cssi/SciSciGPT-SciSciNet huggingface dataset:
Effects of Moisture Absorption on the Dielectric Properties of Nanoclay-Reinforced Epoxy for Radome Applications

The relative permittivity and loss tangent at 10 GHz of a nanoclay-reinforced epoxy is investigated as a function of nanoclay loading percentage and moisture content. The energy dissipation associated with frictional and inertial losses during the reorientation of absorbed dipole water molecules exposed to an oscillating electromagnetic field has a significant impact on the relative permittivity and loss tangent of moisture-contaminated polymer materials. This can damage the performance of polymer-based radar-protecting structures (radomes) designed to protect sensitive radar equipment. Thus, prevention or minimization of water absorption in these materials is critical to mitigating this effect. The moisture barrier properties of nanoclay reinforcement are well known, and are targeted in this study as a potential method to reduce the moisture absorption rate and therefore improve the performance of polymer-based radomes exposed to precipitation and humid air. The ability of a water molecule to rotate freely in the presence of an EM field is dependent on its physical and chemical state; whether it be bound and unable to rotate, or unbound and able to dissipate energy through unrestricted rotation. Therefore, any potential dielectric property changes associated with the physical and chemical interaction of water and nanoclay must be quantified prior to exploiting prospective moisture-barrier benefits. In this study, the relative permittivity and loss tangent of an epoxy system reinforced with nanoclay up to 5% content by weight are assessed using a resonant cavity technique at 10 GHz during moisture uptake due to immersion in distilled water at 25°C. Variations in moisture diffusion behavior are observed due to the nanoclay loading percentage. Although deviations in the dielectric properties due solely to nanoclay loading percentage are minimal, effects due to moisture absorption are much more prominent. In the most extreme case, a nearly 15% increase in relative permittivity is observed at 5% moisture content by weight, with a direct correlation between diffusion behavior and degradation of relative permittivity observed for all samples. Likewise, an increase in the loss tangent of approximately 220% is observed at 5% moisture content by weight.Copyright © 2014 by ASME
Longitudinal variations in the Saturnian atmosphere. I. Equatorial region

Longitudinal variations in the equatorial regions of Saturn are sought in both Voyager orange and methane-filter and ground-based 6000-6600 A observations. The spectral variations found are inconsistent with reflecting layer height variation; they are alternatively modeled by changes in the single-scattering albedo of the haze, as well as in the specific abundance of haze gas. The 500-km spatial resolution data furnished by Voyager are found to be consistent with a specific abundance of haze gas between 10 and 24 km-am. Ammonia and methane mixing ratios are derived.
TCP MaxNet - implementation and experiments on the WAN in Lab

We describe implementation and performance of TCP MaxNet, a new protocol that uses a multi-bit explicit signaling approach to congestion control. The MaxNet sender algorithm operates by adjusting its congestion window in response to explicit feedback from the most congested link encountered in the network. This scheme has numerous theoretical advantages over the ubiquitous practice of adjusting the congestion window based on the total amount of congestion in the path. We implement the MaxNet control scheme on top of the existing Linux TCP/IP protocol framework and evaluate its performance in the high bandwidth-delay environment of the WAN in Lab. Our experiments show that MaxNet possesses the desirable properties that theory predicts: very short router queues and fair sharing among multiple flows of different RTTs.
Neuromodulation in a learning robot: interactions between neural plasticity and behavior

We investigate the effects of behavioral activity on the development of patterns of synaptic connections in a model of neuromodulation embedded in an autonomous robot. Robot behavior produces clustered spatial distributions of rewarding objects in environments initially containing a high density of uniformly distributed objects. The spatial clustering of the rewarding objects restricts robot movements to sectors of high reward density, alters patterns of connections signaling predictions about reward timing, and changes the temporal profile of interactions between the robot and the objects. These effects are outcomes of embodied behavioral activity and are not pre-programmed or externally controlled. We discuss our results in the context of the reciprocal coupling of neural dynamics, behavioral activity and stimulus distributions.
Transcriptional basis for hyporesponsiveness of the human inducible nitric oxide synthase gene to lipopolysaccharide/interferon-gamma.

The work reported here resolves, at the level of gene regulation, the controversy as to whether or not human monocytes/macrophages can produce nitric oxide (NO) when stimulated with lipopolysaccharide (LPS), with or without co-stimulation by interferon-gamma (IFN-gamma). Studies included structural comparison of the promoters for human and mouse inducible NO synthase (iNOS) genes, transfection and assay of human and mouse iNOS promoter regions in response to LPS +/- IFN-gamma, and electrophoretic mobility shift assays of kappa B response elements. Two explanations for hyporesponsiveness of the human iNOS promoter to LPS +/- IFN-gamma were found: (1) multiple inactivating nucleotide substitutions in the human counterpart of the enhancer element that has been shown to regulate LPS/IFN-gamma induced expression of the mouse iNOS gene; and (2) and absence of one or more nuclear factors in human macrophages (e.g., an LPS-inducible nuclear factor-kappa B/Rel complex), that is (are) required for maximal expression of the gene. The importance of resolution of this controversy is that future research in this area should be directed toward the understanding of alternative mechanisms that can result in the successful production of NO.
Constructing Gold-thiolate Oligomers and Polymers on Au(111) Based on the Linear S-Au-S Geometry

