cssi/SciSciGPT-SciSciNet huggingface dataset:
Learning about Regiochemistry from a Hydrogen-Atom Abstraction Reaction in Water

An experiment has been developed in which the hydrogen-atom abstraction and the coupling of propionitrile, using Fenton’s reagent, are investigated. Students learn about the regiochemistry of radical formation, the stereochemistry of product formation, and the interpretation of GC–MS data, in a safe reaction that can be easily completed in one laboratory session.
Accurate analytical solution of photon transport equation in infinite uniform turbid medium

We present an analytical solution of the distribution function and the density distribution for the Boltzmann photon transport equation in an infinite uniform isotropic medium. This solution is quantitatively accurate up to the second order cumulant approximation. The solution shows a clear picture of the time evolution of particle migration, from near ballistic, through snake-like, and then into the diffusive regime.
Soy isoflavones radiosensitize lung cancer while mitigating normal tissue injury

Background We have demonstrated that soy isoflavones radiosensitize cancer cells. Prostate cancer patients receiving radiotherapy (RT) and soy tablets had reduced radiation toxicity to surrounding organs. We have now investigated the combination of soy with RT in lung cancer (NSCLC), for which RT is limited by radiation-induced pneumonitis.
A free boundary problem for a quasi-linear degenerate elliptic equation: Regular reflection of weak shocks

We prove the existence of a solution to the weak regular reflection problem for the unsteady transonic small disturbance (UTSD) model for shock reflection by a wedge. In weak regular reflection, the state immediately behind the reflected shock is supersonic and constant. The flow becomes subsonic further downstream; the equation in self-similar coordinates is degenerate at the sonic line. The reflected shock becomes transonic and begins to curve there; its position is the solution to a free boundary problem for the degenerate equation. Using the Rankine-Hugoniot conditions along the reflected shock, we derive an evolution equation for the transonic shock, and an oblique derivative boundary condition at the unknown shock position. By regularizing the degenerate problem, we construct uniform bounds; we apply local compactness arguments to extract a limit that solves the problem. The solution is smooth in the interior and continuous up to the degenerate boundary. This work completes a stage in our program to construct self-similar solutions of two-dimensional Riemann problems. In a series of papers, we developed techniques for solving the degenerate elliptic equations that arise in self-similar reductions of hyperbolic conservation laws. In other papers, especially in joint work with Gary Lieberman, we developed techniques for solving free boundary problems of the type that arise from Rankine-Hugoniot relations. For the first time, in this paper, we combine these approaches and show that they are compatible. Although our construction is limited to a finite part of the unbounded subsonic region, it suggests that this approach has the potential to solve a variety of problems in weak shock reflection, including Mach and von Neumann reflection in the UTSD equation, and the analogous problems for the unsteady full potential equation. © 2002 John Wiley & Sons, Inc.
The Search for Nonconventional Mitochondrial Determinants of Aging

Mitochondria are conventionally believed to modulate aging by affecting free-radical production and the energy supply. In this issue of Molecular Cell, Caballero et al. (2011) reveal that altering protein complexes involved in mitochondrial translation control extends life span independent of redox homeostasis and oxidative phosphorylation.
Transmural sigmoid colon endometrioma in a young reproductive age woman

INTRODUCTION Endometriosis is a common disease affecting women of reproductive age. Endometrial tissue can implant to various tissues including gastrointestinal tissues and cause significant GI symptoms. Rarely, these implants cause constricting lesions that require surgical intervention.
Nutritional evaluation of tepary bean: Elemental analysis of seed

Abstract Tepary bean (Phaseolus acutifolius var. latifolius), a potential arid‐land legume crop, was analyzed for total protein, oil, fiber and mineral content. Results indicate the bean would be adequate in these nutrients for a human diet if deficient amino acids in the seed‐protein were complimented.
Submicrogram assay of serum and adrenal cholesterol by a simple, direct, nonextraction procedure☆

Abstract A new quantitative submicroassay, based on the ferric acetate reagent system, is described and successfully applied to the analysis of cholesterol in 1-mm diameter, 16-μm thick, single microtome sections of adrenal gland, without requiring prior solvent extraction. The method employs 1 100th of the sample size required in the original method, and is also more sensitive than the quantitative histochemical methods that are currently available. The method permits accurate determination of 0.05–3.0 μg amounts of cholesterol in submicroliter volumes of biological fluids or microgram amounts of frozen-dried tissue.
Polynomial dispersion of trajectories in sticky dynamics

