cssi/SciSciGPT-SciSciNet huggingface dataset:
P01-513 - Interaction between personality, family, and neighborhood factors in substance use initiation among adolescents

Aims This project investigated longitudinal predictors of smoking, drinking and marijuana use initiation among adolescents. Method A community-representative sample of 440 mother-child dyads with equal gender, SES, and ethnic representation was assessed 4 times covering the span of more than 6 years. Children's reports of age of first smoke, drink and marijuana use were collected as part of the Youth Risk Behavior Survey (YRBS) at T3. Child-level predictors at T1 included child gender, race, and sensation seeking personality. Family-level predictors at T1 included maternal education, family income, and children's self-reports about exposure to home violence. Information regarding presence of drugs and gangs in schools/neighborhoods were collected from mothers and children at T1 and combined into a single measure. To examine the timing of events - specifically, the time when children started smoking, drinking and using marijuana as a function of the above T1 predictors - three separate survival models were estimated using the Cox proportional hazards model. Results Controlling for all other predictors, the sensation-seeking temperament and neighborhood quality remained significant predictors of substance use initiation among adolescents across all three substances, such that children initiated these behaviors sooner if they were high sensation-seekers or came form dysfunctional neighborhoods. Significant person X environment interactions were also evident for smoking and marijuana use, such that neighborhood and family risks were especially potent risks among children with high sensation seeking temperaments. These results point to the importance of broader contextual influences on the negative outcomes such as substance use during adolescence.
Response times and handedness in simple reaction-time tasks

The anticipatory (preparatory) cerebral events in simple reaction-time tasks may depend on the ability of a subject to predict accurately the time of occurrence of the stimulus requiring a particular response. In order to examine this hypothesis, we recorded cerebral and muscle responses in two different conditions, each involving three simple reaction-time tasks. Auditory tones were presented either regularly (i.e., predictably) or irregularly and subjects were required to respond to each tone with left hand, right hand or both hands in different runs. Responses were simultaneously averaged both backward and forward from the response (response-synchronized) and forward from the stimulus (stimulus-synchronized). Response-synchronized cerebral potentials to the regular tones were characterized by a slow negative shift, the bereitschaftspotential (BP), that began prior to stimulus onset and whose terminal phase was characterized by a small, higher frequency, negative shift (HFNS). By contrast, response-synchronized cerebral potentials to the irregular tones for both groups did not contain a BP, but a more conspicuous HFNS that began after stimulus onset. Both the response time and the latency of the N1 sensory-related component of the cerebral evoked potential recorded in the stimulus-synchronized averages (which aligns with HFNS) were delayed in the irregular condition. These findings suggest that, for both right- and left-handed subjects, the BP is not required for voluntary movement, and that anticipatory cerebral activity, as reflected by the BP, represents not only a preparation to make a particular response but also a preparation to process the stimulus.
Correlation between electron spin resonance spectra and oil yield in eastern oil shales

Abstract Organic free radical spin concentrations were measured in 60 raw oil shale samples from north Alabama and south Tennessee and compared with Fischer assays and uranium concentrations. No correlation was found between spin concentration and oil yield for the complete set of samples. However, for a 13 sample set taken from a single core hole, a linear correlation was obtained. No correlation between spin concentration and uranium concentration was found.
A GSK3beta phosphorylation site in axin modulates interaction with beta-catenin and Tcf-mediated gene expression.

Abstract Upon binding of a Wnt to its receptor, GSK3β is inhibited through an unknown mechanism involving Dishevelled (Dsh), resulting in the dephosphorylation and stabilization of β-catenin, which translocates to the nucleus and interacts with Lef/Tcf transcription factors to activate target gene expression. Axin is a scaffold protein which binds β-catenin and GSK3β (as well as several other proteins) and thus promotes the phosphorylation of β-catenin. Here we report that Axin is phosphorylated on Ser and Thr residues in several regions in vivo, while only one region (amino acids 600–672) is efficiently phosphorylated by GSK3β in vitro. Site-directed mutagenesis, together with in vitro and in vivo phosphorylation assays, demonstrates that Axin residues T609 and S614 are physiological GSK3β targets. Substitutions for one or more of these residues, which lie within a β-catenin binding site, reduce the ability of Axin to modulate Wnt-induced signaling in a Lef/Tcf reporter assay. These amino acid substitutions also reduce the binding between Axin and β-catenin. We propose a model in which inhibition of GSK3β activity upon Wnt signaling leads to the dephosphorylation of GSK3β sites in Axin, resulting in the release of β-catenin from the phosphorylation complex.
Hydrolysis of α- and β-d-glucosyl fluoride by individual glucosidases: new evidence for separately controlled “plastic” and “conserved” phases in glycosylase catalysis☆

