cssi/SciSciGPT-SciSciNet huggingface dataset:
Structural basis of hyaluronan degradation by Streptococcus pneumoniae hyaluronate lyase.

Streptococcus pneumoniae hyaluronate lyase (spnHL) is a pathogenic bacterial spreading factor and cleaves hyaluronan, an important constituent of the extracellular matrix of connective tissues, through an enzymatic β-elimination process, different from the hyaluronan degradation by hydrolases in animals. The mechanism of hyaluronan binding and degradation was proposed based on the 1.56 A resolution crystal structure, substrate modeling and mutagenesis studies on spnHL. Five mutants, R243V, N349A, H399A, Y408F and N580G, were constructed and their activities confirmed our mechanism hypothesis. The important roles of Tyr408, Asn349 and His399 in enzyme catalysis were proposed, explained and confirmed by mutant studies. The remaining weak enzymatic activity of the H399A mutant, the role of the free carboxylate group on the glucuronate residue, the enzymatic behavior on chondroitin and chondroitin sulfate, and the small activity increase in the N580G mutant were explained based on this mechanism. A possible function of the C-terminal β-sheet domain is to modulate enzyme activity through binding to calcium ions.
Pulling NO out of thin air.

Nitric oxide signaling requires that the heme of soluble guanylate cyclase bind NO preferentially to O2. Engineering of the enzyme's active site reveals a molecular basis for NO binding selectivity.
Acute gastrointestinal bleeding during experimental hypercarbia.

Experimental acute hypercarbia in dogs produced significant blood loss fron the apper gastrointestinal tract, as well as from the small and large intestines. At necropsy, gross and microscopic examinations demonstrated necrotizing lesions throughoat the entire gastrointestinal tract. These lesions resembled the postmortem nlceiations found in some patients with severe hypercarbia. Superior mesenteric arteriograms performed in four animals shortly after onset of hypercarbia showed abnormalities consistent with vasoconstriction. Vagal inhibition by atropine and correction of respiratory acidosis by HUS buffar failed either to reduce the blood loss or to alter the pathologic lesions. Multiple studies of blood coagulation in the hypercarbic animais revealed no consistent changes when compared with eucarbic animals. In four animals treated with pbenoxybenzamine during hypercarbia, blood loss and hemorrhagic gastrointestinal lesions were diminished, suggesting a possible pathogenetic role of alpha-adrenergic stimulation. Although the mechanism is not proved, vasoconstriction secondary to adrenergic stimulation may play an important role in the pathogenesis of acute gastrointestinal bleeding occurring with hypercarbia.
The evaluation of a Putnam integral

(1988). The Evaluation of a Putnam Integral. The American Mathematical Monthly: Vol. 95, No. 10, pp. 935-935.
Diet and chemoprevention of colon polyps and colorectal cancer.

Clinical trials in colorectal cancer prevention are based on carcino-genesis research and epidemiologic observations that relate certain macronutrients, micronutrients, non-nutritive factors in foods, and synthetic chemicals to colon neoplasms. These factors appear to act at various points along the putative normal mucosa adenomatous polyp cancer sequence. This gives an opportunity to develop innovative clinical trials, both in agent selection and in the use of intermediate markers. Clinical colorectal cancer prevention trials are now in progress that employ dietary fiber, a variety of vitamins and minerals and several synthetic drugs, especially the NSAIDs. Most of these trials use the adenomatous polyp as a surrogate marker for colon cancer, thereby reducing trial duration, number of subjects required and overall expense. This paper is a brief review of the basic and epidemiologic background for colorectal cancer prevention trials and their current status. © 1995 Wiley-Liss, Inc.
A robust Gauss-Newton algorithm for analyzing Steady-State Visual Evoked Potentials

Steady-State Visual Evoked Potential (SSVEP) Brain-Computer Interfaces (BCIs) are becoming more interesting with increases in demand for robust BCI systems with real-time control capability. This type of BCI is based on collecting the brain signals from visual cortex while the users' attention is toward an exogenous stimulus. Stimulus with constant frequency rate above 4 Hz evokes the SSVEPs. This research uses the data collected from 4 healthy subjects. Each subject participated in test sessions with 4 different LEDs, flickering at 10, 11, 12 and 13 Hz. A 10-order adaptive priori-based robust Gauss-Newton algorithm is adjusted to estimate the brain source signals. Finally, decision detection is based on the maximum Signal to Noise Ratio (SNR). Results are promising an effective method, which could be later developed for implementation of online BCI systems.
A Comparative Study of Special Education Contrasting Denmark, Sweden, and the United States of America

Abstract Many background factors, such as demography, size of the country and the history development, have created different atmospheres and have influenced philosophies, laws, and procedures for dealing with handicapped students in educational settings in Denmark, Sweden, and the United States of America. Yet, despite the differences, these three countries have developed educational systems that are more similar than different. This report examines both similarities and differences and aims to spread information that could be useful in developing the special education systems of different countries. The authors represent special educational research in the United States of America and Sweden.
Speculations: providing fault-tolerance and improving performance of parallel applications

Transactions are a simple and powerful mechanism for establishing fault-tolerance. To allow multiple processes to cooperate in a transaction we relax the isolation property and use message passing for communication. We call the new abstraction a speculation.
Development of a nurse-assisted preanesthesia evaluation program for pediatric outpatient anesthesia.

