cssi/SciSciGPT-SciSciNet huggingface dataset:
Medial branch blocks and facet joint injections as predictors of successful radiofrequency ablation

Zygapophyseal (z) joints (or facet joints) are a potential source of pain in nearly 15-45% of patients suffering from chronic spinal pain. There are no clinical features or imaging techniques pathognomonic for z-joint pain. Blockade of the medial branch of the spinal nerve primary posterior ramus, using fluoroscopic guidance to ensure positioning of the needle tip and low volumes of local anesthetic, are accepted methods for diagnosing z-joint pain. This is based on the assumption that anesthetizing either the facet joint capsule containing the nerve endings or the main branch innervating it would result in complete or significant pain relief. A positive result presumably means that the z-joint is the anatomical structure where pain originates from. These techniques inherently carry high false-positive rates. The current practice of 2 consecutive positive blocks reduces the false-positive rate. However, the criterion of 2 positive blocks results in an increase of the false-negative rate, which could result in withholding radiofrequency ablation of medial branch. Despite limitations of medial branch blockade, these interventions are crucial in guiding decision on performing treatment modalities such as radiofrequency ablation of the medial branch blocks for chronic spinal pain. Diagnostic facet joint and medial branch blocks are safe, valid, and relatively reliable. There is strong evidence that controlled diagnostic blocks distinguish painful from painless facet joints in the diagnostic workup of chronic spinal pain. Standardization and scientific validation of (controlled) diagnostic medical branch blocks are highly needed to identify its real value in clinical practice.
Fault injection framework for system resilience evaluation: fake faults for finding future failures

As high-performance computing (HPC) systems increase in size and complexity they become more difficult to manage. The enormous component counts associated with these large systems lead to significant challenges in system reliability and availability. This in turn is driving research into the resilience of large scale systems, which seeks to curb the effects of increased failures at large scales by masking the inevitable faults in these systems. The basic premise being that failure must be accepted as a reality of large scale system and coped with accordingly through system resilience.A key component in the development and evaluation of system resilience techniques is having a means to conduct controlled experiments. A common method for performing such experiments is to generate synthetic faults and study the resulting effects. In this paper we discuss the motivation and our initial use of software fault injection to support the evaluation of resilience for HPC systems. We mention background and related work in the area and discuss the design of a tool to aid in fault injection experiments for both user-space (application-level) and system-level failures.
Sleep during the early morning

The intrasleep EEG characteristics of Ss who returned to sleep in the early morning more closely resemble the sleep characteristics which occur late in a full nights sleep rather than the sleep which occurs at the onset of nocturnal sleep. It would appear that sleep does not simply “recycle” with sleep onset.
Computational structures technology: leap frogging into the twenty-first century

Abstract The history, recent developments and trends in computational structures technology (CST) are summarized. Discussion focuses on development of CST software and goals of CST activities. Some recent advances in a number of CST areas are described, including discretization techniques and element technology; computational material modeling; modeling of composite, sandwich and smart structures; computational tools and methodologies for life management; transient response analysis; numerical simulation of frictional contact/impact response; articulated structural dynamics; non-deterministic modeling and analysis methods; qualitative analysis and simulation; neuro-computing; hybrid techniques; error estimation and adaptive improvement strategies; strategies for solution of coupled problems; sensitivity analysis; integrated analysis and design; strategies and numerical algorithms for new computing systems; model generation facilities; and application of object-oriented technology. Research areas in CST that have high potential for meeting the future technological needs are identified.
Idiopathic Alveolar Hypoventilation Related to Head Trauma

The clinical, laboratory, and postmortem findings in a patient with the idiopathic hypoventilation syndrome probably related to head trauma are described.
Risk of catheter-related emboli in patients with atherosclerotic debris in the thoracic aorta

The aim of this study was to evaluate the risk of performing cardiac catheterization or intraaortic balloon pump placement in patients with transesophageal echocardiographically detected atherosclerotic aortic debris. Cardiac catheterization was performed in 70 patients with atherosclerotic aortic debris (in 11 via the brachial approach and in 59 via the femoral approach) and in 71 control patients. An embolic event occurred in 10 (17%) of 59 patients with atherosclerotic aortic debris after femoral catheterization compared to 2 (3%) of 71 control patients without atherosclerotic aortic debris (p = 0.01). None of the 11 patients with atherosclerotic aortic debris who underwent brachial catheterization had an embolic event. An intraaortic balloon pump was placed in 10 patients with atherosclerotic aortic debris and in 12 control patients. An embolic event related to placement of the intraaortic balloon pump occurred in 5 (50%) of 10 patients with atherosclerotic aortic debris; no control patient had an embolic event (p = 0.02). Patients with mobile atherosclerotic aortic debris were at the highest risk for catheter-related embolism. The strongest clinical predictors of atherosclerotic aortic debris were advanced age and peripheral vascular disease. Transesophageal echocardiographic recognition of atherosclerotic aortic debris identifies patients at high risk of stroke or peripheral embolism after cardiac catheterization or intraaortic balloon pump placement. If the aortic debris is mobile, the risk is particularly high. When atherosclerotic aortic debris is detected, especially if the debris is mobile, substituting brachial for femoral catheterization and avoiding placement of an intraaortic balloon pump may reduce the risk of embolism.
Stochastic Modeling of Incident Gust Effects on Aerodynamic Lift

