cssi/SciSciGPT-SciSciNet huggingface dataset:
A structural and functional analysis of the glycosyltransferase BshA from Staphylococcus aureus: Insights into the reaction mechanism and regulation of bacillithiol production.

Bacillithiol is a glucosamine-derived antioxidant found in several pathogenic Gram-positive bacteria. The compound is involved in maintaining the appropriate redox state within the cell as well as detoxifying foreign agents like the antibiotic fosfomycin. Bacillithiol is produced via the action of three enzymes, including BshA, a retaining GT-B glycosyltransferase that utilizes UDP-N-acetylglucosamine and l-malate to produce N-acetylglucosaminyl-malate. Recent studies suggest that retaining GT-B glycosyltransferases like BshA utilize a substrate-assisted mechanism that goes through an SN i-like transition state. In a previous study, we relied on X-ray crystallography as well as computational simulations to hypothesize the manner in which substrates would bind the enzyme, but several questions about substrate binding and the role of one of the amino acid residues persisted. Another study demonstrated that BshA might be subject to feedback inhibition by bacillithiol, but this phenomenon was not analyzed further to determine the exact mechanism of inhibition. Here we present X-ray crystallographic structures and steady-state kinetics results that help elucidate both of these issues. Our ligand-bound crystal structures demonstrate that the active site provides an appropriate steric and geometric arrangement of ligands to facilitate the substrate-assisted mechanism. Finally, we show that bacillithiol is competitive for UDP-N-acetylglucosamine with a Ki value near 120-130 μM and likely binds within the BshA active site, suggesting that bacillithiol modulates BshA activity via feedback inhibition. The work presented here furthers our understanding of bacillithiol metabolism and can aid in the development of inhibitors to counteract resistance to antibiotics such as fosfomycin.
Political Pioneer of the Press: Ida B. Wells-Barnett and Her Transnational Crusade for Social Justice

In a recent essay, I wrote about the growing momentum of twentieth century black press scholarship, highlighting how recent works have expanded analytical and conceptual approaches to the study of ...
A Cellular Multiband DTC-Based Digital Polar Transmitter With −153 dBc/Hz Noise in 14-nm FinFET

A digital polar transmitter is presented that uses a digital-to-time-converter (DTC) to enable high-efficiency polar RFDAC for multiband and wide-channel applications. The transmitter uses coarse division inherent in DTC operation to generate TX output frequencies from 0.7 to 2.2 GHz with DCO tuning range of only 7.3–8.7 GHz (±8.7%). The TX was fabricated in 14-nm FinFET and achieves noise of −153/−150 dBc/Hz for LTE5/LTE20 in Band1 with DTC power dissipation of 27 mW. The DTC was implemented using digital Automatic-Place-and-Route tools, requiring very limited analog layout resources.
Method to Interface Grid-Forming Inverters into Power Hardware in the Loop Setups

During the last decade, utility companies around the world have experienced a significant increase in the occurrences of either planned or unplanned blackouts, and microgrids have emerged as a viable solution to improve grid resiliency and robustness. Recently, power converters with grid-forming capabilities have attracted interest from researchers and utilities as keystone devices enabling modern microgrid architectures. Therefore, proper and thorough testing of Grid-Forming Inverters (GFMIs) is crucial to understand their dynamics and limitations before they are deployed. The use of closed-loop real-time Power Hardware-in-the-Loop (PHIL) simulations will facilitate the testing of GFMIs using a digital twin of the power system under various contingency scenarios within a controlled environment. So far, lower to medium scale commercially available GFMIs are difficult to interface into PHIL simulations because of their lack of a synchronization mechanism that allows a smooth and stable interconnection with a voltage source such as a power amplifier. Under this scenario, the use of the well-known Ideal Transformer Method to create a PHIL setup can lead to catastrophic damages of the GFMI. This paper addresses a simple but novel method to interface commercially available GFMIs into a PHIL testbed. Experimental results showed that the proposed method is stable and accurate under standalone operation with abrupt (step) load-changing dynamics, followed by the corresponding steady state behavior. Such results were validated against the dynamics of the GFMI connected to a linear load bank.
Algal p-coumaric acid induces oxidative stress and siderophore biosynthesis in the bacterial symbiont Phaeobacter inhibens.

Summary The marine alpha-proteobacterium Phaeobacter inhibens engages in intermittent symbioses with microalgae. The symbiosis is biphasic and concludes in a parasitic phase, during which the bacteria release algaecidal metabolites in response to algal p-coumaric acid (pCA). The cell-wide effects of pCA on P. inhibens remain unknown. Herein, we report a microarray-based transcriptomic study and find that genes related to the oxidative stress response and secondary metabolism are upregulated most, while those associated with energy production and motility are downregulated in the presence of pCA. Among genes upregulated is a previously unannotated biosynthetic gene cluster and, using a combination of gene deletions and metabolic profiling, we show that it gives rise to an unreported siderophore, roseobactin. The simultaneous production of algaecides and roseobactin in the parasitic phase allows the bacteria to take up any iron that is released from dying algal cells, thereby securing a limited micronutrient.
SU-D-207-04: GPU-Based 4D Cone-Beam CT Reconstruction Using Adaptive Meshing Method