Although neat gold−thiolate oligomers and polymers made of linear S−Au−S bonds have been well-known, observation of RS−Au−SR linear complexes (RS− being an alkylthiolate group) on Au(111) has been reported only recently. On the basis of the unique geometry and bonding of the RS−Au−SR complex on Au(111), we construct simple geometric models of Au-SR oligomers and polymers on Au(111) by fusing linear S−Au−S units matched to the underlying Au(111) surface lattice. We then optimize these models by density functional theory. The hexagonal geometry of the Au(111) lattice determines three possible angles (60°, 120°, and 180°) for connecting two linear S−Au−S units, which lead to isomerism of the Au−SR oligomers and polymer on Au(111). Here we explore open dimers, trimers, and tetramers and cyclic trimers, tetramers, and hexamers of the Au−SR oligomers on Au(111). We also examine four isomers of the Au−SR polymer on Au(111). We find that the 120° Au−S−Au angle is preferred in constructing both oligomeric and poly...
Composition of the lipids from the adrenal gland of Hippopotamus amphibius.

Abstract 1. 1. Lipids from the cortex and the medulla of the hippopotamus adrenal gland were extracted and separated into various neutral- and phospholipid fractions. The fatty acids of various individual fractions were investigated by gas-chromatography. 2. 2. Both cortex and medulla are characterized by a very high lipid content. Cortex lipids contain 59.6% and medullar lipids 23.3% cholesterol esters. 3. 3. Cholesterol ester fatty acids and free fatty acids from both cortex and medulla are very similar in composition. These fractions are characterized by a low content of homo-γ-linoleic, arachidonic and adrenic acids. The triglycerides contain significantly more palmitic acid. 4. 4. Phosphatidylcholine, phosphatidylethenolamine and phosphatidylinosotol from cortex do not differ in respect of their fatty acid composition from such phospholipids in other organs or species. Sphingomyelin from cortex and all phospholipid fractions from the medulla contain 9–71% of a long chain fatty acid tentatively identified as a tetracosanoic acid.
Bridging Heterogeneous Catalysis and Electro-catalysis: Catalytic Reactions Involving Oxygen

Catalytic reactions that involve oxygen can be found in a large number of processes, including those in energy-related applications, in emission control and in processes important for the chemical industry. Whether the catalytic step is an oxygen insertion step as in a selective oxidation reaction, or an oxygen removal step as in a hydrodeoxygenation reaction, oxygen has proven to be a very challenging component, often determining the selectivity of the reaction. Some examples from our laboratories that bridge catalysis and electro-catalysis will be discussed, ranging from oxidative dehydrogenation of alkanes to oxygen reduction reaction in fuel cells.
Analysis of Return on Hotel Investment: A Comparison of Commercial Hotel Companies and Casino Hotel Companies:

This study examines the performance of commercial hotels and casino hotels in the United States from 1994 to 1998. It analyzes the relationship between hotel performance and type of hotel company. ...
Crystal chemistry of NaMgF3 perovskite at high pressure and temperature

The crystal structure of NaMgF{sub 3} perovskite (neighborite) has been studied at 4 GPa and temperatures up to 1000 C using the Rietveld structure-refinement method. In situ synchrotron X-ray powder diffraction data was collected using monochromatic radiation. The orthorhombic (Pbnm) to cubic (Pm{bar 3}m) transition was observed when the temperature increased from 900 to 1000 C. Structure refinements show that the ratio of polyhedral volumes of the A and B sites (V{sub A}/V{sub B}) of the orthorhombic phase increases with temperature, approaching the ideal value (5) for the cubic structure. However, this ratio becomes smaller at 4 GPa compared to the result from previous studies at the same temperature but ambient pressure, indicating that pressure makes it more difficult to transform from the orthorhombic phase to the cubic phase in this kind of perovskite.
Quinine-induced haemolysis: mechanism of action.

SUMMARY Quinine hydrochloride was found to produce striking haemolysis of whole blood in vitro, preceded by rounding of red cells, K+ leakage, and decreased resistance to hypotonic saline solutions. Evidence is presented to indicate that quinine does not interfere with the pentose phosphate pathway. Its primary damage may be on membranes and is possibly-related to oxidation of sulphhydryl groups.
Insertion of MicroRNA Targets into the Flavivirus Genome Alters Its Highly Neurovirulent Phenotype