The intrusive formulation of polynomial chaos expansion is implemented to determine uncertainty in aerodynamic loads on a rigid airfoil due to imprecise parameters that characterize an incoming gust. The results yield the sensitivity of the lift coefficient to variations in intensities and integral length scales of the gust fluctuations. The results show that lift coefficient fluctuations about the mean of each time step are affected primarily by the intensity ofthe fluctuations of the vertical velocity component, which should be expected. Next in order of importance is the integral length scale of the vertical velocity component. This implementation of the intrusive polynomial chaos expansion provides guidance for future efforts to quantify uncertain gust loads on micro air vehicles with higher fidelity models.
Evidence that two zinc fingers in the methionine aminopeptidase from Saccharomyces cerevisiae are important for normal growth.

Limited proteolysis of intact yeast methionine aminopeptidase (MAP1) with trypsin releases a 34 kDa fragment whose NH2-terminal sequence begins at Asp70, immediately following Lys69. These results suggest that yeast MAP may have a two-domain structure consisting of an NH2-terminal zinc finger domain and a C-terminal catalytic domain. To test this, a mutant MAP lacking residues 2–69 was generated, overexpressed, purified and analyzed. Metal ion analyses indicate that 1 mol of wild-type yeast MAP contains 2 mol of zinc ions and at least 1 mol of cobalt ion, whereas 1 mol of the truncated MAP lacking the putative zinc fingers contains only a trace amount of zinc ions but still contains one mole of cobalt ion. These results suggest that the two zinc ions observed in the native yeast MAP are located at the Cys/His rich region and the cobalt ion is located in the catalytic domain. The k.at and Km values of the purified truncated MAP are similar to those of the wild-type MAP when measured with peptide substrates in vitro and it appears to be as active as the wild-type MAP in vivo. However, the truncated MAP is significantly less effective in rescuing the slow growth phenotype of map mutant than the wild-type MAP. These findings suggest that the zinc fingers are essential for normal MAP function in vivo, even though the in vitro enzyme assays indicate that they are not involved in catalysis. In addition, a series of single mutations were generated by changing the cysteines and the histidines in the zinc finger region to serines and arginines, respectively. Analyses of these point mutations provide further evidence that the cysteines and histidines are important for the growth promotion function of yeast MAP.
Transmission electron microscopy of omega phase in a Zr-15 % Nb alloy

Abstract Transmission electron microscopy has been used to follow the formation and reversion of the metastable ω phase in a Zr-15 % Nb alloy. In a fully aged specimen the ω phase is shown to consist of noncoherent platelets approximately 1000 A in diameter and approximately 200 A thick lying on {111} planes of the retained β phase. The platelets form a regular three-dimensional network having an average spacing of approximately 1000 A. The retained β-phase regions contain a line structure similar to that observed in specimens aged at lower temperatures when the ω phase is coherent. Aging of the foils in the electron microscope resulted in partial reversion of the noncoherent platelets and formation of the coherent structure. Possible mechanisms for the formation of the two types of ω phase are discussed along with an explanation of the changes in mechanical properties which accompany their formation.
The correlation between automated hematology and manually read smears for the determination of nucleated red blood cells in umbilical cord blood.

Objective. To determine the correlation between automated hematology nucleated red blood cell counts and manual counts in umbilical cord blood.Methods. Umbilical cord venous blood was obtained after cord clamping at the time of delivery. The number of nucleated red blood cells per one hundred white blood cells was measured using an automated hematology analyzer and compared with direct microscopic visualization of prepared slides by experienced hematology technicians.Results. The umbilical cord blood from 128 women was studied. The mean, median and standard deviations of nucleated red blood cell counts were not significantly different between the automated reading and the manual reading (mean 9.3 ± 11.2 versus 9.1 ± 13.1, respectively, P = 0.76; median 5.9 versus 5.0, P = 0.95; range 0–77, 0–105). Automated derived nucleated red blood cell counts and manual numbers were highly correlated with a correlation coefficient of 0.794.Conclusion. The automated hematology analyzer readings of nucleated red blood c...
Emergency Medicine Resident Moonlighting: A Survey of Program Directors

