cssi/SciSciGPT-SciSciNet huggingface dataset:
Inference of strata separation and gas emission paths in longwall overburden using continuous wavelet transform of well logs and geostatistical simulation

Abstract Prediction of potential methane emission pathways from various sources into active mine workings or sealed gobs from longwall overburden is important for controlling methane and for improving mining safety. The aim of this paper is to infer strata separation intervals and thus gas emission pathways from standard well log data. The proposed technique was applied to well logs acquired through the Mary Lee/Blue Creek coal seam of the Upper Pottsville Formation in the Black Warrior Basin, Alabama, using well logs from a series of boreholes aligned along a nearly linear profile. For this purpose, continuous wavelet transform (CWT) of digitized gamma well logs was performed by using Mexican hat and Morlet, as the mother wavelets, to identify potential discontinuities in the signal. Pointwise Holder exponents (PHE) of gamma logs were also computed using the generalized quadratic variations (GQV) method to identify the location and strength of singularities of well log signals as a complementary analysis. PHEs and wavelet coefficients were analyzed to find the locations of singularities along the logs. Using the well logs in this study, locations of predicted singularities were used as indicators in single normal equation simulation (SNESIM) to generate equi-probable realizations of potential strata separation intervals. Horizontal and vertical variograms of realizations were then analyzed and compared with those of indicator data and training image (TI) data using the Kruskal–Wallis test. A sum of squared differences was employed to select the most probable realization representing the locations of potential strata separations and methane flow paths. Results indicated that singularities located in well log signals reliably correlated with strata transitions or discontinuities within the strata. Geostatistical simulation of these discontinuities provided information about the location and extents of the continuous channels that may form during mining. If there is a gas source within their zone of influence, paths may develop and allow methane movement towards sealed or active gobs under pressure differentials. Knowledge gained from this research will better prepare mine operations for potential methane inflows, thus improving mine safety.
A Skeletonizing Algorithm With Improved Isotropy

AbstractAn improved algorithm is presented which is capable of transforming thick objects in a discrete binaryimage into thinner representations called skeletons. The skeletal shapes produced are shown to be moreisotropic than those produced using other algorithms. The algorithm uses a non -iterative procedure based on the 4- distance ( "city block ") transform to produce connected reversible skeletons. The types and propertiesof 4- distance neighborhoods, which are used in skeletal pixel selection, are developed. Local- maxima are included in the skeleton, allowing reversibility using a reverse distance transform. Improved isotropy isachieved by defining pixels with certain types of neighborhoods to be interesting. It is shown that theseisotropy- improving pixels may be added to the skeletons produced by any 4- distance -based skeletonizingalgorithm that retains all local- maxima without affecting connectedness. I. IntroductionThick objects in a discrete binary image may be reduced to thinner representations called skeletons, whichare similar to stick figures. Most skeletonizing algorithms iteratively erode the contours in a binary imageuntil a thin skeleton remains. These pixel domain algorithms, which typically examine the neighborhood ofeach of the current contour pixels, may be divided into two groups: those which identify and remove"deletable" contour pixels, and those which identify skeletal pixels on the current contour and label themwith the current iteration number. The labels on skeletons of the latter type allow for partial or completereversibility (Section V). The execution times for these algorithms depend on the maximum thickness of theobjects being skeletonized.The execution times for skeletonizing algorithms that identify skeletal pixels by examining distanceneighborhoods, following a distance transform, may be made independent of object thickness. This isaccomplished by calculating the distance transform using one forward and one reverse raster scan [l].
Fight, flight, or fall: Autonomic nervous system reactivity during skydiving

Abstract Sensation seeking (SS) traits may drive individuals toward high-intensity environments because of a desire for novelty and risk; however, research has not identified the psychophysiological mechanisms underlying SS behavioral expression or disentangled the relative contribution of novelty-seeking for physiological arousal. We used an ambulatory device to measure autonomic nervous system (ANS) activity before, during, and after skydiving in 44 jumpers. To identify the contribution of novelty, we compared novice jumpers to experienced jumpers. Hierarchical linear modeling revealed (1) whether there was physiological activation for each individual and (2) whether there were differences in responsivity between novice and experienced jumpers. All jumpers displayed increases in HR during the jump, indicating that repeated exposure to an unwavering risk did not habituate the response. Group differences in baseline functioning suggest that novelty may initially motivate propensities toward SS behaviors. Interestingly, coactivation of the SNS and PNS emerged during the jump and fall, suggesting that both components of the ANS are necessary to facilitate coping with intense challenges.
Lateral migration of a capsule in a plane Poiseuille flow in a channel

