cssi/SciSciGPT-SciSciNet huggingface dataset:
Eigenstrains and the elastic field of an adatom

Abstract A harmonic lattice model for an adatom at the (001) surface of a cubic crystal is developed, based on the concept of eigenstrains. In this context, eigenstrains represent the distortion introduced by the adatom, affecting the substrate atoms in its vicinity. The distortions which model the relaxations associated with an adatom are obtained directly using embedded atom method (EAM) potentials. The eigenstrains are translated into a set of forces which, in the case of second-neighbor interactions, are applied to five substrate atoms in the immediate vicinity of the adatom. Four of these atoms are located at the surface and one in the first layer below the surface. The resulting set of forces is self-equilibrated as expected by the nature of the adatom. The elastic field of the adatom is described and the limitations of the continuum theory are discussed. Calculations of the interaction energy between adatoms indicate agreement with existing, long-range results. The strength of the leading singularity of the interaction energy changes, however, when the adatoms are closely spaced. Anisotropy plays a significant role in this process; in certain directions, identical adatoms actually attract each other. Independent simulations using EAM potentials clearly demonstrate the accuracy of the elastic field produced by the eigenstrain model. The restrictive assumptions regarding the adatom\force system found in existing models are removed in this distortion-based model. The eigenstrain approach can also be used to represent surface steps and vacancies.
Diffraction effects upon finite‐frequency travel times: A simple 2‐D example

The widespread availability of broad-band digital seismic data makes it possible to measure travel-time anomalies by cross-correlation with spherical-earth synthetic seismograms. Finite-frequency diffraction effects render such measurements sensitive to wave-speed perturbations off of the infinite-frequency geometrical ray path. We show, by consideration of a simple 2-D example, that the Born approximation provides an excellent description of these off-path sensitivity effects, in the absence of caustics and for travel-time shifts that are small compared to the wave period. Remarkably, an isolated low-velocity anomaly may produce fringing fast travel-time anomalies, as measured by cross-correlation.
Academic preparation in biology and advocacy for teaching evolution: Biology versus non-biology teachers

Despite considerable focus on evolution knowledge–belief relationships, little research has targeted populations with strong content backgrounds, such as undergraduate degrees in biology. This study (1) measured precertified biology and non-biology teachers' (n = 167) knowledge of evolution and the nature of science; (2) quantified teacher preferences for the teaching of creationism in schools; (3) examined the associations among knowledge and belief variables; and (4) contrasted the knowledge and beliefs of prospective biology teachers with those of non-biology teachers. Methodologically, teacher knowledge was quantified by using three measures and studied in relation to certification area, self-reported religiosity, personal conflict concerning science and religion, and completion of an evolution course. We found (1) generally low levels of knowledge of evolution and the nature of science—and high misconception magnitudes—in both biology and non-biology teachers; (2) comparable antievolutionary positions in biology and non-biology teachers: nearly half of the teachers in both groups advocated for the inclusion of creationism in school; (3) weak association between knowledge and preference/belief variables; and (4) no difference in preference for teaching creationism between those teachers who had taken an evolution course and those who had not. Overall, biology and non-biology teachers were found to display “mixed” and “novice naturalistic” evolutionary reasoning patterns. © 2009 Wiley Periodicals, Inc. Sci Ed93:1122–1146, 2009
Tritium-processing operations at the oak ridge national laboratory with emphasis on safe-handling practices☆

The ever-increasing world inventory of tritium mandates improvement of handling procedures to prevent accidental releases and/or personnel exposures. Tritium releases to the environment can arise from several sources: tritium production; nuclear weapons testing; natural production by the interaction of cosmic radiation with nitrogen nuclei; reactor operations and nuclear fuel reprocessing; and disposal of consumer products containing tritium. The natural production of tritium by cosmic rays presently accounts for most of the world's inventory of tritium (70 to 140 MCi (2.59 to 5.18 EBq) in 1985); however, fusion power reactor programs will probably increase tritium inventories by about 100 MCi (3.7 EBq). Uncertain long-term effects to processing personnel or the general population resulting from exposure to tritium in the environment necessitate improvement in tritium production and/or processing procedures to minimize tritium releases. Tremendous progress has been made in the handling of tritium since it was first produced by Luis Alvarez in 1936. At the Oak Ridge National Laboratory (ORNL), considerable improvement in tritium-handling procedures has resulted from developments in the Isotope Program. Specific ORNL programs involving tritium will be described with emphasis on the safe-handling practices as developed and used in these programs. 7 refs., 16 figs., 1 tab.
Suicidal behavior and depression in children and adolescents

The Children's Depression Inventory (CDI) and semistructured interview were used to study suicidal ideation, suicide attempt, depression as a syndrome, and diagnosis in 102 psychiatrically referred children and adolescents. We found that severe suicidal ideation increased around puberty and correlated with increasingly severe depression. Suicide attempts were more variable and did not reflect a continuum of suicidal ideation. While most youngsters who felt suicidal felt depressed, those that did not had nonaffective diagnoses. Similarly, youngsters whose suicide attempt did not lead to psychiatric hospitalization felt less depressed and met criteria for nondepressive diagnoses. Hopelessness, chronicity of psychiatric disorders, and family history of psychopathology are also explored.
Pressure dependence of Tc for the shear-stress-induced tetragonal phase of V3Si