Hamiltonian chaotic dynamics is, in general, not ergodic and the boundaries of the ergodic or quasiergodic area (stochastic sea, stochastic layers, stochastic webs, etc.) are sticky, i.e., trajectories can spend an arbitrarily long time in the vicinity of the boundaries with a nonexponentially small probability. Segments of trajectories imposed by the stickiness are called flights. The flights have polynomial dispersion that can lead to non-Gaussian statistics of displacements and to anomalous transport in phase space. In particular, the presence of flights influences the distribution of Poincar\'e recurrences. We use the distribution function of $(l,t;\ensuremath{\epsilon},{\ensuremath{\epsilon}}_{0})$-separation of trajectories that at time instant $t$ and trajectory length $l$ are separated for the first time by $\ensuremath{\epsilon}⪡1$, being initially at a distance ${\ensuremath{\epsilon}}_{0}⪡\ensuremath{\epsilon}$. The connection of this function, called the complexity function [Afraimovich and Zaslavsky, Chaos 13, 519 (2003)], with the distribution of Poincar\'e recurrences is established for three cases: (i) for the case of superdiffusion in standard and web maps for which the stickiness is defined by the boundaries of hierarchical sets of islands; (ii) for the case of the Sinai billiard with infinite horizon, where the stickiness is defined by zero-measure slits in the phase space; (iii) for the square billiard with a slit (bar-in-square billiard) where the Lyapunov exponent is zero and the stickiness is defined by the vicinity of the trajectory to the closest periodic trajectories obtained from the Diophantine approximation. Finally, the powerwise asymptotics of the Poincar\'e recurrences can be connected, in some cases, to the anomalous transport exponent.
Bending-incompetent variants of Flp recombinase mediate strand transfer in half-site recombinations: role of DNA bending in recombination.

Abstract One key feature of the interaction of Flp recombinase with its target site ( FRT ) is the large bend introduced in the substrate as a result of protein binding. The extent of bending was found to depend on the phasing and spacing of the Flp monomers occupying the two Flp-binding elements ( FBE ) bordering the strand-exchange region (spacer) of the substrate. The relative mobilities of the Flp complexes formed by the two permuted substrate fragments, containing the FRT site near the end or in the middle, corresponded to a DNA bend of approx. 140° when each of the two FBE s flanking the spacer was occupied by a protein monomer. The estimated bend angle was the same when the reference DNA fragment with the FRT site at the end was substituted by one with the site in the middle, but containing a 4-bp insertion within the spacer. We used a combination of wild-type Flp and Flp variants that were competent or incompetent in DNA bending, together with full, or half FRT sites, to ask whether bending is a conformational requirement for catalysis, namely cleavage and exchange of strands. We obtained the following results: in full-site ( FRT ) vs. full-site recombinations or in full-site vs. half-site (half FRT ) recombinations, there was a large difference in the reactivity between Flp and a bending-incompetent Flp variant. This difference virtually disappeared when reactions were done with half- FRT sites. We conclude that bending is not a prerequisite for catalysis, but represents the manner in which the substrate accommodates the Flp protomer-protomer interactions that are pertinent to catalysis.
Gene influences timing the development of size and nervous system functional differences.

Changes with age in body weight, tail length, and caudal nerve conduction velocity are described using 916 mice sampled from the DBA/1J and C3H/HeJ strains and their reciprocal hybrid cross groups. Independent samples from each group at 22 ages allow comparisons of genotype-group differences across ages. Differences between hybrid and inbred groups increase substantially with age for both body weight and tail length but only slightly for caudal conduction velocity. Strain differences for caudal conduction velocity increase with age but strain differences in body weight and tail length do not. These results demonstrate that different gene effects influence development of size and nervous system function in this population and they suggest that these two systems may be displaced by selection. Major differences for size and for conduction velocity appear at about 100 and 70 days, respectively, demonstrating that gene differences acting on development may time the appearance of differences in morphological and physiological bases of behavior.
Studies on the mechanism of butyrate-induced morphological changes in KB cells.

Abstract KB cells treated with propionate, butyrate and valerate change drastically in their morphology, displaying long processes and few surface microvilli in scanning electron micrographs. Butyrate was the most effective compound and its effects were blocked by actinomycin D, cycloheximide and colchicine, but not by flurbiprofen or thymidine. Butyrate treatment resulted in a 14-fold increase in the specific activity of CMP-sialic acid: lactosylceramide sialosyltransferase when added to cells grown in medium at pH 7.0; lower induction (10-fold) of this enzyme occurred when the medium was above or below pH 7 (6.5–7.5). The subcellular fraction with the highest specific activity sedimented at 100 000 g. The product (II 3 -α- N -acetylneuraminosyl-lactosylceramide, GM 3 ) of this glycosyltransferase, when added in pure form or in a liposomal complex, was unable to cause morphological changes in KB cells. Surface labelling (galactose oxidase-[ 3 H]sodium borohydride) of KB cells grown with or without butyrate displayed a pronounced incorporation of tritium into globotriglycosylceramide (GL3) with twice control levels in the butyrate-treated cells. The total incorporation of tritium into glycoproteins was unchanged by butyrate treatment. KB cells show a pronounced increase in DNA synthesis 10–11 h after release from butyrate treatment. A broad but symmetrical curve of DNA synthesis versus time indicates that butyrate treatment blocks the KB cells since a synchronous population results when the cells are released from butyrate.
Compassion Fatigue, Burnout, and Compassion Satisfaction Among Colorado Child Protection Workers