Abstract α-Glucosidases from sugar beet seed and ungerminated rice catalyzed the hydrolysis of β- d -glucopyranosyl fluoride to form α- d -glucose. The reactions were slow, with V/K = 11−15 × 10 −3 or ∼ 1−2% of that for hydrolysis of p -nitrophenyl α- d -glucopyranoside, but were not due to any impurity in the substrate or to contaminating β-glucosidase or glucoamylase. Furthermore, almond β-glucosidase promoted hydrolysis of α- d -glucosyl fluoride to form β- d -glucose at an exceedingly low rate, V/K = 4 × 10 −4 . This weak reaction did not stem from any impurity in the substrate or to contamination with α-glucosidase or glucoamylase, but it was partly (∼ 20%) attributable to a trace of accompanying trehalase. That all three glucosidases acted upon both α- and β- d -glucosyl fluoride, albeit at low efficiency with the disfavored anomer, reflects the previously demonstrated ability of each enzyme's catalytic groups to respond flexibly to substrates of different types. That the disfavored d -glucosyl fluoride in each case was converted into a product of the same configuration as from enitols or favored d -glucosyl substrates provides additional evidence for the two-step nature of the chemical mechanisms of glucosidases, in which the stereochemistry of water attack on the enzyme-stabilized oxocarbonium ion is strictly maintained, regardless of the initial anomeric configuration of the substrate.
Role of N2 fixation in the soybean N credit in maize production

Many studies have shown that maize (Zea mays L.) requires less fertilizer N for optimum yield when grown in rotation with soybean [Glycine max (L.) Merr] than when grown in monoculture, which is referred to as the `soybean N credit' in the maize growing areas of the United States. Because the specific source of this soybean N credit is unclear, our objective was to determine the role of nodules and N2 fixation as a contributing source of the soybean N credit. Our research approach was designed to separate the effect of symbiotic N2 fixation from other rotational effects, as the treatments included: maize grown after nodulated (N2 fixing) soybean and maize grown after non-nodulated (non N2 fixing) soybean. A separate experiment examined maize grown after maize. For each previous crop, maize was grown the following year with varying rates of fertilizer applied N. In both years, the yield differences between nodulated and non-nodulated soybean as the previous crop were much smaller than the apparent yield decrease associated with continuous maize. Although small in magnitude, maize following non-nodulated soybean accumulated less total N, was paler in leaf color, and yielded less than maize following nodulated soybean in the more favorable year of 1999, while most of these differences were not observed in 2000. These findings indicate that soybean nodules and N2 fixation, while having a certain role, are not the major determinants of the soybean N credit.
Effects of training on good and poor readers’ use of top‐level structure

Abstract The present study was designed to investigate the effects of classroom instruction on good and poor readers’ use of description and comparison top‐level structures for signalled and non‐signalled passages. The subjects were 52 tenth grade students, 20 good and 32 poor readers, who were randomly assigned to treatment or control conditions within regular classroom settings. Training, provided by the English teacher on four consecutive days, included the use of description and comparison top‐level structures. All subjects were tested on the fifth day using a written recall task for signalled and non‐signalled forms of comparison and description passages. Analysis of variance showed significant differences between good and poor readers on all measures; between treatment and control poor readers for use of structure and signalling; and between description and comparison passages for poor readers in both conditions. It was concluded that training in a natural instructional setting can improve poor read...
Estimation of limits of detection for the flame emission gas chromatographic detector

Abstract The limit of detection theory proposed by W inefordner and V ickers for atomic emission flame spectrometry is applicable to estimation of limits of detection when using the flame emission gas chromatographic detector. Expressions are given for the limiting detectable concentration of the species in concern in the flame gases and for the limiting detectable sample size introduced into the gas chromatographic system when measuring line radiation from radiational deactivation of excited atoms. By means of several assumptions, these same expressions, modified slightly, can be used if the emitting species is a molecule. The expressions given can be used to estimate limits of detection and to optimize the experimental system with respect to gas chromatographic, flame compositional, spectral, and instrumental parameters. The variation of these parameters on the limiting detectable atomic concentration in the flame gases and on the limiting detectable sample size introduced into the gas chromatographic system is discussed.
Mechanism of carbon filament growth on metal catalysts

Abstract Carbon filaments formed on Ni, Co, and α-Fe particles by reaction with methane were studied. The filaments contained faceted single-crystal metal particles located at the growing tips. The crystallographic orientations of the gas/metal and graphite/metal interfaces were identified by TEM/selected area diffraction. Furthermore, extended Huickel molecular orbital calculations indicated that the (111) and (311) faces of Ni provide stronger epitaxial fits with graphite than the (100) and (110) faces and that the order is reversed for their activities for CO decomposition. The results are in agreement with the limited amount of literature data on phase segregation and surface reconstruction for carbon/metal solid solutions. On the basis of these and literature results, a better understanding of the carbon dissolution/diffusion/precipitation mechanism for filament growth is obtained. Also, a temperature-driven carbon diffusion mechanism without resorting to the exothermality of the surface reaction is proposed.
Influence of Flooding on Net CO2Assimilation, Growth and Stem Anatomy of Annona Species