Abstract Three-dimensional numerical simulation is presented on the motion of a deformable capsule undergoing large deformation in a plane Poiseuille flow in a channel at small inertia. The capsule is modeled as a liquid drop surrounded by an elastic membrane which follows neo-Hookean law. The numerical methodology is based on a mixed finite-difference/Fourier transform method for the flow solver and a front-tracking method for the deformable interface. The methodology can address large deformation of a capsule over a wide range of capsule-to-medium viscosity ratio. An extensive validation of the methodology is presented on capsule deformation in linear shear flow and compared with the boundary-element/integral simulations. Motion of a capsule in wall-bounded parabolic flow is simulated over an extended period of time to consider both transient and steady-state motion. Lateral migration of the capsule towards the centerline of the channel is observed. Results are presented over a range of capillary number, viscosity ratio, capsule-to-channel size ratio, and lateral location. After an initial transient phase during which the capsule deforms very quickly, the flow of the capsule is observed to be a quasi-steady process irrespective of capillary number ( Ca ) , capsule-to-channel size ratio ( a / H ) , and viscosity ratio ( λ ) . Migration velocity and capsule deformation are observed to increase with increasing Ca and a / H , but decrease with increasing λ , and increasing distance from the wall. Numerical results on the capsule migration are compared with the analytical results for liquid drops, and capsules with Hookean membrane which are valid in the limit of small deformation. Unlike the prediction for liquid drops, capsules are observed to migrate toward the centerline for 0.2 ⩽ λ ⩽ 5 range considered here. The migration velocity is observed to depend linearly on ( a / H ) 3 , in agreement with the small-deformation theory, but non-linearly on Ca and the distance from the wall, in violation of the theory. Using the present numerical results and the analytical results, we present a correlation that can reasonably predict migration velocity of a capsule for moderate values of a / H and Ca .
Observation of third sound pulses in collision

Abstract We report measurements of collisions of third sound pulses which propagate through each other in a head-on scattering geometry. The amplitude of the waves can be measured throughout the scattering process.
A STUDY OF THE FLAME EMISSION CHARACTERISTICS OF LANTHANUM IN AN AQUEOUS- ALCOHOLIC MEDIUM

Abstract The determination of lanthanum by measuring its flame emission at several wave lengths has been evaluated by means of two recording spectrophotometers equipped with special photomultiplier detecting devices. In addition, a comparison of the effect of an aqueous and alcoholic medium was carried out. In general, the interference from foreign ions is least at the higher wave length of 743 mμ. In most cases, especially with transition elements, the interference is lessened when 1 : 1 water-methanol solution is used. The exceptions to this rule are titanium,thorium and zirconium which cause less interference in an aqueous solution. The method used in conjunction with a standard addition technique, has been applied to the determination of lanthanum in solutions of thorium oxide, uranium, glass, and didymium oxide mixtures.
Studies on cytosol aldosterone binding macromolecules.

Abstract 1. 1. Aldosterone binding macromolecules in the cytosol fraction (104 000 × g supernatant) of rat kidney were demonstrated to exists in vitro in at least two forms. One form, demonstrable in 0.3 M KCL had an apparent molecular weight of 50 000. The other form, present in 0.25 M sucrose, was extremely large with a molecular weight greater than 1.5 · 10 6 . Both forms of aldosterone-macromolecular complexes were demostrated following either in vitro or in vivo exposure to [ 3 H]aldosterone. 2. 2. A comparison of the two forms of binding macromolecules indicated multiple similarities between the two forms. The hierarchy of inhibition of aldosterone binding produced by various steroids was the same for both forms (9 α -fluorocortisol > cortisol = corticosterone > 17 β -estradiol). In addition, K association was found to be virtually identical for both forms of binding macromolecules. 3. 3. The two forms appear to be related in a manner that allowed converstion from on form to the other by the addition or removal of KCl. The presence of 9α-fluorocortisol during either the addition or removal of KCl had no effect on teh quantity of aldosterone bound to macromolecules suggesting that conversion proceeded without dissociation of aldosterone from the binding macromolecules.
Demonstration of placental alkaline phosphatase in human breast cancer

The screening of a series of 11 metastatic breast tumors for the presence of the placental isoenzyme of alkaline phosphatase (EC 3.1.3.1) by RIA revealed one strong producer. The alkaline phosphatase of this tumor was characterized with respect to its immunochemical cross-reactivity, inhibition by L-phenylalanine and levamisole, subunit molecular weight (Mr) and isoelectric point (pl) in two-dimensional electrophoresis, and one-dimensional peptide map. In all parameters of the characterization, the tumor alkaline phosphatase was similar to placental alkaline phosphatase, except for subunit molecular weight which was slightly lower (60,000 versus 64,000 for the placental isoenzyme). No strong placental alkaline phosphatase producers were found among 16 primary tumors examined by RIA. The screening of patients' sera for the placental alkaline phosphatase using RIA indicated elevated levels over post-menopausal controls in 20% of the metastatic patients. Only 3% of the primary patients had elevated serum levels. These results suggest that the placental isoenzyme of alkaline phosphatase may be a useful tumor marker for recurrent breast cancer.
Jamaica's foreign exchange black market

