cssi/SciSciGPT-SciSciNet huggingface dataset:
A Review of Valve Stem Sealing to Prevent Leakage from the Valve and Its Effect on Valve Operation

Stem sealing plays an important role in valve operation, to avoid leakage from the valve stem area to the environment. Additionally, accuracy and tight sealing of stem seals are vital in fugitive emission applications where hazardous fluids such as gases or vapours may escape if a valve is not sealed properly. Soft thermoplastic and elastomer materials such as Teflon (PTFE), lip seal, V-pack, Viton as well as graphite or graphoil can be used for valve stem sealing. Appropriate stem sealing or packing depends on the process conditions where the valve will be used, including being able to withstand extreme temperatures, being resistant to aggressive fluid such as $${\text{H}}_{2}$$ S containing fluid, displaying a low friction factor to the stem, providing very good sealing capability to prevent leakage from the valve stem area, and being adequately strong and economical. The sealing capability of compression packing is defined as the ability to expand laterally against the stem and stuffing box wall when stressed by tightening the gland. The stem sealing arrangement depends on the type of valves being used and the applications. The sealing capability and performance of a valve can be validated by testing the valve stem sealing through mechanical and temperature cycles based on different American Petroleum Institute standards or by finite element analysis. The torque required to operate a valve depends on parameters such as the packing or stem sealing material, number of stem sealing rings, load of gland flange, stem surface finish, temperature, and cycling. Reducing the number of packing rings can reduce the valve torque and the actuator sizing but removing rings can also increase the risk of leakage from the valve and reduce the effectiveness of the valve seals.
ShadowSense: Detecting Human Touch in a Social Robot Using Shadow Image Classification

This paper proposes and evaluates the use of image classification for detailed, full-body human-robot tactile interaction. A camera positioned below a translucent robot skin captures shadows generated from human touch and infers social gestures from the captured images. This approach enables rich tactile interaction with robots without the need for the sensor arrays used in traditional social robot tactile skins. It also supports the use of touch interaction with non-rigid robots, achieves high-resolution sensing for robots with different sizes and shape of surfaces, and removes the requirement of direct contact with the robot. We demonstrate the idea with an inflatable robot and a standing-alone testing device, an algorithm for recognizing touch gestures from shadows that uses Densely Connected Convolutional Networks, and an algorithm for tracking positions of touch and hovering shadows. Our experiments show that the system can distinguish between six touch gestures under three lighting conditions with 87.5 - 96.0% accuracy, depending on the lighting, and can accurately track touch positions as well as infer motion activities in realistic interaction conditions. Additional applications for this method include interactive screens on inflatable robots and privacy-maintaining robots for the home.
Prevalence of Unmet Basic Needs and Association with Diabetes Control and Care Utilization Among Insured Persons with Diabetes.

Unmet basic needs (eg, food insecurity, inadequate housing) are major barriers to diabetes self-management. The purpose of this study was to identify the prevalence of unmet basic needs and examine...
Evaluating the suitability of the case-crossover design under changing baseline outcome risk: A simulation of ambient temperature and preterm birth

Abstract Case-crossover (CCO) studies are case-only within-person analyses of associations between acute exposures and outcomes. By design, the CCO is not confounded by time-invariant characteristics. CCO studies assume stable baseline outcome risks. Since the baseline risk of birth increases secularly over gestation, the validity of CCOs of preterm birth (PTB) is not clear. We simulated associations between temperature and PTB in New York State using historical ambient temperature data for LaGuardia Airport and PTB data from the CDC using different control period durations. CCO analyses were conducted with conditional logistic regression. We calculated bias according to the absolute difference between the simulated and estimated effects in the natural log scale and found that 1-month stratified control period selection yielded bias away from the null across all simulated effects (median = 0.018, IQR: 0.010 − 0.026). In contrast, the 2-week stratification resulted in negligible bias (median: 0.001, IQR: −0.011 − 0.012). Coverage of the 95% confidence intervals decreased with higher effects for the 1-month stratification, with a range 17-87% of estimated intervals including the simulated effect. 2-week stratification had consistent coverage across models (range 95-96%). Our findings suggest that future studies should consider using shorter time strata for PTB.
Interplay between Emerging SARS-CoV-2 Variants and Pandemic Control.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a member of a diverse family of enveloped, nonsegmented RNA viruses. The coronavirus genomic RNA is unusually large, the RNA polymera...
Low Rates of Clinician Monitoring for Second Generation Antipsychotic Medications in Community Pediatric Practice