SummaryBackground Historically, anesthesiologists have conducted preanesthesia evaluation, but more recently, nurse practitioners (NPs) are increasingly assisting with the preanesthesia evaluation of children. In the current economic environment for healthcare, strategies to provide superior outcomes and exceptional patient experience at the lowest possible cost are constantly being explored. We examined whether well trained nurses, working alongside NPs, could safely and effectively assist in preanesthesia evaluation. The aim of this quality improvement project was to implement a new model for preanesthesia evaluation for healthy outpatient pediatric patients: nurse-assisted preanesthesia evaluation (NAPE). Methods Using quality improvement methods, Key Driver Diagrams and SMART aims gave direction for the training and clinical implementation of this new process. Using small tests of change and Plan-Do-Study-Act cycles, we developed a training process and a stepwise process to integrate them into the clinical work flow. The primary outcome measure was the proportion of the total preanesthesia evaluations in which the Anesthesia Nurses assisted. To ensure quality and safety, data on balancing measures and quality metrics were collected. Results The weekly percentage of outpatients evaluated by Anesthesia Nurses increased from 0% to 55% within the first 4 months and was then sustained. The remaining patients were evaluated by the Anesthesia NPs. The balancing measures did not show any significant negative effect. Our perioperative quality metrics were also not changed significantly. Conclusion Using quality improvement methods, we successfully improved the utilization of staff resources by adding an Anesthesia Nurse-assisted preanesthesia evaluation program alongside our NPs to provide outstanding preanesthesia care at the lowest possible cost.
Transforming growth factor‐beta isoform expression during bovine ovarian antral follicle development

Transforming growth factor-beta (TGF-beta) isoforms are important paracrine and autocrine signaling molecules for the regulation of ovarian follicle growth and physiology. Effective communication between the epithelial granulosa cells, the mesenchymal theca cells, and the oocyte is vital for ovarian function and reproductive success. The expression, localization, and regulation of TGF-beta isoforms in the developing bovine follicle was examined using both immunohistochemistry and quantitative reverse transcription-polymerase chain reaction (RT-PCR) procedures. TGF-beta1 protein was found to be present in the granulosa cells of early pre-antral, early antral, and 1-2 mm follicles. Interestingly, there was no visible staining of granulosa cells of 3-5 or 5-10 mm follicles. There was also no TGF-beta1 staining of theca cells. TGF-beta2 and TGF-beta3 staining were present in the granulosa and theca cells of all follicle stages examined. The levels of TGF-beta mRNA expression in granulosa and theca cells from antral follicles was measured using quantitative RT-PCR. For each isoform mRNA expression levels did not change in different sized antral follicles. TGF-beta3 mRNA levels were much higher than those of TGF-beta1 and TGF-beta2 in both granulosa and theca. Expression levels were higher in theca than in granulosa for TGF-beta2 and TGF-beta3. FSH was found to decrease TGF-beta1 mRNA expression in granulosa cells, but had no effect on TGF-beta2 and TGF-beta3. Bovine ovarian follicles were found to have a unique pattern of TGF-beta isoform expression and regulation when compared to other species (i.e., rodent, pig, quail, and human). The similarities and differences between the various species is discussed to help elucidate common functions of TGF-beta in the ovary. In summary, observations demonstrate that as antral follicles develop, TGF-beta3 is the most abundant TGF-beta isoform and TGF-beta1 protein levels decline in large follicles. Granulosa cell TGF-beta1 expression was decreased by FSH and this correlated with reduced levels in large antral follicles. TGF-betas involved in antral follicular growth and development appear to act as paracrine/autocrine signaling molecules having a species-specific pattern of expression.
An Experimental Investigation of Molecular Rarefaction Effects in Gas Lubricated Bearings at Ultra-Low Clearances

Abstract : The experimental investigation discussed here gives experimental confirmation of the slip-flow theory for modeling hydrodynamic gas bearings with clearances below 0.25 microns. An interferometric technique employing two CW lasers is used to measure the small clearances with an accuracy of 0.025 microns. The effects of molecular rarefaction are studied by operating the slider bearing in different gas media of different mean free paths. Bearings operating at extremely high local Knudsen numbers are studied without approaching excessively high bearing numbers. Experimentally measured trailing edge clearances and pitch angles are compared with theoretical predictions using the modified Reynolds equation with velocity slip boundary conditions. Excellent agreement between experiment and theory is found for clearances as high as 1.60 microns to as low as 0.075 microns with corresponding ambient Knudsen numbers of 0.04 and 2.51, respectively.
The current status of the treatment of childhood acute lymphoblastic leukemia

