cssi/SciSciGPT-SciSciNet huggingface dataset:
Anxiety and Depression in Children: A Test of the Positive-Negative Affect Model

ABSTRACT Objective To examine whether the two-factor model of affect presented by Watson and colleagues is applicable to school children. Method A child self-report scale of symptoms of depression and anxiety was administered to 624 school children in the third and sixth grades. Factor analyses were applied to extract factors of positive and negative affect. Reliabilities, correlations, and longitudinal analyses were performed to examine the developmental pathway of positive affect (PA) and negative affect (NA). Results In contrast to Watson's early findings, our results indicate that the PA and NA scales are significantly negatively correlated cross-sectionally as well as longitudinally. Moreover, our findings indicate that children with high NA and low PA in the third grade display a worse prognosis than children who have either high NA or low PA. Conclusions A new affect model is needed for describing children's mood status. In addition, an important implication of these findings is that the occurrence of comorbid mood status in children confers a high risk for later emotional problems.
The stability of the revised Beck Depression Inventory in college students: Relationship with life events

The 1-week stability of Beck Depression Inventory (BDI) scores in a college population was examined. The most recent version of the BDI, in which respondents are instructed to rate the items with respect to the past week, was employed. The test-retest reliability coefficient was 0.64. Scores on the initial administration were significantly higher than retest scores (8.52 vs. 7.05). More than half of the individuals scoring in the depressed range (BDI > 10) on the first test fell into the nondepressed range (BDI < 10) 1 week later. Of the students who scored above 10 on the first BDI, those with high rather than low life event scores were significantly more likely to have their BDI score fall below 10 at the second testing session.
Drug transporters are altered in brain, liver and kidney of rats with chronic epilepsy induced by lithium–pilocarpine

AbstractObjective: Pharmacoresistance is a common problem hindering treatment of epilepsy. A possible cause for this resistance is the overexpression of efflux drug transporters, e.g. P-glycoprotein (P-gp), which may decrease extracellular antiepileptic drugs levels in brains of intractable epilepsy patients. Another transmembrane drug transporter is the organic anion transporting polypeptide 2 (Oatp2), which is colocalized with P-gp in many polarized tissues. However, a role for Oatp2 in the development of multidrug resistance has not been established. In the present work, we investigated the expression of drug transporters Oatp2 and P-gp in brain, liver and kidney of rats with chronic epilepsy induced by lithium–pilocarpine.Methods: Chronic epilepsy was elicited after status epilepticus (SE) induced by lithium–pilocarpine in adult Wistar rats. Following SE, expression of Oatp2 and P-gp protein was detected by immunohistochemistry and Western blot analysis and messenger RNA (mRNA) using reverse transcrip...
Steady states of self-gravitating incompressible fluid in two dimensions

In this paper we develop a simple model for the steady state of two-dimensional self-gravitating incompressible gas which is based on the hydrodynamic equations for stratified fluid. These equations are then reduced to a system of two equations for the mass density and the gravitational field. Analytical analysis and numerical solutions of these equations under different modeling assumptions (with special attention to the isothermal case) are then used to study the structure of the resulting steady state of the fluid.
Effect of Prenatal Steroids on Skin Surface Hydrophobicity in the Premature Rat

The skin surface of the newborn rat at term is highly hydrophobic. This surface hydrophobicity plays a putative role in the transition from an aqueous to a gaseous environment at birth and is dependent on the presence of an intact periderm. Glucocorticoids given to pregnant dams, during late gestation, will accelerate formation of the stratum corneum and reduce transepidermal water loss in prematurely delivered pups. We tested the related hypotheses that surface hydrophobicity and maturation of the periderm are developmentally accelerated by prenatal exposure to steroids. Thirty pregnant Sprague-Dawley rats received either normal saline or 0.5 mg/kg betamethasone on d 17 of gestation. After cesarean delivery on d 18, 19, and 20, dorsal skin surface hydrophobicity was quantified by direct surface electrical capacitance (SEC) measurement. Initial skin surface hydration at birth was significantly lower in steroid-treated pups than in control pups at gestational ages 19 and 20 d (3060 +/- 1379 versus 4441 +/- 153 pF and 646 +/- 295 versus 1493 +/- 1019 pF, respectively, p < 0.001, mean +/- SD). Likewise, after desorption of amniotic fluid, baseline skin hydration was significantly lower in steroid-treated pups than in control pups at gestational ages 19 and 20 d (1862 +/- 1560 pF versus 4278 +/- 97 pF and 60 +/- 56 pF versus 128 +/- 264 pF, p < 0.001). Scanning and transmission electron microscopy showed morphologic maturation of the periderm after steroid treatment. These results demonstrate accelerated development of both functional and structural correlates of skin surface hydrophobicity in the premature rat after prenatal exposure to steroids.
Laser-tissue interactions

Laser-tissue interactions involve (1) the physical mechanism of interaction [photothermal, photochemical, photomechanical], (2) the biological level of interaction [tissue/organ, cellular, organellar], and (3) the time course of the interaction [immediate physical effect, short-term biological response, long-term healing and structure/function].
The IGE Model: An Extension of the Ideal Gas Model to Include Chemical Composition as Part of the Equilibrium State