Abstract The effect of hydrostatic pressure on the superconducting transition temperature (T c ) of the shear-stress-induced tetragonal phase of V 3 Si (T c ≈ 10 K, c/a ≈ 1.05) is reported for the first time. The T c of this phase increases linearly with pressure at a rate of (1.0 ± 0.1) × 10 −5 K bar −1 , substantially lower than values of dT c /dp previously reported for the other two phases of V 3 Si.
Morphological analyses of the neurocranium of a group of rock-dwelling cichlid fishes (Cichlidae: Perciformes) from Lake Malawi, Africa

Variation in the size and the shape of neurocrania of a group of rock-dwelling cichlid fishes (mbuna; from Lake Malawi, Africa was analysed using principal components and regression analyses on a set of 24 neurocranial measurements of 86 individuals from 11 species. The results reveal effective morphological discrimination between species. Most of the structural variation between species demonstrates positive allometry and represents size-dependent species differences. Thus, morphological differentiation in these fish may be largely the result of heterochronic changes in relative growth rates. The vomerine region, however, exhibited shape differentiation. Distinct groupings, based on vomer shape, are identified. Foraging behaviour and diet are found to be correlated with this region of the neurocrania. The correlation of the shape of the vomer and fine-scale resource partitioning suggests that this structure may be important in the evolutionary success of the group. Also, most structural shape variation in neurocranial morphology is associated with structural variation in buccal jaws.
Neoplasia as development gone awry: the role of endocrine disruptors.

The hypothesis that prenatal exposure to endocrine disruptors might cause cancer arose from challenging two well-accepted notions: (i) mammalian development is merely the unfolding of a genetic programme and (ii) only mutagenic agents can cause cancer. This hypothesis required challenging genetic determinism. The ecological developmental biology (eco-devo) movement revitalized the concept of developmental plasticity through the occurrence of polyphenisms (a single genotype produces diverse phenotypes which are determined by environmental cues). Based on the principles of eco-devo and the tissue organization field theory of carcinogenesis and neoplasia, we tested the hypothesis that exposure to xenoestrogens during foetal development in rats increased the propensity to develop mammary cancer during adulthood. We chose exposure to bisphenol A (BPA) as a model for environmental oestrogen exposure. This endocrine disruptor induced the development of ductal hyperplasias and carcinoma in situ. These highly proliferative lesions contained an increased number of oestrogen receptor α-positive cells. Thus, foetal BPA exposure was sufficient to induce the development of oestrogen-sensitive pre-neo-plastic and neoplastic lesions in the mammary gland in the absence of any additional treatment aimed at increasing tumour incidence.
Direct Evidence for a Crucial Role of the Arterial Wall in Control of Atherosclerosis Susceptibility

Background— Inbred mouse strains C57BL/6J (B6) and C3H/HeJ (C3H) exhibit marked differences in atherosclerosis susceptibility. We sought to determine whether the difference in atherosclerosis susceptibility resides at the level of arterial walls. Methods and Results— Thoracic aortic segments from 8-week-old female B6 and C3H apolipoprotein E–deficient mice were transplanted into the infrarenal aorta of 10-week-old female F1 mice. After transplantation, recipients were maintained on a chow diet for 16 weeks. The donor aortic segments of B6 mice developed significantly larger atherosclerotic lesions than those of C3H (44 983±11 702 versus 5600±4885 μm2 per section; P=0.011). Expression of vascular cell adhesion molecule (VCAM)-1 by endothelial cells was examined both in vitro and in vivo. B6 mice expressed significantly more VCAM-1 than their C3H counterparts. Sequence analysis of VCAM-1 cDNA revealed a nucleotide difference in the coding region that resulted in substitution of an amino acid in the protein ...
Dynamics of Metastable β-Hairpin Structures in the Folding Nucleus of Amyloid β-Protein

The amyloid β-protein (Aβ), which is present predominately as a 40- or 42-residue peptide, is postulated to play a seminal role in the pathogenesis of Alzheimer's disease (AD). Folding of the Aβ(21-30) decapeptide region is a critical step in the aggregation of Aβ. We report results of constant temperature all-atom molecular dynamics simulations in explicit water of the dynamics of monomeric Aβ(21-30) and its Dutch [Glu22Gln], Arctic [Glu22Gly], and Iowa [Asp23Asn] isoforms that are associated with familial forms of cerebral amyloid angiopathy and AD. The simulations revealed a variety of loop conformers that exhibited a hydrogen bond network involving the Asp23 and Ser26 amino acids. A population of conformers, not part of the loop population, was found to form metastable β-hairpin structures with the highest probability in the Iowa mutant. At least three β-hairpin structures were found that differed in their hydrogen bonding register, average number of backbone hydrogen bonds, and lifetimes. Analysis revealed that the Dutch mutant had the longest β-hairpin lifetime (≥500 ns), closely followed by the Iowa mutant (≈500 ns). Aβ(21-30) and the Arctic mutant had significantly lower lifetimes (≈200 ns). Hydrophobic packing of side chains was responsible for enhanced β-hairpin lifetimes in the Dutch and Iowa mutants, whereas lifetimes in Aβ(21-30) and its Arctic mutant were influenced by the backbone hydrogen bonding. The data suggest that prolonged β-hairpin lifetimes may impact peptide pathogenicity in vivo.
Control system optimization using genetic algorithms

