cssi/SciSciGPT-SciSciNet huggingface dataset:
Effects of prenatal alcohol exposure at school age: II. Attention and behavior.

Alcohol, a potent teratogen, has been suggested as an etiologic agent in attention deficit disorder with hyperactivity (ADHD), which is often diagnosed in children with fetal alcohol syndrome (FAS) and in children of alcoholics. We studied attentional and behavioral factors associated with diagnosis of this disorder in children selected from a predominantly low-income, black population who were tested as part of a longitudinal follow-up of children with prenatal alcohol exposure. Sixty-eight children with a mean age of 5 years 10 months, born to three groups of mothers, were assessed. These groups consisted of: a) women who reported not drinking during pregnancy (n = 21), b) women who reported drinking throughout pregnancy (n = 25), and c) women who reported drinking an equivalent amount but who stopped drinking after educational intervention during the second trimester (n = 22). Dimensions assessed included factors related to attention on a computerized task, impulsivity, and the presence of psychiatrically significant internalizing and externalizing behaviors. In addition, free play and mother-child interactions were video-taped, and evidence of overactive and noncompliant behaviors were noted. Hyperactivity and impulsive behavior were not evident. Results indicated that children exposed throughout pregnancy showed deficits in the ability to sustain attention and were more often described by teachers, although not by their mothers, as showing attentional and behavioral problems. Problems in both internalizing and externalizing behaviors also were noted by teachers. However, when current drinking was controlled, only externalizing behaviors remained different by group.(ABSTRACT TRUNCATED AT 250 WORDS)
Disk covering methods improve phylogenomic analyses

With the rapid growth rate of newly sequenced genomes, species tree inference from multiple genes has become a basic bioinformatics task in comparative and evolutionary biology. However, accurate species tree estimation is difficult in the presence of gene tree discordance, which is often due to incomplete lineage sorting (ILS), modelled by the multi-species coalescent. Several highly accurate coalescent-based species tree estimation methods have been developed over the last decade, including MP-EST. However, the running time for MP-EST increases rapidly as the number of species grows. We present divide-and-conquer techniques that improve the scalability of MP-EST so that it can run efficiently on large datasets. Surprisingly, this technique also improves the accuracy of species trees estimated by MP-EST, as our study shows on a collection of simulated and biological datasets.
Calculating the charge of a jet

Jet charge has played an important role in experimentally testing the parton model and the Standard Model, and has many potential LHC applications. The energy-weighted charge of a jet is not an infrared-safe quantity, so hadronization must be taken into account. Here we develop the formalism to calculate it, cleanly separating the nonperturbative from the perturbative physics, which we compute at one-loop order. We first study the average and width of the jet charge distribution, for which the nonperturbative input is related to (dihadron) fragmentation functions. In an alternative and novel approach, we consider the full nonperturbative jet charge distribution and calculate its evolution and jet algorithm corrections, which have a natural Monte Carlo-style implementation. Our numerical results are compared to pythia and show reasonable agreement. This calculation can directly be extended to similar track-based observables, such as the total track momentum generated by an energetic parton.
The genomic RNA of avian reticuloendotheliosis virus REV

Purified virus obtained from a subline of chicken bone marrow cells transformed by avian reticuloendotheliosis virus (REV) was found to contain the RNA of REV in excess over the RNA of its associated helper virus REV-A. Electrophoretic and sedimentation analyses resolved these RNAs into a 28 S and a 34 S component, respectively. Comparison of these RNA species with the RNA obtained from plaque-purified preparations of REV-A confirmed that the 28 S RNA represents the genome of transforming REV. The small size of 28 S REV RNA suggests that the defectiveness of REV is due to a deletion of replicative sequences. Hybridization experiments indicated that about 25–30% of REV RNA sequences are unrelated to REV-A. These may include the putative transforming sequences of REV. REV shared 12–15 of 42 identifiable large RNase T1-resistant oligonucleotides with REV-A. The 28 S REV RNA did not contain the transformation-specific oligonucleotides which are largely conserved among avian acute leukemia viruses MC29, MH2, and CMII or the src-specific oligonucleotides of avian sarcoma viruses. It is concluded that the sequences which are unique for REV contain a new class of avian tumor virus transforming genes.
Radioactive Isotopes of Zinc

The existence of zinc radioactivities with half-lives 57 minutes and 13.8 hours is confirmed, by deuteron activation of zinc. In addition, it is found that both these activities are produced by deuteron and by fast neutron irradiation of gallium, so that the two periods must be due to isomers of ${\mathrm{Zn}}^{69}$. Both emit negative electrons and the properties of their radiations are given. It is shown that ${\mathrm{Zn}}^{65}$, produced through deuteron bombardment of zinc, has a half-life of 250 days, agreeing with the period found by others after proton and deuteron bombardment of copper. This isotope appears to decay by $K$ electron capture and also, to a lesser extent, by positron emission. No evidence has been found for radioactive ${\mathrm{Zn}}^{71}$. All previously reported zinc activities are discussed and the following table contains all the known periods that are believed to be genuine.
Optimized synthesis and properties of chemically stabilized CuSr2YCu2O7