The TEST (The Expert System for Thermodynamics, www.thermofluids.net) web portal is a comprehensive thermodynamic courseware consisting of multimedia problems and examples, an online solution manual for educators, traditional thermodynamic charts and tables, fifteen chapters of animations to illustrate thermodynamic systems and fundamental concepts, and a suite of thermodynamic calculators called daemons for evaluating thermodynamic properties and analyzing thermodynamic problems.. The state module offers Java applets for evaluation of thermodynamic states of different working substances grouped into several material models according to underlying assumptions. Gas mixtures are modeled by the perfect gas (PG) or ideal gas (IG) mixture models. In this work, we extend the IG model mixture model into an ideal gas equilibrium (IGE) mixture model by incorporating chemical equilibrium calculations as part of the state evaluation process. Through a simple graphical interface users can set the atomic composition of a gas mixture. In the state panel, the known thermodynamic properties are entered. For a given pressure and temperature, the mixture’s Gibbs function is minimized subject to atomic constraints and the equilibrium composition along with thermodynamic properties of the mixture are calculated and displayed. What is unique about this approach is that equilibrium computations are performed in the background, without requiring any major change in the familiar user interface used in other state daemons. Properties calculated by this equilibrium state daemon are compared with results from other established applications such as NASA CEA and STANJAN. Also, two different algorithms, an iterative approach and a direct approach based on minimizing different thermodynamic functions in different situation are compared.Copyright © 2010 by ASME
Effect of alkyl sulfides on diazomethane-induced methylation of DNA in vitro

Abstract Organosulfur compounds found in Allium species such as garlic and onions inhibit carcinogenesis induced by alkylating agents. One potential mechanism for this activity involves scavenging of ultimate carcinogenic species by the nucleophilic sulfur atom. Carcinogenic methylating agents such as methyl-nitrosourea produce, among others, O6-methylguanine and N7-methylguanine in DNA both in vivo and in vitro. In the present study we have determined the effect of several alkyl sulfides on the formation of O6-methylguanine and N7-methylguanine in DNA reacted with the methylating agent diazomethane in vitro. Dipropyl sulfide and diallyl sulfide affect guanine methylation by increasing the O 6 N 7 ratio without drastic alterations in the total amount of adduct formed. Three similar compounds — diallyl disulfide, allyl methyl sulfide and diallyl ether — had no appreciable effect on the amount of alkylation at either position. These data suggest that scavenging of diazomethane-like ultimate carcinogens does not play a major role in the inhibition of carcinogenesis by organic sulfides.
A Prospective Outcome Evaluation of Arthroscopic Bankart Repairs Minimum 2-Year Follow-up

BackgroundArthroscopic treatment of anterior shoulder dislocation has become possible through improvements in instruments and techniques.ObjectiveTo prospectively evaluate results of arthroscopic B...
1HNMR relaxation and rock permeability

Abstract We investigated the relationships among permeability (k), porosity (φ), and 1HNMR (proton nuclear magnetic resonance) relaxation rate in sandstones with the objective of learning more about the connections between the chemical processes that influence 1HNMR relaxation in a pore-filling aqueous solution and the permeability of the rock. We found that k is a well-correlated function of 1HNMR relaxation time T1 (r2 = 0.79, N = 113); the correlation between k and a bivariate function of T1 and φ (4T12) is slightly better (r2 = 0.86). Furthermore, permeability is a robust function of T1 or (φ4T12); neither relationship is significantly influenced by the range of porosity in the samples. In contrast, the relationship between permeability and porosity is degraded if low-porosity (φ
Orphan GPCRs and their ligands

Due to their diversity, G-protein-coupled receptors (GPCRs) are major regulators of intercellular interactions. They exert their actions by being activated by a vast array of natural ligands, referred to in this article as "transmitters". Yet each GPCR is highly selective in its ligand recognition. Traditionally, the transmitters were found first and served to characterize the receptors pharmacologically. Since the end of the 1980s, however, it is the GPCRs that are first to be found because they are identified molecularly by homology screening approaches. But the GPCRs found this way suffer of one drawback, they lack their natural transmitters, they are "orphan" GPCRs. Searching for transmitters of orphan GPCRs has given birth to the reverse pharmacology approach that uses orphan GPCRs as targets to identify their transmitters. The most salient successes of the reverse pharmacology approach were the discoveries of 9 novel neuropeptide families. These have enriched our understanding of several important behavioral responses. But the application of reverse pharmacology has also led to some surprising results that question some basic pharmacological concepts. This review aims at describing the history of the orphan GPCRs and their impact on our understanding of biology.
Sources of Growth in the Democratic Republic of the Congo: A Cointegration Approach

The paper investigates the sources of growth in the Democratic Republic of the Congo since 1960 and evaluates the relative importance of total factor productivity growth and factor accumulation, using a cointegration method and a growth accounting framework. The main findings confirm that poor economic policies and bad governance (through their effects on total factor productivity and capital accumulation) contributed to the country`s economic decline during the 40-year period, 1960-2000. Looking forward, the paper finds that the right policies are being put in place to pave the way for a restoration of economic growth.
Evaluation of cold temperatures and density as mortality factors of the eucalyptus longhorned borer (Coleoptera: Cerambycidae) in California.