Objectives: 1) To systematically describe emergency medicine (EM) program directors' perceptions of the benefits and risks of resident moonlighting. 2) To assess moonlighting policies of EM residencies, the degree of compliance with these policies, and the methods of dealing with residents who are out of compliance. Methods: A written survey was mailed or hand-delivered to all allopathic and osteopathic EM residency directors in the United States in 1992–93. Incomplete and ambiguous surveys were completed by phone. Results: There was a 96% response rate (113/118). The average EM resident clinical workweek ranged from 38 to 50 hours while the resident was assigned to ED rotations. Most (90%) of the program directors believe moonlighting interferes with residency duties to some degree. Few (10%) programs prohibit moonlighting altogether, although 44% limit moonlighting to an average of 41.5 hours per month. Program directors believe residents moonlight primarily for financial reasons. Most (60%) of the program directors believe moonlighting offers experience not available in the residency, primarily related to autonomous practice. Fifteen programs reported residents who had been sued for malpractice while moonlighting, with one program director named along with the resident. One third of program directors have penalized residents for abuse of moonlighting privileges. Conclusions: EM residency directors are concerned about the effect of moonlighting on resident education. The directors' concerns regarding litigation, excessive work hours, and interference with residency duties are balanced by a general acceptance of the financial need to supplement residency income.
Nonlinear computation of axisymmetric solid rubber deformation

Rubber elasticity is difficult on three counts: it is geometrically nonlinear, it is materially nonlinear, and it is nearly incompressible [1, 2]. Geometric nonlinearity, or the problem of large displacements, makes the algebraic solution of the nonlinear stiffness equation uncertain [3-6], and calls for continuation methods [7] to follow the equilibrium path. Material nonlinearity raises questions on the appropriate energy density function for the sofid [8, 9] and the resulting stress-strain constitutive equations. Near incompressibility demands watchfullness for excessive discretization, and round-off errors [10, 11] that result from a high bulk modulus. The paper is of a technical nature and is devoted essentially to the detailed derivation of the element gradient vector and stiffness matrix for the nonlinear finite element analysis of axisymmetric rubber. The technique, which is based on the discrete sampling of the total potential energy of the deformed solid, is a natural extension of the one employed in the nonlineal analysis of rubber membranes [12]. However, in contrast with the thin membrane case exact incompressibility is avoided here and an extra energy term is added for the change of volume work. Scalars, vectors, and matrices mingle throughout the text and we decided to use some distinctive typography. A vector is described by a single bold face letter, say x, and refers to a column list. A row list is transposed and is written as ( , )'. Matrices are symbolized by a bracketed capital letter, say [G]. The reader is reminded that xty is the scalar product of the two column vectors x and y, while xy t is their tensor product and represents a matrix; all in agreement with the modem conventions of linear algebra. Numerical experiments with a quadratic triangular finite element verifies the axisymmetric loss of stability [13] in short rubber cylinders.
A comparison of contrast detection and discrimination

In order to complement previous studies of contrast detection, we have examined the effects of three stimulus variables (spatial frequency, retinal illuminance, retinal locus) and one visual disorder (amblyopia) on contrast discrimination. Although each factor has a profound effect on the detection of gratings on otherwise unpatterned displays, we find a similar dipper-shaped contrast discrimination function and similar supra-threshold Weber fractions for contrast under all these conditions.
The impact of private benefits on institutional ownership change: evidence from markets with different sentiments

This study investigates the relationship between private benefits and institutional ownership change in markets characterized by different investors’ sentiments. High-sentiment markets tend to overvalue a firm and thereby offer institutional investors a chance to sell shares and profit from overvaluation by forgoing the private benefits otherwise obtainable. Empirical analysis of ownership data from 1990 to 2008 reveals that, in high-sentiment markets, institutional investors sell more shares low in private benefits (dual-class firm share) than shares high in private benefits (non-dual-class firm share). In contrast, firm insiders, who consume significant private benefits in both dual-class and non-dual class firms, sell more dual-class firm shares in both high- and low-sentiment markets. Their ownership disposition is more likely driven by the need for diversification. Subsample analyses show that public pension funds drive the market-sentiment-related change of institutional ownership.
Situational factors affecting the weighting of predictor components in the Fishbein model

Abstract The Fishbein regression model (B ≈ BI ≈ (Aact)w0 + (NBs)w1) is designed to predict behavior (B) from attitudes (Aact) and normative beliefs (NBs). Using a variation of the Ajzen and Fishbein (Journal of Experimental Social Psychology, 1970 ,6, 466–487) method, potential limitations of the model were investigated. It was found that certain situational factors were capable of altering the nature of the model significantly. Aact carried a nonsignificant regression weight when the participant had had no prior direct experience with the act and carried a significant weight when the participant had had experience with the act. NB carried a nonsignificant weight under competitive motivational set conditions and a significant weight under cooperative set conditions. These findings raise the question of the generality of the Fishbein model, since different prediction models were required by different situational conditions. The hypothesized association between attitude and behavior appears to be dependent on prior experience with the behavior, while the association between norms and behavior seems to be dependent on consistency between personal motivation and perceived social expectations.
An in situ IR study coupled with transient kinetic analysis of hydroformylation

The objective of the study is to develop an in situ IR technique coupled with steady-state isotopic transient kinetic analysis for studying heterogeneous hydroformylation
Directional dependence of c-plane slip in single crystals of mercuric iodide