Abstract Synthesis of the CuSr 2 YCu 2 O 7 compounds with Re, W and Mo substituted for Cu has been optimized for the highest T c . Materials prepared in air at 990°C and annealed at 650–700°C in 220 atm. O 2 are tetragonal with the transition elements substituting on the Cu-“chain” site, have oxygen content ∼ 7.3, and are superconducting with T c ∼ 70 K. The irreversibility lines show rather poor pinning characteristics when compared to Y123. Superconducting T c values were increased up to 77 K by additional substitution of small amounts of Ca for Y. Based on a.c. susceptibility and d.c. magnetization measurements, Ca substitution improves superconducting properties making chemically stabilized CuSr 2 YCu 2 O 7 materials interesting for high field applications below 30 K.
Ergonomic redesign of a commercial tool handle

Many commercial hand tools have been designed without ergonomic principles in mind which can result in the occurrence of upper extremity trauma. In this study, therefore, a clamping hand tool, Quick-Grip® bar clamp, was selected, ergonomically evaluated, a new version of the clamp focused on the handle was developed, and the original and ergonomically designed versions were compared using survey questionnaire. Design processes of the development of a new version were evaluation of the original clamp regarding ergonomic guidelines and anthropometric data, an idea sketch, prototype development, drafts and rendering of new design, development of final model, and objective and subjective comparisons to the original handle. Eleven male and eleven female students participated in the subjective testing portion which entailed questions after finishing simulated work. The results revealed that subjects were satisfied with the new version that was comfortable to hold and use in any position due to the rounded shape...
Multifractal subgrid-scale modeling for large-eddy simulation. I. Model development and a priori testing

Results are presented from a new approach to modeling the subgrid-scale stresses in large-eddy simulation of turbulent flows, based on explicit evaluation of the subgrid velocity components from a multifractal representation of the subgrid vorticity field. The approach is motivated by prior studies showing that the enstrophy field exhibits multifractal scale-similarity on inertial-range scales in high Reynolds number turbulence. A scale-invariant multiplicative cascade thus gives the spatial distribution of subgrid vorticity magnitudes within each resolved-scale cell, and an additive cascade gives the progressively isotropic decorrelation of subgrid vorticity orientations from the resolved scale Δ to the viscous scale λν. The subgrid velocities are then obtained from Biot–Savart integrals over this subgrid vorticity field. The resulting subgrid velocity components become simple algebraic expressions in terms of resolved-scale quantities, which then allow explicit evaluation of the subgrid stresses τij*. T...
Update in pediatric sleep medicine.

PURPOSE OF REVIEW To summarize the most important recent scientific developments in the field of clinical pediatric sleep medicine, specifically as relates to sleep disorders and sleep in special pediatric populations. RECENT FINDINGS The major themes covered in this review include sleep-disordered breathing; narcolepsy; restless legs syndrome/periodic limb movement disorder; insomnia; sleep in children with medical conditions; and sleep in children with neurodevelopmental and psychiatric disorders. SUMMARY An expanded understanding of the pathophysiology, epidemiology, clinical evaluation methods, sequelae, and empirically supported treatment options of common pediatric sleep disorders, especially in high-risk populations, is key to a rational approach to diagnosis and management of these children in clinical settings.
Functional and Pharmacological Characteristics of Metabotropic Glutamate Receptors 2/4 Heterodimers

Metabotropic glutamate receptors (mGluRs) were thought until recently to function mainly as stable homodimers, but recent work suggests that heteromerization is possible. Despite the growth in available compounds targeting mGluRs, little is known about the pharmacological profile of mGluR heterodimers. Here, this question was addressed for the mGluR2/4 heterodimer, examined by coexpressing both receptors in isolated sympathetic neurons from the rat superior cervical ganglion (SCG), a native neuronal system with a null mGluR background. Under conditions that favor mGluR2/4 heterodimer formation, activation of the receptor was not evident with the mGluR2-selective agonist (2S,2′R,3′R)-2-(2′,3′-dicarboxycyclopropyl)glycine (DCG-IV) or with the mGluR4 selective agonist l-(+)-2-amino-4-phosphonobutyric acid (l-AP4); however, full activation was apparent when both ligands were applied together, confirming that mGluR dimers require ligand binding in both subunits for full activation. Properties of allosteric modulators were also examined, including the findings that negative allosteric modulators (NAMs) have two binding sites per dimer and that positive allosteric modulators (PAMs) have only a single site per dimer. In SCG neurons, mGluR2/4 dimers were not inhibited by the mGluR2-selective NAM (Z)-1-[2-cycloheptyloxy-2-(2,6-dichlorophenyl)ethenyl]-1H-1,2,4-triazole (Ro 64-5229), supporting the two-site model. Furthermore, application of the mGluR4 selective PAMs N-(4-chloro-3-methoxyphenyl)-2-pyridinecarboxamide (VU0361737) or N-phenyl-7-(hydroxyimino)cyclopropa[b]chromen-1a-carboxamide (PHCCC) and combined application of mGluR4 PAMs with the mGluR2 selective PAM biphenyl indanone-A failed to potentiate glutamate responses through mGluR2/4, suggesting that mGluR2/4 heterodimers are not modulatable by PAMs that are currently available.
Blood alcohol concentration and microencephaly: A dose-response study in the neonatal rat