Second generation antipsychotic (SGA) medications are frequently prescribed to pediatric patients in the United States. This retrospective observational study sought to ascertain the extent of adherence to established pediatric SGA monitoring guidelines in community practice. The team used the electronic health record to determine clinician adherence to SGA monitoring guidelines at baseline, 12-week, and annual times relative to prescribing an SGA. At the time of their SGA prescription, 5.5% of pediatric patients had received all of the orders according to the monitoring guidelines. Annually, 2.5% of patients had received the necessary orders to completely adhere to monitoring guidelines; 42% of patients received no monitoring orders. Monitoring was more likely for children who had multiple types of providers and interacted with the healthcare system beyond a traditional office visit. This research informs healthcare providers about the gap between prescribing and monitoring for SGA medications in community practice for pediatric populations.
Effect of processing parameters on the characteristics of high-Tc superconductor YBa2Cu3Oy

The influence of sintering temperature, sintering and annealing atmospheres, and quench rate on the properties of the high-temperature superconductor YBa2Cu3Oy has been investigated by electrical resistivity and magnetic susceptibility measurements, thermogravimetric analysis, powder x-ray diffraction, and scanning electron microscopy. Room-temperature resistivity and the transition width decreased, and the fraction of the superconducting material and the bulk density increased with increase in the sintering temperature, but had no effect on the transition temperature (Tc) for samples fired in flowing oxygen. A sample that was rapidly quenched from 930 °C to room temperature after sintering in air had a perovskite structure and Tc (onset) ∼90 K but its resistance did not become zero even at 77 K. A sample sintered in air at 930 °C and furnace cooled had Tc (midpoint) of ∼89.6 K and transition width (10%–90%) of ∼2.6 K. The loss and gain of oxygen occurs reversibly in YBa2Cu3Oy.
Intrinsic Sex-Linked Variations in Osteogenic and Adipogenic Differentiation Potential of Bone Marrow Multipotent Stromal Cells

Bone formation and aging are sexually dimorphic. Yet, definition of the intrinsic molecular differences between male and female multipotent mesenchymal stromal cells (MSC) in bone is lacking. This study assessed sex-linked differences in MSC differentiation in 3-, 6-, and 9-month-old C57BL/6J mice. Analysis of tibiae showed that female mice had lower bone volume fraction and higher adipocyte content in the bone marrow compared to age-matched males. While both males and females lost bone mass in early aging, the rate of loss was higher in males. Similar expression of bone- and adipocyte-related genes was seen in males and females at 3 and 9 months, while at 6 months, females exhibited a two-fold greater expression of these genes. Under osteogenic culture conditions, bone marrow MSCs from female 3- and 6-month-old mice expressed similar levels of bone-related genes, but significantly greater levels of adipocyte-related genes, than male MSCs. Female MSCs also responded to rosiglitazone-induced suppression of osteogenesis at a 5-fold lower (10 nM) concentration than male MSCs. Female MSCs grown in estrogen-stripped medium showed similar responses to rosiglitazone as MSCs grown in serum containing estrogen. MSCs from female mice that had undergone ovariectomy before sexual maturity also were sensitive to rosiglitazone-induced effects on osteogenesis. These results suggest that female MSCs are more sensitive to modulation of differentiation by PPARγ and that these differences are intrinsic to the sex of the animal from which the MSCs came. These results also may explain the sensitivity of women to the deleterious effects of rosiglitazone on bone.
The amnionless gene, essential for mouse gastrulation, encodes a visceral-endoderm-specific protein with an extracellular cysteine-rich domain.