Objective The goal of this study was to understand better the risk of compassion fatigue (the trauma suffered by the helping professional) and burnout (emotional exhaustion, depersonalization, and reduced sense of personal accomplishment), and the potential for compassion satisfaction (the fulfillment from helping others and positive collegial relationships) among Colorado county child protection staff using the Compassion Satisfaction/Fatigue Self-Test [Figley, C. R., & Stamm, B. H. (1996). Psychometric review of Compassion Fatigue Self-Test. In B. H. Stamm (Ed.), Measurement of stress, trauma, and adaptation (pp. 127-130). Lutherville, MD: Sidran Press]. An additional goal was to test the relationship of these three constructs to each other. Method A self-report instrument developed by Stamm and Figley was used to measure the risk of compassion fatigue and burnout and the potential for compassion satisfaction among 363 child protection staff participating in a secondary trauma training seminar. Results Participants were significantly more likely to have high risk of compassion fatigue, extremely low risk of burnout, and good potential for compassion satisfaction. Participants with high compassion satisfaction had lower levels of compassion fatigue (p=.000; mean=35.73 high compassion satisfaction group, mean=43.56 low group) and lower levels of burnout (p=.000; mean=32.99 high compassion satisfaction group, mean=41.69 low group). Conclusion Approximately 50% of Colorado county child protection staff suffered from "high" or "very high" levels of compassion fatigue. The risk of burnout was considerably lower. More than 70% of staff expressed a "high" or "good" potential for compassion satisfaction. We believe compassion satisfaction may help mitigate the effects of burnout.
EXACT MEAN INTEGRATED SQUARED ERROR OF HIGHER ORDER KERNEL ESTIMATORS

The exact mean integrated squared error (MISE) of the nonparametric kernel density estimator is derived for the asymptotically optimal smooth polynomial kernels of Muller (1984, Annals of Statistics 12, 766–774) and the trapezoid kernel of Politis and Romano (1999, Journal of Multivariate Analysis 68, 1–25) and is used to contrast their finite-sample efficiency with the higher order Gaussian kernels of Wand and Schucany (1990 Canadian Journal of Statistics 18, 197–204). We find that these three kernels have similar finite-sample efficiency. Of greater importance is the choice of kernel order, as we find that kernel order can have a major impact on finite-sample MISE, even in small samples, but the optimal kernel order depends on the unknown density function. We propose selecting the kernel order by the criterion of minimax regret, where the regret (the loss relative to the infeasible optimum) is maximized over the class of two-component mixture-normal density functions. This minimax regret rule produces a kernel that is a function of sample size only and uniformly bounds the regret below 12% over this density class.The paper also provides new analytic results for the smooth polynomial kernels, including their characteristic function.This research was supported in part by the National Science Foundation. I thank Oliver Linton and a referee for helpful comments and suggestions that improved the paper.
Magnetic ordering in TlCo2-xNixSe2 with the ThCr2Si2 structure

Abstract Nine solid solutions of TlCo2-xNixSe2 with 0 ⩽ x ⩽ 2 were prepared and characterized. From X-ray diffraction patterns it was determined that these solutions adopt the ThCr2Si2 type tetragonal structure. All of the samples are highly metallic with ϱ on the order of 10−4 Ω-cm. TlCo2Se2 exhibits Curie-Weiss behaviour from ∼ 100–300 K and orders antiferromagnetically at TN = 97 K. TlNi2Se2 is Pauli paramagnetic. TlCo2-xNixSe2, with 0.25 ⩽ x ⩽ 1.5, exhibits antiferromagnetic ordering. The Neel temperature, TN vs x, exhibits a maximum at x = 0.5, which suggests that Ni substitution at x ⩽ 0.5 enhances antiferromagnetic interactions in these compounds. Higher Ni content quenches magnetic order; TlCo0,25Ni1.75Se2 and TlNi2Se2 do not show evidence of long range magnetic ordering. Magnetization studies on oriented single crystals of TlCo2Se2 indicate that the magnetic moments are oriented in the ab plane perpendicular to the c axis.
Dental Caries Prevalence in Early Polynesians from the Hawaiian Islands

We examined the skeletal remains of 1338 early Hawaiians (preserved in the Bishop Museum, Honolulu) to determine total caries and root surface caries prevalence. Specimens from seven islands were represented in the collection. Estimation of age at death was made by a combination of dental developmental staging for younger individuals and occlusal attrition and/or alveolar bone loss in adults. Museum records were also consulted for age estimation of adults which was primarily based on osteological criteria. The material was divided into six age groups. Predentate infants and edentulous adults were not included. A total of 19,425 teeth was examined. Caries lesions were observed in 462 individuals (34.5%) and 1895 teeth (9.8%). Coronal caries lesions in children and adolescents tended to be small and not particularly destructive of tooth structure. Root surface lesions in young adults were also small but increased progressively in size in the older groups, resulting in pulp exposure and coronal amputation. Although coronal caries was apparently not a significant dental health problem in children and young adults (compared with contemporary Hawaiians), root surface caries was an increasingly important source of tooth morbidity and tooth mortality in the older population groups. This age-related caries pattern was similar for all of the islands.
ULTRA-WIDEBAND TECHNOLOGY FOR VEHICLE-TO-VEHICLE COMMUNICATION AND SENSING