Abstract A series of experiments was conducted to assess net CO2assimilation and growth responses to waterlogging of grafted and seedling trees in the genus Annona. Seedlings of A. glabra, A. muricata andA. squamosa L., and scions of ‘Gefner’ atemoya (A. squamosa×A. cherimola Mill.), ‘49-11’ (‘Gefner’ atemoya×A. reticulata L.), ‘4-5’ (‘Priestley’ atemoya×A. reticulata), A. reticulata grafted onto either A. glabra, A. reticulata orA. squamosa rootstocks were flooded for up to 60 d. Soil anaerobiosis occurred on the third day of flooding. Seedlings ofA. glabra and A. muricata, and the scions ‘49-11’, ‘Gefner’ atemoya, and A. reticulata grafted onto A. glabra rootstock were considered flood tolerant based on their ability to survive and grow in flooded conditions. Scions of the normally flood-sensitive A. reticulata, ‘Gefner’ atemoya, and ‘49-11’ tolerated root waterlogging when grafted onto the flood-tolerant species, A. glabra. In contrast, flooding of A. squamosa seedlings and rootstocks, and A. reticulata rootstocks greatly reduced growth and net CO2assimilation rates, and resulted in 20–80% tree mortality. Stem anatomical responses to long-term flooding (12 continuous months) were assessed in seedlings of A. glabra and A. muricata, and trees of ‘49-11’ grafted onto A. glabra. Flooded trees developed hypertrophied stem lenticels, particularly in A. glabra, and enlarged xylem cells resulting in thicker stems with reduced xylem density. Flooding did not increase air spaces in pre-existing xylem near the pith or in xylem tissue that was formed during flooding. Thus, flood tolerance did not involve aerenchyma formation in the stem.
Is Group Choice a Part of Economics

Introduction, 362. — I. Ellis and the economic calculus of individual preference, 362. — II. Knight and the science of the price mechanism, 367. — III. Survey of economic education by McKee and Moulton, 373. — IV. Report on undergraduate teaching of economics, 374. — V. Summary, 377.
Pigeons group time intervals according to their relative duration.

In the present research, we asked whether pigeons tended to judge time intervals not only in terms of their absolute value but also relative to a duration from which they must be discriminated (i.e., longer or shorter). Pigeons were trained on two independent temporal discriminations. In one discrimination, sample durations of 2 and 8 sec were associated with, for example, red and green hue comparisons, respectively, and in the other discrimination, sample durations of 4 and 16 sec were associated with vertical and horizontal line comparisons, respectively. If pigeons are trained on a temporal discrimination and tested with intermediate durations, the subjective midpoint typically occurs close to the geometric mean of the two trained values. The 4- and 8-sec values were selected to be the geometric mean of the two values in the other discrimination. When a 4-sec test sample was presented with the comparisons from the 2- and 8-sec discrimination, the pigeons preferred the comparison associated with the shorter sample. Similarly, when an 8-sec test sample was presented with the comparisons from the 4-and 16-sec discrimination, the pigeons preferred the comparison associated with the longer sample. Thus, a relative grouping effect was found. That is, durations that should have produced indifferent choice were influenced by their relative durations (shorter than or longer than the alternative) during training.
Strings at the Hagedorn temperature

An ensemble of free strings may be raised to the Hagedorn temperature with a finite energy density. After this, energy added to the system in an attempt to raise its temperature produces long string; the configuration of the rest of the system is determined by an ordinary thermal distribution at the Hagedorn temperature. These conclusions may be altered by new physics at the string scale.
Regenerating evanescent waves from a silver superlens

We investigated a precursor of superlensing: regenerating evanescent waves by excitation of a surface plasmon. Because the permittivity of a silver slab approaches -1, we experimentally observed a broadening of surface-plasmon bandwidth. Our study identifies a means to access deep subwavelength features by use of a metamaterial superlens.
Dermatologic balneology: The American view of waters, spas, and hot springs

Abundant water is an important part of everyday living. The substance also has therapeutic capabilities, some of which may have been neglected or even ignored by many societies. Whereas Italians are quick to praise the virtues of mineral water and spa treatment, Americans have often forgotten the potential benefits of the waters. A visit to the Dead Sea for the treatment of psoriasis is an accepted modality by many, but others might question a weekend at Saratoga Springs, New York, other than for horse-racing and relaxation. Patients have learned from grammar school hygiene classes about the so-called of cleansing of the body, requiring the drinking of eight glasses of water per day. Washing is also an important ritual in contemporary society, so much so that, one might say: “not even time for a hath”. According to an old Hindustani proverb, “bathe early every day and sickness will avoid you” Nary a practitioner would deny the use of water in the dermatologic armamentatium. The colloidal bath is recognized as an integral part of the therapy for pruritic dermatitis, just as the wet to dry compress is highly useful in the treatment of eczematized skin. In addition, water is a necessary adjunct in acne therapy or for that matter seborrheic dermatitis.
Partitioning Planar Graphs with Vertex Costs: Algorithms and Applications

We prove separator theorems in which the size of the separator is minimized with respect to non-negative vertex costs. We show that for any planar graph G there exists a vertex separator of total sum of vertex costs at most $c\sqrt{\sum_{v\in V(G)}( cost (v))^2}$ and that this bound is optimal to within a constant factor. Moreover, such a separator can be found in linear time. This theorem implies a variety of other separation results. We describe applications of our separator theorems to graph embedding problems, to graph pebbling, and to multicommodity flow problems.
Loss aversion, education, and intergenerational mobility

Existing empirical work looking at the effects of parental income on IQ, schooling, wealth, race, and personality is only able to explain about half of the observed intergenerational income elasticity. This paper provides a possible behavioral explanation for this elasticity in which heterogeneous agents in sequential generations choose their education levels in the face of loss-averse preferences and weak borrowing constraints. These borrowing-constrained agents make education investment choices in part to avoid consumption losses rather than to maximize lifetime resources. The model generates a positive intergenerational income elasticity even when there are functioning capital markets to finance education investments. I find empirical support for the J-shape education decision rule generated by the model and show that it is mostly successful in matching the asymmetric intergenerational transition rates between income quintiles of white families.
Validation of an Instrument for Assessing Teacher Knowledge of Basic Language Constructs of Literacy.