Fate-mapping experiments in the mouse have revealed that the primitive streak can be divided into three functional regions1: the proximal region gives rise to germ cells and the extra-embryonic mesoderm of the yolk sac; the distal region generates cardiac mesoderm and node-derived axial mesendoderm; and the middle streak region produces the paraxial, intermediate and lateral plate mesoderm of the trunk. To gain insight into the mechanisms that mediate the assembly of the primitive streak into these functional regions, we have cloned and functionally identified the gene disrupted in the amnionless (amn) mouse, which has a recessive, embryonic lethal mutation that interferes specifically with the formation and/or specification of the middle primitive streak region during gastrulation2. Here we report that the gene Amn encodes a novel type I transmembrane protein that is expressed exclusively in the extra-embryonic visceral endoderm layer during gastrulation. The extracellular region of the Amn protein contains a cysteine-rich domain with similarity to bone morphogenetic protein (BMP)-binding cysteine-rich domains in chordin, its Drosophila melanogaster homolog (Short gastrulation) and procollagen IIA (ref. 3). Our findings indicate that Amn may direct the production of trunk mesoderm derived from the middle streak by acting in the underlying visceral endoderm to modulate a BMP signaling pathway.
Clinical experience in the treatment of pelvic inflammatory disease with intradermal injections of Bacillus coli vaccine

Abstract The intradermal administration of foreign protein in the treatment of pelvic inflammatory diseases is practical, more safe, and less uncomfortable for the patient. The results obtained in the present series are briefly: 1. 1. Eighty-six per cent required treatment, two months or less. 2. 2. Ninety-six per cent required two series of six injections or less. 3. 3. Twenty-eight and four-tenths per cent of these patients required some surgical procedure during the treatment of their illness. Only 5.8 per cent were advised to have radical abdominal surgery; only 4 per cent consented to abdominal section.
Coronary arteriovenous fistula: Report of an unusual case simulating atrial septal detect

Abstract In a 47 year old man, who suffered recurrent episodes of subacute bacterial endarteritis, the physical, x-ray and cardiac catheterization findings suggested atrial septal defect. At operation a coronary arteriovenous fistula involving the left circumflex artery and the coronary sinus was found and successfully ligated.
State of the union: type inference via Craig interpolation

The ad-hoc use of unions to encode disjoint sum types in C programs and the inability of C's type system to check the safe use of these unions is a long standing source of subtle bugs. We present a dependent type system that rigorously captures the ad-hoc protocols that programmers use to encode disjoint sums, and introduce a novel technique for automatically inferring, via Craig Interpolation, those dependent types and thus those protocols. In addition to checking the safe use of unions, the dependent type information inferred by interpolation gives programmers looking to modify or extend legacy code a precise understanding of the conditions under which some fields may safely be accessed. We present an empirical evaluation of our technique on 350KLOC of open source C code. In 80 out of 90 predicated edges (corresponding to 1472 out of 1684 union accesses), our type system is able to infer the correct dependent types. This demonstrates that our type system captures and explicates programmers' informal reasoning about unions, without requiring manual annotation or rewriting.
Hydrocarbon Formation under Exploding Wire Conditions

Electrically exploded carbon filaments react with a surrounding hydrogen atmosphere to produce hydrocarbon mixtures in which methane, ethylene, and acetylene predominate. Explosions carried out in a mixture of hydrogen and deuterium result in essentially statistical scrambling within the residual hydrogen-deuterium mixture. All possible hydro-deutero methanes, acetylenes, and ethylenes were formed and their relative quantities determined by mass spectrometry. The data are consistent with stepwise formation of methyne, methylene, and methyl radicals. Methane formation can best be explained by four successive combinations of monatomic carbon with dissociated hydrogen. Reaction of exploded graphite filaments with a methane atmosphere is much more complicated and the product distribution must take into account the dissociation of methane in the shock or photolysis phenomena that take place during the explosion process.
Hatch–Waxman Reform and Accelerated Market Entry of Generic Drugs: Is Faster Necessarily Better?

Recently there has been a considerable amount of pressure to accelerate consumer access to generic drugs, which are significantly less expensive than their brand-name counterparts. One way to bring generic drugs on to the market sooner is through revision of the existing law relating to pharmaceutical patents. This iBrief describes recent regulatory changes to the Drug Price Competition and Patent Term Restoration Act (the HatchWaxman Act), which governs the patenting process for new drug products, as well as current legislative efforts to speed generic access through HatchWaxman reform. This iBrief also assesses whether these changes will be beneficial to consumers on a long-term basis.
Detection of influenza C virus by using an in situ esterase assay.