It was hypothesized that the northward spread of the eucalyptus longhorned borer, Phoracantha semipunctata F., in California is limited by winter temperature con­ ditions. The cold tolerance of prepupal stages was tested by exposing infested logs to cold temperature treatments of -5, 0, +5, and + lO"C for periods of 1, 3, 7, and 30 d. Temperature treatments had no affect on survivorship to adulthood or longevity but did reduce adult weight relative to nontreated control logs. Increasing exposure time to all cold temperatures significantly reduced both survivorship and adult weight but had no affect on adult longevity. Long periods of exposure to cold temperatures delayed emergence of adults and resulted in more closely synchronized emergence. Cold temperatures are unlikely to prevent the spread of this pest into most zones occupied by its eucalyptus host plants. In addition, increasing densities of prepupae in logs also resulted in significantly reduced survivorship to adulthood but did not affect adult weight or longevity.
Partial cloning of a squid microtubule‐associated protein (MAP H1) and the identification of the microtubule binding domain

An approximately 420-kDa ATP binding protein, referred to as MAP H1, has previously been shown to be involved in microtubule-dependent vesicle motility in the squid giant axon. To gain further insight into the structure and function of this protein, partially overlapping cDNA clones encoding approximately a quarter of the MAP H1 molecule were identified from two squid optic lobe libraries using affinity-purified antibodies to squid MAP H1. One clone in particular (KS18), which hybridizes to an approximately 13-kb message, encodes a series of almost identical repeats of a 16-amino-acid sequence that is tandemly repeated. The sequence of clone KS18 is unique and does not correspond to any nucleotide or amino acid sequence in the data base. The presence of repeated elements within the microtubule binding domain of several other MAPs prompted us to investigate whether the MAP H1 repeats are involved in microtubule binding. In-vitro-synthesized polypeptides containing these repeats sediment with taxol-stabilized microtubules in a microtubule binding assay. The predicted secondary structure of the 16-amino-acid repeat region of MAP H1 contains alternating β-sheets and turns and could form the globular domain seen in negative-stain electron micrographs of MAP H1.
Functional reciprocal connections of the rat entorhinal cortex and subicular complex with the medial frontal cortex : an in vivo intracellular study

We used in vivo intracellular recording techniques in the rat in order to determine the properties of projections from the medial frontal cortex to the entorhinal cortex and subicular complex. Three main results were obtained. (1) A high proportion (65%) of neurons within the medial frontal cortex were antidromically activated at short latency (0.4-1.9 ms) by electrical stimulation of the entorhinal cortex or subicular complex. This provided physiological evidence for fast direct projections from the medial frontal cortex to the entorhinal cortex and subicular complex. (2) Clear excitatory postsynaptic potentials (EPSPs) were evoked in 8% of the cells within the entorhinal cortex, subicular complex, or adjacent cortices after electrical stimulation of the medial frontal cortex. (3) The most salient synaptic response was inhibition, as shown by the presence of inhibitory postsynaptic potentials (IPSPs) in 50% of the cells sampled. Similar results were obtained for the reciprocal pathway: 56% of the sampled cells in the entorhinal cortex or subicular complex responded with antidromic spikes to stimulation of the medial cortex; 4% of medial frontal neurons responded to stimulation of the entorhinal cortex or subicular complex with clear EPSPs, and 48% with IPSPs. The latencies of most synaptic responses, 15-25 ms, were inconsistent with monosynaptic activation. This suggests that oligosynaptic relays amplified the signal within or en route to their targets, and/or that cells with more slowly propagating axons were also present but not sampled by the intracellular electrodes. Finally, responsive fast-spiking cells (candidate inhibitory neurons) were encountered within target structures. The results provide evidence that these distant cortical regions are functionally connected in a reciprocal manner, and that both principal and inhibitory neurons are excited by this projection system.
Isolated right temporal lobe stroke patients present with Geschwind Gastaut syndrome, frontal network syndrome and delusional misidentification syndromes.

Background: Right temporal lobe lesion syndrome elicitation presents a clinical challenge. Aside from occasional covert quadrantanopias, heralding elementary neurological deficits are absent.
A self-heated thermistor technique to measure effective thermal properties from the tissue surface

A microcomputer based instrument to measure effective thermal conductivity and diffusivity at the surface of a tissue has been developed. Self-heated spherical thermistors, partially embedded in an insulator, are used to simultaneously heat tissue and measure the resulting temperature rise. The temperature increase of the thermistor for a given applied power is a function of the combined thermal properties of the insulator, the thermistor, and the tissue. Once the probe is calibrated, the instrument accurately measures the thermal properties of tissue. Conductivity measurements are accurate to 2 percent and diffusivity measurements are accurate to 4 percent. A simplified bioheat equation is used which assumes the effective tissue thermal conductivity is a linear function of perfusion. Since tissue blood flow strongly affects heat transfer, the surface thermistor probe is quite sensitive to perfusion.
Heat of adsorption of liquid mixtures on solid surfaces: Comparison of theory and experiment