An experimental study of plastic deformation in thin single crystals of mercuric iodide (Hgl2) subjected to (0 0 1) [1 0 0] and (0 0 1) [1 1 0] shear loadings has established a directional dependence to the phenomenon of (0 0 1) orc-plane slip in Hgl2. The average stressess c for the “onset of yielding” were 12.6 psi (86.9 kPa) for (0 0 1) [1 0 0] shear and 16.5 psi (113.8 kPa) for (0 0 1) [1 1 0] shear; the average values of the deformation parameters 0, interpreted as a “bulk yield stress”, were 24.7 psi (170.3 kPa) for (0 0 1) [1 0 0] shear and 37.7 psi (259.9 kPa) for (0 0 1) [1 1 0] shear. These values are in agreement with the theoretical relationss c(θ)=s c(0)/cosθ ands 0(θ)=s 0(0)/cosθ, whereθ is the smallest angle between 〈1 0 0〉 crystallographic axis and the direction of shear stress applied in the (0 0 1) plane.
Cryopreserved bovine mammary cells to model epithelial response to infection

Mammary gland epithelial cells are likely to be important effectors in defending against mastitis, yet little is known about their response mechanisms. Here, we describe a cryopreserved bovine mammary epithelial cell model to study the infection response. Primary cell cultures from four Holstein cows were prepared, and frozen after two passages. The cell cultures from each cow were then thawed and maintained separately, yet simultaneously, and exposed to treatments that included infection with Staphylococcus aureus or exposure to LPS from Escherichia coli. A clear inflammatory response was shown by a significant (P < 0.05), dose dependent, increase of lactoferrin and IL-8 secretion within 24h in response to S. aureus or LPS. Marked increases (P < 0.05) in lactoferrin, TNF-alpha and serum amyloid A (SAA) mRNA expression were also observed. The results indicate the usefulness of our model to study infection responses of mammary epithelial cells, where all cells are simultaneously exposed to the same infection pressure. These responses can be studied over time, and most importantly, biological replication is provided by the four different genotypes being investigated individually. Finally, the results indicate that mammary epithelial cells play an important role in inflammatory response, through the production of pro-inflammatory cytokines, an acute phase protein, and lactoferrin.
Transcatheter occlusion of pulmonary arteriovenous malformations using the Amplatzer Vascular Plug II.

Pulmonary arteriovenous malformations (PAVMs) are a relatively uncommon but potentially life-threatening condition manifested by cyanosis, paradoxical embolization, brain abscess, and rupture. A variety of transcatheter closure devices have been used to occlude PAVMs however risks of device embolization, incomplete closure, or large delivery systems have made each of these methods sub-optimal. The Amplatzer Vascular Plug II (AVP II) is a new multisegmented, woven nitinol cylinder that can be deployed through a small delivery catheter. The AVP II differs from the original AVP in having a finer, more tightly woven nitinol frame and three, rather than one occlusive segment. The authors report the first use of the AVP II for occlusion of bilateral large arteriovenous malformations in a patient with hereditary hemorrhagic telangiectasia. © 2008 Wiley-Liss, Inc.
Influence of foreign-object damage on crack initiation and early crack growth during high-cycle fatigue of Ti–6Al–4V

Abstract The objective of this work is to provide a rationale approach to define the limiting conditions for high-cycle fatigue (HCF) in the presence of foreign-object damage (FOD). This study focused on the role of simulated FOD in affecting the initiation and early growth of small surface fatigue cracks in a Ti–6Al–4V alloy, processed for typical turbine blade applications. Using high-velocity (200–300 m/s) impacts of 3.2 mm diameter steel spheres on the flat surface of fatigue test specimens to simulate FOD, it is found that the resistance to HCF is markedly reduced due to earlier crack initiation. Premature crack initiation and subsequent near-threshold crack growth is primarily affected by the stress concentration associated with the FOD indentation and the presence of small microcracks in the damaged zone (seen only at the higher impact velocities). Furthermore, the effect of residual stresses and microstructural damage from FOD-induced plastic deformation at the indent sites are assessed in terms of fatigue strength degradation. It is shown that FOD-initiated cracks, that are of a size comparable with microstructural dimensions, can propagate at applied stress-intensity ranges on the order of ΔK∼1 MPa √ m , i.e., a factor of roughly two less than the “worst-case” threshold stress-intensity range in Ti–6Al–4V for a crack of a size large compared to microstructural dimensions (a “continuum-sized” crack). Correspondingly, for FOD-initiated failures, where the critical condition for HCF must be defined in the presence of microstructurally small cracks, the Kitagawa–Takahashi diagram, with the limiting conditions of the stress-concentration corrected 107-cycle fatigue limit and the “worst-case” ΔKTH fatigue threshold, is proposed as a basis for design against FOD-induced HCF failures.
Parental behaviour and alcohol misuse among adolescents: A path analysis of mediating influences