A variety of chemically defined compounds were tested to characterize the substrate specificity of the influenza C virus esterase and to determine whether a substrate could be found that would be useful in an assay to detect the virus. Two new substrates, alpha-naphthyl acetate and alpha-naphthyl propionate, were identified; alpha-naphthyl acetate was employed to develop an assay specific for influenza type C virus in MDCK cells. The assay was sufficiently sensitive to detect esterase activity in a single cell and distinguished influenza C virus infections from those of types A and B viruses. Infected cells could be detected as early as 8 h postinfection, with maximal enzyme detection occurring at 24 h. Assay of influenza C virus in the chorioallantoic or amniotic fluid of infected eggs was performed by applying fluids directly onto nitrocellulose strips and then incubating with alpha-naphthyl acetate. Both the cellular and nitrocellulose-bound assays are rapid, inexpensive, and easy to perform, offering advantages for use in clinical laboratories. Images
Correction of Polychromatic Luminescence Signals for Inner-Filter Effects

Fluorescence (FL) and absorbance (ABS) data are acquired simultaneously with a multiple detector spectrometer. The measured ABS is utilized in mathematical equations for automatic correction of fluorescence signals for attenuation (inner-filter effects) caused by significant absorption of the excitation or emission radiation by the fluorophore or other species. Correction equations are presented which apply to situations in which the excitation or emission beam cannot be considered monochromatic, for collection geometries involving optical fibers, and for chemiluminescence measurements. The correction scheme was tested with quinine sulfate (QS) as the analyte in the absence and presence of other chromophores (gentisic acid and methyl red). Even when conditions are such that the FL signal is attenuated by a factor of 5, the correction scheme is accurate to 2% or better. These corrections extend the linear range of the QS calibration curve by a factor of over 100, and they can improve the accuracy up to a factor of ten in cases for which polychromatic effects are important.
Evaluating the Structural Properties of Suprahyoid Muscles and their Potential for Moving the Hyoid

Superior and anterior hyoid movements are important events in pharyngeal deglutition. This cross-sectional study uses a cadaver model to document the structural properties of the muscles underlying these movements in an effort to understand how their morphology influences function. Measurements to determine physiological cross-sectional areas (PCSAs) of swallowing muscles were taken from hemisected head and neck formalin-fixed cadaver specimens (n = 13). Coordinates of muscle attachment sites and PCSAs were used to calculate $$ \hat{i} $$ and $$ \hat{j} $$ unit force vectors, where $$ \hat{i} $$ and $$ \hat{j} $$ represent anterior-posterior and superior-inferior directions, respectively. The suprahyoid muscle subsamples were grouped for analysis as follows: digastric (DG), geniohyoid (GH), mylohyoid (MH), and stylohyoid (SH). The ANOVA with Tukey HSD post hoc analysis of unit force vectors showed the following results: GH (−0.44 ± 0.15 cm2) >MH (−0.02 ± 0.21 cm2), DG (−0.05 ± 0.11 cm2), SH (0.14 ± 0.04 cm2), with negative values representing the anterior direction (p DG (0.29 ± 0.14 cm2), SH (0.22 ± 0.08 cm2), GH (12 ± 0.08 cm2), with positive values representing the superior direction (p < 0.01). The morphology of the suprahyoid muscles suggests that based on structural properties, the geniohyoid has the most potential to displace the hyoid in the anterior direction and the mylohyoid has the most potential to displace the hyoid in the superior direction. These data in complement with physiological findings may provide greater insight into these movements for those developing novel treatments for dysphagia.
Equilibrium uptake of d-glucose by osmotically stressed unilamellar phospholipid vesicles

The assumptions inherent in the use of osmotic manipulation to determine the extent of solute binding to brush border membrane vesicles (the ideal osmotic responsiveness of the vesicles and the independence of solute binding from the incubation medium osmotic pressure) were examined in a model system (large unilamellar lipid vesicles). The equilibrium uptake of D-glucose by unilamellar vesicles composed of egg lecithin (PC), phosphatidic acid (PA), and cholesterol (Chol) was measured as a function of the osmotic concentration of the incubation medium. The variation of the encapsulated aqueous volume of PC:PA and PC:PA:Chol vesicles with the osmotic stress was directly determined by a fluorescence self-quenching technique. Encapsulated volume changes of both PC:PA and PC:PA:Chol vesicles were found to be resistant to the osmotic stress, exhibiting positive deviations from ideal behavior. Equilibrium uptake experiments with these vesicles showed that glucose was taken up in excess of that amount predicted on the basis of the encapsulated volume when the vesicles were subjected to osmotic stress 0.75 osmol/kg, equilibrium uptake could be predicted solely on the basis of the encapsulated volume. These results, based on a model vesicle system, strongly suggest that osmotic manipulation may be an inappropriate method to assess the extent of solute binding to natural membrane vesicle preparations, such as brush border membrane vesicles, without more direct evidence.
Energy trapping in solid He, Ne, Ar, Kr, and Xe by molecule formation - A theoretical interpretation