Flaviviruses such as West Nile, Japanese encephalitis, and tick-borne encephalitis (TBEV) viruses are important neurotropic human pathogens, causing a devastating and often fatal neuroinfection. Here, we demonstrate that incorporation into the viral genome of a target sequence for cellular microRNAs expressed in the central nervous system (CNS) enables alteration of the neurovirulence of the virus and control of the neuropathogenesis of flavivirus infection. As a model virus for this type of modification, we used a neurovirulent chimeric tick-borne encephalitis/dengue virus (TBEV/DEN4) that contained the structural protein genes of a highly pathogenic TBEV. The inclusion of just a single target copy for a brain tissue-expressed mir-9, mir-124a, mir-128a, mir-218, or let-7c microRNA into the TBEV/DEN4 genome was sufficient to prevent the development of otherwise lethal encephalitis in mice infected intracerebrally with a large dose of virus. Viruses bearing a complementary target for mir-9 or mir-124a were highly restricted in replication in primary neuronal cells, had limited access into the CNS of immunodeficient mice, and retained the ability to induce a strong humoral immune response in monkeys. This work suggests that microRNA targeting to control flavivirus tissue tropism and pathogenesis might represent a rational approach for virus attenuation and vaccine development.
Vertical cavity surface emitting laser-based parallel optical data link

Vertical cavity surface emitting laser (VCSEL) arrays are designed and used for 10-channel parallel optical data links, OPTOBUS™, to transmit data at a speed of up to 800 Mbits/s per channel. The interface between the VCSELs and the optical fiber ribbons is based on molded plastic waveguide technology. A bit error rate of 10-15 is demonstrated.
Stabilization and growth of silver nanocrystals in dendritic polyol dispersions

Abstract The chemical and physical properties of metal nanoparticles are governed critically by their size, shape, and morphology. In this work, we present results of the growth of silver nanocrystals in a dispersion medium that allows nanocrystallization comparable to conventional crystal growth from saturated solutions. Dendritic polyol dispersions in an ethanol/water mixture are shown to be dynamic, nanoscopic templates for the growth of silver nanoparticles. Nanocrystals with well-defined shapes in the size range of 10–600 nm are grown using this method.
Multiconductor transmission-line theory in the TEM approximation

Starting with Maxwell's equations, the transmission line equations are derived for a system consisting of an arbitrary number of conductors. The derivation is rigorous for long lossless conductors embedded in a uniform perfect dielectric. The presentation is essentially tutorial, most of the results being well known, at least for two- and three-conductor systems. The novelty lies in the point of view adopted in obtaining a systematic generalization to the case of an arbitrary number of conductors. Explicit expressions are obtained for the electric and magnetic fields in the dielectric surrounding the conductors, and a rigorous formulation is given for the problem of calculating the coefficients of capacitance and inductance.
STUDIES ON THE PYRIDINE NUCLEOTIDE SPECIFICITY OF NITRATE REDUCTASE IN HIGHER PLANTS AND ITS RELATIONSHIP TO SULFHYDRYL LEVEL.

Abstract 1. 1. Nitrate reductase (NAD (P)H: nitrate oxidoreductase, EC 1.6.6.2) present in extracts from 15 of 16 plant species was found to have a specific or preferential requirement for NADH as cofactor. The enzyme present in extracts from soybeans (Glycine max (L) Merr) could utilize either NADH or NADPH. 2. 2. In all extracts, except those from soybeans, optimum nitrate reductase activity was observed at pH of 7.5 when NADH was cofactor. With preparations from soybeans, optimum activity was recorded at pH 6.25 with either NADH or NADPH as cofactor. In other species, the trace of nitrate reductase activity with NADPH as cofactor was maximum at pH 6.25. 3. 3. The relative efficiencies of NADH or NADPH to function as cofactor for the nitrate reductase from soybeans was dependent upon the method of enzyme extraction. NADH was twice as effective as NADPH for the nitrate reductase in extracts of soybeans prepared with a homogenizing medium containing cysteine. In soybean extracts prepared without cysteine, either NADH or NADPH was equally effective as electron donor for nitrate reduction. When corn leaves were the source material, nitrate reductase activity could not be detected when cysteine was omitted from the extracting medium. In extracts from corn leaves prepared with cysteine, the nitrate reductase activity showed a preferential requirement for NADH as cofactor. 4. 4. The increased effectiveness of NADH to serve as cofactor in soybean extracts prepared with cysteine was related to the action of the sulfhydryl group in protecting enzyme binding sites. Soybean tissue extracted with a medium containing cysteine (extracts subsequently subjected to purification procedures, without additional cysteine) gave partially purified preparations with higher sulfhydryl content and activity per unit of protein that comparable preparations extracted in the absence of cysteine. 5. 5. The K m values for substrates NO 3 - or NADH were altered by the inclusion of cysteine during the preparation of the enzyme from soybeans. The K m for NADPH was not affected by the inclusion of cysteine in the extracting medium.
Sex differences in coping styles and implications for depressed mood.