This study investigated the possible effects of parents' alcohol consumption and permissiveness on alcohol misuse among a sample of rural Australian high school students. It sought to determine whether these effects were mediated by three central variables from Ajzen's (1985, 1991) theory of planned behaviour (TPB): Attitudes toward alcohol use, subjective norms, and perceived behavioural control. Our results suggest the TPB variables fully mediated the effects of the parent variables on adolescent alcohol misuse, and that the mediational paths were similar for both male and female adolescents.
Environmental purchasing and supplier management (EPSM): Theory and practice

The purpose of this research is to explore current literature and practice specifically in environmental purchasing and supplier management (EPSM) in order to understand current activities and also to suggest avenues for future research. First, an assessment of the current literature in environmental purchasing was completed which showed that most of the research in environmental purchasing is not grounded in theory, and is just beginning to appear in premiere business journals, as defined by the Financial Times journal list. This was followed by an examination of company practices in environmental purchasing by assessing a targeted cross-industry subsection of 68 corporate sustainability reports. This analysis revealed that the organizations studied are still in the relatively early stages of environmental purchasing and supplier management, and practices vary by industry predominantly because of external pressure towards environmental sustainability. The authors conclude that given the relatively early stage of development of environmental purchasing practice and research, there is significant opportunity in this area to develop theory and to influence practitioner behavior.
Divisorial Extensions and the Computation of Integral Closures

We provide a setting for analyzing the efficiency of algorithms that compute the integral closure of affine rings. It gives quadratic (cubic in the non-homogeneous case) multiplicity-based but dimension-independent bounds for the number of passes the basic construction will make. An approach that does not uses Jacobian ideals is examined in detail.
Solution and biologically relevant conformations of enantiomeric 11-cis-locked cyclopropyl retinals.

To gain information on the conformation of the 11-cis-retinylidene chromophore bound to bovine opsin, the enantiomeric pair (2a and 2b) of 11-cis-locked bicyclo[5.1.0]octyl retinal (retCPr) 2 was prepared and its conformation was investigated by NMR, geometry optimization, and CD calculations. This compound is also of interest since it contains a unique moiety in which a chiral cyclopropyl group is flanked by triene and enal chromophores, and hence would clarify the little-known chiroptical contribution of a cyclopropyl ring linked to polyene systems. NMR revealed that the seven-membered ring of retCPr adopts a twist chair conformation. The NMR-derived structure constraints were then used for optimizing the geometry of 2 with molecular mechanics and ab initio methods. This revealed that enantiomer 2a with a 11β,12β-cyclopropyl group exists as two populations of diastereomers depending on the twist around the 6-s bond; however, the sense of twist around the 12-s is positive in both rotamers. The theoretica...
Bending collapse of thin-walled beams with ultralight filler: numerical simulation and weight optimization

A study on the bending collapse of thin-walled beams filled with aluminum foam or aluminum honeycomb was carried out. The strengthening effects of ultralight metal fillers were quantified numerically and experimentally. The moment-rotation characteristics of filled sections were derived, and the results were then incorporated with structural optimization technique to develop a methodology for crashworthiness optimization of filled members. The proposed methodology requires relatively simple computations and is suitable for early stage design of crash members. Finally, the optimization problem of filled sections under combined compression/bending loading was formulated and solved. The optimization results showed potentials of significant weight saving and volume reduction by utilizing ultralight metal filler.
Mechanism of Lithium Diisopropylamide-Mediated Ester Deprotonation: The Role of Disolvated Monomers

Lithium diisopropylamide (LDA) is one of the most important Bronsted bases in organic synthesis.1 While LDA structure determinations2-4 have progressed quickly, rate studies have also established rate laws for several LDA-mediated reactions.5,6 However, the most important reaction of LDAsenolizationshas remained mechanistically opaque to date. We now report rate studies of an LDA-mediated ester enolization that constitutes the first detailed view of the key solvation and deaggregation events. LDA was generated from diisopropylamine using n-BuLi and was multiply recrystallized from hexane.3b Previous structural investigations have shown LDA to be a disolvated dimer (1) over a range of THF and LDA concentrations.3f,5 Pseudo-first-order conditions were established with LDA at normal concentrations (typically 0.10 M) by restricting the ester concentration to 0.004 M. The THF was maintained at high, yet adjustable, concentrations in toluene to determine the reaction order in THF. IR spectra were recorded with a ReactIR 1000 fitted with an immersible SiComp ATR probe.7 The disappearance of ester 2 (1727 cm-1) and the appearance of enolate 3 (1646-1664 cm-1) was readily monitored. An esterLDA complex is not observable under these conditions.8
A conductivity approach to measuring fixed charge density in intervertebral disc tissue