The use of genetic algorithms as a technique for solving aerospace-related control system optimization problems is explored in this paper. Genetic algorithms are parameter search procedures based on the mechanics of natural genetics. They combine a Darwinian survival-of-the-fittest strategy with a random yet structured information exchange among a population of artificial chromosomes. The genetic algorithm technique is used to design a lateral autopilot and a windshear controller. The results show that a variety of aerospace control system optimization problems can be addressed using genetic algorithms with no special problem-dependent modifications. Suggestions for other uses related to aerospace control system optimization are presented.
Cholesterol Concentrations and Depression in Elderly People

(1995). Cholesterol Concentrations and Depression in Elderly People. Annals of Medicine: Vol. 27, No. 2, pp. 141-142.
Buprenorphine suppresses heroin use by heroin addicts

Heroin-dependent men were given buprenorphine (a partial opiate agonist-antagonist) or a placebo under duoble-blind conditions on a clinical research ward where they could acquire heroin (21 to 40.5 milligrams per day, intravenously). Buprenorphine significantly (P less than .001) suppressed the self-administration of heroin over 10 days. Control subjects took between 93 and 100 percent of the available heroin. The effects of buprenorphine were dose-dependent; a dose of 8 milligrams per day reduced heroin use by 69 to 98 percent; a dose of 4 milligrams per day reduced heroin use by 45 percent. Termination of buprenorphie maintenance did not result in opiate withdrawal signs or symptoms. The subjects liked buprenorphine and indicated that it was preferable to methadone or naltrexone. Buprenorphine should be a safe and effective new pharmacotherapy for heroin dependence.
Rapid transmethylation of microgram amounts of phosphatidylcholine on potassium methoxide/celite columns1,2,3

A rapid and convenient method for the determination of acyl groups in phosphatidylcholine (PC) has been developed. Transmethylation reactions were carried out on potassium methoxideimpregnated Celite microcolumns that were readily prepared from Pasteur pipettes. The methods were tested on microgram amounts of synthetic L-α-phosphatidylcholines (di-14∶0; di-18∶2; α-16∶0-β-14∶0) and on egg yolk lecithin, in methylene chloride or hexane solution. Transmethylation of these lipids occurred rapidly at room temperature. Gas liquid chromatographic (GLC) analysis of the product methyl esters demonstrated that the reaction was neither selective for one acyl position of PC over the other, nor sensitive to the amount of unsaturation within the acyl group. The results of the acyl group analysis of natural egg yolk lecithin compared favorably with the results from an established procedure.
Rohypnol ("roofies") control of drug discrimination: effect of coadministered ethanol or flumenazil.

The benzodiazepine flunitrazepam (Rohypnol) was employed to control differentially discriminative performance in 10 Sprague-Dawley rats on a food-motivated FR10 schedule. The training dose was 2.5 mg/kg, and 20 min was employed between intraperitoneal administration and training; both values were employed in this study, which, in reality, is the first time in the drug discrimination literature for the training of this drug. Dose-response experiments indicated decreasing discriminative performance in concert with decreasing time to reach FR10 lever selection as the dose tested decreased from 2.5 to 0.04 mg/kg. The calculated ED50 for discriminative performance, i.e., lever selection of the drug-correct lever, was 0.076 mg/kg. The relatively few sessions needed to reach discrimination criterion, and the fact that the ED50 value was 1/33 of the training dose, suggests that a lower dose of Rohypnol may be used in the future to train rats in this paradigm. Time course experiments indicate decreasing discriminative performance from 20-240 min postadministration with a calculated half-life of 162.3 min. Administration of 450, 600, and 900 mg/kg ethanol (10% w/v) I.P. produced saline-like discriminative responding, whereas the combination of these doses with the 0.08 mg/kg Rohypnol dose produced increasing discriminative performance with the highest ethanol dose producing 72.2% Rohypnol-appropriate lever selections in a mean time to attain lever selection on the FR10 schedule of 12.8 s. These results suggest that a lower training dose of Rohypnol may allow for testing of a smaller ED50 Rohypnol dose with ethanol to produce a more complete generalization. The ability of flumenazil (Ro 15-1788) to dose dependently block the discrimination of Rohypnol suggests that this benzodiazepine produces its action by its agonistic efficacy at these receptors. The coadministration of Rohypnol and ethanol as a popular drug combination in humans is discussed, and evidence is offered as to their synergistic interactions in rat discrimination.
Static Deflection Behavior of a Piezoelectric Forceps

A model is described for predicting quasi-static behavior of a piezoelectric forceps actuator (PFA), which consists of two slightly curved composite beams with bonded piezoelectric layers. The PFA is an innovative medical device that is potentially useful for minimum invasive surgery. The PFA model is compared to the deflection measurements made by a curvature sensor in experiments. This model, with a slight modification, can also be applied to other types of piezoelectric actuators with curved structural components.Copyright © 2003 by ASME
The Coupling of the Short-Circuit Current to Metabolism in the Urinary Bladder of the Toad.