Summary One can only recapitulate that the treatment of acute lymphoblastic leukemia has developed in a most gratifying fashion during the past few years. Critical parts of the therapy have been identified with progressive improvement in the duration of continuous complete remission. Problems that remain concern those patients who relapse while receiving chemotherapy, patients with poor prognostic features such as CNS disease at diagnosis, patients who fail to go into remission and patients who have that form of the leukemia which is associated with mediastinal masses. Identification of patients at greater risk will be helpful in designing tailor-made forms of therapy to deal with their specific problem. From all indications, simply intensification of current regimens is not going to be successful in eradication of disease in these special situations. It may very well require new drugs, different combinations, or better scheduling of currently available drugs to achieve results in their problem patients to match those obtained in the low-risk group. Perhaps one of the most important lessons to be learned from a review of the developing treatment of acute lymphoblastic leukemia is the importance of the proper design of regimens and their critical factors since these principles can be applied to the treatment of other forms of cancer.
Evaluative bias and issue proximity

This study identifies two forms of evaluative bias toward political objects — positivity and negativity — in addition to the familiar one of partisanship. Bias is measured, predominantly, using open-ended responses to questions on political parties in the NES studies. The incidence of varieties of evaluative orientation toward the parties over time, beginning in 1952, is reported; so also are demographic and cognitive correlates of evaluative bias. Finally, hypotheses on differential assimilation and contrast effects in candidate perception are tested.
Computer Programs for Robust Analyses in Multifactor Analysis of Variance Designs

Robust analyses of multifactor analysis of variance data may be secured even when assumptions are violated, by use of a set of five programs. ANOVR produces means, the summary table, group variances, the variance-covariance matrix on repeated measures, and tests most assumptions. FOLUP tests any set of pairwise contrasts of means, while COMCON tests any set of complex contrasts. Both latter programs permit solutions using heterogeneous group variances, or using a heterogeneous variance-covariance matrix from repeated measures, as well as conventional solutions using mean squares from the summary table. ANOVR produces the Box-Geisser-Greenhouse index when there is just one repeated measure factor, while PVCVRL will produce corresponding indices when there are two or more such factors. BARTKI produces output that generates the robust and flexible Bartlett and Kendall test for homogeneity of variances. Intelligent use of the set of programs frees the user from most assumptions of AOV.
Vibrational spectra of binary disordered linear chains with short-range order

We consider the generation of binary disordered linear chains with short-range order by using the theory of Markov processes. We generate second-order Markov chains in which specific correlations are introduced to first- and second-nearest neighbors. We find the density of vibrational states for several second-order chains in which one of the two kinds of atoms is twice as heavy as the other, but the nearest-neighbor force constants are unchanged. Properties of these spectra can be related to the chain structures, but pair correlation functions do not provide an adequate measure of structure to specify details of the spectra. We derive an expression for the integrated density of states at special frequencies for second-order chains and find that chains with quite different structures may have identical integrated spectra at all special frequencies.
Toxic chemicals in an abandoned phenolic waste site

Abstract The nature and extent of pollution was determined at the site of a former pinetar manufacturer. Compound distributions at various areas about the site revealed that, in addition to groundwater leaching of soluble phenolics, insoluble contaminants were spread by a dike-breach incident and subsequent construction activities. Differences in the patterns of chemicals in various wells suggested that more than one source of pollution occurred. The distribution of compounds about the site indicated that a general clean-up would not be cost-effective. Placement of an interceptor to collect groundwater seepage that contaminates surface water is being considered as an alternative.
Brotherly Intentions? The Egyptian Muslim Brothers and the Politics of a Debate

This article surveys the contemporary debates on the Egyptian Society of Muslim Brothers. It argues that the debate focuses on the unknowable question of the Islamists’ governing intentions or assessing their ‘democratic’ character. This article takes issue with these analytic points of departure and, instead, makes a case for contextualizing the organization’s policies against the backdrop of contemporary Egyptian society. I achieve this by reviewing the group’s philosophical development under the late period of the Mubarak presidency. As such, the Brothers’ recent party platform draft and policies on prominent issues, such as women and minority rights, reveal the Brothers as an organization that appeals to and emerges from national and domestic bases in Egypt as opposed to courting a strictly Islamic constituency.
The characterization of the high-frequency vibronic contributions to the 77 K emission spectra of ruthenium-am(m)ine-bipyridyl complexes, their attenuation with decreasing energy gaps, and the implications of strong electronic coupling for inverted-region electron transfer.

The 77 K emission spectra of a series of [Ru(Am)6-2n(bpy)n]2+ complexes (n = 1−3) have been determined in order to evaluate the effects of appreciable excited state (e)/ground state (g) configurational mixing on the properties of simple electron-transfer systems. The principal focus is on the vibronic contributions, and the correlated distortions of the bipyridine ligand in the emitting MLCT excited state. To address the issues that are involved, the emission band shape at 77 K is interpreted as the sum of a fundamental component, corresponding to the {e,0‘} → {g,0} transition, and progressions in the ground-state vibrational modes that correlate with the excited-state distortion. Literature values of the vibrational parameters determined from the resonance-Raman (rR) for [Ru(NH3)4bpy]2+ and [Ru(bpy)3]2+ are used to model the emission spectra and to evaluate the spectral analysis. The Gaussian fundamental component with an energy Ef and bandwidth Δν1/2 is deconvoluted from the observed emission spectrum. ...
Scheduling larger job shops: a decomposition approach