As in many other less developed nations, the imposition of foreign exchange controls promoted the growth of a foreign exchange black market in Jamaica. This article explains the structure and functioning of the market in recent years. Under controls initially imposed in 1954, this market grew to about US$1.7 billion of transaction value per year by 1990. During the 1980s the main participants in the market seeking to buy foreign exchange were Jamaican importers and savers who either were restricted from obtaining foreign exchange in the official market or chose to evade taxes and other rules by using the black market. On the supply side were Jamaican expatriates living abroad, foreign tourists, ganja exporters, and traders using false invoices. Thousands of black market exchangers provided the market‐making service, sometimes adding the service of funds transfer overseas. A black market exchange rate model supported this interview‐based, institutional description of the market. The foreign exchange black ...
Food Selection and Eating Patterns: Themes Found among People with Type 2 Diabetes Mellitus

Objective The objective of this study was to examine the beliefs and perspectives among people with type 2 diabetes mellitus about dietary requirements, food selection and eating patterns, and attitudes about self-management practices. Design Semistructured, in-depth interviews explored participants' experiences with diabetes prior to their diagnosis, participants' understanding of the guidelines for the nutritional management of diabetes, how participants applied their understanding of dietary guidelines to daily food selection and eating patterns, and the social and personal themes influencing participants' food selection and eating patterns. Subjects Interviews were conducted with members of a convenience sample of 45 men and women diagnosed with type 2 diabetes for at least 1 year. ANALYSES PERFORMED: Interviews were coded using a conceptual matrix derived from participants' statements. Common characteristics were grouped, and broad themes were identified. Results Eating patterns were influenced by participants' knowledge of diabetes management. Challenges that participants encountered when applying nutrition recommendations were linked to their prior eating practices. Dietary self-efficacy, social support, and time management were identified as mediating variables that can influence dietary behaviors. Implications Diabetes nutrition education programs should increase awareness of eating history, spousal support, and time management practices. Future research should include the refinement and validation of a nutritional management model of diabetes.
Retinal Flavoprotein Fluorescence Correlates with Mitochondrial Stress, Apoptosis, and Chemokine Expression

Abstract Oxidative stress and mitochondrial dysfunction occur before apoptosis in many retinal diseases. Under these conditions, a larger fraction of flavoproteins become oxidized and, when excited by blue-light, emit green flavoprotein fluorescence (FPF). In this study, we evaluated the utility of FPF as an early indicator of mitochondrial stress, pre-apoptotic cellular instability, and apoptosis of human retinal pigment epithelial (HRPE) cells subjected to hydrogen peroxide (H2O2) or monocytes (unstimulated or interferon-γ-stimulated) in vitro and of freshly-isolated pieces of human and rat neural retina subjected to H2O2 ex vivo. Increased FPF of HRPE cells exposed to H2O2 correlated with reduced mitochondrial membrane potential (ΔΨm) and increased apoptosis in a time- and dose-dependent manner. HRPE cells co-cultured with monocytes had increased FPF that correlated in a time-dependent manner with reduced ΔΨm, increased apoptosis, and early expression of pro-inflammatory chemokines, interleukin-8 (IL8) and monocyte chemotactic factor-1 (MCP1), which are known to be induced by oxidative stress. Increased FPF, reduced ΔΨm, and upregulation of IL8 and MCP1 occurred as early as 1–2 h after exposure to stressors, while apoptosis did not occur in HRPE cells until later time points. The antioxidant, N-acetyl-cysteine (NAC), inhibited increased FPF and apoptosis of HRPE cells subjected to H2O2. Increased FPF of human and rat neural retina also correlated with increased apoptosis. This study suggests that FPF is a useful measure of mitochondrial function in retinal cells and tissues and can detect early mitochondrial dysfunction that may precede apoptosis.
Minimum Gas Flow Rate for Continuous Liquid Removal in Gas Wells

A model was developed for prediction of the minimum gas flow rate in a tubing wellbore to ensure continuous liquid removal in gas wells. The model is able to predict the maximum amount of liquids that can be entrained for any gas flow rate. It is shown that a higher specific gravity gas is a better carrier than a lower specific gravity gas and that entrainment is dependent not just on the superficial gas velocity but on the actual gas velocity. The model was found to be insensitive to liquid concentrations above 175 bbs/MMscf. Comparison of results from this model with field data shows marked improvement in minimum gas from prediction accuracy that should be beneficial to the industry. 21 refs.
SITES OF INTERFERENCE IN A MULTI-UNIT IDENTIFICATION TASK