Ultra-wideband (UWB) communications is a new field of technology that has a wide range of applications from range finding to wide bandwidth communications. Ultra-wideband signals are unusual because their bandwidth to center frequency ratio is not small and can be greater than 100%. Recent developments of integrating this technology on a chip have made it versatile and low cost. This technology also offers some special features like interference immunity, multi-access communications, and accurate range finding. A number of areas which need cooperative communications can benefit from this technology including automated highway systems (AHS) and military systems. This paper describes the basics of UWB technology, provides background on the technology, and provides some possible applications of UWB.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Degradation of the herbicides bromacil, diuron and chlortoluron in soil

Abstract In laboratory studies, the rate of degradation of 14C-labeled diuron, chlortoluron, and bromacil in soil was determined by monitoring 14CO2 evolution at 25, 30, and 35°C. Degradation of the three herbicides was slow and followed the first-order rate law. The rate of 14CO2 evolution from the treated soil was nearly tripled by a 10°C rise in temperature from 25 to 35°C. The half-lives as well as the activation energies of degradation for the three chemicals were determined and discussed.
Injury Severity Differentially Alters Sensitivity to Dexamethasone after Traumatic Brain Injury

Abstract We have reported differential short- and long-term dysregulation of the neuroendocrine stress response after traumatic brain injury (TBI) produced by controlled cortical impact (CCI). We have now investigated three possible mechanisms for this TBI-induced dysregulation: (1) effects on the sensitivity of negative-feedback systems to glucocorticoids; (2) effects on the sensitivity of pituitary corticotrophs to corticotropin-releasing hormone (CRH); and (3) effects on neuronal loss in the hilar region of the dentate gyrus and in the CA3b layer of the dorsal hippocampus. TBI was induced to the left parietal cortex in adult male rats with a pneumatic piston, at two different impact velocities and compression depths, to produce either moderate or mild CCI. At 7 and 35 days after surgery, the rats were injected SC with the synthetic glucocorticoid analog dexamethasone (DEX; 0.01, 0.10, or 1.00 mg/kg) or saline, and 2 h later were subjected to 30 min of restraint stress and tail vein blood collection. Wh...
Infrared thermography standards for nondestructive testing

Although infrared thermography is a well developed technology, its applications to nondestructive testing (NDT) are only now beginning to approach maturity. The efforts of many to have infrared thermography recognized by the NDT community, as a powerful and reliable tool for the inspection of materials, structures, and assemblies, has been inhibited by the absence of recognized standards for the method. The unavailability of standard test methods, standard practices, and even a standard terminology, has undoubtedly been responsible, to some extent, for the fact that neither the American national standard for the qualification and certification of NDT personnel, nor the comparable ISO standard, include infrared thermography among the recognized NDT methods.
Coronary microcirculation autoregulation and metabolic control

The majority of studies examining the regulation of coronary blood flow and vascular resistance have considered the coronary circulation as being composed of large conduit vessels and resistance vessels. Recently, it has become apparent that regulation of coronary microvascular resistance is not distributed uniformly, but varies across different segments or microdomains of the vasculature. Generally, small arterioles, those less than 100 microns in diameter, respond differently than larger arterioles and small arteries. There are major differences in the level of autoregulatory control, myogenic control, endothelial modulation and control by metabolic factors across these various microvascular domains. There are also transmural variations which may account for some of the differences in coronary blood observed between epicardial and endocardial regions. In addition, interactions between these various regulatory mechanisms further complicate the understanding of coronary microvascular regulation. Importantly however, it may be these complex interactions and heterogeneous regulatory mechanisms which allow for adequate perfusion of the myocardium under an extreme range of metabolic conditions. This segmental distribution of regulation suggests an integrative hypothesis of regulation whereby a variety of mechanisms play a role in the overall response.
Lasertron: generation of powerful nuclear-short electromagnetic bursts

Summary form only given. Sub-femtosecond, electromagnetic pulses, of much interest presently, are short on the time scale of condensed-matter processes. Six orders of magnitude, however, separate them from the next time scale of interest, that of nuclear interactions (10/sup -21/-10/sup -22/ s). Such pulses seem so much out of reach today that no one so far has considered their feasibility. In this paper, we demonstrate theoretically that such pulses can in fact be generated using a Petawatt laser, while more widely available terawatt lasers may generate sub-attosecond pulses. The pulses would be radiated by electrons rotating ultra-relativistically in high-intensity laser fields. It is basically synchrotron radiation; however, no synchrotron can even come close to running electrons with the energy of 50 MeV around a circle of 0.1 /spl mu/m radius, as a Petawatt laser can. We will call such a system "lasertron.".
Relationship of alcohol use and risky sexual behavior: a review and analysis of findings