Recent national reports have stressed the importance of teacher knowledge in teaching reading. However, in the past, teachers’ knowledge of language and literacy constructs has typically been assessed with instruments that are not fully tested for validity. In the present study, an instrument was developed; and its reliability, item difficulty, and item discrimination were computed and examined to identify model fit by applying exploratory factor analysis. Such analyses showed that the instrument demonstrated adequate estimates of reliability in assessing teachers' knowledge of language constructs. The implications for professional development of in-service teachers as well as preservice teacher education are also discussed.
Assessment of pulmonary fibrogenic potential of multiwalled carbon nanotubes in human lung cells

Multiwalled carbon nanotubes have been shown to possess unusual fibrogenic activity in vivo and are currently the focus of intense toxicological investigations. This study further determines the fibrogenic potential of well-dispersed MWCNT in human lung cell culture models and to develop a novel platform for understanding the cellular mechanisms of MWCNT-induced lung fibrosis. Survanta, a natural lung surfactant, showed effectiveness in dispersing agglomerates of MWCNT to fine structures similar in size to aerosolized one. At relevant low doses (0.002-0.2 µg/cm2), MWCNT exhibited a dose-dependent bio-effect on the human lung epithelial cells which is more pronounced in dispersed-MWCNT compared to non-dispersed form. Significantly elevated levels of fibrogenic mediators, such as transforming growth factor-β1 and matrix metalloprotienases-9 were observed in the dispersed-MWCNT treated lung epithelial cells. Based on previous in vivo studies showing that dispersed-MWCNT penetrated the interstitium and caused rapid interstitial fibrosis, we evaluated the potential direct interaction between lung fibroblasts and MWCNT. Direct stimulation of human lung fibroblast cell proliferation, collagen expression and fibroblast growth factor-2 were observed which suggests novel mechanisms of MWCNT-induced lung fibrosis. Our results indicate that the dispersion status of MWCNT determines their fibrogenic activity which is consistent with in vivo findings.
FLAVIN AS AN ACTIVE COMPONENT OF THE PHOTOREVERSIBLE PIGMENT SYSTEM OF THE GREEN ALGA PROTOSIPHON BOTRYOIDES KLEBS

— The photoreversible pigment system from Protosiphon botryoides Klebs can be separated into two fractions, which are individually inactive photobiologically, but can be recombined to form an active system. One fraction contains a component stable to combined heat and dilute acid treatment; this component can be replaced by flavin nucleotides. An essential component in the second fraction is heat labile. A similar pigment system has been isolated from other species of green algae.
Catabolite modification of acid tolerance of Streptococcus mutans GS‐5

The acid tolerance of Streptococcus mutans GS-5 in standard pH-drop assays was found to be affected by the sugar used in the assay and also by the sugar used for growth of the organism. For example, acid tolerance was lower when galactose was used as catabolite than when glucose was used, apparently because galactose/proton symport brought protons extruded by the F-ATPase back into the cell and thus reduced delta pH across the cell membrane. The acid tolerance of glycolysis was related directly to the capacities of the cells to produce acid glycolytically, or probably more correctly, to their capacities to produce adenosine triphosphate but not to acid tolerance of phosphotransferase systems for sugar uptake. Thus, glycolytic acid tolerance of S. mutans depends not only on environmental factors such as potassium or magnesium levels but also on the specific catabolites the organism is metabolizing or to which it has become metabolically adapted.
SUBSTRATE OXIDATIONS BY EMBRYONIC RAT HEART CELL CULTURES

Beating monolayer cultures of fetal rat heart have been utilized to measure oxidation of labelled substrates to 14CO2 and to investigate metabolic interactions of cells in culture. Increased rates of glucose oxidation by proliferating as compared to density inhibited heart cells is due to enhanced pentose phosphate pathway activity during proliferative growth. Oxidation of palmitate by rat heart cultures is independent of stage of growth and is linear with increasing protein concentration and time. Oxidation of palmitate is stimulated by addition of carnitine to the assay medium. Unlabelled palmitate spared the oxidation of glucose-14C to 14CO2 by 50%. Unlabelled glucose had no effect on the oxidation of palmitate. Palmitate did not inhibit lactate production by rat heart cell cultures incubated with buffer alone or with glucose. Embryonic rat heart cultures actively oxidized pyruvate-14C to 14CO2. As observed with glucose, addition of palmitate to the assay medium inhibited oxidation of pyruvate-14C to 14CO2 by 50%. In contrast, palmitate had no effect on 14CO2 production from α-ketoglutarate. Similar to the adult heart, palmitate is the preferred substrate of fetal rat heart cultures. The data suggests that inhibition of glucose oxidation by palmitate is related to direct inhibition of pyruvate dehydrogenase. Cultured myocardial cells provide a relatively homogeneous source of tissue for investigation of metabolic interactions and substrate preferences of the heart.
Existence, uniqueness, and estimation of solutions for a set of equations of perturbed motion