Abstract Trapping of electronic excitations in the rare gas solids is investigated from a dynamical point of view. A resonant transfer deexcitation mechanism is found to cause rapid vibrational relaxation of the R * 2 dimer, believed to be responsible for the trapping, in less than 6 × 10 −12 seconds for all the rare gas systems.
Rifampin and Minocycline in Meningococcal Disease

Military recruits in four companies were given minocycline, rifampin, ampicillin, or placebo for five days. All antibiotics reduced the rate of carriage of Neisseria meningitidis during treatment, but the effect was significantly more prolonged with minocycline and rifampin. The only difference between these two drugs lay in the isolation of rifampin-resistant meningococci from 17 recruits who received that antibiotic. No isolates were found to be resistant to minocycline. During an outbreak of meningococcal disease among military recruits, minocycline (100 mg every 12 hr) was administered to 8,721 trainees for five days. No new cases of meningococcal disease occurred for the next four weeks. Six new cases then developed among recruits who had begun their training after the initial course of treatment. A second cycle of minocycline, followed in one week by administration of group C polysaccharide vaccine, terminated the outbreak.
Comparing waiting times in a multi-stage model: A log-rank approach

Abstract A proper log-rank test for comparing two waiting (i.e. sojourn, gap) times under right censored data has been absent in the survival literature. The classical log-rank test provides a biased comparison even under independent right censoring since the censoring induced on the time since state entry depends on the entry time unless the hazards are semi-Markov. We develop test statistics for comparing K waiting time distributions from a multi-stage model in which censoring and waiting times may be dependent upon the transition history in the multi-stage model. To account for such dependent censoring, the proposed test statistics utilize an inverse probability of censoring weighted (IPCW) approach previously employed to define estimators for the cumulative hazard and survival function for waiting times in multi-stage models. We develop the test statistics as analogues to K -sample log-rank statistics for failure time data, and weak convergence to a Gaussian limit is demonstrated. A simulation study demonstrates the appropriateness of the test statistics in designs that violate typical independence assumptions for multi-stage models, under which naive test statistics for failure time data perform poorly, and illustrates the superiority of the test under proportional hazards alternatives to a Mann–Whitney type test. We apply the test statistics to an existing data set of burn patients.
Niacin in cardiovascular prevention: mechanisms, efficacy, and safety.

Purpose of reviewThis review describes niacin's mechanism of action, efficacy in cardiovascular prevention, and safety.Recent findingsA G-protein-coupled receptor [GPR109A/HM74A, mouse PUMA-G (protein upregulated in macrophages by interferon-γ)] was found to mediate the antilipolytic effect of niaci
Sulfur isotopes and hydrochemical variations in spring waters of southern Indiana, U.S.A.

Abstract Water chemistry and δ 34 S(SO 4 ) studies suggest two flow systems in the karst terrane of southern Indiana: (1) a shallow flow system exists, which is dominated by surface water entering the ground through fractures; and (2) a deeper regional groundwater flow system recharged by diffuse flow. The chemistry of the water in the regional system may be dominated by the solution of gypsum in the Lower St. Louis Limestone. Sulfur-isotope studies suggest two flow systems and show that the high SO 2 − 4 concentrations in local waters result from solution of gypsum. Reported δ 34 S(SO 4 ) for Upper Mississippian evaporites and fresh water range from +14 to +19 to +8 to +12‰, respectively. Isotope analysis of gypsum cores from the Lower St. Louis Limestone evaporite unit shows δ 34 S-values between + 14.10 and + 15.13‰ in the study area. Groundwater chemistry studies show a direct linear relationship between SO 2 − 4 concentrations and δ 34 S-values. Groundwater varies in SO 2 − 4 concentrations between 20 and 1970 mg l −1 . The δ 34 S-values range from + 10.61‰ for a conduit spring to + 18.57‰ for a diffuse spring. The waters with high SO 2 − 4 concentrations have δ 34 S(SO 4 )-values higher than the local gypsum deposits analysed and contain H 2 S, suggesting a deeper flow system in which fractionation by bacterial reduction of SO 2 − 4 is occurring. Waters with low SO 2 − 4 concentrations have δ 34 S(SO 4 )-values in the range of local fresh water, indicating a shallow flow system.
Pressure-induced enhancement of superconductivity and suppression of semiconducting behavior in L n O 0.5 F 0.5 BiS 2 ( L n = La ,Ce) compounds