Purpose: Due to the limited number of projections at each phase, the image quality of a four-dimensional cone-beam CT (4D-CBCT) is often degraded, which decreases the accuracy of subsequent motion modeling. One of the promising methods is the simultaneous motion estimation and image reconstruction (SMEIR) approach. The objective of this work is to enhance the computational speed of the SMEIR algorithm using adaptive feature-based tetrahedral meshing and GPU-based parallelization. Methods: The first step is to generate the tetrahedral mesh based on the features of a reference phase 4D-CBCT, so that the deformation can be well captured and accurately diffused from the mesh vertices to voxels of the image volume. After the mesh generation, the updated motion model and other phases of 4D-CBCT can be obtained by matching the 4D-CBCT projection images at each phase with the corresponding forward projections of the deformed reference phase of 4D-CBCT. The entire process of this 4D-CBCT reconstruction method is implemented on GPU, resulting in significantly increasing the computational efficiency due to its tremendous parallel computing ability. Results: A 4D XCAT digital phantom was used to test the proposed mesh-based image reconstruction algorithm. The image Result shows both bone structures and inside of the lungmore » are well-preserved and the tumor position can be well captured. Compared to the previous voxel-based CPU implementation of SMEIR, the proposed method is about 157 times faster for reconstructing a 10 -phase 4D-CBCT with dimension 256×256×150. Conclusion: The GPU-based parallel 4D CBCT reconstruction method uses the feature-based mesh for estimating motion model and demonstrates equivalent image Result with previous voxel-based SMEIR approach, with significantly improved computational speed.« less
Effects of solids and liquid flows on fermentation in continuous cultures. II. Nitrogen partition and efficiency of microbial synthesis.

The effects of varying solids retention time (SRT) and liquid dilution rate (D) on N partition and microbial efficiency were studied in vitro with a dual flow continuous culture system. SRT's of 14.3, 22.0 and 29.7 hr and D's of .07, .11 and .15 volumes/hr were used. Ammonia N accounted for 2.69 to 7.30% of total effluent N. Highest values were observed with 29.7-hr SRT at .11 and .15/hr D's, and were associated with a slight decrease in microbial N. Between 1.17 and 2.50 g microbial N were produced per 24 hr, accounting for 31.34 to 50.49% of total effluent N. Daily output of microbial N increased (P less than .05) with increasing D at the lowest SRT but showed little or no change at the 22.0- and 29.7-hr SRT's. Feed bypass N was inversely related to microbial N and accounted for 44.91 to 65.10% of total effluent N. Microbial cell yields per mole ATP (YATP) ranged from 10.40 to 24.41 and tended to increase with decreased SRT more than with increased D, although responses were variable. Efficiency of microbial N synthesis ranged from 15.75 to 23.91 g microbial N/kg digested dry matter (DDM), with trends similar to those seen for YATP.
Takings Law and Infrastructure Investment: Certainty, Flexibility and Compensation

Nation states can reduce the risks faced by infrastructure investors by establishing a background norm that limits the state's ability to undermine the profitability of infrastructure projects. This background norm would be an implicit term in every contract and would provide a kind of guarantee against certain types of state actions. A background norm in the constitutions of some developed states is a "takings clause" that requires the state to pay compensation when it "takes" property for public use. The application of takings jurisprudence to the field of infrastructure investment is the subject of this paper. The paper shows how infrastructure investors in developing countries face risks related to public sector activities. It then summarizes United States takings law, emphasizing its application to infrastructure industries. Next, it provides a principled way to think about government compensation and applies the framework to infrastructure industries and to developing countries trying to establish a credible legal framework for capital investment. The central policy analytic issues are the efficiency consequences of takings doctrine and the fairness of alternative rules.
On Transition Metal-Catalyzed Reactions of Norbornadiene and the Concept of π Complex Multicenter Processes

Publisher Summary This chapter focuses on bicyclo[2.2.l]heptadiene-2,5 (norbornadiene), a new versatile substrate for catalytic studies. The chapter describes its transition metal-catalyzed reactions and discusses the mechanism of these reactions and the function of transition metals in catalytic processes of this kind. The chemistry of norbornadiene is characterized by strain and homoconjugation. Hence, the olefin undergoes a series of addition reactions that are frequently accompanied by the formation of the nortricyclene system—the direction of electrophilic attack being usually exo. Transition metal complexes, such as nickel carbonyl or bisacrylonitrile nickel have been found to greatly promote the reaction of acrylonitrile with norbornadiene. Norbornadiene may be carbonylated essentially under the conditions of Reppe's acrylic ester synthesis.
Self-Disclosure in Psychotherapy

The Nature of Self-Disclosure. Clinical Perspectives on Patient Disclosure. Research Perspectives on Patient Disclosure. Patient Self-Disclosure: The Outcome Controversy. Multicultural Perspectives on Patient Disclosure. Historical Perspectives on Therapist Disclosure. Research Perspectives on Therapist Disclosure. Clinical Perspectives on Therapist Disclosure. Supervisee and Supervisor Disclosure. Conclusions.
Towards a Non-deterministic Reading of Pierre Bourdieu: habitus and educational change in urban schools