Abstract The thermodynamics for the adsorption of a binary liquid mixture onto a solid is developed in order to establish the connections between the excess enthalpy and heats of mixing from immersion and frontal analysis experiments. Bulk heat of mixing data are required to make these connections in general, but in the case of dilute solutions it is sufficient to have the heat of solution of solute in the infinitely dilute solution. On the basis of a general “surface phase model,” we develop an equation relating the excess enthalpy to the adsorption isotherm. For dilute solutions it displays two types of behavior corresponding to strong and to weak adsorption of solute. Data on the adsorption of n -butanol from toluene and heptane (strong adsorption) and from water (weak adsorption) onto silica gel fit this expression. Finally, the relationship of these conclusions to Everett's adsorption theory is discussed.
A multiscale cohesive zone model and simulations of fractures

Abstract In this work, a novel multiscale cohesive zone model is proposed, in which the bulk material is modeled as a local quasi-continuum medium that obeys the Cauchy–Born rule while the cohesive force and displacement relations inside the cohesive zone are governed by a coarse grained depletion potential. The interface depletion potential is constructed based on the Derjaguin approximation of nonlocal colloidal interactions. By doing so, the interface constitutive descriptions are made genetically consistent with the bulk constitutive relations that are enriched from underneath atomistic structure. The method provides an effective means to describe properties of material inhomogeneities such as grain boundaries, bi-material interfaces, slip lines, and inclusions, etc. We have developed and implemented the proposed multiscale cohesive zone model in a cohesive finite element weak Galerkin formulation, and we have applied it to simulate dynamic fracture problems in solids. The numerical simulation results have shown that the method has successfully captured the phenomenon of spall fracture during simulations of impacts and penetrations.
Millimeter Wave Radar Systems for Biometric Applications

Millimeter-wave and terahertz radar systems can play an important role in multimodal layered sensing systems targeted at measuring both physiological and behavioral biometric data for security and medical applications. We will describe a 228 GHz heterodyne radar system that is capable of measuring respiration rates at standoff distances of up to 50 meters and simultaneously measure respiration and heartbeat rates at a distance of 10 meters. We will discuss the latest hardware and signal processing developments and a wide range of studies aimed at optimizing the performance of the system under a variety of potential field applications.
White matter fractional anisotropy over two time points in early onset schizophrenia and adolescent cannabis use disorder: A naturalistic diffusion tensor imaging study

Recurrent exposure to cannabis in adolescence increases the risk for later development of psychosis, but there are sparse data regarding the impact of cannabis use on brain structure during adolescence. This pilot study investigated the effect of cannabis use disorder (CUD) upon white matter fractional anisotropy (WM FA) values in non-psychotic treatment-seeking adolescents relative to adolescents with early onset schizophrenia-spectrum disorders (EOSS) and to healthy control (HC) participants. Diffusion tensor imaging (DTI) and tractography methods were used to examine fractional anisotropy (FA) of the cingulum bundle, superior longitudinal fasciculus (SLF), corticospinal tract (CST), inferior longitudinal fasciculus (ILF), inferior fronto-occipital fasciculus (IFOF) and uncinate fasciculus in adolescents with EOSS (n=34), CUD (n=19) and HC (n=29). Participants received DTI and substance use assessments at baseline and at 18-month follow-up. Using multivariate analysis of variance, a significant main effect of diagnostic group was observed. Post-hoc testing revealed that adolescents with CUD showed an altered change in FA values in the left ILF and in the left IFOF (trend level) compared with HC adolescents. Greater consumption of cannabis during the inter-scan interval predicted a greater decrease in left ILF FA in CUD. These preliminary longitudinal data suggest that heavy cannabis use during adolescence, or some factor associated with cannabis use, is associated with an altered change in WM FA values in a fiber bundle that has been implicated in the pathophysiology of EOSS (i.e., the left ILF). Additional studies are needed to clarify the clinical significance of these findings.
Improving discrimination of essential genes by modeling local insertion frequencies in transposon mutagenesis data

Transposon mutagenesis experiments enable the identification of essential genes in bacteria. Deep-sequencing of mutant libraries provides a large amount of high-resolution data on essentiality. Statistical methods developed to analyze this data have traditionally assumed that the probability of observing a transposon insertion is the same across the genome. This assumption, however, is inconsistent with the observed insertion frequencies from transposon mutant libraries of M. tuberculosis. We propose a modified binomial model of essentiality that can characterize the insertion probability of individual genes in which we allow local variation in the background insertion frequency in different non-essential regions of the genome. Using the Metropolis-Hastings algorithm, samples of the posterior insertion probabilities are obtained for each gene, and the probability of each gene being essential is estimated. We compare our predictions to those of previous methods and show that, by taking into consideration local insertion frequencies, our method is capable of making more conservative predictions that better match what is experimentally known about essential and non-essential genes.
Primary Melanoma of the Lung

Primary melanoma of the lung is extremely rare. Eleven cases have been published in the English literature, four of which were unequivocal true primary tumors. Two new cases are being reported. The symptoms of primary pulmonary melanomas are similar to those of bronchogenic carcinomas. Our two cases were asymptomatic at the time of diagnosis. The prognosis may be extremely grave, but long survival has been reported in isolated cases following surgical treatment.
Structure and Dynamics of the EIIC Sugar Uptake System

