However, the usefulness of this strategy is limited to reservoir operating pressures below the fracture extension pressure, and may lead to excessive water losses, particularly in less-confined reservoirs. Under such conditions, a downhole production-well pump may be employed to increase productivity by recovering more of the injected fluid at lower mean reservoir operating pressures.     

The North Carolina High School Athletic Injury Study: design and methodology

PURPOSE: Organized interscholastic athletics are an integral part of the educational program at almost every school level. With this growing popularity of sports and their inclusion in more public school programs, it becomes increasingly apparent that additional consideration must be given to the injury problem associated with sport. The North Carolina High School Athletic Injury Study (NCHSAIS) was undertaken to identify patterns of injury among male and female athletes in North Carolina high schools participating in any of 12 sports. Specific aims are to measure the incidence, severity and etiology of injuries; to determine the relationship of demographic factors and protective equipment, exposure to play, and school characteristics to injuries; to study the relationship of coaches' training and experience to injury occurrence; and to compare the incidence and severity of injury among female and male athletes in the same or comparable sports. METHODS: A two-stage cluster sample of 100 high schools in North Carolina was selected for this 4-yr prospective study. RESULTS: Participation by the initial sample or a random replacement was achieved for 91 of the 100 schools. Nonresponse occurred at multiple levels of the sample for this study, and the weekly participation form posed the greatest respondent burden. CONCLUSIONS: The NCHSIAS offers a successful methodology for addressing sports injuries. In this paper we describe the design, methodology, and implementation issues that emerge in conducting a large scale epidemiological study in a population of high school athletes.     

South Turkwel: a new pliocene hominid site in Kenya

New fossils discovered south of the Turkwel River in northern Kenya include an associated metacarpal, capitate, hamate, lunate, pedal phalanx, mandibular fragment, and teeth. These fossils probably date to around 3.5 m.y.a. Faunal information suggests that the environment at South Turkwel was predominantly bushland. The mandibular and dental remains are fragmentary, but the postcranial fossils are informative. Comparisons with Australopithecus, modern human, chimpanzee and gorilla hand bones suggest that the Turkwel hominid was most like Australopithecus afarensis and A. africanus. Carpometacarpal articulations are intermediate between those of modern humans and African apes, suggesting enhanced gripping capabilities compared with extant apes. The hamulus was strikingly large, similar in proportion only to Neandertals and some gorillas, suggesting the presence of powerful forearms and hands. There are no indicators of adaptations to knuckle-walking or suspensory locomotion in the hand, and the pedal phalanx suggests that this hominid was habitually bipedal.     

Radiation down-regulates replication origin activity throughout the S phase in mammalian cells

An asynchronous culture of mammalian cells responds acutely to ionizing radiation by inhibiting the overall rate of DNA replication by approximately 50% for a period of several hours, presumably to allow time to repair DNA damage. At low and moderate doses, this S phase damage-sensing (SDS) pathway appears to function primarily at the level of individual origins of replication, with only a modest inhibition of chain elongation per se. We have shown previously that the majority of the inhibition observed in an asynchronous culture can be accounted for by late G1cells that were within 2-3 h of entering the S period at the time of irradiation and which then fail to do so. A much smaller effect was observed on the overall rate of replication in cells that had already entered the S phase. This raised the question whether origins of replication that are activated within S phase per se are inhibited in response to ionizing radiation. Here we have used a two-dimensional gel replicon mapping strategy to show that cells with an intact SDS pathway completely down-regulate initiation in both early- and late-firing rDNA origins in human cells. We also show that initiation in mid- or late-firing rDNA origins is not inhibited in cells from patients with ataxia telangiectasia, confirming the suggestion that these individuals lack the SDS pathway.     

Assessment of conformational parameters as predictors of limited proteolytic sites in native protein structures

Despite the importance of limited proteolysis in biological systems it is often difficult to rationalize why a proteinase hydrolyses a particular bond, given a simple sequence specificity alone. Understanding of the structural properties limiting the proteolysis represents a first step on the pathway to control and manipulation of this phenomena. An expanded set of nick-sites in proteins of known tertiary structure, cut by both narrow and broad specificity proteinases, has been generated yielding a robust data set of strictly limited sites. A critical evaluation of an expanded set of conformational parameters revealed a strong correlation with limited proteolytic sites, although they are only modest predictors in isolation. The overall predictive power is significantly improved when the conformational parameters are combined in a weighted predictive scheme that permits their relative importance to be compared via a Metropolis search protocol. A subset of the parameters performs equally well demonstrating the key determinants of susceptibility. The derived predictive algorithm has been made available via the internet. Its utility for predicting other surface-correlated features is also discussed.      

<Emphasis Type="Italic">In-Situ</Emphasis> Neutron Scattering Measurement of Stress-Strain Behavior of a Bulk Metallic Glass

Bulk metallic glasses (BMGs) are an emerging class of materials whose unique properties make them excellent choices for many applications. As with crystalline metals, the processing and forming techniques used to produce BMG components necessarily result in residual stresses. However, traditional diffraction stress analysis is difficult to apply to BMG components, because they lack the long-range order necessary to produce sharp diffraction patterns, and thus, the internal strains for BMG have not been examined until recently. In this work, in-situ neutron scattering was used to measure the local elastic internal strain distribution in a Zr₅₇Nb₅Cu_15.4Ni_12.6Al₁₀ BMG as a function of applied stress. Various techniques were used to evaluate the internal strain. The strain was determined in real space, by measuring changes in the atomic pair distribution function (PDF). These results can be used to help understand the elastic deformation of BMGs as well be to evaluate current models of BMG deformation. This article is based on a presentation given in the symposium entitled “Bulk Metallic Glasses IV,” which occurred February 25–March 1, 2007 during the TMS Annual Meeting in Orlando, Florida under the auspices of the TMS/ASM Mechanical Behavior of Materials Committee.     

Progression into and out of binge drinking among high school students.

The current study examined binge drinking among high school students over an academic year. Adolescent drinkers (N?=?621; 58% female) were grouped into 4 trajectories: drinkers (35%), increasers (14%), decreasers (16%), and persistent binge drinkers (35%). Prospective analyses indicated several factors that predicted escalation and de-escalation of binge drinking. Increasers were more likely to regularly use alcohol and cigarettes at a younger age than drinkers. Compared with decreasers, persistent binge drinkers reported regular alcohol and marijuana use at younger ages. Lower levels of perceived student drinking appeared to be a protective factor for onset of binge drinking. The results highlight the need to study precursors to the naturally occurring fluctuations in binge drinking and suggest factors that may accentuate the risk of binge drinking. (PsycINFO Database Record (c) 2010 APA, all rights reserved)