Building on the social reproduction theory of Pierre Bourdieu, this study examines the impact of school context and institutional agency on shaping urban students' access to social and cultural cap...
Sida ravii Sivad. & Anil Kumar (Malvaceae) a new record from Tamilnadu, India

Sida ravii Sivad. & Anil Kumar, (Malvaceae) is an undershrub is reported first time for Tamil Nadu from the Pachchaimalai hills of Eastern Ghats, India. A detailed description and illustration of the species are provided here for the easy identification.
Surface speciation of calcite observed in situ by high-resolution X-ray reflectivity

High-resolution, in situ X-ray reflectivity measurements were made of the calcite (104)–water interface in calcite-saturated aqueous solutions at pH values ranging from 6.8 to 12.1 and low PCO2. The X-ray reflectivity data, taken over a momentum transfer range of 6 A−1, indicate that the calcite surface does not vary significantly over this range of experimental conditions. From an analysis of the data at pH 8.3, the best-fit reflectivity model requires the presence of 1.0 ± 0.4 monolayer of a hydroxyl species (OH or OH2) at 2.50 ± 0.12 A above the surface Ca ions and involves rotations of the surface carbonate groups toward the (104) plane. The X-ray reflectivity data for pH 6.8 and 12.1 can be explained without invoking changes other than protonation reactions in the surface speciation of terrace areas. This is consistent with scanning force microscopy studies of calcite growth and dissolution near equilibrium, which show that attachment and detachment of Ca and CO3 ions occurs primarily at step-edge kink sites. These results demonstrate how high-resolution X-ray reflectivity can be used for direct, in situ measurement of mineral surface structure, to provide strong constraints on chemical speciation and reactivity at the mineral-fluid interface.
Evoked potential abnormalities in myotonic dystrophy.

Abstract Past investigators have reported evidence of central nervous system involvement in myotonic dystrophy (MYD), including EEG abnormalities, ventricular enlargement, thalamic inclusion bodies, and impaired tests of cognitive function. Brain stem auditory evoked potentials have not been reported in myotonic dystrophy. We report the results of brain stem auditory (BAEP) and median nerve somatosensory (MSSEP) evoked potentials in 15 patients with MYD (9 males, 6 females, mean age = 35.8 ± 11.4 years). BAEPs were abnormal in 53.3% (P No correlation was found between abnormal evoked potentials and patient age. A sex difference, however, was noted with 8/9 males having one or more abnormal evoked potentials compared with 0/6 females. Though our finding of abnormal MSSEPs was not statistically significant, both patients showed delay at the thalamic level, where pathology has been described. Abnormal ocular pursuit and sluggish pupillary reaction have implicated brain stem involvement in MYD. The abnormal BAEPs at the level of the pons and midbrain in this study provide neurophysiological evidence of brain stem pathology in MYD.
Stand-off and up-close Raman detection of nitrates buried in sand and soils

Raman measurements, using a 785nm laser, are taken of Ammonium Nitrate and Sodium Nitrate buried in sand. Nitrate is kept in clear plastic containers and buried underneath sand at various depths. Raman measurements are then taken at distances of 5m and 20m, with the sand being completely dry as well as completely wet. A different set of experiments was conducted with Nitrate buried in sand in a glass container, where no Raman signal was seen in dry sand. Water was then added at the edge of the container and allowed to migrate to the bottom. Raman measurements are then taken at a distance of 7mm over time to detect Nitrates brought to the surface by water as it wicks to the surface.
Modified electron-gas study of the stability, elastic properties, and high-pressure behavior of MgO and CaO crystals

A theoretical study of the crystal structure and bonding in the simple inorganic oxide crystals magnesium oxide and calcium oxide is reported. An a priori method based on an electron-gas approximation is applied to an ionic description of these crystals. The quantities calculated are the equilibrium interionic separation, the elastic constants and their pressure derivatives, the transition pressures and volume changes in high-pressure-induced phase transitions, and the thermodynamic stability of the crystal structures. Comparison with available experimental data shows good agreement, without any adjustable parameters in the theory. We conclude that the ionic description of these crystals is rather accurate for energy calculations, provided that a suitably stabilized oxide ion is used in the theory.
Abnormal hyperexcitability of hippocampal slices from kindled rats is transient

Abstract The anatomic substrates and mechanisms responsible for the development and permanence of kindling remain to be determined. One region believed to play an important role in kindling development is the hippocampus. Epileptiform (K+-induced spontaneous bursting) was recently shown to be enhanced in hippocampal slices from kindled rats studied 1 day after kindling from the lateral entorhinal cortex (LEC). Identical results one month after kindling raised the possibility that hippocampal excitability might be permanently increased in kindled animals. One goal of the present study was to confirm this finding, and also to extend it in terms of both the anatomic extent and the duration of this excitability increase. Stimulus train-induced bursting (STIB) is an vitro model of hippocampal epileptogeness. Parallels between STIB and kindling suggested STIB might prove useful for studying mechanisms underlying kindling. To strengthen the relation of STIB to kindling, we examined whether slices animals would behave as if they had undergone STIB during kindling. K+-induced bursting and STIB were studied in hippocampal slices from control and kindled rats one day and about 3 months after completion of kindling from the right LEC. Both K+-induced bursting and STIB development were enhanced one day after kindling. The enhancement of K+-induced bursting was present in both temporal and septal slices from both the ipsilateral and the contralateral hippocampus. Neither of these proepileptic changes was detected 3 months after kindling. These results suggest: (1) the site of the permanent change in kindling appears to reside outside area CA3 of the hippocampus, (2) changes thought to underlie the permanence of kindling should be confirmed substantially longer after kindling than one month, and (3) STIB may prove useful for studying mechanisms of hippocampal regulation of kindling development.
Codes for Write-Once Memories