Identification learning has been extensively st~~died both in the form of tasks utilizing verbal paired associaces (Underwood & Shulz, 1960) and somewhat less frequently in a form in which non-verbal stimuli are associated with motor responses (Crafts, 1935; Fitts & Seeger, 1953; Gagne & Foster, 1949; Noble, 1957b). Although Underwood (1962) suggests chat there may be important differences between these two task varieties, it is commonly supposed thac they also have many characteristics in common, which would lead to rhe expectation of similar effects for certain intervening processes. One of these effects is the phenomenon of inrerference. It has long been known thac the difficulty of learning idencification tasks increases with the number of stimulus-response units in the task, assuming thac these units are in other respects equivalent to each other (Noble, 1957a). Presumably, this increase in difficulty is attributable mainly, if not entirely, to the action of interference, both proactive and retroactive. Beginning with a single stimulus-response unit representing an act of identification, as soon as another is added, interference exerts its effects. The second, new, unit is harder to learn because of associative incerference from the firsc unit, and the original unit is harder to recall because of retroactive interference from the new addition. Similar inrerference effects continue to accum~~late in this manner as more units are added, resulting in a continual increase in learning difficulty ns length of task is increased. It would be of some interest and conceptual value to know more precisely where incerference occurs with greatest prominence when new units are added to an identification task. Do the old, previously learned units suddenly develop interference among themselves? Is the interference mainly among the added new unirs, beca~~se they haven't been "sorted out" yet? Or is there interference between old and new unics? Can one, in fact, identify the sites of interference in an idencification task with some consistency? The present study attempts to find the different amounts of interference
C0 Zigzag Kinematic Displacement Models for the Analysis of Laminated Composites

Three new theories for analysis of laminated composite and sandwich structures are presented and assessed for accuracy and for suitability for finite-element analysis. These theories are based on assumed displacement fields that consist of a smooth polynomial expansion (quadratic, fully cubic, and partly cubic) in the thickness coordinate with a piecewise (layerwise) linear field superposed upon them. Interlaminar transverse shear continuity is enforced to make the number of degrees of freedom in the theories independent of the number of layers (plies) in the structure. In the case of the quadratic and partly cubic theories, a special formulation is developed that yields a theory in which all variables are C0continuous. In addition, a new transverse normal strain field is derived by assuming the transverse normal stress to be constant through the thickness of the laminate. The final form of the model uses only engineering-type degrees of freedom-displacements and rotations. To verify the accuracy of the p...
Single-electron charging in double and triple quantum dots with tunable coupling.

We report low-temperature tunneling measurements at zero magnetic field through double and triple quantum dots with adjustable interdot coupling, fabricated in a GaAs/AlGaAs heterostructure. As the coupling is increased, Coulomb blockade conductance peaks split into two (double dot) or three (triple dot) peaks each. The splitting tracks closely the measured tunnel conductance and experimentally determines the total interaction energy. Coupled double and triple dots with different gate capacitance show quasiperiodic beating.
Visual discrimination between rectangular and nonrectangular parallelopipeds

Twenty-seven university students judged whether each of 128 drawings of parallelopipeds appeared to represent three-dimensional rectangular boxes. Half the pictures could not geometrically have been projections of rectangular boxes. The null hypothesis that Ss’ judgments were unrelated to geometry was rejected at the .001 level of significance, and the correlation between Ss’ judgments and perfect discrimination averaged .86 over three variations of the experiment. The results support a general hypothesis about the perception of simple space forms according to which viewers impose geometric constraints, such as rectangularity and symmetry, but only when the constraints are projectively possible.
3 Taking a History from the Challenging Patient in the Emergency Department

This exhibit will use DVD footage, written material, and live real-time interaction to demonstrate an innovative methodology to teaching residents and medical students to gain comfort and expertise in communicating with and taking a history from challenging patients in the ED. I teach this course at our institution every year. Professional actors with improvisational experience play out unscripted interactions with students based on a character or characters, a set scene, and predefined goals and endpoints. Their dialogue and choices evolve from the student's response and the tone, direction, and approach that the student takes. These scenarios are much more realistic and educational than OSCEs which are often described as artificial and flat. Some of the scenarios that I will present include: Daughter trying to make End-of-life choices for her mother, type A man with chest pain trying to sign out, a woman with “dental pain” who is seductive and drug-seeking, an intoxicated attending MD brought in from a motor vehicle crash (MVC) who uses power in a manipulative way. Many of the scenarios contain potential ethical, sexual, gender, racial issues that the student must address along with the medical problems.
Trichromatic fluorescent vital labeling of bone in the fetal macque.

Mineralizing tissue was labeled in the macaque fetus by administering sequential vital bone labels to the pregnant female. The 3 labels used (DCAF, xylenol orange and minocycline) fluoresce different colors, thereby facilitating identification of discrete lines in the rapidly growing bone and a quantitatige analysis of bone deposition in utero.
Minimum-energy vortex configurations in anisotropic superconductors.

In a type-II superconductor, the optimal vortex configuration is the one that minimizes the free energy for a given value of [bold B], the spatial average of the magnetic field. Using anisotropic London theory, we compare the free energy of two very different configurations: (I) a lattice of vortex lines parallel to [bold B] and (II) a combination of a lattice of lines parallel to [bold [cflx c]] and a lattice of lines parallel to [bold [cflx a]], producing the same [bold B] as in (I). For large enough anisotropy, configuration (II) can have the lower free energy, for a wide range of [bold B].
Oxygen tension measurements of tumors growing in mice.