A new method for measuring the fixed charge density (FCD) in intervertebral disc (IVD) tissues employing a two-point electrical conductivity approach was developed. In this technique, the tissue is first confined and equilibrated in a potassium chloride (KCl) solution, and the tissue conductivity is then measured. This is then repeated with a second concentration of KCl solution. The FCD can be determined from the conductivity measurements. Using this method, the FCD values of bovine annulus fibrosus (AF) and nucleus pulposus (NP) tissues were determined to be 0.060 ± 0.027 mEq/g wet tissue and 0.19 ± 0.039 mEq/g wet tissue, respectively. The FCD of AF was significantly lower than that of NP tissue, similar to results in the literature for human IVD tissues. In order to verify the accuracy of the new method, the glycosaminoglycan (GAG) contents of the tissues were measured and used to estimate the tissue FCD. A strong correlation (R 2 = 0.84–0.87) was found to exist between FCD values measured and those estimated from GAG contents, indicating that the conductivity approach is a reliable technique for measuring the FCD of IVD tissues.
Social norms and self-efficacy among heavy using adolescent marijuana smokers.

Adolescence is a time in which individuals are particularly likely to engage in health-risk behaviors, with marijuana being the most prevalent illicit drug used. Perceptions of others’ use (i.e., norms) have previously been found to be related to increased marijuana use. Additionally, low refusal self-efficacy has been associated with increased marijuana consumption. This cross-sectional study examined the effects of normative perceptions and self-efficacy on negative marijuana outcomes for a heavy using adolescent population. A structural equation model was tested and supported such that significant indirect paths were present from descriptive norms to marijuana outcomes through self-efficacy. Implications for prevention and intervention with heavy using adolescent marijuana users are discussed.
Locus of control and perceptions of human aggression.

116 college students were given a locus of control scale and a measure of misconceptions about human aggression. A negative correlation of -.52 indicated that as feelings of mastery and control increased, belief in a human propensity for aggression decreased. Language: en
Teachers' Perspectives on the Challenges of Teaching Physical Education in Urban Schools: The Student Emotional Filter.

The purpose of this study was to analyze how the challenges of urban schools influence physical education teachers' emotional understanding and connections with their students and the implications on their teaching. Sixty-one elementary physical educators from an urban school district in the midwestern U.S. were interviewed multiple times (N = 136) over 3 years using interpretive methodology. Teachers reported five unique challenges that significantly shaped their thinking about students and their careers, along with strategies they used to overcome or manage those challenges. The challenges were: (a) insufficient instructional resources, (b) implementing culturally relevant pedagogy, (c) dealing with community violence, (d) integrating more games in curricula, and (e) teaching in a culture of basketball. Implications centered on the guilt-inducing nature of urban teaching, developing an informed and realistic vision of urban physical education, and the role of teacher preparation and professional develop...
Radiative electron capture by high-energy oxygen ions in hydrogen and helium.

X rays produced in the collisions of 94--222-MeV ${\mathrm{O}}^{8+}$ ions with ${\mathrm{H}}_{2}$ and He targets have been measured. Resulting spectra have been analyzed to determine absolute yields, profile widths, and energies for x rays emitted in the process of radiative electron capture (REC). These measurements are compared with predictions based on impulse-approximation calculations, using differential cross sections for radiative recombination (RR) folded with target Compton profiles. Measured absolute peak energy positions and profiles are found to be in good agreement with these simple theoretical estimates. Cross sections derived from REC yields are compared with other measurements and with theoretical RR values. A small systematic discrepancy between experimental and theoretical cross sections is noted.
Moving into a new neighborhood: NOS goes nuclear.

Regulation of heart function during physiological and/or pathological stresses occurs via numerous cellular signal transduction systems. Since there are a limited number of second messengers, these pathways are spatially and temporally compartmentalized resulting in tightly controlled localized signaling. In ventricular myocytes, prominent signaling cascades occur through G-protein coupled receptors (GPCRs) with the β-adrenergic (β-AR) and endothelin pathways being two important illustrations.
Freedom of expression in commerce

Does commercial speech deserve the same freedom from governmental interference as do noncommercial forms of expression? Examination of this question forces a reappraisal of the grounds upon which freedom of expression rests. I urge an analysis of those grounds which founds freedom of speech upon the requirements of individual autonomy over against society. I then apply the autonomy analysis to commercial expression by examining the empirical features which distinguish commercial forms of expression. Some such features - e.g., “triviality” — have been cited by others as justification for limiting the freedom accorded commercial speech, but I reject the power of those features to limit freedom of expression. Instead, I identify three features of commercial expression which are relevant to the task: resiliency (coupled with potential for abuse), action-orientation, and intimate connection with conventional commercial structures. I discuss the implications of these features for legitimizing governmental restriction of freedom in commercial expression, with the general conclusion that such restriction must be more severely limited than is commonly thought.
Solution-Processed Chalcopyrite Thin-film Solar Cell

An air-stable solution-processed inorganic thin-film solar cell is demonstrated with a power conversion efficiency of 3.50 % under 1-sun condition. This demonstration offers new insight into cost-effect processing for solar energy conversion.
Monoamine oxidase activity of peripheral organs and sympathetic ganglia of the rat after immunosympathectomy