The relationship of the short-circuit current to metabolism was studied in the toad bladder in vitro . Substrates and inhibitors were added to the bathing medium and the effect on the short-circuit current was determined. The spontaneous decline in the short-circuit current that occurred in substrate-free media was prevented or reversed by the addition of glucose, pyruvate, lactate, or s-hydroxybutyrate, whereas acetate and tricarboxylic acid cycle intermediates had no effect. A variety of metabolic inhibitors depressed the short-circuit current; depression by iodoacetate and by malonate was delayed by prior addition of pyruvate or lactate but not by glucose. The ability of a substrate to stimulate the current did not correlate with its rate of oxidation to CO2. On the basis of earlier studies, the metabolic effects on the short-circuit current were assumed to reflect equivalent effects on the rate of active Na transport. It is suggested that the energy for Na transport is provided not by a general cellular metabolic pool but by a specific metabolic pathway or pathways spatially linked to the transport mechanism.
Comparison and evaluation of the synthetic biopolymer poly-l-aspartic acid and the synthetic “plastic” polymer poly-acrylic acid for use in metal ion-exchange systems

Poly-L-aspartic acid (PLAsp), a biopolymer, and a similar synthetic polymer, poly-acrylic acid (PAA), each consisting of approximately 50 repeating Asp and acrylic acid monomers, respectively, were immobilized onto controlled pore glass (CPG) and evaluated for use as metal ion-exchange materials. Both polymers achieve metal complexation primarily through their repeating carboxylate side groups resulting in a similar binding trend for the metals tested (Ca(2+), Cd(2+), Co(2+), Cu(2+), Mg(2+), Mn(2+), Na(+), Ni(2+), Pb(2+)), with metal binding capacities ranging from <0.1 to 12 micromol metal/g column and <0.1 to 32 micromol metal/g column for PLAsp and PAA respectively. Cu(2+) and Pb(2+) exhibited strong binding to both materials, while the other metals demonstrated only weak or minimal binding. Both columns allowed for quantitative release of bound metals through acid stripping and experienced increased overall metal binding with increasing pH. Both systems also maintained similar structural and chemical stability when continuously exposed to neutral buffered, highly acidic, oxidizing, large molecule rich, and elevated temperature environments. The main differences between the two systems are the material cost and system biodegradability.
QUASIPHASE-MATCHED SECOND HARMONIC GENERATION OF BLUE LIGHT IN ELECTRICALLY PERIODICALLY-POLED LITHIUM TANTALATE WAVEGUIDES

Blue light was generated at room temperature by quasiphase-matched second harmonic generation in planar and channel lithium tantalate (LiTaO3) annealed proton exchange waveguides using the d33 nonlinear coefficient. Alternating ferroelectric domains for third order quasiphase matching were created by poling the substrates with a periodic electric field.
Phase Slips and Weak Links: Experiments with Superfluid Atom Circuits

In recent experiments with a ring-shaped Bose Einstein condensate, we have directly measured resistive flow across a weak link. In addition, we have also developed a new technique to directly measure the current-phase relationship of weak links.
Toward unobtrusive measurement of reading comprehension using low-cost EEG

Assessment of reading comprehension can be costly and obtrusive. In this paper, we use inexpensive EEG to detect reading comprehension of readers in a school environment. We use EEG signals to produce above-chance predictors of student performance on end-of-sentence cloze questions. We also attempt (unsuccessfully) to distinguish among student mental states evoked by distracters that violate either syntactic, semantic, or contextual constraints. In total, this work investigates the practicality of classroom use of inexpensive EEG devices as an unobtrusive measure of reading comprehension.
Decreased CREB levels suppress epilepsy

Epilepsy is a common neurologic disorder yet no treatments aimed at preventing epilepsy have been developed. Several molecules including genes containing cAMP response elements (CREs) in their promoters have been identified that contribute to the development of epilepsy, a process called epileptogenesis. When phosphorylated cAMP response element binding protein (CREB) increases transcription from CRE regulated promoters. CREB phosphorylation is increased in rodent epilepsy models, and in the seizure onset region of humans with medically intractable epilepsy (Rakhade et al., 2005; Lee et al., 2007; Lund et al., 2008). Here we show that mice with decreased CREB levels (CREB(α∆) mutants) have a ~50% reduction in spontaneous seizures following pilocarpine induced status epilepticus (SE) and require more stimulation to electrically kindle. Following SE, brain derived neurotrophic factor (BDNF) and inducible cAMP early repressor (ICER) mRNAs are differentially up-regulated in the hippocampus and cortex of the CREB(α∆) mutants compared to wild-type mice, which may be contributing to differences in the severity of epilepsy. In contrast, we found no difference in KCC2 mRNA levels between the CREB(α∆) and wild-type mice after SE. The mechanism by which BDNF and ICER mRNAs increase specifically in the CREB(α∆) compared to wild-type mice following SE is not known. We did, however, find an increase in specific cAMP response element modulator (CREM) mRNA transcripts in the CREB(α∆) mutants that might be responsible for the differential regulation of BDNF and ICER after SE. Altering CREB activity following a neurologic insult provides a therapeutic strategy for modifying epileptogenesis.
Identification of methyl triclosan and halogenated analogues in male common carp (Cyprinus carpio) from Las Vegas Bay and semipermeable membrane devices from Las Vegas Wash, Nevada