Abstract Purpose: Clinical studies using the Eppendorf histograph have shown that patients whose tumors have a low pO 2 have worse local control after radiotherapy, and have higher metastatic rates. Because preclinical studies of methods of overcoming, or exploiting, hypoxia generally use transplanted tumors in mice, we have compared the oxygenation of mouse tumors with human tumors to determine the appropriateness of the transplanted mouse model for such preclinical studies. Methods and Materials: We evaluated the oxygenation status of subcutaneous (s.c.) tissue and of 12 intradermally (i.d.)- and 7 s.c.-growing mouse or human transplanted tumors in mice using the Eppendorf histograph, and compared the values obtained with measurements of human head and neck nodes. Results: The normal tissue pO 2 profile of air-breathing mice showed a nearly Gaussian distribution (38.2 ± 14.9 mmHg). Breathing 10% O 2 or carbogen resulted in dramatic changes in normal tissue oxygenation. Tumors growing intradermally in the back of air-breathing mice were extremely hypoxic and resistant to expected changes in oxygenation (carbogen breathing, size, and use of anesthetics). Tumors growing s.c. in the foot showed higher oxygen profiles with marked changes in oxygenation when exposing the animals to different levels of oxygen. However, the oxygenation of the mouse tumors transplanted in either site was only a fraction of that of the majority of human tumors. Conclusion: Experimental mouse tumors are markedly hypoxic, with median values of 10–20% of those of human tumors. Hence, mouse tumors are probably good models for the most hypoxic human tumors that respond poorly to radiotherapy; however, caution has to be exercised in extrapolating data from mouse to man.
Side-Bonded Pd-η2-(C2H2)1,2 and Pd2-η2-(C2H2) Complexes: Infrared Spectra and Density Functional Calculations

Laser-ablated palladium atoms react with acetylene in excess argon to form the strong Pd-η2-(C2H2) and Pd-η2-(C2H2)2 π complexes. The C−C and C−H stretching modes and two C−H deformation modes are observed in the matrix infrared spectrum and identified through isotopic substitution (13C2H2, C2D2, C2HD) and density functional theory (DFT) isotopic frequency calculations. The Pd(C2H2) complex is characterized by a C−C stretching mode near 1710 cm-1 and a 39.8 kcal/mol binding energy predicted by DFT. The antisymmetric C−C stretching mode for Pd-η2-(C2H2)2 is observed at 1765 cm-1. The Pd2-η2-(C2H2) complex produced from the reaction of two Pd atoms with C2H2 is characterized by a C−C mode at 1566 cm-1. The interaction between atomic Pd and C2H2 involves a small amount of charge transfer based on NBO analysis, which is enhanced by a Pd2 dimer coordinated to C2H2. As a result, Pd2 dimer can reduce the C−C triple bond to a double bond. These complexes represent first steps in the Pd−C2H2 interaction culminatin...
Distribution of C-type allatostatin (C-AST)-like immunoreactivity in the central nervous system of the copepod Calanus finmarchicus.

Abstract The C-type allatostatins (C-ASTs) are a family of highly pleiotropic arthropod neuropeptides. In crustaceans, transcriptomic/mass spectral studies have identified C-ASTs in the nervous systems of many species; the cellular distributions of these peptides remain unknown. Here, the distribution of C-AST was mapped in the nervous system of the copepod Calanus finmarchicus , the major contributor to the North Atlantic’s zooplanktonic biomass; C-AST-immunopositive neurons were identified in the protocerebrum, in several peripheral ganglia associated with feeding appendages, and in the ganglia controlling the swimming legs, with immunopositive axons present throughout the ventral nerve cord. In addition, axons innervating the dorsal longitudinal and ventral longitudinal muscles of the body wall of the metasome were labeled by the C-AST antibody. While the distribution of C-AST-like immunoreactivity was similar between sexes, several differences were noted, i.e. , two pair of somata located at the deutocerebral/tritocerebral border in males and immunopositive fibers that surround the genital opening in females. To place the C-AST-like labeling into context with those of several previously mapped peptides, i.e. , A-type allatostatin (A-AST) and tachykinin-related peptide (TRP), we conducted double-labeling studies; the C-AST-like immunopositive neurons appear distinct from those expressing either A-AST or TRP (and through extrapolation, pigment dispersing hormone). Collectively, our data represent the first mapping of C-AST in crustacean neural tissue, show that sex-specific differences in the distribution of C-AST exist in the C. finmarchicus CNS, and suggest that the peptide may be involved in the modulation of both feeding and postural control/locomotion.
Purification and partial characterization of the Pyrococcus horikoshii methylmalonyl-CoA epimerase

Methylmalonyl-CoA epimerase (MCE) from the hyperthermophilic archaeon, Pyrococcus horikoshii, was expressed at high levels in Escherichia coli, purified, and partially characterized. The P. horikoshii MCE enzyme was a homodimer with an apparent molecular mass of 31,700 Da. The Km of the enzyme for methylmalonyl-CoA was 79 μM and the kcat was 240 s−1. The P. horikoshii enzyme was extremely heat-stable and withstood boiling for 60 min without detectable loss in activity.
Monocyte markers and the common acute lymphoblastic leukemia antigen on chronic lymphocytic leukemia cells