A write-once memory (WOM) is a storage device that consists of cells that can take on $q$ values, with the added constraint that rewrites can only increase a cell's value. A length- $n$ , $t$ -write WOM-code is a coding scheme that allows $t$ messages to be stored in $n$ cells. If on the $i$ th write we write one of $M_{i}$ messages, then the rate of this write is the ratio of the number of written bits to the total number of cells, i.e., $\log_{2}M_{i}/n$ . The sum-rate of the WOM-code is the sum of all individual rates on all writes. A WOM-code is called a fixed-rate WOM-code if the rates on all writes are the same, and otherwise, it is called a variable-rate WOM-code. We address two different problems when analyzing the sum-rate of WOM-codes. In the first one, called the fixed-rate WOM-code problem, the sum-rate is analyzed over all fixed-rate WOM-codes, and in the second problem, called the unrestricted-rate WOM-code problem, the sum-rate is analyzed over all fixed-rate and variable-rate WOM-codes. In this paper, we first present a family of two-write WOM-codes. The construction is inspired by the coset coding scheme, which was used to construct multiple-write WOM-codes by Cohen and recently by Wu, in order to construct from each linear code a two-write WOM-code. This construction improves the best known sum-rates for the fixed- and unrestricted-rate WOM-code problems. We also show how to take advantage of two-write WOM-codes in order to construct codes for the Blackwell channel. The two-write construction is generalized for two-write WOM-codes with $q$ levels per cell, which is used with ternary cells to construct three- and four-write binary WOM-codes. This construction is used recursively in order to generate a family of $t$ -write WOM-codes for all $t$ . A further generalization of these $t$ -write WOM-codes yields additional families of efficient WOM-codes. Finally, we show a recursive method that uses the previously constructed WOM-codes in order to construct fixed-rate WOM-codes. We conclude and show that the WOM-codes constructed here outperform all previously known WOM-codes for $2\leqslant t\leqslant 10$ for both the fixed- and unrestricted-rate WOM-code problems.
A component analysis of performance visualization

This study was designed to determine whether all three components of performance visualization (education, guided imagery, and modeling) are necessary to help people enhance speech performance and reduce public speaking apprehension. These data indicate that the education component appears to be unnecessary. It is speculated that cognitive processing differences with regard to language and images may be at the root of these findings.
Report of workshop on role of water and ions in biological membrane function

A joint U.S.-Romanian exchange workshop on the role of water and ions in biological membrane function was held in conjunction with the Biophysical Society meeting in San Antonio, Texas. The meeting was sponsored by the National Science Foundation and by the National Council of Romania. American participants included Drs. Wally Boron, Ivan Cameron, James Clegg, John and Lois Crowe, David Deamer, Laura Eisenstein, Sidney Fleischer, Philip Morse, Richard Nuccitelli, Lester Packer, Elizabeth Simons, and Stephen Scheiner. Romanian participants included Drs. Ion Baciu, Constanta Ganea, Eva Katona, Doru-Georg Margineanu, Ioan Nicolascu, Valeriu Rusu, Mioara Tripsa, Vasilie Vasilescu, and Cornelia Zaciu. This report provides an overview of the research themes and observations reported at the conference.
Counting Efficiency of the Api Aerosizer

Abstract The Aerosizer (Amherst Process Instruments, Inc. Hadley MA) is a time-of-flight instrument frequently used to measure the size distribution of an aerosol. However, if the Aerosizer’s counting efficiency, defined as the number of particles counted divided by the total number entering the instrument, is not 100% or varies with particle size, the resulting size distribution will be inaccurate. Experiments were conducted to determine the effect of particle diameter, particle concentration, photomultiplier tube (PMT) voltage, and model type on the Aerosizer’s counting efficiency. To calculate counting efficiency, the number of particles between 0.3 and 10 μm recorded by the Aerosizer was divided by the number of particles of the same size collected on each stage of a cascade impactor. Particle diameter, aerosol concentration, Aerosizer model, PMT voltage, and the diameter interaction terms influenced counting efficiency. Counting efficiencies were less than 1% for particles smaller than 0.45 μm, and more than 100% for particles larger than 7 μm. Increasing the PMT voltage increased the counting efficiency for the smaller particles, but also created false, larger particles. Counting efficiency decreased as count rate increased for count rates greater than 20,000 particles per second. The Aerosizer LD counted particles more efficiently than the Aerosizer Mach 2 because of improved laser and optics systems. Four regression models that relate counting efficiency to the salient operating parameters were developed, one for each combination of Aerosizer model and photomultiplier tube voltage studied.
Location and Function of Erythropoietin (Epo) and its Receptor (Epo-R) in the Developing Human Brain • 1876