The relationships among microencephaly, peak blood alcohol concentration (BAC), and dose of alcohol were examined in a rat model of third-trimester fetal alcohol effects. Ethyl alcohol was administered to neonatal rats from postnatal day 4 to day 10 during the brain growth spurt via an artificial rearing technique. Groups of rats received one of nine doses of alcohol (0.0, 2.5, 3.3, 4.0, 4.5, 5.3, 6.6, 7.5, or 8.5 g/kg body weight) administered in 8 hours each day. BACs were determined on postnatal days 6 and 7 at times corresponding to peak and trough BACs, respectively. On postnatal day 10, brains were removed, and total brain weights, cerebellar weights and brainstem weights were measured. Pups receiving 4.0 g/kg/day or less had mean peak BACs below 150 mg/dl and did not exhibit significant microencephaly when compared with controls. Higher dosages further increased the peak BAC and produced significant microencephaly. While a dose of 4.5 g/kg/day was sufficient to decrease significantly both total brain weight and cerebellar weight, a minimum dose of 6.6 g/kg/day was required for significant restriction of brainstem weight. The dose of 7.5 g/kg/day yielded a mean peak BAC of 420 mg/dl and reduced total brain weight, cerebellar weight, and brainstem weight by 33%, 52%, and 22%, respectively, relative to controls. Exposure to 8.5 g/kg/day was uniformly lethal. Peak BAC and total brain weight were highly correlated (r = -.916). As peak BAC increased, total brain weight decreased linearly. Comparisons with previous studies indicate that condensing the daily dose of alcohol effectively reduced the threshold doses for microencephaly and lethality.
Right and left cortical lesions asymmetrically alter cerebrovascular permeability in the rat

Vascular permeability and intravascular space in the rat cerebral cortex and hypothalamus were assessed 5 and 14 days after the production of either right or left hemisphere frontal cortical suction lesions. Rats were intravenously injected with large (dextran, 50,000 kdalton) and small (inulin, 5000 kdalton) molecular tracers and tissue samples were removed for assay after 7 min. Five days following lesions of the right but not left hemisphere, inulin levels in the cortical region posterior and contralateral to the lesion site were significantly higher than control values. Dextran levels were not increased in this region by lesions of either hemisphere. However, both right and left hemisphere lesions led to a significant elevation of inulin and dextran levels (inulin higher than dextran) in the cortex surrounding the lesion site. Fourteen days after lesion of either hemisphere, tracer levels were not elevated over control in any region examined. These results suggest that both right and left hemisphere cortical lesions transiently increase local vasopermeability (and perhaps intravascular space), but that only right hemisphere lesions selectively increase inulin in cortex distant from the lesion site, probably from lesion-induced alterations in cerebrovascular permeability.
Outsourced call centers and English in the Philippines

ABSTRACT: The influx of outsourced call centers from the United States to the Philippines since the late 1990s has paved the way for the creation of thousands of jobs for Filipino professionals who are able to communicate in English and provide telephone-based customer services to American customers. The Philippines has become one of the major centers for outsourcing because of its tradition of bilingual education, affinity to the American culture, and cheap labor market. This study examined the effectiveness of micro language policies of a US-owned call center relative to the variety of English spoken in the Philippines in preparing Filipino professionals to work in outsourced call centers. The relationship between ESL proficiency and success in delivery of support was also analyzed by comparing English communication and transaction monitoring scores of Filipino customer service representatives (N = 74) collected for over a period of seven months in 2003–4. Although the initial English scores of participants were below the expected level of proficiency set by the call center company, assessment data indicated that with proper training and effective language-based programs, the participants exhibited improvement in English during transactions. ESL proficiency, however, only accounted for 10 per cent of the variability in the transaction monitoring scores of the participants.
Cloning and expression of complementary DNA encoding an antigen of Trichinella spiralis

Complementary DNA (cDNA) encoding a 49-kDa antigen of Trichinella spiralis was cloned, characterized, and expressed in Escherichia coli by recombinant DNA methods. As a first step, 29 residues of N-terminal amino acid sequence were determined by direct analysis of highly purified antigen. Mixed-sequence primers based on the amino acid sequence were then synthesized and used as primers to generate a partial cDNA by the polymerase chain reaction (PCR). A nearly full-length cDNA was then obtained by PCR using a specific 5'-end primer and a non-specific 3'-end primer. Complete sequence of the 1133-bp cDNA was determined. Translation of this sequence predicts an N-glycosylated polypeptide of 322 amino acids. The cDNA was expressed as a fusion protein in bacteria which could be recognized in Western blots both by sera from mice immunized with purified native 49-kDa antigen and by sera from swine infected with the parasite. These findings suggest that recombinant P49 is a potentially valuable antigen both for vaccine development and immunodiagnosis.
Spontaneous imbibition characteristics of diatomite