Electrical resistivity measurements as a function of temperature between 1 and 300 K were performed at various pressures up to 3 GPa on the superconducting layered compounds $\mathit{Ln}$O${}_{0.5}$F${}_{0.5}$BiS${}_{2}$ ($\mathit{Ln}$ = La, Ce). At atmospheric pressure, LaO${}_{0.5}$F${}_{0.5}$BiS${}_{2}$ and CeO${}_{0.5}$F${}_{0.5}$BiS${}_{2}$ have superconducting critical temperatures ${T}_{c}$ of 3.3 and 2.3 K, respectively. For both compounds, the superconducting critical temperature ${T}_{c}$ initially increases, reaches a maximum value of 10.1 K for LaO${}_{0.5}$F${}_{0.5}$BiS${}_{2}$ and 6.7 K for CeO${}_{0.5}$F${}_{0.5}$BiS${}_{2}$, and then gradually decreases with increasing pressure. Both samples also exhibit transient behavior in the region between the lower ${T}_{c}$ phase near atmospheric pressure and the higher ${T}_{c}$ phase at higher pressures. This region is characterized by a broadening of the superconducting transition, in which ${T}_{c}$ and the transition width $\ensuremath{\Delta}$${T}_{c}$ are reversible with increasing and decreasing pressure. There is also an appreciable pressure-induced and hysteretic suppression of semiconducting behavior up to the pressure at which the maximum value of ${T}_{c}$ is found. At pressures above the value at which the maximum in ${T}_{c}$ occurs, there is a gradual decrease of ${T}_{c}$ and further suppression of the semiconducting behavior with pressure, both of which are reversible.
Wheel keeps turning for antiviral combination chemotherapy.

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Chemical and Isotopic Methods for Quantifying Ground‐Water Recharge in a Regional, Semiarid Environment

The High Plains aquifer underlying the semiarid Southern High Plains of Texas and New Mexico, USA was used to illustrate solute and isotopic methods for evaluating recharge fluxes, runoff, and spatial and temporal distribution of recharge. The chloride mass-balance method can provide, under certain conditions, a time-integrated technique for evaluation of recharge flux to regional aquifers that is independent of physical parameters. Applying this method to the High Plains aquifer of the Southern High Plains suggests that recharge flux is approximately 2% of precipitation, or approximately 11 ± 2 mm/y, consistent with previous estimates based on a variety of physically based measurements. The method is useful because long-term average precipitation and chloride concentrations in rain and ground water have less uncertainty and are generally less expensive to acquire than physically based parameters commonly used in analyzing recharge. Spatial and temporal distribution of recharge was evaluated by use of δ2H, δ18O, and tritium concentrations in both ground water and the unsaturated zone. Analyses suggest that nearly half of the recharge to the Southern High Plains occurs as piston flow through playa basin floors that occupy approximately 6% of the area, and that macropore recharge may be important in the remaining recharge. Tritium and chloride concentrations in the unsaturated zone were used in a new equation developed to quantify runoff. Using this equation and data from a representative basin, runoff was found to be 24 ± 3 mm/y; that is in close agreement with values obtained from water-balance measurements on experimental watersheds in the area. Such geochemical estimates are possible because tritium is used to calculate a recharge flux that is independent of precipitation and runoff, whereas recharge flux based on chloride concentration in the unsaturated zone is dependent upon the amount of runoff. The difference between these two estimates yields the amount of runoff to the basin.
Legal Responsibilities Toward Students with Disabilities: What Every Administrator Should Know