Large scale job scheduling problems are addressed in this paper through a divide and conquer scheme. With the scheme, a job shop is first decomposed into cells, a shop scheduling problem is then solved through iteratively defining, solving and coordinating cell scheduling problems. So-called proxy operations and dummy machines are employed to account for the interactions between the cell scheduling problems. The scheme is tested on total flow time reduction job shop scheduling problems with the problem sizes up to 120 machines and 200 jobs. The computational results show that the scheme is effective.
A Short Motif in Kir6.1 Consisting of Four Phosphorylation Repeats Underlies the Vascular KATP Channel Inhibition by Protein Kinase C

Vascular ATP-sensitive K(+) channels are inhibited by multiple vasoconstricting hormones via the protein kinase C (PKC) pathway. However, the molecular substrates for PKC phosphorylation remain unknown. To identify the PKC sites, Kir6.1/SUR2B and Kir6.2/SUR2B were expressed in HEK293 cells. Following channel activation by pinacidil, the catalytic fragment of PKC inhibited the Kir6.1/SUR2B currents but not the Kir6.2/SUR2B currents. Phorbol 12-myristate 13-acetate (a PKC activator) had similar effects. Using Kir6.1-Kir6.2 chimeras, two critical protein domains for the PKC-dependent channel inhibition were identified. The proximal N terminus of Kir6.1 was necessary for channel inhibition. Because there was no PKC phosphorylation site in the N-terminal region, our results suggest its potential involvement in channel gating. The distal C terminus of Kir6.1 was crucial where there are several consensus PKC sites. Mutation of Ser-354, Ser-379, Ser-385, Ser-391, or Ser-397 to nonphosphorylatable alanine reduced PKC inhibition moderately but significantly. Combined mutations of these residues had greater effects. The channel inhibition was almost completely abolished when 5 of them were jointly mutated. In vitro phosphorylation assay showed that 4 of the serine residues were necessary for the PKC-dependent (32)P incorporation into the distal C-terminal peptides. Thus, a motif containing four phosphorylation repeats is identified in the Kir6.1 subunit underlying the PKC-dependent inhibition of the Kir6.1/SUR2B channel. The presence of the phosphorylation motif in Kir6.1, but not in its close relative Kir6.2, suggests that the vascular K(ATP) channel may have undergone evolutionary optimization, allowing it to be regulated by a variety of vasoconstricting hormones and neurotransmitters.
Medium resolution transmission measurements of CO2 at high temperature

Abstract Medium resolution transmissivities of CO2 were measured at temperatures between 300 and 1550 K for the 4.3, 2.7 and 2.0 μm bands. Measurements were made with a new drop tube design, which guarantees a truly isothermal high-temperature gas column. Data were collected with an FTIR-spectrometer, allowing for much better spectral resolution than most previous high-temperature measurements. The measured data were compared with two line-by-line and two narrow band databases. The data show some discrepancies with high-resolution databases at higher temperatures, indicating missing and/or incorrectly extrapolated spectral lines.
The primary structure of rat ribosomal protein L17

The amino acid sequence of the rat 60S ribosomal subunit protein L17 was deduced from the sequence of nucleotides in two recombinant cDNAs. Ribosomal protein L17 has 184 amino acids and has a molecular weight of 21,383. Hybridization of the cDNA to digests of nuclear DNA suggests that there are 17-19 copies of the L17 gene. The mRNA for the protein is about 720 nucleotides in length. Rat L17 is homologous to human L17 and related to Saccharomyces cerevisiae YL17, Halobacterium marismortui L23, Halobacterium halobium L22e, Escherichia coli L22 and other members of the prokaryotic L22 family.
BITTER BOTTLE GOURD (LAGENARIA SICERARIA) TOXICITY

Abstract Background Bottle gourd ( Lagenaria siceraria ) is an edible plant in the Cucurbitaceae family. When extremely bitter, ingestion of bottle gourd can cause rapid onset diarrhea, vomiting, gastrointestinal bleeding, and hypotension due to release of a substance named cucurbitacin. Objective Our aim was to increase physician awareness of cucurbitacin poisoning in order to facilitate accurate diagnosis and appropriate management. Case Report Five adult patients presented with nausea, vomiting, and diarrhea within 5 to 25 min of ingesting cooked bitter bottle gourd. One patient developed severe diarrhea, hematemesis, and hypotension requiring hospitalization. All patients improved within a few days with intravenous fluids and proton pump inhibitors. To our knowledge, this is the first reported group of patients with toxicity due to ingestion of bottle gourd in the United States (US). Conclusions Physicians should be suspicious of cucurbitacin toxicity in patients who present with symptoms within minutes of ingestion of a plant in the Cucurbitaceae family. Patients should be asked if the plant tasted unusually bitter. The most common symptoms include diarrhea and hematemesis. More than half of patients develop hypotension. There is no known antidote for bottle gourd poisoning; treatment is supportive. Proton pump inhibitors should be given to patients with gastrointestinal mucosal injury.
Age and sex performance differences as measured by a new nonverbal visual perceptual test