Based on a sample of young adults in Miami-Dade County, Florida, this paper examined the extent to which there were sex differences in 3 coping style types: problem focused, emotion focused, and avoidance focused (Endler & Parker, 1990). Further examined were the extent to which sex differences in coping styles could be explained by sex differences in chronic strain; the extent to which sex differences in depressed mood could be explained by sex differences in coping style; and whether the effects of different coping style types on depressed mood varied by sex. Results suggested somewhat complex relationships among sex, coping, chronic strain, and depression. No sex differences in the use of problemfocused coping were observed when statistical controls for socioeconomic status were applied; however, women more often used avoidance-focused techniques. Although female respondents more often used emotion-oriented strategies compared to male respondents, such use did not prove to be fundamentally harmful for women. In fact, the effects of using emotion-focused strategies, such as the expression of feelings, reduced depressed mood for women, but not for men. Implications for practice and policy are discussed.
Stigma or Legitimation? A Historical Examination of the Social Potentials of Addiction Disease Models

This article presents a historical discussion of disease models of opiate addiction in the United States in the twentieth century. First, several approaches to defining disease are discussed. Then, the shifts in formulations of opiate addiction as a disease in the twentieth century in the U.S. are analysed in light of the preceding theoretical discussion. The period before 1920 is described as heterodox, as researchers attempted to develop scientific models of opiate addiction, while various medically legitimate and quasi-legitimate treatment approaches flourished in an unregulated marketplace. After 1920, a stigmatizing disease model of opiate addiction was based on a psychiatric formulation that linked chronic addiction with psychoneurotic deficits in certain individuals. After 1940, this model dominated medical and scientific thinking about opiate addiction for several decades. After 1970, enormous changes in the demographics of drug use forced changes to the prevailing model of addiction. A new focus on behavioral aspects of addiction allowed the creation of a nonstigmatizing Parsonian disease model.
A 0.96mW, 5.3–6.75GHz, phase-interpolation and quadrature-generation method using parametric energy transfer in 65nm CMOS

We present a quadrature-generation method that is based on parametric energy transfer to an LC resonator. The phase-sensitive nature of parametric pumping is used to generate a signal in quadrature with an incoming clock signal. The pumped LC resonator is tuned by a digital calibration loop toward the input signal frequency across the tuning range. Phase interpolation is achieved by tuning the resonator frequency away from the incoming signal frequency. Implemented in 65nm CMOS, the prototype dissipates 0.96mW and provides quadrature signals with an accuracy of 2 degrees (~1ps) over an input frequency range of 5.3-to-6.75GHz. The method is also used to achieve a phase interpolation range of 23 to 170 degrees at 6GHz.
The relation of temperament and behavior disorders in a preschool clinical sample

This study reports on the putative role of temperamental traits in the development of psychiatric disorders in preschool children. The study utilized the Behavior Screening Questionnaire and Dimensions of Temperament Survey on 55 clinically referred preschoolers (43 boys and 12 girls). The results indicated that children with a low score on the Behavior Screening Questionnaire (indicating low psychopathology) were found to have a significantly lower activity level and lower distractibility, but had a higher score on rhythmicity.
Identification of the SSB binding site on E. coli RecQ reveals a conserved surface for binding SSB’s C-terminus

RecQ DNA helicases act in conjunction with heterologous partner proteins to catalyze DNA metabolic activities, including recombination initiation and stalled replication fork processing. For the prototypical Escherichia coli RecQ protein, direct interaction with single-stranded DNA-binding protein (SSB) stimulates its DNA unwinding activity. Complex formation between RecQ and SSB is mediated by the RecQ winged-helix domain, which binds the nine C-terminal-most residues of SSB, a highly conserved sequence known as the SSB-Ct element. Using nuclear magnetic resonance and mutational analyses, we identify the SSB-Ct binding pocket on E. coli RecQ. The binding site shares a striking electrostatic similarity with the previously identified SSB-Ct binding site on E. coli exonuclease I, although the SSB binding domains in the two proteins are not otherwise related structurally. Substitutions that alter RecQ residues implicated in SSB-Ct binding impair RecQ binding to SSB and SSB/DNA nucleoprotein complexes. These substitutions also diminish SSB-stimulated DNA helicase activity in the variants, although additional biochemical changes in the RecQ variants indicate a role for the winged-helix domain in helicase activity beyond SSB protein binding. Sequence changes in the SSB-Ct element are sufficient to abolish interaction with RecQ in the absence of DNA and to diminish RecQ binding and helicase activity on SSB/DNA substrates. These results support a model in which RecQ has evolved an SSB-Ct binding site on its winged-helix domain as an adaptation that aids its cellular functions on SSB/DNA nucleoprotein substrates.
Evaluation of two trap deployment methods to manage the apple maggot fly (Dipt., Tephritidae)

: Two red sphere trap deployment methods were evaluated for their potential to capture apple maggot flies, Rhagoletis pomonella, and prevent oviposition. The first method was designed to simulate the interception of flies immigrating into an orchard by deploying odour-baited traps on perimeter trees. The second method was designed to simulate the control of flies emerging from within an orchard by using odour-baited traps on interior trees. Both methods were evaluated in an artificial orchard consisting of potted trees. In tests with hawthorn fruit (a favoured fly host) and released flies of high egg load, both the perimeter and within-orchard trap deployment methods were successful at reducing oviposition compared with a control treatment without traps. Similar trends were observed with apples, a lower ranking fly host, although the results were not statistically significant. Spheres baited with butyl hexanoate (fruit odour) and ammonium carbonate (food odour) were more effective than unbaited spheres in terms of capturing released flies and preventing oviposition. Based on the results of this study, both perimeter and within-orchard trapping appear to have potential to reduce fruit injury and manage R. pomonella in commercial orchards.
Effect of Chelates vs. Ionic Salts of Microelements and Nitrogen Form on Hydroponic Solution pH