Methyl triclosan and four halogenated analogues have been identified in extracts of individual whole-body male carp (Cyprinus carpio) tissue that were collected from Las Vegas Bay, Nevada, and Semipermeable Membrane Devices (SPMD) that were deployed in Las Vegas Wash, Nevada. Methyl triclosan is believed to be the microbially methylated product of the antibacterial agent triclosan (2, 4, 4'-trichloro-4-hydroxydiphenyl ether, Chemical Abstract Service Registry Number 3380-34-5, Irgasan DP300). The presence of methyl triclosan and four halogenated analogues was confirmed in SPMD extracts by comparing low- and high-resolution mass spectral data and Kovats retention indices of methyl triclosan with commercially obtained triclosan that was derivatized to the methyl ether with ethereal diazomethane. The four halogenated analogues of methyl triclosan detected in both whole-body tissue and SPMD extracts were tentatively identified by high resolution mass spectrometry. Methyl triclosan was detected in all 29 male common carp from Las Vegas Bay with a mean concentration of 596 microg kg(-1) wet weight (ww) which is more than an order of magnitude higher than previously reported concentrations in the literature. The halogenated analogs were detected less frequently (21%-76%) and at much lower concentrations (<51 microg kg(-1) ww). None of these compounds were detected in common carp from a Lake Mead reference site in Overton Arm, Nevada.
Simulation of Particle Property Effects in Energy Transport in Brownian Motion

The change in particle concentration and heat transfer in a slot filled with a nano-fluid is computed using a 2-fluid model. The slot has a width L of 5000 micron slot with a 30 K temperature differential. The working fluid is glycerine. The nano-particle materials used are aluminum oxide, copper, silicon oxide, and titanium oxide. The particle diameter is 5 nm, and a volumetric particle concentrations ϕ of 0, 0.005, 0.01, 0.015, and 0.02 are used. Simulation of the transport equations shows that the change in volumetric concentration across the slot is approximately 5% of the total volumetric concentration, and does not change based on the particle material for the four materials selected. The calculated heat transfer in the slot changes by up to 35%, and is dependent on the nano-particle material and concentration. These results show that the significance of nano-particle material in nano-fluid effectiveness is a result of the varying specific heat of the particles.Copyright © 2012 by ASME
Computationally efficient algorithms for convection-permeation-diffusion models for blood-tissue exchange

Analysis of data on tissue depositions obtained by positron tomographic or NMR imaging, or of multiple tracer outflow dilution curves, requires fitting data with models composed of aggregates of capillary-tissue units. These units account for heterogeneities of flows and multisolute exchanges between longitudinally distributed regions across capillary and cell barriers within an organ. Because the analytic solutions to the partial differential equations require convolution integration, solutions are obtained relatively efficiently by a fast numerical method. Our approach centers on the use of a sliding fluid element algorithm for capillary convection, with the time step set equal to the length step divided by the fluid velocity. Radial fluxes by permeation between plasma, interstitial fluid, and cells and axial diffusion exchanges within each time step are calculated analytically. The method enforces mass conservation unless there is regional consumption. Solution for a 2-barrier, 3-region model, accurate to within 0.5%, are 100 to 1000 times faster than the corresponding, purely analytic solution, and over 10,000 times for a 4-region model. Applications include multiple indicator dilution studies of kinetics of transcapillary exchange and positron emission tomographic studies of the mechanisms of substrate transport into cells of organsin vivo.
The relationship between nutritional adequacy and brain myelin accumulation: a comparison of varying degrees of well fed and undernourished rats

Rats undernourished through 17 days of age to produce mild weight lag (less than 20%) had either the same amount, or slightly more myelin than well fed controls. Schedules of undernourishment producing approximately 30, 40 and 50% body weight lags produced corresponding rank-ordered myelin deficits of 25, 55 and 60%, respectively. Brain growth was relatively spared in all cases, never exceeding a deficit of 10%. Absolute myelin deficits did not recover following nutritional rehabilitation, although myelin continued to increase in both normal and all test populations.
A mark on the arm: myths of carrier status in sibs of individuals with ataxia-telangiectasia.

The ATM gene, mutated in ataxia-telangiectasia (A-T), was identified by positional cloning. The discovery of the ATM gene now allows the identification of A-T heterozygotes [Telatar et al., 1998], who may be at increased risk of cancer. The purpose of this study was to (a) identify sib's interest in carrier testing, (b) explore perception of carrier status, and (c) assess levels of understanding of genetics of A-T. This is the sib component of a study of 103 parents and sibs (68 parents and 35 sibs) of individuals with A-T. Thirty-five sibs from 24 families, including 26 adults and 9 adolescents, drawn from the University of California, Los Angeles, the A-T Clinical Center at the Johns Hopkins University School of Medicine, and the A-T Children's Project, were interviewed. Eighty-five percent of adult sibs stated correctly that if a child has A-T, both parents are heterozygotes; 76% knew the A-T gene had been identified. Ninety-two percent would request carrier testing for themselves if available. Seventy-nine percent would want their child tested for carrier status prior to the age of 18. Seventy-three percent believed that being a carrier is associated with increased health risks. Sibs have numerous misconceptions surrounding carrier status and genetics of A-T. Provision of factual information about genetic transmission is necessary, but unfortunately insufficient, to counter deeply held views of self and others. Genetic counseling, which explores the way in which this information is filtered and interpreted, could be an effective tool in dispelling family myths. We conclude that A-T sibs need comprehensive support in relation to carrier testing.
Olefin Epoxidation by the Hydrogen Peroxide Adduct of a Novel Non-heme Mangangese(IV) Complex: Demonstration of Oxygen Transfer by Multiple Mechanisms