Abstract A systematic investigation of fluid flow characteristics within diatomite (a high porosity, low permeability, siliceous rock) is reported. Using an X-ray computerized tomography (CT) scanner, and a novel, CT-compatible imbibition cell, we study spontaneous cocurrent water imbibition into diatomite samples. Air–water and oil–water systems are used and the initial water saturation is variable. Mercury porosimetry and a scanning electron microscope (SEM) are employed to describe diatomite pore structure and the rock framework. Diatomite exhibits a fine pore structure and significant pore-level roughness relative to sandstone thereby aiding the flow of imbibing water. Despite a marked difference in permeability and porosity as compared to sandstone, we find similar trends in saturation profiles and dimensionless weight gain vs. time functions. Although diatomite is roughly 100 times less permeable than sandstone, capillary forces result in a strong imbibition potential for water such that imbibition rates rival and surpass those for sandstone
The Roles of Execution and Analysis in Algorthm Design

The analysis and execution of partial algorithm descriptions is an important part of the algorithm design process (as is borne out by studying the behavior of human algorithm designers). In this paper, we describe a language for representing partially designed algorithms and a process, developmental evaluation, that can discover useful knowledge to guide design. Using these and other results from our research in artificial intelligence, we are building a system, DESIGNER, that automatically designs algorithms. This paper also compares developmental evaluation to execution and analysis techniques used for testing complete programs and for validation of abstract specifications; concepts similar to those found in developmental evaluation are thus shown to apply to all stages of the software life cycle.
Relationships among cold hardiness, water-soluble protein, anthocyanins, & free sugars in Hedera helix L.

It has been much disputed whether seasonal variations in proteins or in sugars are better related to cold hardiness changes in certain over-wintering plants (for example, 1, 2, 3, 8, 12, 14). But proteins have been difficult to study, since they are not easily extracted from such plants as our native winter-hardy trees. This is because such proteins are often precipitated by vacuolar substances during tissue homogenation. The inner bark of black locust (Robinia pseudoacacia L.) is one of the few tree species which yields substantial amounts of water-soluble protein (6,10,14). As a result, much work on the concept of protein relationships to hardiness is based on work with this species. It, therefore, seemed of interest to find another plant that would yield sufficient watersoluble protein and would also be easy to study for cold hardiness. A survey of a number of evergreen woody plants showed that English ivy (Hedera helix L.) yielded large amounts of water-soluble protein. Protein determinations (13) as well as sugar analyses (5) have been previously made on this species, but no concomitant studies of these changes with cold hardiness in English ivy have been made. Closely related to sugar changes is the question of whether the reddening or purpling of evergreen leaves in autumn is any measure of their cold hardiness. Since this is a visual observation easily made in the field it is of much interest to foresters and horticulturalists. There appears to be some connection between cold resistance and the red coloration in some species (16, 18) but to our knowledge this has never been clearly demonstrated. Anthocyanins as well as free sugars were, therefore, studied in English ivy.
The incorporation of glycerol into mitochondrial lipids during neonatal renal compensatory growth.

Abstract [14C]glycerol incorporation into isolated inner and outer mitochondrial membrane is enhanced in the remaining kidney after unilateral nephrectomy. Serum from neonatal rabbits taken 24 hours after unilateral nephrectomy and added to tissue slice incubations appears to stimulate incorporation of [14C]glycerol into mitochondrial lipids of normal kidney cortex. Post-nephrectomy serum, however, depresses incorporation of [14C] glycerol and [3H]leucine into mitochondria when added to kidney cortex from animals in which uninephrectomy was performed 24 or 48 hours previously.
The intramolecular nucleophilic reaction of a phenolic hydroxyl group at the active site of papain.

Abstract Sulfonylation of the sulfhydryl protease papain with β-(2-hydroxy-3,5-dinitrophenyl)ethanesulfonic acid sultone 1 at pH 5.2 and 25° gives a thiosulfonate species 2 , the desulfonylation of which has been studied. Recyclization to give the sultone 1 via the nucleophilic attack of the phenolic hydroxyl group in 2 on the sulfonyl function has been found to compete effectively with hydrolysis. This is the first case in which a recyclization reaction has been observed where the central atom of the newly generated nucleophilic group produced by the ring-opening reaction of a cyclic ester with a protease is different in kind from that present in the active site of the enzyme.
The Status of Proving Among US Secondary Mathematics Teachers

This report examines teachers’ self-espoused attitudes and beliefs on proving in the secondary mathematics classroom. Conclusions were based on a questionnaire of 78 US mathematics teachers who had completed at least 2 years of teaching mathematics at the secondary level. While these teachers placed importance on proving as a general mathematical skill, when they discuss their own classrooms, procedural skill consistently surpasses proof-related activities in importance for a majority of high school teachers. Furthermore, teachers labeling their own past experiences in proving as causing anxiety are predictably more likely to put less value on proving. Interestingly, the quantity of past college mathematics courses is a reverse predictor indicating that further study should consider how students perceptions of proving change as they pass through a mathematics major.
Infectious complications of tumor necrosis factor blockade.