We propose a regularization procedure for a set of equations of perturbed motion with uncertain values of the parameters. We use the comparison principle to establish conditions for the existence of solutions of the original and regularized systems.
324 ROLE OF ENDOGENOUS FACTORS IN POST-NATAL DEVELOPMENT OF HEPATIC MICROSOMAL OXIDATIVE METABOLISM IN THE RABBIT

Indomethacin (I) undergoes both microsomal oxidation to desmethyl-indomethacin (DMI) and cytosolic deacylation to desbenzoylchloro-indomethacin (DBI). The in vitro postnatal development of these two pathways was examined in the rabbit liver using collagenase-isolated hepatocytes and liver fractions incubated with 0.5 mM 14C-I and appropriate cofactors for drug metabolism activity. Samples were removed at 5 to 15 min intervals for analysis of I metabolites. Deacylation of I to DBI in the 10,000g liver homogenate increased rapidly during the 1st 2 wks after births and demonstrated adult values within day 12 of postnatal age. Results from freshly isolated hepatocytes were very similar to the 10,000g liver homogenate in the pattern of postnatal development of the DBI pathway. Oxidative demethylation of I to DMI in the 10,000g homogenate and isolated cells demonstrated a significant increase only after day 14 of postnatal age and demonstrated only 83% of adult value by day 32 of postnatal age. The isolated microsomal fraction demonstrated a significant postnatal increase in DMI formation during the first 2 wks of postnatal life and reached adult values within day 32 of postnatal age. It is postulated that the difference in postnatal development of I metabolism to DMI between isolated microsomes and the 10,000g homogenate or the isolated hepatocyte is due to endogenous substrates which are competitive for oxidative drug metabolism.
Social Cognition in the Internet Age: Same As It Ever Was?

The World Wide Web has inarguably become an integral part of the daily lives of the majority of the world's population. Many people spend more time online than with any given person on any particular day, yet the cognitive impact of being online remains understudied in psychology. We examine the research that has been done, and relate other related research findings, in an effort to attract more research to this area. We analyze some of the key factors that may have an impact on what and how we learn online, whether we are interacting with the cloud mind interpreted by Google or with other people via text based communication. We investigate how this development changes our perception of reality and how we may evaluate online information in ways that differ from face-to-face encounters. Living our lives in cyberspace changes what kinds of information we most frequently process and how we habitually deploy our cognitive resources, for better and for worse. When people interact with the Internet they may ado...
Influence of vitamin A on growth somatomedin and glycosaminoglycan metabolism

Abstract The effects of dietary depletion and repletion of vitamin A on growth rate, organ weights, cartilage metabolism, and somatomedin activity were studied. Weanling rats were fed control diet ad libitum or were depleted of vitamin A over a 52-day period. Synchronized depletion of vitamin A stores was accomplished by administration of retinoic acid to deficient animals until all experimental rats were depleted. Vitamin A deficient rats (A-) were repleted with either retinyl palmitate (RP) or retinoic acid (RA) 2 ug/day/rat, by gavage. Rats were sacrificed after 0, 6, 12, 24, 48, or 96 hours of refeeding. Serum and liver vitamin A levels were significantly decreased in the A- compared to controls (5.0±3.8 vs. 25.9±3.8 ug/100 ml serum, p 35 SO 4 uptake by glycosaminoglycans (GAG) was significantly increased in the A- animals compared to controls at depletion (110,394±9,148 vs 61 380±9,148 cpm/mg uronic acid, p 35 SO 4 uptake by GAG. It appears that the aberrations in cartilage metabolism and growth seen in vitamin A deficiency are independent of somatomedin activity.
Charged current neutral pion cross section measurement at K2K

In this paper we report the measurement of the rate of single charged current π0 production in the K2K near detector. The inclusive charged current π0 production is measured in the SciBar detector (in C8H8) and the cross section ratio to the charged current quasi elastic neutrino cross section is found to be σccπ0/σCCQE = 0.443±0.033(stat.)±0.036(syst.).
The Nurse's Role in Office Hysteroscopy

In recent years, hysteroscopy has been developed to provide physicians with direct visibility of the uterine cavity. Using carbon dioxide gas as a distending medium, office hysteroscopy has few side effects for women. It is also more cost effective than outpatient surgery. The nurse's role is pivotal in simplifying office hysteroscopy through empathetic preparation and support of women, careful planning, procurement of necessary items, and finally, conscientious care of the instruments.
Actions of Tefluthrin on Rat Nav1.7 Voltage-Gated Sodium Channels Expressed in Xenopus Oocytes