In this review article, three methodologic approaches that have been used to examine the association between adolescents' alcohol use and their involvement in risky sex are discussed: global correlation studies, situational covariation studies, and event analyses. The strengths and limitations of each of these research methods are discussed. An extensive review of the most rigorous studies, which used event analysis to examine the alcohol-risky sex link, reveals positive results for first-time sexual events but equivocal findings for other types of sexual relationships. It is argued that differences in the types of sexual relationships studied have been confounded, limiting our ability to evaluate the extent to which alcohol has a causal influence on adolescents' condom use. It is suggested that future investigations consider the nature of the sexual relationship, and go beyond studying the length or status of the relationship to explore how variation in relationship dimensions such as trust and intimacy affect adolescents' sexual behavior.
Controlling bioprocesses with inorganic surfaces: Layered clay hemostatic agents

Layered clays are shown to have a wide range of blood-clotting properties that appear to be influenced by surface charge. The most active clay clotting agent is as effective as a commercial zeolite...
PARABOLIC GENERALIZED MODULAR FORMS AND THEIR CHARACTERS

We make a detailed study of the generalized modular forms of weight zero and their associated multiplier systems (characters) on an arbitrary subgroup Γ of finite index in the modular group. Among other things, we show that every generalized divisor on the compact Riemann surface associated to Γ is the divisor of a modular form (with unitary character) which is unique up to scalars. This extends a result of Petersson, and has applications to the Eichler cohomology.
Cannabinoid receptor stimulation of guanosine-5′-O-(3-[35S]thio)triphosphate binding in rat brain membranes

Cannabinoid receptors belong to the class of G-protein-coupled receptors which inhibit adenylyl cyclase. Coupling of receptors to G-proteins can be assessed by the ability of agonists to stimulate guanosine-5′-O-(3-[35S]thio)triphosphate ([35S]GTPγS) binding in the presence of excess GDP. The present study examined the effect of cannabinoid agonists on [35S]GTPγS binding in rat brain membranes. Assays were conducted with 0.05 nM [35S]GTPγS, incubated with rat cerebellar membranes, 1–30 μM GDP and the cannabinoid agonist WIN 55212-2. Results showed that the ability of WIN 55212-2 to stimulate [35S]GTPγS binding increased with increasing concentrations of GDP, with 10–30 μM GDP providing approximately 150–200% stimulation by the cannabinoid agonist. The pharmacology of cannabinoid agonist stimulation of [35S]GTPγS binding paralleled that of previously reported receptor binding and adenylyl cyclase assays, and agonist stimulation of [35S]GTPγS binding was blocked by the cannabinoid antagonist SR141716A. Brain regional studies revealed widespread stimulation of [35S]GTPγS binding by WIN 55212-2 in a number of brain areas, consistent with in vitro [35S]GTPγS autoradiography. These results demonstrate that [35S]GTPγS binding in the presence of excess GDP is an effective measure of cannabinoid receptor coupling to G-proteins in brain membranes.
Optimizing genetic operator rates using a markov chain model of genetic algorithms

This work is concerned with proposing a robust framework for optimizing operator rates of simple Genetic Algorithms (GAs) during a GA run. The suggested framework is built upon a formerly proposed GA Markov chain model to estimate the optimal values of the operator rates based on the time and the current state of the evolution. Though the proposed framework has been formalized for optimizing both mutation and crossover rates, in the current paper, we only implemented it as the mutation rate optimizer and kept the crossover rate constant. To demonstrate the efficacy of the proposed algorithm, the method is evaluated using a set of benchmark problems and the outcome is compared with a series of well-known relevant algorithms. The results demonstrate that the newly suggested algorithm significantly outperforms its rivals.
When Baby Maisy came to school

Abstract Fifteen 4–5-year-old children experienced a surprise event in their classroom — the visit of their former teacher and her new baby. The same day, children were interviewed about the event by their mothers, who had not been present and were naive to details. Mothers questioned their children in whatever way they wished. Three weeks later, children were interviewed by a researcher who had not been present during the original event and who had no information about the content of the parent–child interviews. Results showed that mothers' conversational style predicted the amount of information children provided during the mother–child interview, which in turn predicted how much accurate information children remembered during the researcher–child interview. The findings suggest that parent–child memory talk affects children's long-term memory reports, even when parents do not share in the event and have no knowledge of its details.
Observation and Photophysical Characterization of Silicon Phthalocyanine J‐Aggregate Dimers in Aqueous Solutions

The use of macrocyclic molecules for both imaging and photodynamic therapy (PDT) has proven to be a powerful method for assessing and treating diseases, respectively. However, many potential candidates for these applications rely on rigid organic structures which are hydrophobic and thus lead to possible aggregation in aqueous solutions such as blood. Here, we describe the discovery of noncovalent J-aggregate dimers of the asymmetrically, axially modified silicon phthalocyanine 4 (Pc 4) in aqueous solutions through steady-state and time-resolved spectroscopy. Remarkably, the monomer–dimer equilibrium is dictated by water content and pH, with free monomers resulting in favorable solvation conditions even after formation of the dimer complex. This work sheds light on previous observations of Pc 4 behavior in cells during PDT, and can further elucidate the structure–activity relationship of these important molecules.
Indentation induced crack nucleation and propagation in single crystal MgO