Purpose of reviewOur understanding of the infection risks posed by tumor necrosis factor (TNF) antagonists has continued to evolve in the 10 years since these drugs were first introduced. This review summarizes recent data regarding infection risk, examines potential structure–function relationships
Gulf Stream dynamic topography measured from space

On March 9, 1989, the Navy-sponsored GEOSAT radar altimeter satellite completed 50 cycles over its 17-day exact repeat ground track. Results obtained from analyzing the mission data set were presented at the Eleventh GEOSAT Users Meeting held March 23 at the Johns Hopkins University Applied Physics Laboratory (APL). Publication of the results is planned for a special 1989 issue of the Journal of Geophysical Research, which will focus on GEOSAT. Development of a synthetic geoid processing technique that allows the total dynamic topography of the Gulf Stream front and eddy system to be measured was reported by scientists from the Naval Ocean Research and Development Activity (NORDA), Woods Hole Oceanographic Institution (WHOI), Harvard University and APL. The “synthetic geoid” is realized by subtracting the climatology of the surface topography along a ground track (the mean circulation topography) from the mean of the altimeter data along the track. The technique dramatically increases the scientific value of radar altimeter data by removing the distortion and signal reduction caused by subtracting a mean sea surface that includes the mean circulation.
On coverage probability, independence and normality in batch means algorithms

Abstract We consider the batching approach to interval estimation of the mean of a stochastic process based upon simulation output. In particular, using batch means processes generated from underlying AR(1) processes and M/M/1 queueing systems, we study the effects of undetected autocorrelation on both the probability of coverage and the performance of the Shapiro-Wilk test of normality. We also conduct power comparisons of two tests used to detect first-order autocorrelation in batch means processes: the von Neumann ratio test and a rank version thereof proposed by Bartels (1982). Our results indicate that a large number of batches (perhaps at least 100) be used when testing for the presence of autocorrelation.
The JIBS 2014 Decade Award: Innovation, organizational capabilities, and the born-global firm

The Selection Committee for the JIBS Decade Award was pleased to recommend the presentation of the 2014 JIBS Decade Award, recognizing the most influential article published in JIBS 10 years ago, to Gary Knight (Williamette University) and Tamer Cavusgil (Georgia State University) for their 2004 article, “Innovation, organizational capabilities, and the born-global firm” (JIBS, 35(2): 124–141).
Comparison of global and local response surface techniques in reliability-based optimization of composite structures

This paper discusses the development and application of two alternative strategies, in the form of global and sequential local response surface (RS) techniques, for the solution of reliability-based optimization (RBO) problems. The problem of a thin-walled composite circular cylinder under axial buckling instability is used as a demonstrative example. In this case, the global technique uses a single second-order RS model to estimate the axial buckling load over the entire feasible design space (FDS), whereas the local technique uses multiple first-order RS models, with each applied to a small subregion of the FDS. Alternative methods for the calculation of unknown coefficients in each RS model are explored prior to the solution of the optimization problem. The example RBO problem is formulated as a function of 23 uncorrelated random variables that include material properties, the thickness and orientation angle of each ply, the diameter and length of the cylinder, as well as the applied load. The mean values of the 8 ply thicknesses are treated as independent design variables. While the coefficients of variation of all random variables are held fixed, the standard deviations of the ply thicknesses can vary during the optimization process as a result of changes in the design variables. The structural reliability analysis is based on the first-order reliability method with the reliability index treated as the design constraint. In addition to the probabilistic sensitivity analysis of the reliability index, the results of the RBO problem are presented for different combinations of cylinder length and diameter and laminate ply patterns. The two strategies are found to produce similar results in terms of accuracy, with the sequential local RS technique having a considerably better computational efficiency.
On the collision density in recoil hot atom systems. Effect of reactive events

Abstract Characteristics of the collisional distribution function for reactive hot atoms in nuclear recoil systems are examined and illustrated for the T + H 2 system both unmoderated and moderated with argon. Reaction induced extrema are evident in the collision density of the unmoderated case. For this system depletion of hot atoms from the collisional distribution function due to reactive events is reflected significantly in the product yields even at high moderation.
Device Physics of Heterojunction with Intrinsic Thin Layer (HIT) Solar Cells