The phosphoenolpyruvate-dependent carbohydrate phosphotransferase system (PTS) is a sugar uptake system unique to bacteria. It is a multicomponent system consisting of several cytosolic proteins and a dimeric transmembrane protein (EIIC in most PTS systems), which transports extracellular sugar across the membrane. Although EIIC is a uniporter, it is able to drive concentrative transport of its ligand because the sugar is phosphorylated by a cytosolic protein, EIIB, while still bound to the transporter. Phosphorylation prevents the sugar from escaping the cell and primes it for consumption by the cell. Little is known regarding the mechanism of sugar translocation and phosphorylation. Currently, the only available crystal structure of an EIIC is that of the N,N′-diacetylchitobiose transporter, bcChbC (1). We have proposed a mechanism for sugar translocation and phosphorylation, and we will report our progress in characterizing the mechanism.Reference1. Cao Y, Jin X, Levin EJ, et al. Crystal structure of a phosphorylation-coupled saccharide transporter. Nature. 2011;473(7345):50-4.
Expression of parafibromin in major renal cell tumors.

Parafibromin, encoded by HRPT2 gene, is a recently identified tumor suppressor. Complete and partial loss of its expression have been observed in hyperparathyroidism-jaw tumor (HPT-JT), parathyroid carcinoma, breast carcinoma, lung carcinoma, gastric and colorectal carcinoma. However, little has been known about its expression in renal tumors. In order to study the expression of parafibromin in a series of the 4 major renal cell tumors - clear cell renal cell carcinoma (ccRCC), papillary renal cell carcinoma (pRCC), chromophobe renal cell carcinoma (chRCC) and oncocytoma. One hundred thirty nine renal tumors including 61 ccRCCs, 37 pRCCs, 22 chRCCs and 19 oncocytomas were retrieved and used for the construction of renal tissue microarrays (TMAs). The expression of parafibromin was detected by immunohistochemical method on the constructed TMAs. Positive parafibromin stains are seen in 4 out of 61 ccRCCs (7%), 7 out of 37 pRCCs (19%), 12 out of 23 chRCCs (52%) and all 19 oncocytomas (100%). Parafibromin expression varies significantly (P< 8.8 x10-16) among the four major renal cell tumors and were correlated closely with tumor types. No correlation of parafibromin expression with tumor staging in ccRCCs, pRCCs and chRCCs, and Fuhrman nuclear grading in ccRCCs and pRCCs. In summary, parafibromin expression was strongly correlated with tumor types, which may suggest that it plays a role in the tumorigenesis in renal cell tumors.
Catalytic coupling of carboxylic acids by ketonization as a processing step in biomass conversion

Abstract Carboxylic acids, common intermediate products in biomass conversion processes, can be converted into ketones via ketonization reactions over a ceria–zirconia catalyst. Reaction kinetics studies were carried out using hexanoic acid, as a representative carboxylic acid, in the presence of 1-pentanol and 2-butanone, as representative biomass-derived alcohol and ketone species. Studies were carried out at temperatures from 448 to 623 K, and employing a range of hexanoic acid partial pressures from 0.05 to 0.3 atm. Two different reactions were observed to take place at these reaction conditions: esterification and ketonization, both consuming hexanoic acid. Product inhibition by water and carbon dioxide was observed and studied by co-feeding these components to the reactor. Hexanoic acid adsorption on the catalyst surface is an important step in the reaction, and the rate of ketonization shifts from second order to zero order as the partial pressure of acid increases. The measured activation energy for the ketonization of hexanoic acid (132 kJ/mol) is higher than the esterification reaction (40 kJ/mol), such that the irreversible ketonization reaction is favored at higher temperatures (>573 K) compared to the reversible esterification reaction. Direct ketonization of esters does not take place in the presence of acids, and instead takes place by hydrolysis with water followed by ketonization of the corresponding acid. The results of this study can be described by a simple kinetic model including site blocking by adsorbed hexanoic acid, carbon dioxide, and water.
Development and validation of a measure to assess head start children's appraisals of teacher support

In this study, we present data on the development of Young Children's Appraisals of Teacher Support (Y-CATS), a measure designed to explore children's perceptions of their relations with teachers along dimensions that comprise warmth, conflict, and autonomy. Three cohorts of Head Start children and prior Head Start attendees (N=364) served as the sample. Cohort 1 children (n1=108) were in first grade, cohort 2 children (n2=123) were in kindergarten, and cohort 3 children (n3=133) attended the Head Start program. Factor analyses supported a three-factor solution, with acceptable internal consistency, along hypothesized dimensions. Males, compared to females, reported more conflictual relationships with their teachers. Conflict scores were particularly pronounced for African American males. Children's reports on the Y-CATS were significantly associated with academic achievement and with teachers' ratings of social skills and behavior problems.
The four‐card problem resolved? Formal operational reasoning and reasoning to a contradiction