Abstract A study of indentation induced cracks in single crystal Magnesium Oxide ([001] orientation) was conducted to understand the micromechanisms controlling crack nucleation (and subsequent propagation) in semibrittle solids. Contrary to the expectations based on generally accepted crack nucleation models, no evidence of dislocation pile-ups was observed. However, SEM and TEM study of the deformation structure within the indent impression did reveal the presence of shear fault induced microcracking. This phenomenon was confirmed by examination of cross-sections through the indents using SEM. When the indentation temperature was varied from ambient to 800°C, a direct correlation was observed between the degree of subsurface damage, and the absence or presence of surface radial cracks. Based on the afore-mentioned results, an alternate crack nucleation mechanism is proposed, whereby shear fault induced microcracks act as nuclei for subsequent radial cracking. Further, microdiffraction analysis of the misorientations induced outside the indent suggest that crack propagation parallel to {110} is the result of severe plastic incompatibility across this plane.
Compound specific isotopic variability in Uinta Basin native bitumens: paleoenvironmental implications

Abstract We have analyzed the solvent extracts from three different types of native bitumens from the Uinta Basin in northeastern Utah by a variety of analytical techniques, including GC-IRMS, to evaluate variations in the paleodepositional environment during two periods of Lake Uinta deposition. The gilsonite and tabbyite bitumens are associated with Parachute Creek Member sediments deposited during a major expansion of ancient Lake Uinta. Compound specific isotopic analyses of s-carotane and phytane ( δ 13 C = −32.6 to −32.1% 0 ) from these bitumens reflect input from primary photosynthetic producers such as cyanobacteria. Sterane δ 13C values (−34.5 to −29.2%0) refflect contributions from lacustrine algae, while extremely depleted δ 13C values for methylhopanes (−58.1 to −61.5%0) suggest input from methanotrophic bacteria. Variations in the δ 13C values of the αβ-hopanes (−51.4 to 37.7%0) imply additional input from other bacterial sources. The wurtzilite bitumen was generated from the Saline Facies of the Green River Formation deposited during a later regression of Lake Uinta. Compound specific isotopic analyses of phytane ( δ 13 C = −30.1% 0 ) and steranes δ 13 C = −29.6 to −26.7% 0 ) from this bitumen indicate continued input from primary producers and eukaryotes. The higher relative concentrations of gammacerane ( δ 13 C = −26.9% 0 ) indicate increasing input from aerobic protozoa. We observed a slight enrichment in δ 13C in the wurtzilite extract (and several biomarkers) and suggest that this is a result of sulfate-reducing bacteria outcompeting methanogens, thereby, eliminating the influence of methanotrophs in this later saline stage of deposition.
Cost-benefit methodology for office systems

The time savings times salary (TSTS) approach is a widely used methodology for the financial justification of office information systems, yet its theoretical basis is largely unexplored. In this paper, we identify its underlying economic model, including five critical assumptions. We find that the model, though somewhat restrictive, is not unreasonable. However, we find that the time-saving-times-salary calculation, per se, is implicitly based on a very particular assumption about how saved time will be used. This assumption has neither a behavioral nor normative basis, and we conclude that the TSTS calculation is not meaningful in most cases. An alternate approach, the hedonic wage model, is proposed. This model overcomes most of the deficiencies of the TSTS approach, although it has somewhat greater data requirements and computational complexity. A case study illustrating the use of the hedonic wage model is presented.
Human leukocyte antigen-DQB1* 03 alleles are associated with alopecia areata

Alopecia areata (AA) is characterized by hair loss in patches (patchy AA), over the entire scalp (AT, totalis), or universally (AU). An autoimmune mechanism has been hypothesized, because the inflammatory infiltrate targeted to the hair follicles includes activated T cells. To investigate whether or not genetic polymorphism of the human leukocyte antigen (HLA) region contributes to disease susceptibility, we used sequence-specific oligonucleotides and amplified genomic DNA to define HLA-DQA1, -DQB1, and -DPB1 alleles in a cohort of 85 white patients. The frequency of DQB1*1301 was significantly increased to 41% in all patients, and to 47% in AT/AU patients relative to controls (27%). Analyzed together, DQB1*03 alleles (DQB1*0301-*0303) were increased to 80% (all patients) and to 92% (AT/AU) (odds ratio = 12.14, p = 0.00003, corrected). This striking association implicates the DQB1*03 alleles in the pathogenesis of AA. DQB1*06 was decreased relative to controls (56%) in all patients (32%, odds ratio = 0.37, p = 0.0045, corrected). An increase was observed in the HLA- DRB1*11(DR5) allele DRB1*1104, which may result from linkage disequilibrium with DQB1 alleles. Sequence comparison among the allele products associated with AA indicates that the DQB1*03 alleles carry a unique proline at position 55 that is not present in alleles that are neutral or negatively associated with the disease. This highly significant association may exert considerable control over immune responsiveness and the initiation or persistence of a T-cell autoimmune response against the hair follicle.
Ethical considerations in pulmonary genetic testing and gene therapy