Administrators are crucial to the success or failure of the special edu cation process. They must know the law, for their failure to do so may result in expensive and time-consuming litigation. They should focus on key laws and understand them thoroughly, and keep abreast of spe cial education court decisions. Using this knowledge to avoid inappro priate administrative practices, they can then model positive, appro priate behavior and attitudes.
Rubeosis and Anterior Segment Ischemia Associated With Systemic Cryoglobulinemia

Purpose To report two cases of iris neovascularization associated with systemic cryoglobulinemia. Design Retrospective case report. Methods Patient chart review and review of literature. Results Two patients with iris neovascularization in the absence of retinal ischemia were subsequently found to have systemic cryoglobulinemia. Successful treatment of one patient's underlying lymphoma led to stabilization and resolution of neovascularization. Conclusions Systemic cryoglobulinemia may be associated with anterior segment ischemia and neovascularization, and should be considered in the differential diagnosis of iris neovascularization in the absence of apparent retinal ischemia.
Lesions Observed in Arterial Autogenous Vein Grafts Light and Electron Microscopic Evaluation

Autogenous vein grafts used for canine femoral and aortocoronary arterial bypasses were evaluated from 2 to 365 days postoperatively. Femoral grafts showed focal endothelial disruption, mural fibrin deposition, and medial edema with inflammatory infiltrates during the first week; loss of medial smooth muscle cells and focal subendothelial lesions with intact endothelium by 2 weeks; and diffuse subendothelial lesions by 12 weeks, Coronary grafts studied at 6, 9, and 12 months had medial fibrosis and extensive intimal proliferation causing up to 90% luminal narrowing. Extension of the intimal process into the coronary artery distal to the bypass graft also compromised the arterial lumen. Coronary grafts obtained from humans dying 17 and 57 days after graft insertion revealed a similar subendothelial proliferation. Electron microscopy showed that the subendothelial lesions were composed of mature smooth muscle cells and collagen primarily oriented parallel to the axis of blood flow. Recurrent endothelial cell damage, followed by mural fibrin deposition and organization, appears to be the cause of the subendothelial proliferative lesions.
Symptomatic Blunt Head Injury in Children—A Prospective, Single-Investigator Study

The goal of this study was to describe a single emergency physician's experience with symptomatic blunt head injury in children and prospectively assess the sensitivity and predictive value of the neurologic examination. The author utilized a prospective patient series comparing neurologic examination with computed tomography (CT) of the head. Nine of 42 patients had intracranial injury for a prevalence of 21%; two patients (5%) had intracranial injury with only subtle neurologic examination findings. Twenty-six patients had a negative neurologic examination, and all had normal-appearing CT scans. Sixteen patients had a positive neurologic examination, of whom nine had a positive CT scan. The properties of the neurologic examination as a diagnostic test, with CT as the gold standard, were as follows: sensitivity = 100%, specificity = 78%, positive predictive value = 56%, negative predictive value = 100%. Normal findings from neurologic examination can be used in some children with symptomatic blunt head injury to delay or eliminate the need for CT of the head.
Molecular biology of the major myelin genes

Abstract Recent work in several laboratories has resulted in the molecular cloning of the major myelin genes-those encoding myelin basic protein (MBP), the glycoprotein P 0 , and the myelin proteolipid protein (PLP). Although still at an early stage, this work has provided important insights into the structure, function and regulated expression of these essential myelin-specific genes.
Evaluation of Radiation Loss from Coupled Microstrip Line Discontinuities using a Planar Lumped Model and a Multiport Network Modeling Approach

This paper presents a convenient method for evaluating radiation loss from coupled microstrip line discontinuities. A planar lumped model and the multiport network model are used to find voltage distributions around the discontinuity edges and along the coupled line section and an equivalent magnetic current model is used to compute the resulting radiation fields. Results of radiation loss from a coupled line section with four chamfered bends are given in this paper.
Coefficient matrices for implicit finite difference solution of the inviscid fluid conservation law equations

Although the Navier-Stokes equations describe most flows of interest in aerodynamics, the inviscid conservation law equations may be used for small regions with viscous forces. Thus, Euler equations and several time-accurate finite difference procedures, explicit and implicit, are discussed. Although implicit techniques require more computational work, they permit larger time steps to be taken without instability. It is noted that the Jacobian matrices for Euler equations in conservation-law form have certain eigenvalue-eigenvector properties which may be used to construct conservative-form coefficient matrices. This reduces the computation time of several implicit and semiimplicit schemes. Extensions of the basic approach to other areas are suggested.
Infrared and nuclear magnetic resonance studies of the microstructures of polychloroprenes