Olefin epoxidations are a class of reactions appropriate for the investigation of oxygenation processes in general. Here, we report the catalytic epoxidation of various olefins with a novel, cross-bridged cyclam manganese complex, Mn(Me2EBC)Cl2 (Me2EBC is 4,11-dimethyl-1,4,8,11-tetraazabicyclo[6.6.2]hexadecane), using hydrogen peroxide as the terminal oxidant, in acetone/water (ratio 4:1) as the solvent medium. Catalytic epoxidation studies with this system have disclosed reactions that proceed by a nonradical pathway other than the expected oxygen-rebound mechanism that is characteristic of high-valent, late-transition-metal catalysts. Direct treatment of olefins with freshly synthesized [MnIV(Me2EBC)(OH)2](PF6)2 (pKa = 6.86) in either neutral or basic solution confirms earlier observations that neither the oxo−MnIV nor oxo−MnV species is responsible for olefin epoxidization in this case. Catalytic epoxidation experiments using the 18O labels in an acetone/water (H218O) solvent demonstrate that no 18O fr...
Achieving Reproducible Performance of Electrochemical, Folding Aptamer-Based Sensors on Microelectrodes: Challenges and Prospects

Combining specific recognition capabilities with the excellent spatiotemporal resolution of small electrodes represents a promising methodology in bioanalytical and chemical sensing. In this paper, we report the development of reproducible electrochemical, aptamer-based (E-AB) sensors on a gold microelectrode platform. Specifically, we develop microscale sensors (25 μm diameter) for two representative small molecule targets–adenosine triphosphate and tobramycin. Furthermore, we report on the challenges encountered at this size scale including small-magnitude signals and interference from the irreversible reduction of dissolved oxygen and present methods to circumvent these challenges. Through the electrochemical deposition of dendritic gold nanostructures, we demonstrate microscale sensors with improved performance by increasing signal-to-noise and consequently sensitivity. Finally, we report on the use of the nonspecific adsorption of serum proteins as an additional layer of surface passivation for stabl...
Avoid Overtraining in Young Athletes

(2011). Avoid Overtraining in Young Athletes. Journal of Physical Education, Recreation & Dance: Vol. 82, No. 5, pp. 25-36.
Expression and function of colony-stimulating factors and their receptors in human prostate carcinoma cell lines

BACKGROUND The predeliction for prostate carcinoma cells to metastasize to bone suggests the hypothesis that bone and/or bone marrow-derived factors may promote prostate carcinoma cell growth or survival, or serve as chemoattractants for these cells. METHODS We screened three prostate carcinoma cell lines, DU-145, PC-3, and LNCaP, for the expression of several hematopoiesis-associated colony-stimulating factors (CSFs) and their receptors using RT-PCR (reverse transcriptase-polymerase chain reaction) and immunohistochemical methods, and examined their functional effects. RESULTS All of these cell lines express granulocyte-macrophage colony-stimulating factor (GM-CSF) and macrophage colony-stimulating factor (M-CSF), and the DU-145 and PC-3 lines express stem-cell factor (SCF), as determined by RT-PCR and ELISA. Each of these cell lines expresses the receptors for SCF, GM-CSF, M-CSF, and granulocyte colony-stimulating factor (G-CSF). M-CSF enhanced the soft-agar clonogenicity of PC-3 and DU-145 cells, and GM-CSF stimulated all three cell lines. SCF stimulated the clonogenic growth of DU-145 cells. G-CSF marginally abrogated the induction of cell death in the PC-3 and LNCaP cell lines under serum-free conditions. GM-CSF and M-CSF stimulated modest chemotaxis of PC-3, DU-145, and LNCaP cells (most prominently in PC-3 cells). CONCLUSIONS These data suggest that 1) CSFs may be part of a network of paracrine and autocrine loops that modulate prostate carcinoma cell activity, and 2) the growth-stimulatory, survival-enhancing, and/or chemotactic actions of bone marrow-derived CSFs on prostate carcinoma cells may explain in part why bone is a preferential site of prostatic carcinoma metastases. Prostate 34:80–91, 1998. © 1998 Wiley-Liss, Inc.
Mechanisms of stress relief cracking in a ferritic steel