Six hundred and twenty-three Ss in Grades 1-6 and 11 were tested with a new nonverbal group-administered visual perceptual test, Wolf's Embedded Figures Test. The resuIts indicated school and age differences at the .0001 level, which were virtually unmodified with the effects of IQ removed. Significant sex differences were found on the individually and group-administered versions and were accounted for by common variance with the spatial test, which has been shown to have high hereditary variance. All figures were unique; therefore, practice, as predicted from short- and long-term memory theory, did not reduce the sex differences. The embedded figures test loaded lowest on the factor with high loading on two fluency tests that are associated with creativity or divergent thinking, casting doubt on Witkin's theory. One of the current emphases in education is the adjustment of curriculum to the individual characteristics and abilities of the learner. A new test was developed to measure one of these individual abilities, visual perception. Research was focused on the components that modify the results of different forrns of the test. This test refinement was based on a review of the literature and was guided by current theory. The resuIts of three separate trials of the test are summarized. The reader is referred to Wolf (1969) for a detailed account of this research. BACKGROUND One means of studying differences in visual perception is to put a small picture in a larger more complex picture and have the S try to find it. Witkin (1950) developed such a test by selecting so me figures of Gottschalk's whieh correlated with tests (the rod-and-frame test, the tilting-room test, and the
The effect of shear, specific surface, and air interface on the development of blood emboli and hemolysis.

Heparinized dog blood was exposed to shear and foreign surfaces in conicylindrical test cells. The cells were injection molded from polycarbonate and were filled using a technique that avoided contact of the blood with air. Particulate-matter formation was measured and was found to be dominated by the surface-to-blood–volume ratio and to be independent of shear rate. Hemolysis was also measured and was found to vary linearly with shear rate and to increase with increasing surface-to-blood volume ratio. Thus, at low shear rates and high specific surface conditions, the degree of hemolysis was found to be minimal while particulate-matter formation was high. The results suggest that the safety of extracorporeal perfusion procedures cannot be inferred from hemolysis measurements alone. In one series of tests, a gas–blood interface was generated at a rate equivalent to the rate of surface renewal in conventional disc oxygenators. The gas–blood interface failed to contribute significantly to the damage indices, which suggests that the apparent superiority of membrane oxygenators may be a result of factors other than the absence of a blood–gas interface.
Hormonal influence on behavior in brain lesioned male rats

Abstract Either adrenalectomy, gonadectomy or hypophysectomy was performed in conjunction with lesions of the limbic lobe in order to test the hypothesis that the associated altered behavior resulted from altered endocrine functions. Neither adrenalectomy or gonadectomy nor hypophysectomy was found to alter the characteristic aggressive behavior of septally lesioned animals. The same was true with the docile behavior seen in amygdaloid lesioned animals. Dual lesioned animals (septal and amygdaloid) show both a delay in the septal syndrome and also a decrease in hypersensitivity.
What are the Most Influential Articles in Business and Management Education Research

Although business and management education research has made great strides over the last decade, its ability to attract new scholars to this area of inquiry continue to be a concern. One possible i...
Effect of nitrogen additives on flame retardant action of tributyl phosphate: Phosphorus–nitrogen synergism

Abstract The effects of three nitrogen additives (urea, guanidine carbonate, and melamine formaldehyde) on the flame retardant action of cotton cellulose treated with tributyl phosphate (TBP) were investigated in this research. The limiting oxygen index (LOI) of treated cotton cellulose clearly revealed the synergistic interactions of TBP and nitrogen compounds. The Kissinger method was used to evaluate the kinetics of thermal decomposition on treated cellulose. The results show that adding nitrogen additives increases the activation energy at a higher degree of degradation, thus indicating better thermal stability at higher temperatures. Scanning electron microscope pictures of chars formed after a LOI test show the formation of protective polymeric coatings on char surfaces. Evaluating char surfaces using attenuated total reflectance-Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy suggests that these coatings are composed of species containing phosphorus–nitrogen–oxygen. Possible chemical interactions of phosphorus and nitrogen compounds during the burning process and the formation of a protective coating could be the reason for the observed synergism. Potential reaction pathways contributing to the formation of this protective polymeric coating have also been proposed.
Improved growth morphology of Si–Ge–C heterostructures through the use of Sb surfactant-assisted molecular beam epitaxy