To test the hypothesis that adolescents classified as formal operational, based upon use of proportional reasoning on the “Pouring Water Task” (Lawson, Karplus, & Adi, 1978) have acquired the mental structures necessary to comprehend hypothetico-deductive arguments of a pattern referred to as “reasoning to a contradiction,” while adolescents classified as concrete operational, based upon use of additive reasoning on the same task have not, a sample of 100 high school students were administered the task and three versions of a problem requiring use of reasoning to a contradiction before, immediately after, and one month after brief verbal instruction in use of that reasoning pattern. Results were generally supportive of the hypothesis as most of the concrete students failed the immediate and delayed posttest problems (62 and 80%, respectively) while most of the formal students succeeded (80 and 71%, respectively). Group differences were significant (p < .001) in both cases. These results suggest that, contrary to those who have argued that content plays a substantial role in logical performance, a general hypothetico-deductive reasoning competence exists in some adolescents and is applicable across a wide variety of task domains. Science instruction which aims to teach this competence is recommended.
Benders decomposition for variational inequalities

The partitioning technique of J.F. Benders, which was generalized to nonlinear programming by Geoffrion, is further generalized to linearly constrained variational inequality problems. The conditions under which such a generalization is possible and appropriate are examined. An important area of application is the asymmetric traffic assignment problem for which the decomposition assumes a simple and effective form. A computational example demonstrates the algorithm.
A facile elaboration of aldehydes to 2-alkyl-3-thiophenylfurans

Abstract A two-step procedure for the elaboration of aldehydes to 2-substituted 3-thiofurans has been developed. The key step involves a site-selective deprotonation of a substituted vinyl sulfide.
Analytical techniques for trace element determinations in plant tissues

Abstract Recent developments in the analytical procedures for trace element assay in plant tissue ash have been toward automated procedures utilizing highly sophisticated instrumentation such as activation analysis, flameless atomic absorption spectroscopy, emission spectroscopy with plasma excitation, x‐ray fluorescence spectroscopy and voltometry. These techniques provide the analyst the ability to determine the concentration of trace elements well into the subparts per million range. Although the instrumentation procedures have their limitations and require special skills on the part of the analyst, the problem of sample preparation is still a major concern limiting the assay for a number of important elements. Trace level determination for elements, As, B, Cd, Co, Hg, Mo, Pb and Se is difficult. Acceptable reference standards are still needed as the current U.S. National Bureau of Standard Reference materials are not completely adequate. There is considerable evidence that there is significant element...
Cellular senescence in the pathogenesis of benign prostatic hyperplasia.

BACKGROUND Senescent cells accumulate in tissues with age and show changes in protein expression that may influence the function of adjacent cells and contribute to the development of tissue pathologies associated with aging. Benign prostatic hyperplasia (BPH) is an extremely common disease of older men characterized by increased growth of prostatic epithelial and stromal cells. In BPH, there is an increased expression of Il-1α by prostatic epithelial cells that results in elevated expression of FGF7 by stromal cells, which in turn is strongly correlated with epithelial proliferation. METHODS Human BPH tissue and primary cultures of prostatic epithelial cells were analyzed by histochemical and quantitative assays for senescence-associated β galactosidase (SA-β gal). Il-1α expression was localized by immunohistochemistry and Il-1α tissue content determined by enzyme-linked immunoabsorption assay. RESULTS Expression of Il-1α is significantly increased in vitro when cultured prostatic epithelial cells undergo senescence. In BPH tissue a substantial population of epithelial cells express senescence-associated β galactosidase (SA-β gal), a marker of cellular senescence. By quantitative assay, SA-β gal activity is correlated with both tissue levels of Il-1α and the severity of BPH. CONCLUSIONS One mechanism driving BPH in older men is the accumulation of senescent epithelial cells expressing Il-1α, which in turn increases FGF7 secretion and proliferation of non-senescent epithelial cells. Thus there is a mechanistic linkage between cellular senescence and one of the most common pathologies of older men. Prostate 55:30–38, 2003. © 2003 Wiley-Liss, Inc.
Ginzburg-Landau Parameters of Type-II Superconductors

Specific heats in a magnetic field were measured for three specimens of niobium, a 50% Nb-50% Ta specimen, and an In + 1.9% Bi specimen. These data were supplemented by magnetization measurements on one niobium specimen. From the data, two Ginzburg-Landau parameters are calculated: ${K}_{1}$, determined by the magnitude of the upper critical field, and ${K}_{2}$, determined by the slope of the magnetization curve at this field. For the niobium specimens, ${K}_{2}$ exceeds ${K}_{1}$ at all temperatures below the transition temperature, in qualitative agreement with the theory of pure type-II superconductors of Maki and Tsuzuki. The ratio $\frac{{K}_{2}}{{K}_{1}}$ at a given temperature is largest in the purest Nb and less in impure Nb. In the pure specimens, the temperature dependence of ${K}_{1}$ is more rapid than predicted by theory, the experimental value of ${K}_{1}(0)$ being about 25% larger than the theoretical value of 0\ensuremath{\rightarrow}K. For the alloy specimens, ${K}_{2}\ensuremath{\sim}{K}_{1}$, over the temperature range measured, and both parameters increase with decreasing temperature. This result contradicts the inequality ${K}_{2}lK$ (where $K$ is the Ginzburg-Landau parameter at ${T}_{c}$) derived by Maki for type-II superconductors of short electron mean free path.
Pyrolusite (β-MnO2)-mediated, near dry-phase oxidation of 2,4,6-trichlorophenol