In rats expression of the Na(v)1.7 voltage-gated sodium channel isoform is restricted to the peripheral nervous system and is abundant in the sensory neurons of the dorsal root ganglion. We expressed the rat Na(v)1.7 sodium channel α subunit together with the rat auxiliary β1 and β2 subunits in Xenopus laevis oocytes and assessed the effects of the pyrethroid insecticide tefluthrin on the expressed currents using the two-electrode voltage clamp method. Tefluthrin at 100 µM modified of Na(v)1.7 channels to prolong inactivation of the peak current during a depolarizing pulse, resulting in a marked "late current" at the end of a 40-ms depolarization, and induced a sodium tail current following repolarization. Tefluthrin modification was enhanced up to two-fold by the application of a train of up to 100 5-ms depolarizing prepulses. These effects of tefluthrin on Na(v)1.7 channels were qualitatively similar to its effects on rat Na(v)1.2, Na(v)1.3 and Na(v)1.6 channels assayed previously under identical conditions. However, Na(v)1.7 sodium channels were distinguished by their low sensitivity to modification by tefluthrin, especially compared to Na(v)1.3 and Na(v)1.6 channels. It is likely that Na(v)1.7 channels contribute significantly to the tetrodotoxin-sensitive, pyrethroid-resistant current found in cultured dorsal root ganglion neurons. We aligned the complete amino acid sequences of four pyrethroid-sensitive isoforms (house fly Vssc1; rat Na(v)1.3, Na(v)1.6 and Na(v)1.8) and two pyrethroid-resistant isoforms (rat Na(v)1.2 and Na(v)1.7) and found only a single site, located in transmembrane segment 6 of homology domain I, at which the amino acid sequence was conserved among all four sensitive isoform sequences but differed in the two resistant isoform sequences. This position, corresponding to Val410 of the house fly Vssc1 sequence, also aligns with sites of multiple amino acid substitutions identified in the sodium channel sequences of pyrethroid-resistant insect populations. These results implicate this single amino acid polymorphism in transmembrane segment 6 of sodium channel homology domain I as a determinant of the differential pyrethroid sensitivity of rat sodium channel isoforms.
Male Reproductive Tract Malformations in Rats Following Gestational and Lactational Exposure to Di(n-butyl) Phthalate: An Antiandrogenic Mechanism?

Di(n-butyl) phthalate (DBP), a widely used plasticizer suspected of having estrogenic properties, was investigated for its effects on the prenatal and early neonatal development of the reproductive tract. Pregnant CD rats (n = 10) were given DBP at 0, 250, 500, or 750 mg/kg/day (p.o.) throughout pregnancy and lactation until their offspring were at postnatal day 20. Maternal body weights throughout the dosing period were comparable in all groups. At 750 mg/kg/day, the number of live pups per litter at birth was decreased and maternal effects on pregnancy and postimplantation loss are likely to have occurred. Anogenital distance was decreased at birth in the male offspring at 500 and 750 mg/kg/day. The epididymis was absent or underdeveloped in 9, 50, and 71% of adult offspring (100 days old) at 250, 500, and 750 mg/kg/day, respectively, and was associated with testicular atrophy and widespread germ cell loss. Hypospadias occurred in 3, 21, and 43% of males and ectopic or absent testes in 3, 6, and 29% of males at 250, 500, and 750 mg/kg/day, respectively. Absence of prostate gland and seminal vesicles as well as small testes and seminal vesicles were noted at 500 and 750 mg/kg/day. Vaginal opening and estrous cyclicity, both estrogen-dependent events, were not affected in the female offspring, although low incidences of reproductive tract malformations were observed at 500 and 750 mg/kg/day. In the male offspring, DBP produced the same spectrum of effects elicited by the antiandrogen flutamide. Thus, DBP specifically impaired the androgen-dependent development of the male reproductive tract, suggesting that DBP is not estrogenic but antiandrogenic in the rat at these high dose levels. For human risk assessment, determining if this toxicity is metabolite-mediated will be critical, since marked species differences in metabolism exist.
Electrolyte parameter effects in the electrowinning of nickel from sulfate electrolytes

Abstract Nickel deposits were electrowon from acid sulfate electrolytes to determine the effects of various parameters when buffer agents were not present. The nickel concentration, pH and temperature of the electrolyte were varied over a relatively broad range to evaluate changes in cathode morphology and current efficiency. Both good quality deposits, ones which were flat, smooth and ductile, and degraded deposits, which were characterized by cracking, curling, pitting and brittleness, were obtained depending on the conditions chosen for these three variables. A good quality deposit morphology and a high current efficiency were favored by high nickel concentrations and electrolyte temperatures. The deposit morphology was improved at lower pH, but a decrease in deposit current efficiency resulted. Deposit orientations were determined, but no specific trends were evident. Cyclic voltammetry tests did show some correlation to deposit morphology but not to current efficiency.
Early development of the circumferential axonal pathway in mouse and chick spinal cord.

The early development of the circumferential axonal pathway in the brachial and lumbar spinal cord of mouse and chick embryos was studied by scanning and transmission electron microscopy. The cellular processes which comprise this pathway grow in the transverse plane and along the lateral margin of the marginal zone (i.e., circumferentially oriented), as typified by the early embryonic commissural axons. The first formative event observed was in the ventrolateral margin of the primitive spinal cord ventricular zone. Cellular processes were found near the external limiting membrane that appeared to grow a variable distance either dorsally or ventrally. Later in development, presumptive motor column neurons migrated into the ventrolateral region, distal to these early circumferentially oriented processes. Concurrently, other circumferentially oriented perikarya and processes appeared along the dorsolateral margin. Due to their aligned sites of origin and parallel growth, the circumferential processes formed a more or less continuous line or pathway, which in about 10% of the scanned specimens could be followed along the entire lateral margin of the embryonic spinal cord. Several specimens later in development had two sets of aligned circumferential processes in the ventral region. Large numbers of circumferential axons were then found to follow the preformed pathway by fasciculation, after the primitive motor column had become established. Since the earliest circumferential processes appeared to differentiate into axons and were found nearly 24 hours prior to growth of most circumferential axons, their role in guidance as pioneering axons was suggested.
Nests and Nesting Materials: Aspects of the Realism of La gaviota