Abstract Carbon incorporation in Si and SiGe heteroepitaxial structures offers exciting opportunities in the design of novel, Si-based electronics. Recent results suggest that in order to realize the potential of this material system, methods for achieving high carbon concentrations (in excess of 5 at.%) without sacrificing crystalline quality must be developed. We have investigated the use of Sb as a surfactant to assist in the incorporation of carbon during growth of Si and SiGe epitaxial layers by molecular beam epitaxy. For samples in which Sb is not used, reflection high-energy electron diffraction (RHEED) shows that the wafer surfaces roughen soon after the carbon is introduced. As growth proceeds, the layers eventually twin and become defective, especially for thicker layers and higher carbon concentrations (>2%). Roughening occurs at even lower carbon concentrations for the case of SiGeC growth as we have grown Si 1−x−y Ge x C y /Si 1−y ′ C y ′ heterostructures with y ′> y , and observe RHEED patterns are streaked during the Si 1−y ′ C y ′ deposition but spotted during the Si 1−x−y Ge x C y deposition. The presence of ≤1 monolayer of Sb on the surface of the substrate prior to epitaxy is shown in this work to substantially reduce roughening of the growth front, resulting in a dramatic reduction in defect density with minimal Sb incorporation ( 17 cm −3 ). Transmission electron microscopy and secondary ion mass spectrometry data relating to the quality of the layers and the amount of Sb incorporation will be discussed.
The Human Immunodeficiency Virus Type 1 gp120 V2 Domain Mediates gp41-Independent Intersubunit Contacts

The envelope protein of human immunodeficiency virus type 1 HIV-1 undergoes proteolytic cleavage in the Golgi complex to produce subunits designated gp120 and gp41, which remain noncovalently associated. While gp41 has a well-characterized oligomeric structure, the maintenance of gp41-independent gp120 intersubunit contacts remains a contentious issue. Using recombinant vaccinia virus to achieve high-level expression of gp120 in mammalian cells combined with gel filtration analysis, we were able to isolate a discrete oligomeric form of gp120. Oligomerization of gp120 occurred intracellularly between 30 and 120 min after synthesis. Analysis by sedimentation equilibrium unequivocally identified the oligomeric species as a dimer. In order to identify the domains involved in the intersubunit contact, we expressed a series of gp120 proteins lacking various domains and assessed the effects of mutation on oligomeric structure. Deletion of the V1 or V3 loops had little effect on the relative amounts of monomer and dimer in comparison to wild-type gp120. In contrast, deletion of either all or part of the V2 loop drastically reduced dimer formation, indicating that this domain is required for intersubunit contact formation. Consistent with this, the V2 loop of the dimer was less accessible than that of the monomer to a specific monoclonal antibody. Previous studies have shown that while the V2 loop is not an absolute requirement for viral entry, the absence of this domain reduces viral resistance to neutralization by monoclonal antibodies or sera. We propose that the quaternary structure of gp120 may contribute to resistance to neutralization by limiting the exposure of conserved epitopes.
Combined urinary and fecal diversion using a no bowel anastomosis technique

Purpose: We present the experience at our institution with combined fecal and urinary diversion using 3 variations of a no anastomosis technique that avoids bowel anastomosis.Materials and Methods: The charts of 10 female and 2 male patients who underwent the no bowel anastomosis technique were identified and reviewed. Information on the etiology of urination and defecation abnormalities, surgical resolution, complications, hospital stay and other pertinent aspects of management were retrospectively reviewed.Results: Mean patient age was 64 years (range 36 to 83). Of the 12 patients 7 had a history of cancer treated with external beam radiotherapy, while 4 had neurological disorders with combined fecal and urinary incontinence or a history of colostomy. Mean hospital stay was 14.6 days (range 6 to 31) and mean followup was 26.6 months (range 14 to 52). There were no postoperative deaths, although a nonQ wave myocardial infarction occurred in 1 patient.Conclusions: The no anastomosis technique of combined ...
Killing of coccidioides immitis by hypochlorous acid or monochloramine

To identify possible explanations for the resistance of Coccidioides immitis to killing by human neutrophils, its susceptibility to typical oxidants generated during the neutrophil respiratory burst was compared to the sensitivity of other microbes. When microbial suspensions were exposed to hypochlorous acid, arthroconidia or spherules of C. immitis were killed more slowly than yeast cells of Candida (Torulopsis) glabrata or Staphylococcus aureus. In contrast, exposure to the more lipophilic oxidant, monochloramine, produced equivalent rates of killing for spherules and yeast cells of C. glabrata, and arthroconidia were killed more rapidly. When larger microbial concentrations were used, significantly greater concentrations of hypochlorous acid were required to kill equivalent percentages of spherules as compared to yeast cells of C. glabrata. Mixing studies with either whole spherules or extracts of spherules demonstrated that these substances could also block hypochlorous acid killing of S. aureus. The...
Early crustal genesis: A report of the Airlie House Meeting

Over 100 scientists from seven countries met at Airlie House, Warrenton, Virginia, November 13–17, 1981, to discuss relevant scientific issues concerning the early evolution of the crusts of the terrestrial planets. The impetus for this meeting was twofold: to bring the planetary and Archean scientific communities together and to lay the framework for a long-term multidisciplinary research project. The motivation for such a project stems from the fact that during the past several decades vast quantities of new data relevant to the origin and evolution of the planets have been acquired. As a result, a revolution has occurred in our approach to the evolution of crust-mantle systems of planetary bodies, with the appreciation that all but the smallest bodies in the solar system probably underwent a period of extensive melting and differentiation during their first few hundred million years of existence.
Simulation of flow and transport phenomena in a polymer electrolyte fuel cell under low-humidity operation