We have previously identified the presence of Epo and its receptor in the human fetal CNS, and reported that pharmacologic doses of rEpo decrease hypoxia-induced apoptosis in human neuronal precursor cells (NT2). We now describe specific changes in the cellular distribution of Epo and Epo-R during neurodevelopment. We also report that physiologic concentrations of rEpo protect NT2 cells from UV-induced apoptosis. Two antibodies against human Epo-R, and Epo were used to identify immunoreactive cells in brains at 5, 10, 20, 24, 28, 32 weeks post conception, and in adult brains. The specificity of antibody reactions were checked by Western analysis. Controls for immunohistochemistry included specific and non-specific blocking peptides, absence of primary antibody, and substitution of pre-immune serum for specific antibody. At 5 weeks gestation, anti-Epo and Epo-R antibodies were both immunoreactive in the ventricular zone, while at 10 weeks only Epo staining was prominent in the ventricular zone, with Epo-R staining primarily the subventricular zone. Both antibodies stained the cortical plate. As development progressed, Epo reactivity became most prominent in neurons, although a subpopulation of astrocytes were also immunoreactive. This was in contrast to Epo-R staining, which was most prominent in astrocytes, although weak immunoreactivity was also present on neurons. To test the hypothesis that Epo is neuroprotective at physiologic doses, we pretreated NT2 cells for 16 hrs with either 50mU/mL rEpo, 50mU/mL rEpo+neutralizing antibody, or PBS(n=8). Cells were exposed to 11 sec UV irradiation (vs no UV control). After 16 hrs, cells were stained with trypan blue and counted, and nuclear matrix protein (NMP) released into the media was measured by ELISA. Cells exposed to 50 mU/mL Epo were rescued from UV-induced apoptotic cell death, as evaluated by both cell counts and decreased NMP (p<0.05). We have previously documented Epo concentration in neonatal CSF as high as 68 mU/mL, thus 50 mU/mL is within the physiologic range. We conclude that Epo and its receptor are present within the developing human brain, that the pattern of distribution of these proteins change with development, and that inhibiting apoptotic cell death may be one function of this cytokine-ligand pair.
Duration and resolution effects on visual persistence (positive afterimages)

The effects of varying target duration and target size on the duration of visual persistence were assessed in a probe-matching task for both foveal and peripheral targets presented against scotopic, mesopic, and photopic background fields. Persistence was found to increase with increasing target duration and increasing target size under all conditions of retinal location and background field. Results are discussed in terms of an early sensory locus to the persistence assessed by the task employed. The possible bases for discrepancies with other work are proposed in terms of differing processes within the visual system that may be involved by the different persistence tasks favored by various investigators.
Nicotine withdrawal-induced deficits in trace fear conditioning in C57BL / 6 mice – a role for high-affinity β2 subunit-containing nicotinic acetylcholine receptors

Nicotine alters cognitive processes that include working memory and long-term memory. Trace fear conditioning may involve working memory during acquisition while also allowing the assessment of long-term memory. The present study used trace fear conditioning in C57BL/6 mice to investigate the effects of acute nicotine, chronic nicotine, and withdrawal of chronic nicotine on processes active during acquisition and recall 24 hours later and examine the nicotinic acetylcholine receptor subtypes (nAChRs) involved in withdrawal-deficits in trace fear conditioning. During training, acute nicotine (0.09 mg/kg) enhanced, but chronic nicotine (6.3 mg/kg/day, 13 days) and withdrawal of chronic nicotine (6.3 mg/kg/day, 12 days) had no significant effect on acquisition of trace conditioning. At recall, acute treatment enhanced conditioning while chronic nicotine had no effect and withdrawal of chronic nicotine resulted in deficits. Antagonist precipitated withdrawal was used to characterize the nAChRs involved in the withdrawal deficits. The low-affinity nAChR antagonist MLA (1.5, 3, 9 mg/kg) had no effect on trace fear conditioning, but the high-affinity nAChR antagonist DHβE (3 mg/kg) precipitated deficits in trace fear conditioning if administered at training or training and testing, but not if administered at testing alone. The β2 nAChR subunit is involved in the withdrawal effects as withdrawal of chronic nicotine produced deficits in trace fear conditioning in wildtype but not in β2 knockout mice. Thus, nicotine alters processes involved in both acquisition and long-term memory of trace-fear conditioning, and high-affinity β2 subunit containing nAChRs are critically involved in the effects of nicotine withdrawal on trace fear conditioning.
Measuring the Structure of Visual Fields in Nursing Units

Objective:The purpose of this study was to develop quantitative measures of the structure of visual fields in nursing units.Background:The structure of visual fields in nursing units—especially vis...
Low-density helium monolayers as two-dimensional imperfect gases: An analysis employing the second virial coefficient

The quantum second virial coefficient of two-dimensional systems interacting with a hard-core or Lennard-Jones 6-12 potential are calculated together with the contribution this coefficient makes to the specific heat of such systems. The results are compared with experimental data from low-density ${\mathrm{He}}^{3}$ and ${\mathrm{He}}^{4}$ monolayers adsorbed on graphite. The calculation provides a qualitative and quantitative understandiang of the experimental measurements. In particular it illuminates the manner in which the interaction and the difference in statistics cause the very different specific-heat measurements in the two isotopes. The magnetic susceptibility of low-density ${\mathrm{He}}^{3}$ monolayers is predicted.
Lower Extremity Motor Evoked Potentials in Multiple Sclerosis