The mononuclear cells from 42 patients with chronic lymphocytic leukemia (CLL) were analyzed for surface markers using monoclonal antibodies and flow cytofluorimetry. All 42 CLLs were Ig+ HLA.DR+OKT3−OKT4−OKT6−OKT8− and monoclonal with respect to light chain type. Thirty of the 42 tumours expressed the common acute lymphocytic leukemia antigen, and cells from 18 leukemias stained with the antibodies OKM1 and 63D3, which are specific for different antigens characteristic of myeloid cells. Eight of the leukemias failed to stain with PI153, which has been reported to recognize all B-cell CLLs.
Condomless Sex: Gay Men, Barebacking, and Harm Reduction

Social science research as well as a rise in sexually transmitted diseases and new HIV infections among men who have sex with men point to increasing numbers of gay men engaging in unprotected anal intercourse without condoms, a practice called "barebacking". There is some evidence that barebacking is linked to the rise of crystal methamphetamine use (by men of all races and socioeconomic groups) and surfing the Internet to locate sex partners, although these are not the only factors contributing to this phenomenon. This article summarizes current research findings on sexual risk taking among gay men, discusses psychosocial issues that contribute to barebacking, and suggests a harm-reduction approach to clinical work with gay men who bareback as an effective method of addressing the behavior.
AGE, PEERS, AND DELINQUENCY*

Hirschi and Gottfredson (1983; Gottfredson and Hirschi, 1990) have argued that the age distribution of crime cannot be explained by any known variables. and they point specifically to the failure of sociological theories to explain this phenomenon. This paper examines a quintessentially sociological theory of crime—differential association—and evaluates its ability to explain the age distribution of crime. Analysis of data from the National Youth Survey on persons aged 11–21 reveals that peer relations (exposure to delinquent peers, time spent with peers, loyalty to peers) change dramatically over this age span, following much the same pattern as crime itself When measures of peer influence are controlled, the effects of age on self-reported delinquency are largely rendered insignificant. Additional analyses show that delinquent friends tend to be “sticky” friends (once acquired, they are not quickly lost) and that Sutherland's arguments concerning the duration and priority of delinquent associations are only partially correct.
Stretching of polymer chains by fluctuating flow fields

We investigate polymer stretching by fluctuating flow fields via numerical solutions of the Brownian dynamics of multibead polymer chains taking into account nonlinear elasticity, hydrodynamic interactions and good solvent, excluded volume interaction effects. By varying the scaling exponent of the energy spectrum whilst keeping the same Reynolds and Deborah numbers, as well as microscale length and turnover times, we show that steeper spectra are associated with stronger stretching. We compute the probability density functions of chain length, and explain their main features by examining explicit molecular histories. We quantify the interaction between strain rate tensor structure and chain geometry as a means of understanding better the different stretching mechanisms in mild, moderate and strong polymer stretching regimes.
Right Ventricular Dysfunction Compromises Accuracy of Echocardiographic Diagnosis of Pulmonary Hypertension in Heart Failure

Abstract Background The Swan-Ganz catheter and echocardiography (ECHO) are commonly used to measure pulmonary artery systolic pressure. It is unknown how right ventricular dysfunction influences the accuracy of ECHO-derived estimation of pulmonary hypertension in patients with severe left ventricular systolic dysfunction. Methods and Results We analyzed a limited-access dataset from the ESCAPE (Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness) trial provided by the National Heart, Lung, and Blood Institute. Patients enrolled in this trial had left ventricular ejection fraction Conclusions Accuracy of echocardiographic estimation of pulmonary hypertension in patients with systolic HF is better when right ventricular systolic function is preserved.
Time integration procedures for finite element analysis of blast-resistant reinforced concrete structures

Abstract This paper is concerned with solution procedures for the nonlinear dynamic finite element analysis of above-ground reinforced concrete structures under airblast loading conditions. The equations of motion due to airblast loading and airblast-induced ground excitations are derived using the principle of virtual displacements using a total Langrangian approach. The kinematic equations for the spatial discretization of concrete and steel are used in accordance with isoparametric formulations. A modified form of the explicit central difference time integration scheme is proposed for the semi-discretized dynamic equilibrium equations including damping forces defined in explicit terms, to advance the nodal displacements, velocities and accelerations in time. For numerical stability, limiting time steps postulated by previous workers are considered. To limit the effects of discretization errors in the numerical solution, considerations such as energy balance check and control of spurious oscillations are discussed. The Euler explicit integration scheme is adopted for the time rate dependent constitutive equations of contrete and steel to advance viscoplastic strains in time. A priori stability criteria based on theoretical and experimental considerations are derived for the calculation of time increment. A computational algorithm for the explicit schemes is described as part of a comprehensive computer program, FEABRS, for linear and nonlinear dynamic problems. As illustration, the solution of some dynamic problems, a beam and a circular slab, are presented and a comparison is made with results from other sources.
Acute Rupture of the Pulmonic Valve by a Balloon-tipped Catheter Producing a Musical Diastolic Murmur