The pyrolusite (β-MnO2)-mediated oxidation of 2,4,6-trichlorophenol (TCP) under nonaqueous conditions was investigated to assess the potential for abiotic transformations of chlorophenols and their transformation pathways when they are released to soils and the vadose zone. Lower rates of TCP oxidation were found at lower relative humidities, but the rates were still relatively high under near-dry conditions, with 86% of the TCP transformed within 24 h at less than 2% relative humidity. The rates of TCP transformation and soluble manganese formation at less than 2% relative humidity were not affected by atmospheric oxygen content. The manganese oxide-mediated oxidation of TCP resulted in the formation of 2,6-dichloro-1,4-benzoquinone and dimers, including polychlorinated phenoxyphenols and at least one tetrachlorodibenzo-p-dioxin. The products are consistent with the proposed mechanism in which some of the TCP is transformed into trichlorophenoxy radicals that attack TCP and its transformation products. The present results demonstrate that naturally occurring manganese oxides have the potential to oxidize industrial compounds such as TCP; however, the transformation products may be more toxic and persistent than the parent compound.
European foreign exchange market efficiency: Evidence based on crisis and noncrisis periods

Abstract This study investigates the impact on foreign exchange market efficiency of the 1992 European financial market crisis by studying precrisis, crisis, and postcrisis periods. Long-term relationships among European currency values are identified during the three periods, although the relationships are not stable during the precrisis and the postcrisis periods. These results may be due to one or more of the following: (1) market inefficiency, (2) a risk premium, or (3) common policy guidelines for European monetary system (EMS) members. Evidence of market inefficiency is strong. Forecasting results demonstrate better performance by an error correction model (ECM) than by a random walk model (RWM) for the British pound and German mark, while results for the French franc and Italian lira are mixed. Dominance tests using Granger causality indicate only weak German mark dominance both in the short and long run.
Transhiatal esophagectomy: A safe alternative for selected patients☆

Abstract One hundred one consecutive patients underwent an esophagectomy with gastric interposition for benign and malignant processes from January 1982 through July 1990. Seventy-seven underwent transhiatal esophagectomy and 24, transthoracic esophagectomy. Multivariate analysis was performed comparing the hospitalization experience of the two groups. There was no significant difference found between the mean intraoperative blood loss for transhiatal esophagectomy (770 ± 105 mL) and that of transthoracic esophagectomy (700 ± 175 mL). There was a significant difference between operative time, with transhiatal esophagectomy averaging 5.4 hours and transthoracic esophagectomy averaging 7.3 hours. Postoperative stay was not significantly different although there was a wide range of values for the transthoracic esophagectomy group. An 8% operative mortality was experienced by both groups. There were a significant number of minor anastomotic leaks at the cervical anastomotic level for the transhiatal esophagectomy group, but all responded to nonoperative management. The highest morbidity and mortality were seen in the subgroup of transhiatal esophagectomies done for laryngocervical malignancies. The lowest morbidity and mortality were seen in the subgroup of 12 patients who underwent transhiatal esophagectomy for nonmalignant esophageal conditions. Transhiatal esophagectomy appears to be a safe alternative for early intrathoracic esophageal malignancies at any level, for bulky distal esophageal lesions, and for benign conditions requiring total esophagectomy.
‘Lord only of the ruffians and fiends’? William Whewell and the plurality of worlds debate

Abstract By the middle of the nineteenth century, the opinion of science, as well as of philosophy and even religion, was, at least in Britain, firmly in the camp of the plurality of worlds, the view that intelligent life exists on other celestial bodies. William Whewell, considered an expert on science, philosophy and religion (among other areas), would have been expected to support this position. Yet he surprised everyone in 1853 by publishing a work arguing strongly against the plurality view. This was even stranger given that he had endorsed pluralism twenty years earlier in his contribution to the Bridgewater Treatises. In this paper I show that the shift in Whewell’s view was motivated by three factors: the influence of Richard Owen’s theory of archetypes on Whewell’s view of the argument from design, and Whewell’s perception of the need to strengthen such arguments in light of evolutionary accounts of human origins; important developments in his view of philosophy and his role as a scientific expert; and new findings in astronomy. An examination of the development of Whewell’s position provides a lens through which we can view the interplay of theology, philosophy and science in the plurality of worlds debate.
Mechanisms of cellular recruitment in aseptic loosening of prosthetic joint implants.