Abstract Treatment of litter-mate rats with the antiserum to the mouse submaxillary gland nerve growth factor of Levi-Montalcini and Cohen resulted in significant decreases in monoamine oxidase activity of the superior cervical, stellate, and thoracic chain ganglia, the spleen, submaxillary glands, kidneys, and liver. The monoamine oxidase activity of the retinas, pineal gland, pituitary gland, lungs, atria, and uterus showed small but statistically insignificant decreases. The monoamine oxidase activity of the ventricles, various portions of the stomach, and proximal and distal small intestine was not affected by treatment with the antiserum. It is postulated that a relation can be shown between sympathetic innervation and monoamine oxidase activity. This can be shown only in those tissues in which the monoamine oxidase associated with sympathetic function constitutes an appreciable portion of the total monoamine oxidase activity. In most of the organs and tissues studied, only a small portion of the monoamine oxidase activity is associated with the nerve endings of the sympathetic postganglionic fibers, whereas the larger portion of the total activity is associated with nonadrenergic sites. Monoamine oxidase activity was measured by the method of Lovenberg and co-workers ( J. Pharmac. exp. Ther. , 1962), with slight modifications found to give reproducible, quantitative results (Klingman and Klingman, Biochem. Pharmac. , 1966).
Electron effective mass in InuGa1−uPvAs1−v for 0 ≤ v ≤ 1

The electron effective mass in InuGa1−uPvAs1−v has been measured on seven samples lattice-matched to InP and evenly spaced in values of v between 0 and 1, using the temperature dependence of the amplitude of the Shubnikov-de Haas oscillations at high magnetic fields. Values of the carrier concentrations, Hall mobilities and Dingle temperatures measured on these samples are also reported.
Subcellular localization of human platelet antiheparin proteins.

Abstract The distribution of two platelet antiheparin proteins, platelet factor 4 (PF4) and low affinity platelet factor 4 (LA-PF4) measured by radioimmunoassays and of antiheparin activity measured by a chromogenic assay, was determined in human platelet granule fractions separated by sucrose density centrifugation. Subcellular fractions were characterized by the levels of serotonin (dense granule marker) and β-N-acetylglucosaminidase (lysosomal enzyme marker). PF4 and LA-PF4 antigens and antiheparin activity showed an identical distribution pattern with the highest specific activities occurring in a fraction lighter than that containing serotonin. The fraction with the highest specific activity of β-N-acetylglucosaminidase was observed at a lighter sucrose density than the fraction most enriched in platelet antiheparin proteins. These results indicate that PF4, LA-PF4 and heparin-neutralizing activity are located in the same granule fraction (α-granules) which is different from both the serotonin and the β-N-acetylglucosaminidase-containing fractions. The PF4 and LA-PF4 amounted to 13% of the total proteins of α-granules as determined by radioimmunoassay and SDS polyacrylamide gel densitometric scanning.
Why do the published data fail to clarify the relationship between gastroesophageal reflux and asthma

Abstract The relationship between gastroesophageal reflux (GER) and asthma has troubled physicians for centuries and has been a source of debate among pulmonologists, allergists, and gastroenterologists for decades. Attempting to tie together the pieces of the puzzle, numerous investigators have struggled to show that in patients with asthma, GER symptoms occur too frequently, gastric acid dwells for too long in the esophageal lumen, and refluxed gastric acid injures the esophageal mucosa more than expected. Unfortunately, all of the work done by these fine investigators has failed to demonstrate a "cause and effect" relationship. Although they have succeeded in convincing us that GER occurs more frequently in asthmatics than in nonasthmatics, they still must continue until we all know how to predict which patients have gastroesophageal-induced or gastroesophageal-exacerbated asthma.
A correlative ultrastructural and enzymatic study of cotyledonary microbodies following germination of fat-storing seeds.

Sunflower, cucumber, and tomato cotyledons, which contain microbodies in both the early lipid-degrading and the later photosynthetic stages of post-germinative growth, were processed for electron microscopy according to conventional procedures and examined 1, 4 and 7 days after germination. Homogenates of sunflower cotyledons were assayed for enzymes characteristic of glyoxysomes and leaf peroxisomes (both of which are defined morphologically as microbodies) at stages corresponding to the fixations for electron microscopy. The particulate nature of these enzymes was demonstrated by differential and equilibrium density centrifugation, making it possible to relate them to the microbodies seen in situ.One day after germination, the microbodies are present as small organelles among large numbers of protein and lipid storage bodies; the cell homogenate contains catalase but no detectable isocitrate lyase (characteristic of glyoxysomes) or glycolic acid oxidase (characteristic of leaf peroxisomes). 4 days after germination, numerous microbodies (glyoxysomes) are in extensive and frequent contact with lipid bodies. The microbodies often have cytoplasmic invaginations. At this stage the cells are rapidly converting lipids to carbohydrates, and the homogenate has high isocitrate lyase activity. 7 days after germination, microbodies (peroxisomes) are appressed to chloroplasts and frequently squeezed between them in the green photosynthetic cells. The homogenate at this stage has substantial glycolic acid oxidase activity but a reduced level of isocitrate lyase. It is yet to be determined whether the peroxisomes present at day 7 are derived from preexisting glyoxysomes or arise as a separate population of organelles.
Palliative Care Beyond Cancer: Reliable comfort and meaningfulness.