The development of efficient DNA sequencing techniques as well as more recent advances in recombinant DNA technology have brought about a new phase in the diagnosis and treatment of pulmonary diseases. The Human Genome Project will likely identify abnormal genes that contribute to a significant number of pulmonary disorders (Table 1). This Project will provide the foundation for the development of numerous genetic tests, and it will eventually lead to the treatment of genetic diseases. As methods for genetic testing and treatment are developed and used, the complexities of decision-making by pulmonologists will increase, forcing them to face questions not previously encountered. Answering these questions will require a greater understanding of the medical and social implications of genetic disorders. In any discussion of medical genetics, it is important to realize that the scientific process generally evolves in three phases. The first is the descriptive phase, in which traits or clinical characteristics are recognized and familial associations are noted. The second phase is the information phase, in which the genes linked to particular traits or disorders are identified, enabling the development of diagnostic and prognostic genetic tests. The third phase is the development of treatment techniques based upon discoveries in the second phase. The chronologic gap between the development of diagnostic and therapeutic procedures for genetic disorders (Figure 1) creates ethical dilemmas that cannot be resolved by simply referring to the old ethics. Currently, because of the infancy of the field of gene identification, pulmonary physicians are more likely to encounter ethical questions pertaining to the information phase, including the issues of informed consent for testing, test result confidentiality, and selective abortion based on genetic information. The ethical implications of both somatic and germ-line gene therapy, though perhaps not of immediate concern to a practitioner, are likely to become increasingly important in the next several decades. Through the use of examples familiar to most pulmonologists, an effort is made to present guidelines that can be used in confronting ethical dilemmas pertaining to both genetic testing and gene therapy.
Preterm delivery: a public health perspective.

And his daughter-in-law, the wife of Phinehas, was pregnant near to giving birth, and got to hear the report that the ark of the true God was captured and that her father-in-law and her husband had died. At that she bowed herself and began giving birth, because her pangs came unexpectedly upon her.
A quantitative in vitro assay of polymorphonuclear leukocyte migration through human amnion membrane utilizing 111In-oxine

Abstract A modified amnion chemotaxis assay is described for measurement of polymorphonuclear leukocyte(s) (PMNL) migration (random and directed) into a viable membrane. The primary modifications are the use of 111In-oxide-labelled PMNL and replacement of the nitrocellulose ‘trap’ filter with a type I collagen sponge. The modifications resulted in four important benefits: (1) the quantification of PMNL migration was simplified; (2) reader subjectivity was eliminated; (3) the information gained of the migration process was enhanced; and (4) the assay time was decreased. The amnion chemotaxis assay with the modifications reported should provide the means of evaluating several aspects of the inflammatory response of PMNL.
A Large-Eddy Simulation Model for Boundary-Layer Flow Over Surfaces with Horizontally Resolved but Vertically Unresolved Roughness Elements

Accurate prescription of ground-level boundary conditions is a key requirement for large-eddy simulation (LES) of atmospheric boundary-layer (ABL) flow. When the lower boundary is a homogeneously rough surface, the Monin–Obokhov (MO) similarity theory is a well-tested approach for specification of the boundary fluxes. This approach requires an empirically calibrated hydrodynamic roughness length to represent the aggregate effects of all flow-resisting surface details at unresolved scales, and a displacement height to represent a vertical shift in the velocity profiles. For cases in which the surface height distribution varies slowly enough in the horizontal direction that it is spatially resolvable in the LES, but where the height itself is small enough to fall below the first vertical grid point, special challenges arise. First, it is shown herein that prescription of a horizontally varying displacement height, in the context of MO similarity, is insufficient to produce realistic results in this unique application. A subsequent approach, which is relatively easy to implement, and can be used in LES without the need to use a “terrain-following” coordinate system or computationally expensive alternatives such as local grid refinement, is proposed. The approach is based on a form drag expressed in terms of the frontal area and the corresponding incoming momentum flux of the flow. The frontal area is evaluated in terms of the flow-normal gradient of the resolved height distribution. The proposed model, named the surface gradient-based drag (SGD) model, is applied to a variety of rough surfaces for which appropriate data exist. These surfaces are horizontally resolved, but vertically unresolved. The resulting mean velocity distributions are compared with available data and good agreement is observed. In addition, we apply the SGD model in flow over two synthetic multiscale surfaces with prescribed, power-law surface-height spectra. For these cases, first- and second-order flow statistics agree with established results. Future perspectives are outlined.
An instrument for measuring the oscillatory electric birefringence properties of polymer solutions.