Abstract Microelements are supplied at low concentrations, yet have a profound effect on plant growth. These experiments explore the role of their chemical form and that of nitrogen on plant uptake. Chrysanthemum × morifolium cv. Bright Golden Anne, which is sensitive to ammonium, was the test plant. There were four hydroponic treatments with nitrogen supplied at 200 ppm as either 100% nitrate or 25:75 ammonium to nitrate. Micronutrients were supplied either in the chelate or ionic salt form. All other macro cations and anions were the same concentration. All solutions were allowed to stand for 24 h and then adjusted to pH 5.9–6.0. Once the plants were set into the solution they were allowed to adjust for 1 h before the pH was measured hourly for 24 h and then measured 4 times per day for 14 days. As expected both solutions of 100% showed an increase in pH from 6.2 and 7.1 within 5 h. As expected, the pH of the 25:75 ammonium:nitrate, with micronutrients as ionic salts decreased from 5.8 to 5.2, while the...
Non-volatile and reprogrammable MQCA-based majority gates

Single-domain, lithographically-defined nanomagnets can form circuits in a quantum-dot-cellular-automata-like architecture scheme (MQCA). Lines, gates, and inverters have been experimentally realized (Fig. 1), and operate at room temperature1. It is estimated that if 1010 magnets switch 108 times/s, the magnets would dissipate ~ 0.1 W.
Spin from Oblique Impact of Batted Sports Balls

The spin of a batted ball is needed to describe the ensuing trajectory. The following considers experimental spin measurements collected by impacting a stationary ball with a swinging bat. Each collision was recorded with two high speed cameras from which velocity and positional data was obtained. Both baseballs and softballs were hit at swing speeds from 28m/s to 39m/s producing ball trajectories from 0° to 25°. The effect of hit angle, barrel surface friction, bat circumferential moment of inertia, barrel diameter and ball inertia were observed using four different bat constructions and two different ball types. Ball spin increased with hit angle and bat speed, and decreased with ball inertia. Ball spin was not influenced by barrel surface friction, barrel diameter, or bat circumferential moment of inertia.
Powder compaction, sintering, and rolling of ultra high molecular weight polyethylene and its composites

Abstract The applicability of powder compaction and sintering techniques to the processing of ultra high molecular weight polyethylene (UHMWPE) powder is demonstrated. With proper processing procedure and type of UHMWPE powder, the mechanical properties obtained are nearly equivalent to those obtained by conventional melt processes. The properties were optimized by selection of a sintering temperature just above the melting point and by close control of particle size and distribution. The processability of UHMWPE is dependent on the morphology of the powder. Only those powders with a fibrous morphology provided good mechanical properties after sintering. The mechanical properties of powder compacts can be improved by several techniques. Liquid sintering with added normal molecular weight polyethylene, with close control of particle size and distribution and amount of the second component, yielded improved properties. Composites of UHMWPE, with short glass and graphite fiber reinforcement, processed by pow...
Effect of estrus and estrogen on thyroid uptake of I131 in rats.

HYPERTHYROIDISM, nodular goiter and other types of thyroid disease are more frequently found in women than in men. Goiter, also, often becomes strikingly manifest during puberty, pregnancy and the menopause. This apparent relationship between ovarian function and thyroid pathology has been studied by many investigators. Unfortunately the results have been conflicting. Some have reported that ovarian hormones depress thyroid function (Franck, 1937; Gardner, 1949; Heyl et al., 1934; Karp and Kostkiewicz, 1934; Kreitmar and Sieckman, 1939; Miiller and Aeppli, 1949); others, that ovarian hormones increase thyroid activity (Andersen, 1935; Chouke et al., 1935; De Amilbia et al., 1936; Desclin and Ermans, 1951); and still others have observed no distinct influence upon thyroid structure and physiology (Arnold et al., 1938; Paschkis et al. 1948). A few reports have indicated that estrogens both stimulate and depress thyroid function, depending upon the dose and period of administration (Freudenberger and Clausen...
Jeener-Broekaert three-pulse NMR sequences in solid hydrogen using the packer analysis

Jeener-Broekaert 90 x -τ-45 y -T-45 y nuclear magnetic resonance pulse sequences have been applied to solid hydrogen for ortho concentrations <0.5. Below 1 K for τ longer than the free induction decay time we have observed multiple echoes quantitatively obeying the theory due to K. J. Packer.
Faculty and student perceptions of effective study strategies and materials.