Heterojunction with intrinsic thin layer (HIT) solar cells have achieved conversion efficiencies higher than 22%. Yet, many questions concerning the device physics governing these cells remain unanswered. We use numerical modeling to analyze the role of a-Si:H layers and tunneling on cell performance. For cells with n-type c-Si (n-HIT cells), incorporating the indium-tin-oxide (ITO) as an n-type semiconductor creates an n +/p/n structure. Most device simulations do not work with this structure. Our modeling indicates that the n +/p/n device often produces irregular S-shaped current density–voltage (J-V) curves, which have been observed experimentally but were not previously understood. However, if tunneling is included, there are specific conditions where the n +/p/n structure performs as a robust solar cell with efficiencies exceeding 20%. Additional analysis examines voltage-dependent carrier collection in n-HIT cells, as well as material and interface properties that limit fill factor. In p-HIT cells, modeling the ITO layer as a semiconductor, rather than as a metallic contact, significantly reduces the impact of a-Si:H layer parameters on device performance. In p-HIT cells, the a-Si:H layers adjacent to the ITO layer play the role of a buffer that reduces interface recombination at the a-Si:H/c-Si interface and prevents tunneling of electrons from the ITO layer to the c-Si absorber. Tunneling through the a-Si:H layers adjacent to the back contact is important to attain regular J-V curves.
Lactate dehydrogenase kinetics and inhibition using a microplate reader

A lactate dehydrogenase (LDH) enzyme kinetics laboratory experiment has been developed in which students obtain kinetic data using a microplate spectrophotometer (reader). These instruments have the capability of reading absorbances of many samples in a very short time frame. In this experiment 12 samples are prepared at a time and the absorbances read in less than 1 min. In a 3-hr laboratory period, students collect data at five different substrate concentrations without inhibitor and also in the presence of two different concentrations of inhibitor. Students have enough time to repeat each part if they obtain too much scatter in their data. The enzyme examined, LDH, correlates with the study of metabolism and has particular relevance for students who are interested in medical careers. The LDH assay itself is not new, but the microplate format and the use of urea as a quench reagent are novel features. Students plot Michaelis-Menten and Lineweaver-Burk plots and calculate values for V(max) , apparent V(max) (V(max) (app) ), K(m) , apparent K(m) (K(m) (app) ), k(cat) , and K(I) . Students typically obtain results correctly showing that oxalic acid is a competitive inhibitor and oxamic acid is a noncompetitive inhibitor when lactate is the substrate of the reaction.
Exploring the Potential of Computers to Enrich Home and Community-Based Services Clients' Social Networks

Older persons receiving services in community settings, rather than Nursing Homes, are at risk of social isolation. Computer mediated communication offers technological resources that recipients of Home and Community-Based Services (HCBS) might use to reduce their social isolation. The present study involved personal interviews with 40 HCBS clients regarding their interest in communicating with members of their social networks and using computers. At the time of the interview, 30 of the 40 participants did not use computers and reported cost, lack of training, physical limitations, lack of interest and access, and fraud as the reasons for not using computers. After watching a videotape illustrating an easy-to-use computer interface that allows older persons to communicate with families and friends, 90% reported that it would be helpful for people like them. Participants said such a computer would be helpful because it would make communication with friends and family easy, it could accommodate visual and m...
The Bjerknes effect: Explaining pulsed‐flow behavior in bubble columns

New experimental data for a range of gas velocities from 0.1 to 1.5 cm/s are explained by an elementary theory that combines the effect of bubble retardation owing to Bjerknes forces with the breakage relationship of Hinze in a pulsed-bubble column. A frequency range from 10 to 30 Hz, and two amplitudes of fluid oscillation were used in the 8.9 cm column: 1.66 and 2.46 mm. Experimental values of volumetric mass-transfer coefficient for oxygen dissolution followed predictions of theory using a modified penetration model. A new phenomenon was observed and was predictable from theory, namely “flooding”, which arises when bubbles are partially or fully retarded by Bjerknes forces at the point of injection. Under flooding conditions, transport enhancement levels off as frequency or amplitude is increased. Bubble-size distribution was measured as a function of frequency, and the calculated Sauter-mean diameter was satisfactorily fitted by the Hinze breakage formula. © 2007 American Institute of Chemical Engineers AIChE J, 2007
Stress testing and reliability

Two empirical equations giving the test strength of constant temperature and thermal cycling environments are compared for effectiveness in precipitating defects in electronic components. Analysis of the equations shows that they can be put into a form which has a theoretical basis although the structure still remains empirical.
PMA12: RELATIONSHIP BETWEEN NONPARAMETRIC RECEIVER OPERATING CHARACTERISTIC ANALYSIS AND A LIKELIHOOD-RATIO TEST FOR MODEL SELECTION: I. A MONTE CARLO SIMULATION USING CONTINUOUS DATA