Numerical simulations of a 50 cm 2 polymer electrolyte fuel cell (PEFC) with 36 channels are carried out to study the lateral transport of moisture and reactant between two neighboring channels with counter flow on the cathode side. Massive computations with 2.7 million computational elements are performed to capture the intricate electrochemical and transport phenomena in PEFC in three-dimensions. Two cases are examined and compared. One is under the common assumption that molecular diffusion dominates the species transport in the gas diffusion layer (GDL) and thus, the lateral convection effect is neglected. The other case is to include the flow and convection effects in the GDL using a realistic permeability of the porous GDL. Numerical results elucidate the mechanism and extent of internal humidification induced by lateral moisture diffusion. In addition, it is found that given the typical GDL, there exists a large pressure drop between two adjacent channels in counter flow, one flowing in from the inlet and the other flowing out to the outlet, causing severe reactant bypass between the two flow paths of reverse direction. The bypass results in reactant flow “short-circuit” and greatly diminishes the internal humidification benefit intended by the counter-flow design. © 2005 Elsevier B.V. All rights reserved.
Hepatitis A among schoolchildren in a US-Mexico border community.

OBJECTIVES: A cross-sectional study investigated the association of hepatitis A seropositivity with environmental and personal risk factors among children in a United States-Mexico border community. METHODS: Hepatitis A serological markers and a questionnaire identifying risk factors were evaluated for 523 primary school children. RESULTS: Of the children studied, 16.9% tested positive for total antihepatitis A virus. Risk factors included being in the first grade, low maternal educational attainment, living in Mexico for more than 6 months, household crowding, and inadequate excreta disposal systems. CONCLUSIONS: To decrease enteric disease, improvements in excreta disposal infrastructures and educational programs are needed. Hepatitis A vaccine should be administered before school age.
Maternal and Child Anxiety: Do Attachment Beliefs or Children's Perceptions of Maternal Control Mediate Their Association?

This study tested a model of the association between maternal and child anxiety that views mother and child attachment beliefs and children's perceptions of maternal control as mediators of the association. The study was conducted with mothers and their children aged 6 to 17 (N = 88). Maternal anxiety was significantly associated with child anxiety and maternal anxious attachment beliefs, whereas child anxiety was associated with maternal anxious attachment beliefs, child insecure attachment beliefs, and children's perceptions of maternal control. Maternal anxious attachment beliefs mediated the association between maternal and child anxiety; however, child attachment beliefs and children's perceptions of maternal control did not. The influence of age and gender is also addressed. The findings are discussed in terms of elucidating the role of attachment beliefs and children's perceptions of maternal control on the association between maternal and child anxiety.
Neonatal Abstinence Syndrome

Neonatal abstinence syndrome (NAS) is a result of the sudden discontinuation of fetal exposure to substances that were used or abused by the mother during pregnancy. Withdrawal from licit or illicit substances is becoming more common among neonates in both developed and developing countries. NAS continues to be an important clinical entity throughout much of the world. NAS leads to a constellation of signs and symptoms involving multiple systems. The pathophysiology of NAS is not completely understood. Urine or meconium confirmation may assist the diagnosis and management of NAS. The Finnegan scoring system is commonly used to assess the severity of NAS; scoring can be helpful for initiating, monitoring, and terminating treatment in neonates. Nonpharmacological care is the initial treatment option, and pharmacological treatment is required if an improvement is not observed after nonpharmacological measures or if the infant develops severe withdrawal. Morphine is the most commonly used drug in the treatment of NAS secondary to opioids. An algorithmic approach to the management of infants with NAS is suggested. Breastfeeding is not contraindicated in NAS, unless the mother is taking street drugs, is involved in polydrug abuse, or is infected with HIV. Future studies are required to assess the long-term effects of NAS on children after prenatal exposure.
Knudsen Cell Studies of the Reaction of Gaseous Nitric Acid with Synthetic Sea Salt at 298 K

The uptake of nitric acid on synthetic sea salt (SSS) was studied at 298 K using a Knudsen cell with mass spectrometric detection of the gaseous reactant and products. HCl was the only product observed, with yields of 100% within experimental error. Nitric acid reaction probabilities decreased with reaction time by a factor of ∼2−3, ultimately reaching a constant value. Both the higher initial reaction probabilities (which ranged from 0.07 to 0.75) and the final steady-state values (which ranged from 0.03 to 0.25) decreased if the salt had been heated at 75 °C while pumping to decrease the amount of water on the salt surface prior to reaction. Several experiments using MgCl2·6H2O also gave very large nitric acid reaction probabilities, ≥0.14 in all cases, consistent with the important role of crystalline hydrates in the reactivity of SSS observed in earlier studies. The presence of large amounts of water on the SSS surface was illustrated by two phenomena: (1) the uptake of D2O and liberation of large am...
Nitrite photoreduction in vivo is inhibited by oxygen.