Scott Murray and Aziz Sheikh (doi: 10.1136/bmj.39535.491238.94) say that the lessons learnt from palliative care for cancer need to be applied to other fatal conditions. Healthcare delivery that is tailored to the varying needs of patients with these diseases will be crucial in making a difference, says Joanne Lynn
Dioxygen binding to diferrous centers. Models for diiron-oxo proteins

Dioxygen adducts of [Fe 2 L(O 2 CC 6 H 5 )]X 2 , where L represents the dinucleating ligands HPTB (anion of N,N-N',N'-tetrakis(2-benzimidazolylmethyl)-2-hydroxy-1,3-diaminopropane), its N-ethyl analogue, and its tetrakis(pyridine) analogue, HPTP, cand form and serve as models for the putative oxygenated intermediates of methane monooxygenase and ribonucleotide reductase. [FE 2 (N-Et-HPTB)(O 2 CC 6 H 5 )](BF 4 ) 2 crystallizes in the triclinic space group P1.
Occipital artery anastomosis to vertebral artery causing pulsatile tinnitus

Pulsatile tinnitus can result from various vascular etiologies that cause transmission of pulsatile turbulent flow into the inner ear. Less commonly, non-vascular sources cause increased blood flow and transmission of sound perceived as tinnitus. Thorough clinical examination leads to appropriate imaging evaluation and therapeutic planning. Most pulsatile tinnitus results from expected mechanisms, such as dural arteriovenous fistula, jugular bulb dehiscence, or paraganglioma; however, the literature contains reports of numerous rare causes, particularly variant anatomic morphologies. We present the case of a novel cause of pulsatile tinnitus in which collateral vascular flow compensated for decreased normal intracranial cerebral arterial supply and might have caused catastrophic consequences if intervened upon after assumptions based on an incomplete evaluation.
Acetylcholine and learning in a cortical associative memory

Implementing associative memory function in biologically realistic networks raises difficulties not dealt with in previous associative memory models. In particular, during learning of overlapping input patterns, recall of previously stored patterns can interfere with the learning of new patterns. Most associative memory models avoid this difficulty by ignoring the effect of previously modified connections during learning, thereby clamping activity to the patterns to be learned. Here I propose that the effects of acetylcholine in cortical structures may provide a neuropsychological mechanism for this clamping. Recent brain slice experiments have shown that acetylcholine selectively suppresses excitatory intrinsic fiber synaptic transmission within the olfactory cortex, while leaving excitatory afferent input unaffected. In a computational model of olfactory cortex, this selective suppression, applied during learning, prevents interference from previously stored patterns during the learning of new patterns. Analysis of the model shows that the amount of suppression necessary to prevent interference depends on cortical parameters such as inhibition and the threshold of synaptic modification, as well as input parameters such as the amount of overlap between the patterns being stored.
Closing of the Indonesian seaway as a precursor to east African aridification around 3-4 million years ago.

Global climate change around 3‐4 Myr ago is thought to have influenced the evolution of hominids, via the aridification of Africa, and may have been the precursor to Pleistocene glaciation about 2.75 Myr ago. Most explanations of these climatic events involve changes in circulation of the North Atlantic Ocean due to the closing of the Isthmus of Panama. Here we suggest, instead, that closure of the Indonesian seaway 3‐4 Myr ago could be responsible for these climate changes, in particular the aridification of Africa. We use simple theory and results from an ocean circulation model to show that the northward displacement of New Guinea, about 5 Myr ago, may have switched the source of flow through Indonesia—from warm South Pacific to relatively cold North Pacific waters. This would have decreased sea surface temperatures in the Indian Ocean, leading to reduced rainfall over eastern Africa. We further suggest that the changes in the equatorial Pacific may have reduced atmospheric heat transport from the tropics to higher latitudes, stimulating global cooling and the eventual growth of ice sheets. Eastern Africa used to be more humid than it is now, and Canada used to be devoid of ice sheets; New Guinea lay south of its present position, and the island of Halmahera (part of Indonesia; see Fig. 1) lay mostly below sea level. The collision of Australia with the Banda arc occurred about 3 Myr ago, when Timor began to emerge within what had been the eastward continuation of the Java trench 1,2
Wavelet despiking of fractographs

Fractographs are elevation maps of the fracture zone of some broken material. The technique employed to create these maps often introduces noise composed of positive or negative 'spikes' that must be removed before further analysis. Since the roughness of these maps contains useful information, it must be preserved. Consequently, conventional denoising techniques cannot be employed. We use continuous and discrete wavelet transforms of these images, and the properties of wavelet coefficients related to pointwise Hoelder regularity, to detect and remove the spikes.