Objectives. To evaluate faculty members’ and students’ perceptions of study strategies and materials. Methods. Focus groups were conducted with course directors and first- and second-year students to generate ideas relating to use of course materials, technology, class attendance, and study strategies for mastering class concepts. Results. Students and faculty members differed in their opinions about the utility of textbooks and supplemental resources. The main learning method recommended by students and faculty members was repeated review of course material. Students recommended viewing classroom lectures again online, if possible. Course directors reported believing that class attendance is important, but students based their opinions regarding the importance of attendance on their perceptions of lecture and handout quality. Results did not differ by campus or by student group (first-year vs. second-year students). Conclusions. Students and faculty members have differing opinions on the process that could influence learning and course design. Faculty members should understand the strategies students are using to learn course material and consider additional or alternative course design and delivery techniques based on student feedback.
The cost-effectiveness of routine antenatal screening for maternal herpes simplex virus-1 and -2 antibodies.

Objective The purpose of this study was to determine the cost-effectiveness of routine antenatal screening for herpes simplex virus 1 and 2 in women without a known history of genital herpes. Study design Decision analysis was used to compare 3 treatment strategies to prevent neonatal herpes infection in women without a known history of genital herpes simplex virus: (1) the current standard of care (no herpes simplex virus screening), (2) antepartum herpes simplex virus–1 and –2 antibody screening of the pregnant woman and her male partner with appropriate counseling, and (3) antepartum herpes simplex virus–1 and –2 antibody screening with appropriate counseling and acyclovir prophylaxis at 36 weeks of gestation in seropositive women. Results Our model predicts that using current guidelines, 1 of 5469 women will have a herpes-infected neonate. Strategy 2 and 3 cost $5,812,819 and $4,130,297, respectively, for every significant neurologic sequela or death prevented. The cost-effectiveness of these strategies, expressed as cost per quality life-year gained, was $219,513 and $155,988 respectively. These results were robust in the sensitivity analysis. Conclusion Routine herpes simplex virus screening in pregnancy is not cost-effective.
Acetabular augmentation for progressive hip subluxation in cerebral palsy

Between 1969 and 1981, 20 acetabular augmentations were performed on 17 cerebral palsied patients with progressive hip instability. Average follow-up was 41.5 months, with a range from 24 to 147 months. Evaluation of results was based on assessment of hip stability, center edge (CE) angle, range of motion, and postoperative complications. Eighteen hips were rated good, one fair, and one poor. Stability was achieved in 19 hips. The CE angle was increased from a preoperative mean of -17 degrees to a follow-up mean of 50 degrees. There was no significant difference between preoperative and follow-up hip range of motion. The only complication encountered was a supracondylar femur fracture sustained after spica cast immobilization. Acetabular augmentation can be used effectively in the treatment of progressive hip instability in patients with cerebral palsy.
Social Influence and Contextual Utilization of Customer Relationship Management Technology in an International Field Sales Organization

Building from related interdisciplinary theories, this research identifies social influence–related variables that are linked to customer relationship management (CRM) technology utilization within an international business-to-business field sales force. Field sales employees (n = 147) in a multinational organization from Australia, Canada, New Zealand, the United Kingdom, and the United States were surveyed to test the research model. Four of 7 primary hypotheses were supported, predicting more than 65% of the variance in the research model. Effort expectancy, uncertainty avoidance, collective performance expectancy, and internal/organizational social influence all showed antecedent significance to contextual utilization of CRM technology. The results of this study suggest that group-oriented individual decision making and the related concept of institutional collectivism are equally as important as individual-oriented decision making in the international utilization of organizational technology. Based o...
Multivariate gaussian model for designing additive distortion for steganography

Currently, the most successful approach to steganography in empirical objects, such as digital media, is to cast the embedding problem as source coding with a fidelity constraint. The sender specifies the costs of changing each cover element and then embeds a given payload by minimizing the total embedding cost. Since efficient practical codes exist that embed near the rate-distortion bound, the remaining task left to the steganographer is the fidelity measure - the choice of the costs. In the past, the costs were obtained either in an ad hoc manner or determined from the effects of embedding in a chosen feature space. In this paper, we adopt a different strategy in which the cover is modeled as a sequence of independent but not necessarily identically distributed quantized Gaussians and the embedding change probabilities are derived to minimize the total KL divergence within the chosen model for a given embedding operation and payload. Despite the simplicity of the adopted model, the resulting stegosystem exhibits security that is comparable to current state-of-the-art methods methods across a wide range of payloads.
Composite-variable modeling for service parts logistics

Service parts logistics focuses on providing repair parts for computer, medical, and other high-cost equipment, typically in a very short period of time. Problems within this domain are often challenging to solve, due to the complexity of the network, tight constraints on time and warehouse capacity, and the high costs of inventory and transportation resources. Mathematical modeling can be critical in solving such difficult problems, but basic modeling approaches often suffer from complicating factors such as large numbers of constraints and integer variables, non-linearities, and weak linear programming relaxations. To address some of these difficulties, we present a modeling framework based on composite variables---variables that encompass multiple decisions. We begin by considering the problem of how to stock those repair parts which are both high cost and very low demand. We then discuss how this relatively simple problem can become much more computationally challenging when we expand the scope to consider a more global view of the system. As an example, we consider what happens when warehouse capacity constraints are added. We show that a basic modeling approach to this new problem is intractable for many instances of realistic size. We then present a composite-variable model and show how it enables us to improve tractability significantly. Our experience suggests potential opportunities to be found in modeling other SPL problems within a composite-variable framework as well. We conclude by presenting modeling approaches to address a broad class of problems within this challenging and important arena.
Energy Efficient Self-Sustaining Wireless Neighborhood Area Network Design for Smart Grid