Abstract The mechanism of stress relief cracking was studied in three heats of commercially produced MnMoNiCr pressure vessel steel (A508-2) using notched specimens austenitized briefly at high temperatures to simulate a weld heat-affected zone (HAZ) and then loaded in pure bending after a fixed stress-relief temperature had been reached. Thus, the effects of applied stress and temperature could be studied separately. Stress relief cracking always began by microcrack formation ahead of the notch. At lower loads at all temperatures (823–923 K), microcracking occurred mainly by cavitation nucleated on re-precipitated sulfides. As the initial load was raised cavity growth became more crack-like and a transition occurred to a brittle cracking mode, which was the mode of macrocrack growth in all specimens heated to a sufficiently high HAZ-simulation temperature. Surface analyses by Auger electron spectroscopy indicated that sulfur was the element primarily responsible for the brittle cracking, which occurred quasi-statically at a rate controlled by temperature and stress intensity. A qualitative model is proposed which treats this sulfur-induced diffusion-controlled brittle fracture in the framework of the theory of plasticity-aided crack-like growth of creep cavities. The effect of the HAZ-stimulation temperature is rationalized in terms of the extent of dissolution of sulfides and of alloy carbides, the latter being important because they control the rate of stress relaxation.
Making knowledge management work: tactical to practical

Over the past 20 years, many researchers and theorists have generated a significant body of literature in the interrelated fields of knowledge management (KM), organizational learning (OL), and knowledge creation (KC). A large body of work generated by proponents of technology as a primary facilitator of KM, OL, and KC supports the expenditure of billions of dollars in information technology infrastructure and knowledge management systems. A separate body of work generated by behaviourists illustrates how organizational culture is a major determinate in the effectiveness of the technology. Ultimately, corporate executives measure success in terms recognizable to financial markets. Yet, an empirical link connecting the interrelated dots needed to provide practical guidance to practitioners and executives remains elusive. This paper summarizes historical and current perspectives within the field and identifies the need for continue empirical research to build a practical construct.
Genetic and environmental influences and covariance among meaning in life, religiousness, and spirituality

Meaning in life, spirituality, and religiousness have been empirically linked in previous research. This study aimed to advance knowledge of the interrelations among these variables by examining their heritable and non-heritable sources of influence, as well as the genetic and environmental contributions to their inter-relations. A sample of 343 middle-aged twins drawn from the Minnesota Twin Registry completed measures of meaning in life and spirituality. There was evidence that religiousness, spirituality, and meaning in life shared common genetic and environmental influences, suggesting that these people's attitudes concerning these variables may arise from shared factors. These results provide novel evidence of a shared genetic substrate for meaning in life, religiousness, and spirituality, and support the possibility that people's basic attitudes about the meaning of existence are commonly rooted in evolved biological factors and conjointly influenced through people's experiences with life.
Lyapunov exponent and transfer-matrix spectrum of the random binary alloy.

The one-dimensional Anderson model with binary distributed onsite disorder is investigated using the transfer-matrix approach. The random matrix product is transformed into an iterated conformal map and the convergence of the mapping is studied for various values of the concentration of onsite impurities and the energy. For dilute impurity concentrations the convergence of the mapping is strongly energy dependent and exhibits interesting behavior in the complex mapping plane. As the impurity concentration increases the mapping converges to the unit circle which results from the underlying conformal structure. Explicit expressions for the Lyapunov exponent and the eigenvalues of the transfer matrix are obtained in terms of the conformal map. From the Lyapunov exponent, the localization length and the integrated density of states are calculated. In the dilute limit there exist states in which the localizaiton length exceeds the system size. These states correspond to extended electronic states and it is shown that the number of extended states scales with system size as ${\mathit{N}}_{\mathrm{extended}}$\ensuremath{\propto}${\mathit{N}}^{\mathrm{\ensuremath{-}}2}$. Increasing the impurity concentration beyond a critical value destroys these states and the localization length over the entire energy range becomes smaller than the system size.
The Transcription Factor DksA Prevents Conflicts between DNA Replication and Transcription Machinery

Actively dividing cells perform robust and accurate DNA replication during fluctuating nutrient availability, yet factors that prevent disruption of replication remain largely unknown. Here we report that DksA, a nutrient-responsive transcription factor, ensures replication completion in Escherichia coli by removing transcription roadblocks. In the absence of DksA, replication is rapidly arrested upon amino acid starvation. This arrest requires active transcription and is alleviated by RNA polymerase mutants that compensate for DksA activity. This replication arrest occurs independently of exogenous DNA damage, yet it induces the DNA-damage response and recruits the main recombination protein RecA. This function of DksA is independent of its transcription initiation activity but requires its less-studied transcription elongation activity. Finally, GreA/B elongation factors also prevent replication arrest during nutrient stress. We conclude that transcription elongation factors alleviate fundamental conflicts between replication and transcription, thereby protecting replication fork progression and DNA integrity.
Prediction of band profiles in displacement chromatography by numerical integration of a semi-ideal model

Abstract A numerical solution for the semi-ideal model of chromatography, incorporating dispersion in the numerical integration scheme, has been developed for the prediction of intermediate and isotachic peak profiles of a multi-component mixture in displacement chromatography. The model was used here to study the effect of various operating parameters on the band shapes, production and yield for a binary mixture. The effect of the displacer concentration and the column length on the yield and the production was investigated. Optimal concentrations can be found that maximize the yield or the production. Very low displacer concentrations lead to peak shapes identical with those in overloaded elution chromatography and extremely large displacer concentrations result in the lack of a separation. The band profiles obtained prior to the formation of the isotachic train are in agreement with profiles taken from the literature.
REVIEW ■ : Multiple Representations of Space in the Brain