Cecila Bohl de Faber (Fernan Caballero) figures as a proto-Realist in the context of nineteenth-century letters, but also incorporates aspects of the traditional Spanish realism and costumbrismo into La gaviota (1849). This novel becomes a veritable intertextual gallery, in which Cervantes and Don Quijote have a crucial, albeit often ironic, position. She also incorporates much folkloric material into her text: prominent is the story of “Medio-pollito,” whose characters parallel and even explicate those in the larger narrative. This and other inclusions highlight her understanding of mimesis and verisimilitude, of the fictive and the “real.” Numerous writers have pointed out how the novelist was particularly conflicted about her protagonist, Marisalada. This ambivalence carries over into her narratological framework and role as an artist, for dona Cecilia confronts what has been termed the “anxiety of authorship” experienced by women writers in the nineteenth century. In La gaviota– no matter what gender, genre, or genealogy the author may invoke – one can document her belief that “la novela no se inventa, se observa,” as well as her efforts to “poetizar la realidad.” Likewise, Fernan Caballero is able creatively to “realizar la poesia” and “observar la invencion.”
Generalized equations, variational inequalities and a weak Kantorovich theorem

We prove a Kantorovich-type theorem on the existence and uniqueness of the solution of a generalized equation of the form $f(u)+g(u)\owns 0$ where f is a Frechet-differentiable function and g is a maximal monotone operator defined on a Hilbert space. The depth and scope of this theorem is such that when we specialize it to nonlinear operator equations, variational inequalities and nonlinear complementarity problems we obtain novel results for these problems as well. Our approach to the solution of a generalized equation is iterative, and the solution is obtained as the limit of the solutions of partially linearized generalized Newton subproblems of the type $Az+g(z)\owns b$ where A is a linear operator.
Characterization of Guanylate cyclase of rod outer segments of the bovine retina

Abstract Guanylate cyclase (GTP pyrophosphate-lyase (cyclizing), EC 4.6.1.2) of bovine retinal rod outer segments is almost completely particulate, i.e. associated with rod outer segment membranes. In contrast to particulate guanylate cyclase is other tissues, treatment of rod outer segments with Triton X-100 does not solubilize the enzyme but inhibits it. Enzyme activity is dependent on the presence of divalent cation, especially Mn2+ with only poor activation by Mg2+ (10-fold lower) and no activation seen with other cations. Expression of maximal activity required Mn2+ and GTP in equimolar concentrations with an apparent K m of 8 · 10−4 M and V of 10 nmol/min per mg protein. Excess of Mn2+ over that required for the formation of the Mn · GTP complex was inhibitory , Ca2+, Ba2+ and Co2+ inhibited enzyme activity when assayed with the Mn · GTP substrate complex. In the presence of a fixed concentration of 1 mM Mn2+, the enzyme exhibited strong negative cooperative interactions with GTP, characterized by an intermediary plateau region in the substrate vs. enzyme activity curve, a curve of downward concavity in the double reciprocal plot and a Hill coefficient of 0.5. Nucleotides such as ITP, ATP and UTP at higher concentrations (1 mM) inhibit enzyme activity while ATP at lower concentrations (0.1 mM) stimulates activity by 40%. NaN3 has no efffect on the guanylate cyclase. It is thus possible that the guanylate cyclase may be regulated in vivo by both the metal : GTP substrate ratio and the free divalent cation concentration as well as by the ATP concentration and thus play an important but yet undefined role in the visual process.
Responding to the Special Needs of Children Educating HIV/AIDS Orphans in Kenya

(2004). Responding to the Special Needs of Children Educating HIV/AIDS Orphans in Kenya. Childhood Education: Vol. 80, International Focus Issue 2004: Challenges Issues and Rays of Hope, pp. 304-309.
Large protonic conductivity in copper formate tetrahydrate single crystals

Abstract Using proton injecting electrodes, the protonic conductivity of copper formate tetrahydrate single crystals has been found to be quite large. At 300°K, the conductivity measured parallel to the (001) planes and perpendicular to the (110) planes is 4.5 × 10−7 (ohm-cm)−1. The conductivity is ohmic at low fields with non-ohmic behavior exhibited at higher fields (space-charge limited current). The temperature dependence of the ohmic conductivity was examined from 223–298°K. There is an abrupt decrease of the conductivity in passing through the antiferroelectric phase transition at 235°K.
Back Electron Transfer from TiO2 Nanoparticles to FeIII(CN)63-: Origin of Non-Single-Exponential and Particle Size Independent Dynamics

Back-electron-transfer (ET) dynamics in FeII(CN)64--sensitized colloidal TiO2 nanoparticles are studied using ultrafast pump probe spectroscopy. Excitation of the adsorbate-to-nanoparticle charge-transfer band at 400 nm leads to direct injection of electrons from FeII(CN)64- to TiO2. The kinetics of back electron transfer from TiO2 to the FeIII(CN)63- are measured by monitoring the bleach recovery of the charge-transfer band in the 430−600 nm region. The measured back-ET kinetics are non-single-exponential, and a multiexponential fit requires at least four components on the <1 ns time scale. The kinetics are independent of pump power, indicating a geminate recombination process. Recombination kinetics are very similar in two samples of 5 and 11 nm (A-type) particles prepared from dried nanoparticle powder, but they are noticeably different from those in samples of 3 and 9 nm (B-type) nanoparticles prepared directly from colloids without drying. This result indicates that the back-ET kinetics in this syste...
Sparfloxacin: a review.