• Transcranial magnetic stimulation was performed on 25 patients with definite multiple sclerosis. Motor evoked potentials were recorded from the anterior tibial muscle. Central motor conduction time was calculated using the equation (F + M-1)/2 by stimulation of the common peroneal nerve. Motor evoked potentials were capable of detecting subclinical pyramidal tract lesions in multiple sclerosis. In patients with multiple sclerosis, the incidence of abnormality of motor and somatosensory evoked potentials was similar. Central motor conduction time was correlated with overall and pyramidal tract subscores on the Kurtzke Disability Status Scale and the Scripps Neurological Rating Scale. Central motor conduction time abnormalities correlated best with the presence of a Babinski's sign but also correlated significantly with weakness and hyperreflexia.
Arterial Oxygenation and Pulmonary Function with Saralasin in Chronic Lung Disease

During our earlier saralasin infusion study in hypertensive patients, we found a drug-induced rise in arterial oxygen tension (PaO 2 ) associated with unchanged mixed venous Po 2 or the PaCO 2 and unrelated to cardiopulmonary hemodynamic changes. To test the hypothesis that saralasin improved pulmonary mechanics, blood gases, lung mechanics, lung volumes, diffusing capacity, and distribution of ventilation were analyzed and cardiac output (CO) measured in 12 normotensive men with chronic pulmonary disease before and during a 2½ hour infusion of Saralasin (5 µg/kg/min). The PaO 2 increased from a mean of 63 ± 3 (SEM) to 70 ± 3 mm Hg (p 2 (r = —0.67, p 5 (p 2 and other measurements remained unchanged. We conclude that saralasin raised the PaO 2 not by changing pulmonary function or mechanics, but by redistributing pulmonary blood flow and improving the ventilation-perfusion relationship.
Mapping with a ground robot in GPS denied and degraded environments

A robot system operating in an unknown environment must be able to track its position to perform its mission. Vehicles with a consistent view of the sky, e.g., aerial or water surface platforms, can reliably make use of GPS signals to correct accumulated error from inertial measurements and feature-based mapping techniques. However, ground robots that must operate across a wide range of environments suffer from additional constraints which degrade the performance of GPS such as multipath and occlusion. In this paper, we present a methodology for incorporating GPS measurements into a feature-based mapping system for two purposes: providing geo-referenced coordinates for high-level mission execution and correcting accumulated map error over long-term operation. We will present both the underlying system and experimental results from a variety of relevant environments such as military training facilities and large-scale mixed indoor and outdoor environments.
Patterns of Sexuality Communication Between Preadolescents and Their Mothers and Fathers

The purpose of the current study was to examine communication about sexual topics between preadolescents and their mothers and fathers. Participants were 135 African-American mothers, fathers, and their 9- to 12-year-old offspring. Each member of the triad completed a 10-item measure of communication about risk factors for sexual activity, sexual communication, and sexual risk prevention. A majority of parents and their preadolescents reported communication had occurred about most topics. Mothers and fathers were equally likely to communicate with sons whereas mothers were more likely to communicate with daughters than were fathers. Based on the study results, preadolescence may be the optimal time for parents to provide sexual risk prevention messages to their children before sexual behaviors are initiated.
Characterization of the invasive and inflammatory traits of oral Campylobacter rectus in a murine model of fetoplacental growth restriction and in trophoblast cultures

Campylobacter species (C. jejuni, C. fetus) are enteric abortifacient bacteria in humans and ungulates. Campylobacter rectus is a periodontal pathogen associated with human fetal exposure and adverse pregnancy outcomes including preterm delivery. Experiments in pregnant mice have demonstrated that C. rectus can translocate from a distant site of infection to the placenta to induce fetal growth restriction and impair placental development. However, placental tissues from human, small-for-gestational age deliveries have not been reported to harbor C. rectus despite evidence of maternal infection and fetal exposure by fetal IgM response. This investigation examined the temporal relationship between the placental translocation of C. rectus and the effects on fetal growth in mice. BALB/c mice were infected at gestational day E7.5 to examine placental translocation of C. rectus by immunohistology. C. rectus significantly decreased fetoplacental weight at E14.5 and at E16.5. C. rectus was detected in 63% of placentas at E14.5, but not at E16.5. In in vitro trophoblast invasion assays, C. rectus was able to effectively invade human trophoblasts (BeWo) but not murine trophoblasts (SM9-1), and showed a trend for more invasiveness than C. jejuni. C. rectus challenge significantly upregulated both mRNA and protein levels of IL-6 and TNFα in a dose-dependent manner in human trophoblasts, but did not increase cytokine expression in murine cells, suggesting a correlation between invasion and cytokine activation. In conclusion, the trophoblast-invasive trait of C. rectus that appears limited to human trophoblasts may play a role in facilitating bacterial translocation and placental inflammation during early gestation.
A wide frequency range surface integral formulation for 3-D RLC extraction