Lesions of the posterior parietal cortex have long been known to produce visuospatial deficits in both humans and monkeys. Yet there is no known "map" of space in the parietal cortex. The posterior parietal cortex projects to a number of other areas that are involved in specialized spatial functions. In these areas, space is represented at the level of single neurons and, in many of them, there is a topographically organized map of space. These extraparietal areas include the premotor cortex and the putamen, involved in visuomotor space, the frontal eye fields and the superior colliculus, involved in oculomotor space, the hippocampus, involved in environmental space, and the dorsolateral prefrontal cortex, involved in mnemonic space. In many of these areas, space is represented by means of a coordinate system that is fixed to a particular body part. Thus, the processing of space is not unitary but is divided among several brain areas and several coordinate systems, in addition to those in the posterior pa...
Heyday of the Boffins

This dense, thoughtful, and provocative book advances several important arguments about the relationship between science and technology on the one hand and war and the state on the other. Three seem especially important. First, Britain was militarized in the middle decades of the twentieth century far more than it was socialized. It was less a welfare state than a warfare state. Second, this militarization infected science and technology. These activities were not primarily civilian realms enlisted by the state in wartime. They were rather permanently mobilized instruments of state policy. What David Edgerton calls the military-industrial-scientific complex in Britain was an arm of what others have called the national security state. Finally, the growth of the warfare state was masked by a national myth of welfarism and declinism that represented science and technology as civilian. Edgerton begins his revisionism in the period between the world wars. British armed forces are conventionally portrayed as starved for funds in the 1920s and 1930s, falling behind not just Germany but other great powers as well. Edgerton argues persuasively that Britain actually sustained its armed forces during the interwar period and that it supported military research and development at a high level, especially for the navy and the air force. Britain was not a military-technological superpower in the interwar years, says Edgerton, for there was then no such thing; but it could claim to be the most powerful of the great powers (p. 58). The 'could' in that sentence and the displacement of agency from the author to Britain call attention to the care with which Edgerton articulates his claims and the care with which the reader must appraise them.
Measurement updating using the U-D factorization

In this paper we describe a fresh approach to the discrete linear filtering problem. Our method involves an upper triangular factorization of the filter error covariance matrix, i.e. P = UDUT. Efficient and stable measurement updating recursions are developed for the unit upper triangular factor, U, and the diagonal factor, D. This paper treats only the parameter estimation problem; effects of mapping, inclusion of process noise and other aspects of filtering are treated in separate publications. The algorithm is surprisingly simple and, except for the fact that square roots are not involved, can be likened to square root filtering. Indeed, like the square root filter our algorithm guarantees nonnegativity of the computed covariance matrix. As in the case of the Kalman filter, our algorithm is well suited for use in real time. Attributes of our factorization update include: efficient one point at a time processing that requires little more computation than does the optimal but numerically unstable conventional Kalman measurement update algorithm; stability that compares with the square root filter and the variable dimension flexibility that is enjoyed by the square root information filter. These properties are the subject of this paper.
AN ASYMPTOTICALLY DISTRIBUTION-FREE MULTIPLE COMPARISON METHOD WITH APPLICATION TO THE PROBLEM OF n RANKINGS OF m OBJECTS

The statistic known as Hotelling's T2 is shown to be asymptotically distribution-free and thus to provide a multi-dimensional confidence ellipsoid for the joint population means which enables multiple comparisons of sample means to be made. If m objects are ranked in order by each of n judges, Friedman's test is usually used to test the hypothesis that the judges rank the objects at random. It is of interest, however, to enquire which of the objects are ranked significantly higher than others, in which case Hotelling's T2 may be used to provide asymptotically distribution-free multiple comparisons.
Probiotic use decreases intestinal inflammation and increases bone density in healthy male but not female mice

Osteoporosis can result from intestinal inflammation, as is seen with inflammatory bowel disease. Probiotics, microorganisms that provide a health benefit to the host when ingested in adequate amounts, can have anti-inflammatory properties and are currently being examined to treat inflammatory bowel disease. Here, we examined if treating healthy male mice with Lactobacillus reuteri ATCC PTA 6475 (a candidate probiotic with anti-TNFα activity) could affect intestinal TNFα levels and enhance bone density. Adult male mice were given L. reuteri 6475 orally by gavage for 3×/week for 4 weeks. Examination of jejunal and ileal RNA profiles indicates that L. reuteri suppressed basal TNFα mRNA levels in the jejunum and ileum in male mice, but surprisingly not in female mice. Next, we examined bone responses. Micro-computed tomography demonstrated that L. reuteri 6475 treatment increased male trabecular bone parameters (mineral density, bone volume fraction, trabecular number, and trabecular thickness) in the distal femur metaphyseal region as well as in the lumbar vertebrae. Cortical bone parameters were unaffected. Dynamic and static histomorphometry and serum remodeling parameters indicate that L. reuteri ingestion increases osteoblast serum markers and dynamic measures of bone formation in male mice. In contrast to male mice, L. reuteri had no effect on bone parameters in female mice. Taken together our studies indicate that femoral and vertebral bone formation increases in response to oral probiotic use, leading to increased trabecular bone volume in male mice.