It was hypothesized previously that an O2 inhibition of NO2− photoreduction would reflect a competition between O2 and NO2− for electrons from ferredoxin at the site of plastid nitrite reductase. In order to test this in vivo, intact spinach (Spinacia oleracea L.) leaf chloroplast and mesophyll cell isolates held in high light were aerated with streams of 20% O2/80% N2 (250 micromolar O2 in aqueous solution) or, alternatively, streams of 100% N2. Bicarbonate plus CO2 and NO2− were supplied to reaction mixtures at levels just sufficient to promote maximal assimilations of CO2 and NO2−. In chloroplast isolates, there was a 9 to 30% O2 inhibition of NO2− reduction while there were high rates of CO2 fixation. In spinach and soybean (Glycine max) leaf cell isolates, NO2− photoreduction rates were 10 to 55% inhibited by O2 at near ambient levels. It is possible that O2 may compete, albeit weakly, with NO2− (nitrite reductase) for equivalents derived from reduced ferredoxin. Also, O2 may oxidize sulfhydryl groups on nitrite reductase which are involved in substrate binding and/or activation.
Neural dynamics of saccadic and smooth pursuit eye movement coordination during visual tracking of unpredictably moving targets

How does the brain coordinate saccadic and smooth pursuit eye movements to track objects that move in unpredictable directions and speeds? Saccadic eye movements rapidly foveate peripheral visual or auditory targets, and smooth pursuit eye movements keep the fovea pointed toward an attended moving target. Analyses of tracking data in monkeys and humans reveal systematic deviations from predictions of the simplest model of saccade-pursuit interactions, which would use no interactions other than common target selection and recruitment of shared motoneurons. Instead, saccadic and smooth pursuit movements cooperate to cancel errors of gaze position and velocity, and thus to maximize target visibility through time. How are these two systems coordinated to promote visual localization and identification of moving targets? How are saccades calibrated to correctly foveate a target despite its continued motion during the saccade? The neural model proposed here answers these questions. Modeled interactions encompass motion processing areas MT, MST, FPA, DLPN and NRTP; saccade planning and execution areas FEF, LIP, and SC; the saccadic generator in the brain stem; and the cerebellum. Simulations illustrate the model's ability to functionally explain and quantitatively simulate anatomical, neurophysiological and behavioral data about coordinated saccade-pursuit tracking.
A compact representation of locally-shortest paths and its application to a human-robot interface

The space of all possible paths through a finite-dimensional configuration space is infinite-dimensional. Nevertheless, paths taken by “real” robotic systems often cluster on a finite-dimensional manifold that is embedded in this infinite-dimensional space and that is governed by a principle of optimality. We take advantage of this property to enable a human user to efficiently specify a desired path for a robot moving through a planar workspace with polygonal obstacles using a sequence of noisy binary inputs, as might be derived from a brain-machine interface. First, we show that the space of all such paths having length that is bounded and locally minimal is homeomorphic to the unit disk. Second, we note that any path mapped to the interior of this disk is a subset of some other path mapped to its boundary. Third, we provide an optimal communication protocol by which the user can, with vanishing error probability, select a point on this boundary. Finally, we validate our approach in preliminary experiments with human subjects.
Fundamental limits on phase and frequency tracking and estimation in drifting oscillators

Distributed beamforming requires phase and frequency synchronization. As oscillators drift, through Brownian motion induced phase noise, their instantaneous phases must be tracked and compensated. Several papers and IEEE 1588 have proposed Kalman Filter (KF) based tracking algorithms using the unwrapped phase measurements. This paper quantifies the effect of Brownian Motion induced drift at two levels. First we derive Cramer-Rao Lower Bounds (CRLB) manifest in one shot estimation of frequency and phase from unwrapped phase observations, and reveal fundamental and illuminating differences with the existing frequency and phase estimation CRLBs in the literature derived in the absence of Brownian motion. Second, we consider a KF that tracks the instantaneous phase in intervals where there is no beamforming, and is switched off during beamforming. Bounds are derived relating the error growth as a function of the underlying duty cycle.
Complete Genome Sequence of a Klebsiella pneumoniae Strain Isolated from a Known Cotton Insect Boll Vector

ABSTRACT Klebsiella pneumoniae (associated with bacterial pneumonia) was previously isolated from Nezara viridula, a significant vector of cotton boll-rot pathogens. We provide the first annotated genome sequence of the cotton opportunistic strain K. pneumoniae 5-1. This data provides guidance to study the bases of cotton pathogenesis by bacteria associated with vectors.
Intuition: An Ignored Dimension of Management

The article focuses on the role of intuition in management, which is overlooked in traditional management literature, and examines research in brain organization and parapsychology. The provisional definitions of “intellect” and “intuition,” which work in tandem and are used in this article, were influenced by the research of Henri Bergson, Carl G. Jung, Arthur Koestler, and Jacques Maritain. An example of the quantitative decision-making process is given. Studies on the brain's right and left hemispheres show that analytical processes are dominant on the left while spatial information is processed on the right. Split brain research by John Marsh Jr. and a study by Douglas Dean concerning executives and precognitive abilities are mentioned.