A new surface integral formulation and discretization approach for computing electromagnetoquasistatic impedance of general conductors is described. The key advantages of the formulation is that it avoids volume discretization of the conductors and the substrate, and a single discretization is accurate over the entire frequency range. Computational results from an on-chip inductor, a connector and a transmission line are used to show that the formulation is accurate and is "acceleration" ready. That is, the results demonstrate that an efficiently computed preconditioner insures rapid iterative method convergence and tests with projection show the required kernels can be approximated easily using a coarse grid.
Black Male Sexual Politics: Avoidance of HIV/AIDS Testing as a Masculine Health Practice

This paper reports on a study of the effects of the sexual, racial and status identity on health and health seeking behavior among a cohort of African American men. Focus groups and structured interviews were conducted to explore the attitudes of a cohort of African American men about their masculinity and its relationship to their health related behaviors. Their narratives indicate that being sexually active is an important component of masculinity. Both younger and older members of the cohort described their use, intended use, and avoidance of sexual activity as a health behavior to preserve a masculine identity. They stated that avoidance would be especially necessary if they were faced with an “incurable” medical diagnosis that could interfere with the freedom of their sexual activities. A diagnosis of HIV/AIDS, for example, was information they said they would avoid by not being tested for AIDS. Evaluating this behavior within the framework of hegemonic masculinity suggests that the behavior is irrational. To remedy this, the paper considers leading theories of gender and masculinity, including “hyper” and hegemonic masculinity and attempts—with the aid of the men’s narratives about masculinity—to formulate a notion of masculinity with greater relevance to African American men.
An Accommodations Model for the Secondary Inclusive Classroom.

Despite expectations for accommodations in inclusive classrooms, little guidance for effective practice is available. Most accommodations policies and evidence-based practices address assessments. ...
Identification of a δ isoform of preprotachykinin mRNA in human mononuclear phagocytes and lymphocytes

Abstract We have characterized preprotachykinin (PPT-A) gene transcript splicing products and identified a fourth isoform of PPT-A mRNA transcript in human peripheral blood-isolated monocytes and PBL. Using RT-PCR, Southern blot analysis and nucleotide sequencing analysis, we have identified the four isoforms of PPT-A transcripts (α, β, γ and δ) in human peripheral blood-isolated monocytes and PBL. The δ-PPT transcript present in the immune cells lacks exons 4 and 6. The sequences of exons 3, 5 and 7 of δ-PPT transcript completely match those of β-PPT transcript. The α-PPT and β-PPT sequences in these cells are identical to those obtained by Tan and Too (GenBank accession number U37539) and Harmar et al. (Genbank accession number X54469), but differ by a single nucleotide from another entry by Chiwakata et al. (Genbank accession number M68906). In comparison to this latter sequence, there was a C→T change at amino acid position 87 (CCT→CTT) which may result in a Pro to Leu change. Identification of the new SP mRNA transcript in both human CNS and immune cells supports the concept of an important biological link between CNS and immune system.
Vitamin D receptor and coactivators SRC2 and 3 regulate epidermis-specific sphingolipid production and permeability barrier formation

The vitamin D receptor (VDR) is a nuclear hormone receptor that controls transcription of target genes. It exerts its biological effects through transcriptional coactivators. Previously, we identified two distinct classes of VDR coactivators, VDR-interacting protein (DRIP) and steroid receptor coactivator (SRC) at different stages of keratinocyte differentiation. Here, we determined the functions of VDR and coactivators in lipid production and permeability barrier formation. Silencing of either VDR, SRC2, or SRC3 resulted in decreases in specific glucosylceramide (GlcCer) species but not other lipids such as cholesterol and free fatty acids. Their silencing also caused decreased transcription of fatty acid elongase and ceramide glucosyltransferase, which are critical for the synthesis of epidermis-unique GlcCer species, and defects in lamellar body formation associated with decreased expression of the lipid transporter ATP-binding cassette transporter protein 12. VDR null mice exhibit abnormal barrier function with altered lipid composition in vivo. These results demonstrate that VDR and coactivators SRC2 and SRC3, which are also involved in other nuclear receptors as well, are critical for epidermis-specific sphingolipid production and barrier formation. In contrast, DRIP silencing had no apparent effect on these processes indicating that the two classes of coactivators are differentially utilized.
Exploring the erythroblastic island

Two new studies suggest a crucial role for macrophages in boosting the number of red blood cells produced in vivo during stress, with translational implications for disease states such as β-thalassemia and polycythemia vera (pages 429–436 and 437–445).
Electrochemical behavior and X-ray crystal structure of the unusual dimeric ruthenium(cyclooctadiene) complex, (tri-μ-chloro)(chloro)(acetonitrile)bis(η4-cyclooctadiene)-diruthenium(II)

Abstract A novel Ru(II)(COD) dimer containing triply-bridging chloride ligands has been prepared and its crystal structure determined. The metal atoms each contain axial COD ligands and are separated by a distance of 3.251 A. Both transition metals possess octahedral coordination geometries. One contains a coordinated molecule of acetonitrile and the other contains an axial halide ligand. Electrochemical investigations show that the complex undergoes two one-electron oxidations that satisfy the criteria for a fully reversible diffusion controlled process. An improved method of preparing this dimeric Ru(II) cycloolefin complex is also presented. The crystals are monoclinic, space group C2/c, a=21.258(6), b=7.179(2), c=27.068(7) A, β=93.18(2)°, V=4124(2) A3. Convergence to conventional R values of R=0.0368 and Rw=0.0394 with a goodness-of-fit of 0.95 was obtained for 226 variable parameters and 2710 reflections with I>0σ(I).
Physiological and behavioural indices of hostility: An extension of the capacity model to include exposure to affective stress and right lateralized motor stress