Neighborhood area network (NAN) is one of the most important sections in smart grid communications. It connects residential customers as part of a two-way communication infrastructure responsible for transmitting power grid sensing and measuring status, as well as the control messages. In this paper, we propose a cost-effective, flexible, and sustainable NAN design using wireless technologies such as IEEE 802.11s and IEEE 802.16, as well as renewable energy such as solar power. We propose an optimization problem to minimize total cost. To solve the problem, we also study the problem of selecting the optimal number of gateways in a NAN. Moreover, in order to achieve fairness for the customers and to meet the most critical latency requirements, we propose geographical deployment methods for gateway data aggregate points (DAPs). Different transmission power of each gateway DAP is also carefully determined for the fairness, as well as for the maximum power efficiency. Unlike other researches using game theoretical approaches in multiaccess systems, we manage to achieve the global optimum solution and our results are more energy efficient.
Structure of the p53 Transactivation Domain in Complex with the Nuclear Receptor Coactivator Binding Domain of CREB Binding Protein

The activity and stability of the tumor suppressor p53 are regulated by interactions with key cellular proteins such as MDM2 and CBP/p300. The transactivation domain (TAD) of p53 contains two subdomains (AD1 and AD2) and interacts directly with the N-terminal domain of MDM2 and with several domains of CBP/p300. Here we report the NMR structure of the full-length p53 TAD in complex with the nuclear coactivator binding domain (NCBD) of CBP. Both the p53 TAD and NCBD are intrinsically disordered and fold synergistically upon binding, as evidenced by the observed increase in helicity and increased level of dispersion of the amide proton resonances. The p53 TAD folds to form a pair of helices (denoted Pα1 and Pα2), which extend from Phe19 to Leu25 and from Pro47 to Trp53, respectively. In the complex, the NCBD forms a bundle of three helices (Cα1, residues 2066−2075; Cα2, residues 2081−2092; and Cα3, residues 2095−2105) with a hydrophobic groove into which p53 helices Pα1 and Pα2 dock. The polypeptide chain be...
Photoactivated and photopassivated benzylic oxidation catalyzed by pristine and oxidized carbons

Abstract The link between the structure of carbons and their performance toward catalytic benzylic oxidation by air is studied. Catalytic activity and selectivity of pristine and oxidized carbons can be enhanced, altered, or suppressed by ambient light. The photocatalytical performance of a carbonaceous material depends on the presence of defects, surface area, porosity, and surface oxidation. Adsorption of the hydroperoxide intermediate on the catalyst's surface is suggested as a key process that links the structure of the carbonaceous material with its catalytic activity. The potential of catalysis by carbon black and photocatalysis by graphite nanofibers for greener organic synthesis has been demonstrated.
The formation of cis-3-nonenal, trans-2-nonenal and hexanal from linoleic acid hydroperoxide isomers by a hydroperoxide cleavage enzyme system in cucumber (Cucumis sativus) fruits.

Abstract 1. 1. A participate enzyme fraction and an acetone powder preparation from cucumber fruits cleaved 9- and 13-hydroperoxyoctadecadienoic acids to form volatile aldehydes and oxoacid fragments. 2. 2. From the 9-hydroperoxide, the major volatile fragments were cis -3-nonenal and trans -2-nonenal using particulate enzyme and acetone powder preparations, respectively. 3. 3. Hexanal was the only significant volatile fragment from the 13-hydroperoxide. 4. 4. The particulate enzyme system was equally effective on both 9- and 13-hydroperoxide isomers and was fully active under anaerobic conditions and at pH 6.4. 5. 5. An enzymic pathway for the biogenesis of hexanal, cis -3- and trans -2-nonenal (components of the characteristic flavour volatiles of cucumber) from linoleic acid is proposed. This involves the sequential activity of lipoxygenase, hydroperoxide cleavage and cis -3-: trans -2-enal isomerase enzymes.
Astrocyte survival and HSP70 heat shock protein induction following heat shock and acidosis.