Abstract An instrument for measuring the oscillatory electric birefringence properties of synthetic polymer dissolved in organic solvents has been designed and constructed. Novel features of the design include an in situ variable inter-electrode spacing Kerr cell and a double-beam optical train. The accessible frequency range extends from below 1 Hz to at least 100 kHz, with electric fields variable up to approximately 6000 V cm −1 (peak-to-peak). Measurements are made with a powerful computerized data acquisition and processing system, based on an approach previously used for viscoelastic and oscillatory flow birefringence experiments. Preliminary results on a viscous liquid, Aroclor-1248, indicate that time-temperature superposition holds to reduced frequencies of at least 100 MHz. Comparison with theoretical predictions for rigid rod suspensions suggests that this liquid exhibits relaxation behavior with a time constants of ca. 6 ns at 25.00°C.
Social and behavioral factors associated with high-risk sexual behavior among adolescents

Relationships among risky sexual behaviors, other problem behaviors, and the family and peer context were examined for two samples of adolescents. Many adolescents reported behaviors (e.g., promiscuity or nonuse of condoms) which risked HIV or other sexually transmitted disease infection. Such risky behaviors were significantly intercorrelated. Consistent condom use was rare among those whose behavior otherwise entailed the greatest risk of infection. In both samples, an index of high-risk sexual behavior was significantly related to antisocial behavior, cigarette smoking, and illicit drug or alcohol use. Social context variables, including family structure, parenting practices, and friends' engagement in problem behaviors, were associated with high-risk sexual behavior. Finally, for sexually active adolescents, problem behaviors and social context variables were predictive of nonuse of condoms. Results were consistent across the two studies and regression weights held up well under cross-validation.
Two-dimensional chemical-shift tensor correlation spectroscopy. Multiple-axis sample-reorientation mechanism

Abstract A new two-dimensional NMR method for measuring chemical-shift tensors in complex single crystals has been developed. The technique obtains both the principal values and the orientations of the principal axes of all tensors in the sample. The crystal is mounted only once in a new sample-orienting mechanism which then places it in six orientations selected to fully characterize the chemical-shift tensors. The mechanism is designed to move rapidly between any pair of the six orientations so that it combines with a previously described two-dimensional chemical-shift correlation technique to form a uniquely powerful method for measuring tensors in complex single crystals. Data sufficient to resolve ambiguities from overlap of peaks at particular crystal orientations are available and optimal extraction of the tensor values from the measured peak frequencies is straightforward. Methods are developed for analyzing the data and calibrating the mechanism when symmetry relations exist between the tensors. The 12 carbon-13 tensors in sucrose are measured.
The Stories We Tell: A Reconsideration of AS / AD Analysis

This paper explains that the AS/AD model as currently presented in the tests is seriously flawed. It does not fulfill the minimum requirement of a model: logical consistency. Its component parts are derived from models that reflect different, and inconsistent, models of the economy. Moreover, the appropriate disequilibrium adjustment story that appropriately accompanies it is inconsistent with observed reality. In this alternative model, Keynesian adjustment occurs through shifting AS/AD curves along institutionally determined price level vectors rather than through movements along the AS/AD curves.
The effect of cerium additions on the tensile ductility of nickel-chromium-cerium alloys

The effect trace concentrations of Ce have on the tensile ductilities and fracture modes of nickel base alloys was examined for various additive levels of Ce. Ni-Cr-Ce alloy specimens with concentrations of 0-120 ppm Ce were induction melted, cast, hot rolled and heat treated at 1010 C for an hour. Strain rates of 5/100,000 to 0.2 per sec were imparted at 20 and 700 C with a velocity tensile machine to study the yield strengths, ultimate tensile strengths and ductilities. Additional specimens were heat treated at 700 C for 24 hr for similar comparisons of carbide-containing and carbon-free alloys. The addition of Ce displaces O and S atoms in the alloys and increases the ductility and modifies the fracture mode. The ductility increase was maximized at 700 C with concentrations of Ce of 60-80 ppm. Finally, the presence of Ce in the alloys reduced the strain rate from the transgranular to intergranular fracture mode. 12 references.
Reliability of detecting prosthesis/cement interface radiolucencies in total hip arthroplasty.

Abstract A laboratory study assessed the reliability of detecting radiolucencies at the prosthesis/cement interface in femoral components for total hip replacement. Radiolucencies (thicknesses=0.1, 0.3, 0.5 and 0.7 mm) were created by randomly masking non-tip Gruen zones (six per stem) in a group of 72 matte-finish femoral components. Only half of all Gruen zones were masked. The femoral components were reproducibly implanted in composite fiberglass replicate femurs. Anteroposterior and lateral radiographs taken using conventional techniques were then presented to 10 experienced readers, who scored each of 432 non-tip Gruen zones for radiolucency presence or absence. The series-average radiolucency detection rate was 47.1%, with a breakdown of 9.8%, 20.7%, 69.8% and 88.0% for radiolucency thicknesses of 0.1, 0.3, 0.5 and 0.7 mm, respectively. The false positive rate was 7.5%. The findings argue strongly that in many or most instances, initial cement–prosthesis debonding is not reliably detected from conventional plain film radiographs. Radiolucencies of at least 0.7 mm width are necessary to be accurately detectable by most viewers.