Right hemisphere functional cerebral systems have reliably been associated with sympathetic nervous system arousal and the perception of negative affective events. The goal of the current research was to provide additional support for the capacity model of hostility by examining changes attributable to functional cerebral systems within the right hemisphere using a dual concurrent task paradigm. To incorporate exposure to negative affective and right-lateralized motor stress using this approach, high and low hostile individuals completed a series of grip-strength tasks before and after hearing a recording of angry infant vocalizations. Results supported the capacity model in that high hostile individuals were unable to maintain regulatory control over right hemisphere activation as indicated through increased motor perseveration in the pre- and post-affective stress conditions, heightened systolic blood pressure (SBP) upon exposure to negative emotional sounds, and increased heart rate (HR) following stre...
Bronchoalveolar carcinoma (adenocarcinoma) mimicking recurrent bacterial community-acquired pneumonia (CAP)

Depending on the community-acquired pneumonia (CAP) pathogen, host factors, and immune status, CAPs resolve on chest x-rays at different rates. CAPs that resolve more slowly than expected, or not at all, are termed "slowly or non-resolving CAPs." In contrast, recurrent CAPs may be due to host defense defects (eg, multiple myelomas) or post-obstructive bronchogenic carcinomas. There are a variety of noninfectious disorders that may mimic CAPs on chest x-ray: alveolar hemorrhage, pulmonary drug reactions, radiation pneumonitis, Wegener's granulomatosis, bronchiolitis obliterans organizing pneumonia, bronchogenic carcinomas, and lymphomas. Noninfectious mimics of recurrent CAPs include congestive heart failure, pulmonary emboli, infarctions, sarcoidosis, and systemic lupus erythematosus pneumonitis. We present the case of a middle-aged man who presented with recurrent right middle lobe and right lower lobe CAPs. Diagnostic bronchoscopy showed no bronchial obstruction, but open lung biopsy showed bronchoalveolar carcinoma (well-differentiated adenocarcinoma). Bronchoalveolar carcinomas presenting as post-obstructive or recurrent CAPs are rare because the spread is along tissue planes and not endobronchially. The case described demonstrates a rare cause of bronchogenic carcinoma mimicking recurrent CAP.
Computational studies of the reactions of B10H13- with alkynes and olefins: pathways for dehydrogenative alkyne-insertion and olefin-hydroboration reactions.

Quantum mechanical computational studies of possible mechanistic pathways for B10H13− dehydrogenative alkyne-insertion and olefin-hydroboration reactions demonstrate that, depending on the reactant and reaction conditions, B10H13− can function as either an electrophile or nucleophile. For reactions with nucleophilic alkynes, such as propyne, the calculations indicate that at the temperatures (∼110−120 °C) required for these reactions, the ground-state B10H13− (1) structure can rearrange to an electrophilic-type cage structure 3 having a LUMO orbital strongly localized on the B6 cage-boron. Alkyne binding at this site followed by subsequent steps involving the formation of additional boron−carbon bonds, hydrogen elimination, protonation, and further hydrogen elimination then lead in a straightforward manner to the experimentally observed ortho-carborane products resulting from alkyne insertion into the decaborane framework. A similar mechanistic sequence was identified for the reaction of propyne with 6-R-...
Human factors challenges in creating a principal support office system—the speech filing system approach

This paper identifies the key behavioral challenges in designing a principal-support office system and our approaches to them. These challenges included designing a system which office principals would find useful and would directly use themselves. Ultimately, the system, called the Speech Filing System (SFS), became primarily a voice store and forward message system with which users compose, edit, send, and receive audio messages, using telephones as terminals. Our approaches included behavioral analyses of principals' needs and irritations, controlled laboratory experiments, several years of training, observing, and interviewing hundreds of actual SFS users, several years of demonstrating SFS to thousands of potential users and receiving feedback, empirical studies of alternative methods of training and documentation, continual major modifications of the user interface, simulations of alternative user interfaces, and actual SFS usage analyses. The results indicate that SFS is now relatively easy to learn, solves real business problems, and leads to user satisfaction.
PHOSPHOCREATINE AND NUCLEOTIDE CHANGES IN PIG LONGISSIMUS MUSCLE DURING THE DEVELOPMENT OF RIGOR MORTIS UNDER CONTROLLED ENVIRONMENTAL CONDITIONS

SUMMARY This study was conducted to compare the depletion of phosphocreatine (PC) and nucleotides (ATP and ADP) in strips of muscle which had been used for extensibility meesurements in the rigorometer with control strips of muscle which had been held unrestrained in the same environment. There were no significant differences in PC and ATP between the rigorometer and control strips. Rigorometer strips from “Stress-susceptible” pigs had less rapid and less extensive depletion of ADP than did control strips from the same animals. It appeared that extensibility remained in the tissue after the A TP had been depleted, but not after AOP reached a low level.