The association of macrophages engaged in polymethylmethacrylate (PMMA) particle phagocytosis with pockets of inflammatory cells is a pathognomonic feature of the aseptically loose interface not present at the well-fixed interface. The mechanism by which the presence of PMMA particles leads to cellular recruitment, bone resorption, and ultimate loosening is poorly understood. Granulocyte macrophage colony stimulating factor (GM-CSF) and interleukin 6 (IL-6), cytokines released by osteoblasts, stimulate the recruitment of macrophages into sites of inflammation. We show that exposure of macrophages to PMMA particles stimulated release of tumor necrosis factor (TNF), but no increase in prostaglandin E2 (PGE-2) or interleukin 1. Incubation of osteoblasts with conditioned medium from macrophages exposed to PMMA particles led to release of GMCSF, IL-6, and PGE-2. Incubation of the PMMA/macrophage medium with antibodies to TNF prior to osteoblast exposure inhibited release of GM-CSF, IL-6, and PGE-2 by the osteoblasts. Our data demonstrate that exposure of macrophages to PMMA particles leads to the release of TNF which then stimulates osteoblasts to produce GMCSF, IL-6, and PGE-2. Based upon the results of this study, we propose that the process of cellular recruitment in aseptic loosening is initiated when the mechanical failure of the cement mantle leads to the production of PMMA particles. These particles are phagocytized by macrophages leading to the production of TNF. TNF stimulates surrounding osteoblasts to produce GM-CSF, IL-6, and PGE-2 which leads to recruitment of macrophages and osteoclasts into the area of the bone-cement interface. The recruitment of these cells potentiates this process leading to bone resorption and ultimately, clinical loosening of prosthetic joint implants.
CoZSM-5: Why This Catalyst Selectively Reduces NOx with Methane

Methane oxidation with NO2, NO, O2 catalyzed by CoZSM-5 and CuZSM-5 was studied, as well as NO oxidation with O2 to form NO2. The efficacy of NO, NO2, and O2 for the oxidation of CH4 has been evaluated. CuZSM-5 is very active for combustion and it is thus the dominant pathway for NOx SCR with CH4. CoZSM-5 is much less active than CuZSM-5 for the same reaction. Although CH4 conversion with NO2 is approximately the same for both catalysts, the paths of NO2 conversion differ dramatically. Whereas with CoZSM-5, 50% of NO2 converts to N2 in the presence of CH4 at temperatures below 450°C, only 10% of NO2 is converted to N2 with CuZSM-5. However, the selectivity toward N2 for CuZSM-5 increases with temperature and reaches approximately 50% at 600°C. Despite the completely different behavior of both catalysts in the CH4+NO2 reaction they are equally selective for the CH4+NO reaction: only CO2 and N2 form but CuZSM-5 was more active. The catalytic behavior of CuZSM-5 and CoZSM-5 under SCR conditions with CH4 is related to the unique chemistry of Cu and Co species in the host ZSM-5. In CuZSM-5, dispersed Cu oxide clusters are highly active in a direct (reaction with O2) and an indirect (reaction with NO2 to form NO followed by its oxidation with O2) methane combustion. The different intrinsic ability of Cu2+ and Co2+ ions to activate NOx results in the formation of an adsorbed species that is reactive toward gaseous CH4 and also has a significant impact on the origin of CoZSM-5's ability to selectively reduce NOx with methane.
The Rhetoric of Thabo Mbeki on HIV/AIDS: Strategic Scapegoating?

South African President Thabo Mbeki's rhetoric on HIV/AIDS has been severely criticized in his nation and, especially, in “The West”. A close examination of this rhetoric reveals not only how it evolved rather quickly through very different phases but how it was arguably sincere, angry, and shrewd. Mbeki had sincere questions to ask and, eventually, angry accusations to make. As he did so, he also attempted to unite the Black majority behind his government in opposition to “The West”. “The West” was, in the drama Mbeki created, the scapegoat. A similar scapegoating strategy is used in Mbeki's 1999 inaugural address and is incipient in 1996 and 1998 speeches. In these other addresses, Mbeki scapegoats the apartheid government, not “The West”. His rhetorical goal (i.e., to unify South Africa's black majority as victims) was, however, the same.
Aerosol Deposition in a Nasopharyngolaryngeal Replica of a 5-Year-Old Child

Particle deposition in a child's nasal cavity is much different than that in the nasal airway of an adult because of the differences in geometry and breathing patterns. However, most deposition studies have focused on adults, and only a limited number of studies have been reported in a child's nasal cavity. This study was conducted as an in vitro test and computational fluid dynamics (CFD) analysis of particle deposition in the nasal replica of a 5-year-old child; both total and regional depositions were evaluated. The geometry of the nasal replica was based on magnetic resonance images of the head of the child. The replica was made by a rapid-prototyping machine. Monodisperse oleic acid and polystyrene latex aerosols ranging in size between 1 and 20 μm were delivered into the replica at flow rates of 10 and 20 L/min. Results showed that the total deposition from the in vitro experiments and CFD predictions matched to a high degree. Good agreement was also obtained when results were compared to existing i...
Density functional theory approach to thiols and disulfides on gold: Au(111) surface and clusters

We discuss our recent ab initio calculations of the adsorption configurations (both dissociative and not) of methanethiol and dimethyl disulfide on Au(111) at low coverage, which are based on density functional theory using gradient-corrected exchange–correlation functionals (both BLYP and PBE). A complete characterization of their structure, binding energies, and type of bonding is obtained. Dissociation is clearly favored for the disulfide with subsequent formation of strongly bound thiolates, in agreement with experimental evidence, whereas thiolates resulting from S–H bond cleavage in thiols can coexist with the adsorbed “intact” species and become favored if accompanied by the formation of molecular hydrogen. New calculations are also presented for the thiolates and the disulfide on a 38-atom gold cluster. Differences and similarities of the bonding on the cluster and on the surface are described in detail. © 2000 John Wiley & Sons, Inc. Int J Quant Chem 80: 598–608, 2000