BACKGROUND: In a simulation using continuous data, we compared the performance of DeLong's test for nonparametric receiver operating characteristic (ROC) curves (Biometrics 1988; 44: 837–845) with that of Vuong's test for model selection (Econometrica 1989; 57: 307–333). Both tests were found to yield similar results regardless of sample size. Diagnostic tests are often measured on an ordinal rating scale, and nonparametric methods tend to underestimate the area under the ROC curve (AUC) when used with discrete data. Thus, it was conceivable that level of measurement might influence the performance of DeLong's test. OBJECTIVE: A second Monte Carlo simulation was performed to determine whether DeLong's and Vuong's tests behave differently when used with discrete data. METHODS: One thousand observations were randomly generated for a Bernoulli dependent variable and 11 binomial independent variables. The independents were generated such that realizations were integers ranging from 1–10. Bootstrapped estimates for AUC and logistic regression model log-likelihood (LL) were derived using 1000 replications of sample size 10, 25, 50, 100, 175, 250, and 500. At each sample size, predictors were compared on the basis of AUC using DeLong's test and model LL using Vuong's test. The random number seed was set so that identical samples were compared with each test. RESULTS: In general, the two tests yielded similar statistical conclusions. Asymptotically, the observed power of Vuong's test was greater than that of DeLong's test. In smaller samples, however, Vuong's test was slightly less powerful. The results of the two tests diverged in only three cases in small samples. CONCLUSIONS: The results of this analysis correspond to those of our simulation using continuous data. Though slightly less powerful than DeLong's test, Vuong's test is more flexible and is less time consuming. Given the results of both simulations, Vuong's test appears to present a useful alternative to ROC analysis for comparing the accuracy of diagnostic tests.
Electron mean-free-path calculations using a model dielectric function

The inelastic electron mean free path as a function of energy is calculated for Cu, Ag, Au, and Al. The calculations are based on a model dielectric function \ensuremath{\epsilon}(q,\ensuremath{\omega}), which is obtained from a modification of the statistical approximation. In this approach \ensuremath{\epsilon}(0,\ensuremath{\omega}) is determined by the experimentally measured optical dielectric function. Calculated mean free paths are compared to experimental data and to other theories.
Variable complexity design of composite fuselage frames by response surface techniques

Curved frame structures are often used as part of the internal skeletal structure in aircraft. Laminated composite materials offer potential weight savings for such structures, but composite frames have different and more complex failure mechanisms than metallic frames. In particular, failure mechanisms involving interlaminar stresses are important in composite structures. Interlaminar stresses can be directly computed from three-dimensional finite element models, but the computational expense of these models is prohibitive. In this work, two- and three-dimensional (2D and 3D) finite element models are combined to reduce the computational expense associated with designing composite frames. A response surface design approach is used to approximate the failure response of curved composite C-section frames subjected to an axial tensile loading using a minimum number of finite element analyses. Results are presented for two examples with two and five design variables, respectively.
Sexual Harassment in High School.

This study presents results of a survey that asked current university students to recall instances of sexual harassment by high school teachers. Although most respondents did not think that sexual harassment by teachers was frequent or serious in their high schools, half cited examples of such incidents involving other students. Approximately 6% of the respondents reported having personally experienced sexually inappropriate attention from high school teachers. In addition, over one third noted that they knew of a sexual relationship between a high school student and a teacher. In these cases, the majority of the respondents thought the student and the teacher were equally interested in the affair. This finding, in conjunction with other responses, provided evidence that students often disclaimed instances of sexual harassment in high school.
Binaural response patterns in subdivisions of the medial geniculate body

Auditory evoked potentials (AEPs) to binaural click stimulation were examined in the ventral (MGv) and caudomedial (MGcm) subdivisions of the medial geniculate body (MG) in guinea pigs. Binaural stimulation caused a decrease in amplitude for the response component recorded from the MGv, but an increase in amplitude for the AEP component recorded from the MGcm. Findings suggest that the evoked responses recorded from MGv and MGcm are functionally distinct. The inhibitory binaural response (BR) pattern seen in MGv was similar to that of the middle latency response (MLR) component recorded over the temporal cortex, while the additive BR pattern typical of the MGcm was similar to that of the surface midline MLR component. Furthermore, these data imply that the binaural response patterns seen in the primary and non-primary auditory cortex may be processed and encoded at the thalamic level. It is concluded that the distinct BR patterns noted for the two MG subdivisions reflect the predominant type of binaurally responsive neurons within the respective pathways.
Deposition of platinum from Pt(PF3)4 on atomically clean platinum surfaces

Abstract The surface reactions of Pt(PF3)4 on Pt(111) and polycrystalline platinum have been examined under ultra-high vacuum conditions using Auger electron spectroscopy, temperature programmed desorption and secondary ion mass spectrometry techniques. For both surfaces, the dissociation of Pt(PF3)4 on platinum takes place below 500 K and gives rise to an intermediate state in which PF3 is chemisorbed on the platinum surface. On Pt(111) single crystal surface, a condensed state of Pt(PF3)4 is observed at 170 K for high coverage dosing. On a polycrystalline Pt surface, a desorption state of the reactant occurs at very high temperature, presumably from a recombination reaction of chemisorbed surface fragments.
Role of Cyclic AMP in Hydrogen Peroxide-Induced Potentiation of Sympathetic Neurotransmission in the Bovine Iris

ABSTRACT Hydrogen peroxide (H2O2) has been shown to enhance electrically-evoked norepinephrine (NE) release from isolated, superfused bovine irides. Since stimulation of presynaptic adenylyl cyclas...
Alterations of hemodynamics and myocardial mechanics in patients with congestive heart failure: pathophysiologic mechanisms and assessment of cardiac function and ventricular contractility.

