Predicting Performance Times From Deliberate Practice Hours for Triathletes and Swimmers: What, When, and Where Is Practice Important?

In Studies 1 and 2, the authors evaluated deliberate practice theory through analyses of the relationship between practice and performance for 2 populations of athletes: triathletes and swimmers, respectively. In Study 3, the authors obtained evaluations of practice from athletes' diaries. Across athletes, length of time involved in fitness activities was not related to performance. For the triathletes, a significant percentage of variance in performance was captured by practice. This was not so for sprint events for the swimmers, in which gender was a significant predictor. In the diaries, physical activities were perceived as enjoyable. In contrast to the results obtained from questionnaires, enjoyment did not covary with an activity's relevance to improving performance. Although these findings highlight the importance of sport-specific practice, the authors question a domain-independent account of expertise based on deliberate practice. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Molecular morphology of petaloid bases of PET bottles: A small‐angle X‐ray scattering study

Small‐angle X‐ray scattering (SAXS) studies were undertaken to explore possible morphological explanations for poor mechanical strength in the petaloid bases of poly(ethylene terephthalate) (PET) bottles. The bottles were manufactured using a two‐stage injection stretch blow molding process. Splitting of PET bottle bases under load is both inconvenient and expensive. In this study, SAXS data were collected with a 100 μm square X‐ray beam to establish the molecular morphology as a function of position across the base topology. An amorphous region was identified in the base center (i.e., close to the injection gate of the preform) with biaxially orientated, semicrystalline regions in the feet and valleys of the bottle bases. For bottles that had split under load, the transition between these two regions displayed uniaxial orientation that would lead to reduced mechanical strength in the circumferential direction. Reasons for this effect are explored. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 99: 3328–3335, 2006     

Finite elements for three-dimensional elastic crack analysis

An elastic three-dimensional finite element which allows the mode I–mode II inverse square root crack front singularity is described. A three-dimensional solution for the compact tension fracture specimen resulting from use of the element is given. The variation of the stress intensity factor along the crack front is discussed along with the general features of the stress variation from the front. The computer programming of the formulation is discussed and a FORTRAN listing of it is described.     

Validation of the Child Premorbid Intelligence Estimate method to predict premorbid Wechsler Intelligence Scale for Children-Fourth Edition Full Scale IQ among children with brain injury.

Determination of neuropsychological impairment involves contrasting obtained performances with a comparison standard, which is often an estimate of premorbid IQ. M. R. Schoenberg, R. T. Lange, T. A. Brickell, and D. H. Saklofske (2007) proposed the Child Premorbid Intelligence Estimate (CPIE) to predict premorbid Full Scale IQ (FSIQ) using the Wechsler Intelligence Scale for Children-4th Edition (WISC-IV; Wechsler, 2003). The CPIE includes 12 algorithms to predict FSIQ, 1 using demographic variables and 11 algorithms combining WISC-IV subtest raw scores with demographic variables. The CPIE was applied to a sample of children with acquired traumatic brain injury (TBI sample; n = 40) and a healthy demographically matched sample (n = 40). Paired-samples t tests found estimated premorbid FSIQ differed from obtained FSIQ when applied to the TBI sample (ps ≤ .01). When applied to healthy peers, estimated and obtained FSIQ did not differ (ps > .02). The demographic only algorithm performed well at a group level, but estimates were restricted in range. Algorithms combining single subtest scores with demographics performed adequately. Results support the clinical application of the CPIE algorithms. However, limitations to estimating individual premorbid ability, including statistical and developmental factors, must be considered. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Facile Synthesis of Monodisperse Mesoporous Zirconium Titanium Oxide Microspheres with Varying Compositions and High Surface Areas for Heavy Metal Ion Sequestration

Monodisperse mesoporous zirconium titanium oxide microspheres with varying compositions (Zr content from 0 to 100%), high surface areas (up to 413 m²/g) and well‐interconnected mesopores are synthesized via a combined sol–gel self‐assembly and solvothermal process. Surface areas, pore diameters, crystallinity and mesostructures of the products are controlled by changing the composition of the microspheres. The resulting mesoporous microspheres are tested as adsorbents to remove Cr (VI) anions from solution and the binary oxides show very high adsorption capacities (>25.40 mg/g, that is 0.49 mmol/g) in contrast to previously reported oxides (4.25 mg/g for TiO₂, 4.47 mg/g for α‐Fe₂O₃, 5.8 mg/g for CeO₂). The maximum adsorption capacities of the mesoporous microspheres of varying compositions correlate with the amount of surface hydroxyl groups on the materials. A maximum adsorption capacity of 29.46 mg/g (0.57 mmol/g) is achieved on the microspheres containing 30% Zr due to abundant active hydroxyl groups for heavy metal ion adsorption. Owing to their integrated features (including variable compositions, high specific surface area, tunable pore size and monodisperse grain size) as well as specific acid‐base surface properties, such mesoporous zirconium titanium oxide microspheres are also expected to have potential either as catalysts or catalyst supports for industrial applications.     

Uranyl-sorption properties of amorphous and crystalline TiO₂/ZrO₂ millimeter-sized hierarchically porous beads

Hierarchically porous TiO(2)/ZrO(2) millimeter-sized beads were synthesized using a sol-gel templating technique, and investigated for suitability as radionuclide sorbents using uranyl as a radionuclide-representative probe. The bead properties were varied by altering either composition (22, 36, and 82 wt % Zr in the Ti/Zr composite) or calcination temperature (500 or 700 °C). Uranyl adsorption was higher for the crystalline beads (surface area: 52-59 m(2) g(-1)) than the amorphous beads (surface area: 95-247 m(2) g(-1)), reaching a maximum of 0.170 mmol g(-1) for the 22 wt % Zr sample. This was attributed to the higher surface hydroxyl density (OH nm(-2)), presence of limited microporosity, and larger mesopores in the crystalline beads. Mass transport properties of the crystalline beads were not compromised by the large bead diameter: sorption rates comparable to those reported for powders were achieved and rates were higher than exclusively mesoporous reported systems, thereby highlighting the importance of pore hierarchy in designing materials with improved kinetics. Chemical stability of the sorbent, an important property for processes involving corrosive effluents (e.g., radioactive waste), was also assessed. Crystalline beads displayed superior resistance against matrix leaching in HNO(3). Stability varied with composition: the 22 wt % Zr sample demonstrated the highest stability.     

Ibogaine attenuates morphine-induced conditioned place preference.

Ibogaine, a putative anticraving drug in humans, reduces the ability of a single injection of morphine to produce a place preference in rats (Rattus norvegicus). The attenuation of morphine's effect is seen even if ibogaine is administered 24 hr before the opiate. However, after the 4th morphine conditioning trial, ibogaine no longer modified morphine reward. Ibogaine alone is neither reinforcing nor aversive, and ibogaine does not affect place aversions produced by naloxone or lithium chloride. (PsycINFO Database Record (c) 2010 APA, all rights reserved)