Attention is called to the development of severe pulmonic-valve regurgitation during withdrawal of a balloon-tipped catheter that had been in place for six days. The resulting pulmonic regurgitation produced a loud (grade 5/6), musical diastolic murmur recorded by phonocardiogram at the time of its initial production. Autopsy disclosed a noninfected tear in one of the three pulmonic valve cusps.
Collateral damage: Evolution with displacement of fracture distribution and secondary fault strands in fault damage zones

resulting in an apparently more gradual decay with distance, and (3) a change in apparent decay and fault zone thickness becomes evident in faults that have displaced more than ∼150 m. This last observation is consistent with a stochastic model where strand formation is related to the number of fractures within the damage zone, which in turn is a function of displacement. These three observations together suggest that the apparent break in scaling between small and large faults is due to the nucleation of secondary faults and not a change in process.
Implementing a quality control model for technical communication instruction in an engineering curriculum: an update

Already burdened with overloaded curricula and diminishing budgets, many engineering schools are struggling to implement recent accreditation directives to (1) ensure alt their graduates have the ability to communicate effectively; (2) demonstrate these capabilities via student outcomes; and (3) develop processes for continual improvement while few, if any, argue the legitimacy of this urgent need, many engineering schools face difficult implementation challenges. To help schools analyze their current technical communication (TC) status, devise strategies to overcome specific obstacles, and incorporate suggestions for improvement from pivotal stakeholders e.g., engineering professors, recent graduates, engineering employers, TC professionals, professional engineering organizations, we offer an experience-based, quality-control (QC) model as a framework for incorporating TC instruction and practice directly into an engineering curriculum.
Similarities between communication dynamics in the Internet and the autonomic nervous system

The Internet is a world-wide communication network, whose optimization depends on the knowledge of the statistical characterization of the aggregated traffic flow. Internet traffic is dependent on a number of factors, including communication protocols, network topology, and human behavior. Using a recently proposed segmentation algorithm, we find a surprising analogy between the nonstationarity and the correlations in the communication dynamics in the Internet and in another communication network of great interest: the autonomic nervous system (ANS). The ANS controls involuntary muscle motion, secreting glands, and the heart, hence, we surmise that the time interval between successive heartbeats—an easily measured physiological signal—provides a probe of the communication dynamics for the ANS. We find quantitative similarities between the statistical properties of i) healthy heart rate variability and non-congested Internet traffic, and ii) diseased heart rate variability and congested Internet traffic. Our findings suggest that the understanding of the mechanisms underlying the "human-made" Internet could help to understand the "natural" network that controls the heart.
Constitutive Expression of the CIRCADIAN CLOCK ASSOCIATED 1 (CCA1) Gene Disrupts Circadian Rhythms and Suppresses Its Own Expression

The CIRCADIAN CLOCK ASSOCIATED 1 (CCA1) gene encodes a MYB-related transcription factor involved in the phytochrome induction of a light-harvesting chlorophyll a/b-protein (Lhcb) gene. Expression of the CCA1 gene is transiently induced by phytochrome and oscillates with a circadian rhythm. Constitutive expression of CCA1 protein in transgenic plants abolished the circadian rhythm of several genes with dramatically different phases. These plants also had longer hypocotyls and delayed flowering, developmental processes regulated by light and the circadian clock. Furthermore, the expression of both endogenous CCA1 and the related LHY gene was suppressed. Our results suggest that CCA1 is a part of a feedback loop that is closely associated with the circadian clock in Arabidopsis.
Thermo-optic Characteristics and Switching Power Limit of Slow-light Silicon-on-insulator Photonic Crystal Structures

We study the influence of key structural/optical parameters on silicon-on-insulator photonic crystal thermo-optic switching structures. Our semi-analytic theory agrees well with finite-element simulations and experiments. Switching with sub-milliwatt power is shown viable.
Cross-control of magnetization and polarization by electric and magnetic fields with competing multiferroic and weak-ferromagnetic phases.

From our investigation of magnetoelectric properties of a multiferroic phase in ${\mathrm{Eu}}_{0.75}{\mathrm{Y}}_{0.25}{\mathrm{MnO}}_{3}$ competing with a weak-ferromagnetic phase in magnetic fields, we found intriguing hysteretic behaviors of physical properties with variation of temperature and magnetic field. These hysteretic behaviors arise from the kinetic arrest (dearrest) processes of the first-order multiferroic-weak-ferromagnetic transition, resulting in frozen (melted) magnetoelectric glass states with coexisting two phases. Tipping the delicate balance of two competing phases by applying electric and magnetic fields leads to a remarkable control of magnetization and electric polarization.
Help from My "Friends": Social Capital in the Social Network Sites of Low-Income Students