Abstract Background The continuing increase in the rate of penicillin and cephalosporin resistance among respiratory pathogens and of cross-resistance to macrolide antibiotics has led to the recommendation that fluoroquinolone antibiotics be used to treat high-risk patients with community-acquired pneumonia (CAP) and acute bacterial exacerbations of chronic bronchitis (ABECB). Objective This review focuses on sparfloxacin, an oral fluoroquinolone, discussing its mechanism of action, activity, pharmacokinetic characteristics, safety, and efficacy in CAP and ABECB. Methods Studies were identified by a MEDLINE ® search of the literature from 1990 to 1999, supplemented by educational materials from conferences and symposia. Results Sparfloxacin is active against the major respiratory pathogens and against the atypical pathogens in pneumonia that are being reported with increasing frequency. Its long half-life permits once-daily dosing. In large trials in CAP and ABECB in which all isolates were susceptible to both comparators, sparfloxacin was found to have similar efficacy to erythromycin, cefaclor, amoxicillin, ofloxacin, and clarithromycin. Its safety profile is similar to that of the macrolides and other quinolone antimicrobial agents. Photosensitivity, nausea, and diarrhea are the most common adverse events reported in clinical trials of sparfloxacin. Its use is contraindicated in patients with QT c -interval prolongation. Conclusion The increasing prevalence of beta-lactam- and macrolide-resistant bacteria in respiratory infections emphasizes the need for newer agents such as the fluoroquinolones. The choice between agents should be based on activity against the relevant respiratory pathogens in high-risk patients.
Effect of slow compression on the linear stability of an accelerated shear layer

An analysis is given of the effect of a slow uniform anisotropic compression or expansion on the linear stability of a normally accelerated planar interface between two fluids with different densities and tangential velocities, i.e., a combined Kelvin-Helmholtz and Rayleigh-Taylor instability, but generalized to an arbitrary time-dependent acceleration history. The compression is presumed to be sufficiently slow that the density remains uniform within each fluid and hence depends only on time. The perturbation is taken to be sinusoidal with amplitude $h(t).$ The time evolution of h is determined by requiring pressure continuity across the interface in the usual way. The resulting linearized stability equation is a second-order linear ordinary differential equation for $h(t).$ Compared to the corresponding well-known result for incompressible fluids, it is found that normal compression has the effect of reducing the perturbation growth rate $\mathrm{h\ifmmode \dot{}\else \.{}\fi{}}$ by an obvious geometrical correction, while transverse compression does not directly affect the net growth rate but rather has the dynamical effect of increasing its time derivative. When attention is focused on the masses transported across the initial interface rather than h, the purely geometrical effects of compression no longer appear explicitly, while the dynamical effects remain. It is thereby shown that both normal and transverse compression dynamically enhance the mixing of material masses, in spite of the corresponding purely geometrical reduction in $\mathrm{h\ifmmode \dot{}\else \.{}\fi{}}.$
Effect of Compton scattering on the double-to-single photoionization ratio in helium

The effect of Compton scattering on the ratio of double-to-single ionization from photon impact in helium has been measured for 2.1\ensuremath{\le}h\ensuremath{\nu}\ensuremath{\le}5.5 keV using a time-of-flight ion spectrometer with a high relative collection efficiency for Compton ions. Single ionization from Compton scattering is found to contribute measurably to a reduction in the ionization ratio for h\ensuremath{\nu}\ensuremath{\gtrsim}3.5 keV. Our measurements are compared with predictions based on recent calculations of the single and double ionization cross sections for photoabsorption and Compton scattering by Hino et al. [Phys. Rev. A 48, 1271 (1993), Phys. Rev. Lett. 72, 1620 (1994)], Andersson et al. [Phys. Rev. Lett. 71, 50 (1993)], and Suri\ifmmode \acute{c}\else \'{c}\fi{} et al. [Phys. Rev. Lett. 73, 790 (1994)].
Phosphorylated H2AX in Noninvasive Low Grade Urothelial Carcinoma of the Bladder: Correlation With Tumor Recurrence

Purpose: Histone modifications have been linked to DNA replication, transcription and repair. The phosphorylation of histone H2AX at serine 139 (γ-H2AX) is associated with DNA breaks. γ-H2AX has been shown to be expressed in bladder urothelial carcinoma. To our knowledge studies of the relationship of γ-H2AX expression and the clinical outcome of urothelial carcinoma are lacking. Hence, we evaluated the rate of H2AX phosphorylation in low grade bladder urothelial carcinoma and assessed its potential role for predicting recurrence and/or progression.Materials and Methods: Immunohistochemical expression of γ-H2AX using a polyclonal antibody was retrospectively assessed in 2 groups of patients from The Johns Hopkins Hospital with low grade bladder urothelial carcinoma. Group 1 consisted of transurethral resection biopsies from 18 patients from 2004 to 2006 that were retrieved from our surgical pathology files. Group 2 consisted of 42 archival transurethral biopsies obtained between 1971 and 1995 with longer ...