Although severe acidosis is an important mediator of brain infarction, recent evidence suggests that mild acidosis may protect ischemic cells. The HSP70 heat shock protein is induced by acidosis in cultured cells and in ischemic brain and protects cells against many types of injury. Therefore, this study determined whether induction of heat shock proteins protects cultured astrocytes against acidosis. Brief exposure of cultured cortical astrocytes to acid (pH 5.2 for 40 min) or heat shock (45°C for 40 min) markedly induced hsp70 mRNA and HSP70 protein. HSP70 protein was detected with the C92 monoclonal antibody (Welch and Suhan: J Cell Biol 103:2035, 1986), which has been shown to recognize the protein product of the full-length rat hsp70 cDNA (Longo et al: J Neurosci Res 36:325, 1993). Heat shock of the cultured cortical astrocytes completely protected the astrocytes from an otherwise lethal heat exposure 24 h later (45°C for 4 h). In contrast, heat pretreatment sensitized the astrocytes to injury from acidosis 24 h later. Acid pretreatment, which markedly induced the HSP70 protein without producing astrocytic cell death, similarly sensitized the cells to injury from acidosis 24 h later (60% survival following pH 5.2 for 3 h versus 90% survival in controls; P < 0.0001). Surprisingly, heat shock pretreatment protected astrocytes against exposure to acid 48 h later (P < 0.05, 1.5–3 h), whereas acid pretreatment had no effect on astrocyte survival 48 h later. Since heat shock did not protect against acidosis at 24 h when HSP70 induction was maximal but did protect at 48 h when HSP70 was markedly diminished, the protective effect of heat shock at 48 h may be related to stress proteins present at 48 h. It is concluded that induction of HSP70 and other heat shock proteins by heat shock protects astrocytes against subsequent lethal heat shock. However, heat shock and acid treatment increase the vulnerability of astrocytes to acidosis 24 h later in spite of the induction of HSP70 heat shock proteins. The finding that heat shock protected astrocytes against acidosis 2 days later may suggest that delayed induction of stress proteins partially protects the astrocytes against damage produced by high concentrations of hydrogen ions. © 1996 Wiley-Liss, Inc.
ATTEMPT TO ISOLATE INFECTIOUS AGENT FROM BONE-MARROW OF PATIENTS WITH MULTIPLE SCLEROSIS

Bone-marrow was aspirated into 10 ml Eagle's minimal essential medium (EMEM) containing preservative-free heparin. After washing, the samples were divided into four parts; A for tube cultures,. B for coverslip cultures in multidish wells; C was placed on a 'Ficoll'-'Hypaque' gradient to obtain free mononuclear cells, and D was frozen in liquid nitrogen in cryopreservative medium containing 1% dimethyl sulphoxide.
Effect of pore size on adsorption of hydrocarbons in phenolic-based activated carbon fibers

Abstract The combined effect of pore size and pore volume on the equilibrium adsorption capacity and the adsorption kinetics for a series of normal alkanes is determined. The selected adsorbents, activated carbon fibers (ACFs) and air activated phenolic fibers (AAPFs), possess a range of micropore sizes and have been thoroughly characterized in past work. For the normal alkane series, the lower surface area (smaller pore size) adsorbents demonstrate higher adsorption capacities for low boiling point alkanes and for adsorbing molecules at low concentrations. For higher boiling point alkanes and at higher concentrations, the adsorption capacity is greater for higher surface area materials (larger pore size) due to increasing pore volumes. This data was modeled using the DR equation to develop a predictive capability for adsorption based on boiling point and micropore size. For the full range of gas concentrations, the average initial mass rates of adsorption increase as the average pore size increases.
Consecutive collision orbits in the limiting case μ=0 of the elliptic restricted problem

A timing condition for consecutive collision orbits in the planar, circular three-body problem has been extended to the elliptic restricted problem for μ=0. The expression developed relates eccentric anomalies at the time of collision. Some families of solutions are presented.
Mental impairment in cytogenetically positive fragile X females

Prenatal diagnosis is now available to fragile X (fra[X]) syndrome families and has proven reliable when testing male fetuses. It has been reported that approximately one-third of heterozygous fra(X) females demonstrate mental impairment. Based on this, families usually continue pregnancies involving a female fetus. The purpose of this study is to investigate whether a 35% risk for mental impairment is appropriate when counseling heterozygous women carrying fra(X)-positive female fetuses. Forty-three cytogenetically positive (greater than or equal to 2%) daughters of known fra(X) carrier women were ascertained postnatally in an unbiased fashion. Their mother's carrier status was determined on the basis of at least one son with Martin-Bell syndrome. In addition to peripheral blood cytogenetic studies, all daughters had cognitive testing to determine full-scale IQ. In this study, 55.8% (24/43) were mentally impaired (IQ less than 85) compared with the expected 35%. Of these, 42% were mentally retarded (IQ less than 70). Although we do not know the correlation between percent fragility by peripheral blood compared with the percent fragility by amniocentesis or CVS, we assume that they are relatively comparable such that a female who is positive with greater than or equal to 2% fragility would probably be positive by all methods. This report suggests that the penetrance of mental impairment in females with a percent fragility of greater than or equal to 2% may be as high as 55%. Further studies are necessary to clarify this issue so that accurate information can be given in genetic counseling.
A Flow Augmentation Approach to the Network with Gains Minimum Cost Flow Problem

A network with gains has branches in which the ratio between the flow leaving a branch and the flow entering a branch is a positive constant called the gain. Branch gains may be greater or less than one. Such networks arise in water resources and electrical power planning problems, among others. This paper presents a dual method of finding the minimum cost flows in such a network. Computerized versions of the procedure have been tested on networks with up to 7,000 branches.