The development of social capital in young people is positively associated with educational attainment, achievement, and psychosocial factors. Prior research has explored factors that contribute to social capital, such as offline social networks. To a lesser extent, studies have analyzed the relationship between online social networks and students’ social capital. However, educational researchers have yet to examine this relationship among students from low-income families. It is especially important to consider low-income students since historically they have not reached the same educational attainment and achievement levels as their higher income peers. In this article, we conduct a regression analysis on survey responses from high school students from low-income families (n = 607) to examine the relationship between intensity of online social network site use, social capital, and other measures of psychological well-being. Results suggest positive associations between use of online social network sites and two forms of social capital. Qualitative data were also utilized to illuminate low income students’ opportunities or barriers for forging and sustaining relationships through online social network sites and implications for future research and education are discussed.
Alternative Approaches to Proficiency Testing in Molecular Genetics

Clinical genetic testing laboratories have come under scrutiny in the US and Europe with increasing public awareness of genomic research. Such increased publicly driven demand for quality can improve laboratories and encourage high standards of excellence. The Department of Health and Human Services Secretary’s Advisory Committee on Genetic Testing (1) was instrumental in placing genetic testing in the public eye and exerted pressure on genetic providers to organize our profession and address public concerns, particularly concerns about laboratory quality. Are safeguards in place to prevent poor-quality genetic testing? Multiple federal and state agencies as well as professional organizations have developed guidelines, recommendations, and checklists with which laboratories must comply. In the US these include the Clinical Laboratory Improvement Amendments (CLIA) of 1988 (2), Genetic Testing Under the Clinical Laboratory Improvement Amendments (3), New York State Department of Health Laboratory Standards (4), the College of American Pathologists (CAP) checklist for molecular pathology laboratories (5), the American College of Medical Genetics (ACMG) Standards and Guidelines for Clinical Genetics Laboratories (6), and a NCCLS guideline (7). A recent review of quality assurance in genetic testing has been addressed in the ACCE [analytical validity, clinical validity, clinical utility, and ELSI (ethical, legal, and social issues of genetic testing)] report on carrier screening for cystic fibrosis, a CDC-sponsored project (8). Internal and external quality assurance and quality-control programs have been established to ensure that laboratories can reliably produce (and reproduce) high-quality results in a timely manner and with clinical utility for patients and healthcare providers. Proficiency testing (PT) identifies weaknesses and provides guidance for improvement. The ACMG/CAP PT program has been providing a molecular genetics laboratory survey with challenges on multiple genetic disorders since 1995, and CAP has provided on-site laboratory inspection and a certification …
Clinical relevance of exercise-induced S-T segment elevation.

Abstract Patients with exercise-induced S-T elevation or S-T depression were evaluated with demographic, treadmill and angiographic data. When 541 patients with S-T depression ware compared with 109 patients with S-T elevation, a greater proportion of the former had chest pain (71 versus 58 percent) and a normal-sized ventricle (86 versus 61 percent) with normal wall motion (54 versus 30 percent). A greater proportion of patients with S-T elevation had had a previous myocardial infarction (61 versus 33 percent). Among patients without prior Infarction (360 with S-T depression and 42 with S-T elevation), these differences disappeared. In this group of 42 patients with S-T elevation, 83 percent had a normal-sized ventricle, 64 percent had normal contractlity and none had a ventricular aneurysm; the severlty of coronary disease and ventricular dysfunction did not differ from the severity in patients with S-T depression. Thus, in patients without prier myocardial infarction, the cause of the development of S-T elevation or S-T depression during exercise does not appear to be related to the the severlty of the coronary lesions, ventricular function or wall abnormalities at rest. In patients with prior myocardial infarction, exercise-induced S-T elevation appears to be a marker of depressed left ventricular function.
1. The Nature of the Firm: Origin

"It is difficult for a man to speak long of himself without vanity." So said David Hume at the beginning of his autobiography. If David Hume felt such a warning to be necessary, a man who, according to Adam Smith, approached "as nearly to the idea of a perfectly wise and virtuous man, as perhaps the nature of human frailty will permit," it is hardly to be expected that my lectures will be free from vanity. However, a natural tendency to be overindulgent in dealing with my own work will be somewhat curbed by a real desire on my part to understand why "The Nature of the Firm" has been treated by the economics profession in the way it has. It is an article which is usually referred to with respect, has been reprinted in a number of books of readings, including Readings in Price Theory, sponsored by the American Economic Association, but which, until comparatively recently, has been largely without influence. It has had what the French call "un succes d'estime." To understand why this has been the case would be more difficult, if not indeed impossible, if I did not deal honestly with the circumstances surrounding its writing, with the ideas that it was intended to convey and with how they were expressed. There is no problem in discovering when I formulated the ideas to be found in "The Nature of the Firm." They must have crystallized in my mind sometime in the summer of 1932. In October 1932 (or thereabouts) I was appointed an assistant lecturer at the Dundee School of Economics and Commerce. Duncan Black, the other assistant lecturer, has recalled that I