HE FUNDAMENTAL PHYSIOLOGIC DERANGEMENTS, the disturbed events comprising cardiac contraction, the altered modulation of cardiovascular function, and the role of compensatory mechanisms in patients with congestive heart failure have been the subject of intense interest and investigation for many years. In the past, considerable attention has been focused on the clinical manifestations of heart failure and the hemodynamic alterations characteristic of this common pathologic condition. More recently, following the development of a multiplicity of improved technics and their application to experimental biologic systems and patients, a great body of new information has been provided which has permitted important advances in our understanding of the pathophysiology of congestive heart failure. Therefore, it is desirable at this time to examine certain of these findings, methods of evaluation, and current concepts concerning the mechanisms and regulation of contraction of the failing heart in man. This work begins with consideration of the principal determinants governing the performance of the intact ventricle and progresses to interpretation of the experimental data which form the basis for the conclusion that, of these major determinants, the fundamental abnormality in congestive heart failure
Detached Eddy Simulation of Transonic Rotor Stall Flutter Using a Fully Coupled Fluid-Structure Interaction

Detached eddy simulation of an aeroelastic self-excited instability, flutter in NASA Rotor 67 is conducted using a fully coupled fluid/structre interaction. Time accurate compressible 3D Navier-Stokes equations are solved with a system of 5 decoupled modal equations in a fully coupled manner. The 5th order WENO scheme for the inviscid flux and the 4th order central differencing for the viscous flux are used to accurately capture interactions between the flow and vibrating blades with the DES (detached eddy simulation) of turbulence. A moving mesh concept that can improve mesh quality over the rotor tip clearance was implemented. Flutter simulations were first conducted from choke to stall using 4 blade passages. Stall flutter initiated at rotating stall onset, grows dramatically with resonance. The frequency analysis shows that resonance occurs at the first mode of the rotor blade. Before stall, the predicted responses of rotor blades decayed with time, resulting in no flutter. Full annulus simulation at peak point verifies that one can use the multi-passage approach with periodic boundary for the flutter prediction.© 2011 ASME
Valley formation in Margaritifer Sinus, Mars, by precipitation-recharged ground-water sapping

Drainage morphometry and geologic mapping place new constraints on valley origin in Margaritifer Sinus, Mars. Preserved valleys are constant width, typically head near divides, possess fourth-order trunk segments, and were formed from late Noachian into earliest Hesperian time. Relative to terrestrial systems, the Martian valleys have low densities (<0.1 km/km2), relief ratios (0.001–0.13), and ruggedness numbers (0.005–0.086), and the sediment volume in associated sinks exceeds the volume excavated by upstream segments. Valley characteristics are consistent with formation by precipitation-recharged ground-water sapping within a layered, permeable substrate.
Effect of the infectious laryngotracheitis virus (ILTV) glycoprotein G on virus attachment, penetration, growth curve and direct cell-to-cell spread

The secreted alphaherpesvirus glycoprotein G (gG) works differently from other proteins. Analysis of the role of ILTV gG in virus attachment, penetration, direct cell-to-cell spread (CTCS) and the growth curve showed that gG or its antibody had no effect on ILTV attachment and penetration and that the gG antibody reduced the virus plaque size and the one-step growth curve on chicken embryo liver (CEL) cells, but gG did not affect the virus plaque size or the one-step growth curve on CEL cells. Laser scanning confocal microscopy (LSCM) detection showed that ILTV gG is located in the perinuclear region and the membrane of the CEL cells. These results suggested that ILTV gG might contribute to direct cell-to-cell transmission.
Impact of exposure of crude oil and dispersant (COREXIT® EC 9500A) on denitrification and organic matter mineralization in a Louisiana salt marsh sediment

Abstract In response to the 2010 oil spill from the explosion of the Deepwater Horizon oil rig in the Gulf of Mexico, this experiment aims to study the ecological impact of the crude oil and dispersant (COREXIT® EC 9500A) in a coastal salt marsh ecosystem. The marsh sediment was incubated under an anaerobic condition with exposure to the crude oil or/and dispersant. The experiments were conducted in two continuous phases of nitrate addition to study denitrification potential using acetylene blockage technique and organic matter mineralization potential indicated by CO2 production in the sediment. Results show that the oil slightly (with no statistical significance p > 0.05) increased both the denitrification and organic matter mineralization activities, likely due to oil components serving as additional organic matter. In contrast, the dispersant significantly (p