High resolution infrared and nuclear magnetic resonance spectra confirm the structure of cis-polychloroprene prepared by a stereospecific route. Head-to-tail, head-to-head, and tail-to-tail sequence isomerism in both cis- and trans-polychloroprenes has been discovered and measured quantitatively by high resolution NMR spectroscopy. The irregularity in the microstructure of neoprenes proves to be more extensive than was previously suspected.
Physicians' experiences of caring for late-stage HIV patients in the post-HAART era: challenges and adaptations.

Abstract As medical treatment for AIDS has become more complex, the need for good palliative and end-of-life care has also increased for patients with advanced disease. Such care is often inadequate, especially among low-income, ethnic minority patients. The current study investigated physicians’ experiences with caring for dying HIV patients in an underserved, inner city community in the Bronx, NY. The goals of the study included: (1) to investigate the barriers to effective end-of-life care for HIV patients; and (2) to examine physicians’ experiences of role hindrance and frustration in caring for dying patients in the era of HAART. Qualitative, open-ended interviews were conducted with 16 physicians. Physicians identified two core, prescriptive myths shaping their care for patients with HIV. The ‘Good Doctor Myth’ equates good medical care with the delivery of efficacious biomedical care. The role of the physician is defined as technical curer, while the patient's role is limited to consultation and compliance. The ‘Good Death Myth’ envisions an ideal death which is acknowledged, organized, and pain free: the role of the physician is defined as that of comforter and supporter in the dying process. Role expectations associated with these myths were often disappointed. First, late-stage patients refused to adhere to treatment and were thus dying “unnecessarily.” Second, patients often refused to acknowledge, accept, or plan for the end of life and as a result died painful, chaotic deaths. These realities presented intense psychological and practical challenges for providers. Adaptive coping included both behavioral and cognitive strategies. Successful adaptation resulted in “positive engagement,” experienced by participants as a continuing sense of fascination, gratification, and joy. Less successful adaptation could result in detachment or anger. Participants believed that engagement had a powerful impact on patient care. Working with dying HIV patients in the post-HAART era of efficacious treatment challenges physician's cherished roles and values. Physicians adapt to the challenge through a variety of cognitive and behavioral strategies. The failure to adapt successfully has psychological consequences for providers that may impact patient care.
Frequency specificity of human auditory brainstem responses as revealed by pure-tone masking profiles.

The frequency specificity of the auditory brainstem response (ABR) was examined by means of pure‐tone masking profiles using click, 4000‐Hz, and 1000‐Hz filtered‐click stimuli. Simultaneous pure‐tone maskers were presented at one‐half octave intervals around stimulus center frequency. Masking profiles at two intensities (60 and 40 dB SL) were obtained by measuring both latency and amplitude shifts in wave V as a result of the discrete‐frequency maskers. Both latency and amplitude analyses showed masking profiles at 40 dB SL that were narrow and centered around stimulus frequency, whereas profiles at 60 dB SL showed high‐frequency spread of the cochlear excitation area.
Influence of Die Surface Texture on Tribological Performace for Tube Hydroforming

Tube hydroforming (THF) is an innovative method with a potential to form parts of various geometric complexities from tubular materials using pressurized fluid as a soft die. The process has numerous advantages over stamping: a) high strength to weight ratio, b) part consolidation, c) accuracy, d) improved stiffness, e) reduced scrap rate, and f) design flexibility. Optimal utilization of this method, particularly for hydoforming of complex parts, could be realized if better lubrication systems are devised. In an attempt to develop robust lubrication system for THF, the influence of textured die surfaces on tribological performance were studied through numerical modeling and experimentation. The pear shaped tooling developed by the author was used for evaluating the performance of hydroforming lubricants at the expansion zone. The effects of textured surfaces imprinted on the pear shaped dies were studied.Copyright © 2005 by ASME
Twinning dislocations on {1¯011} and {1¯013} planes in hexagonal close-packed crystals

Abstract The objective of this investigation was to identify the elementary twinning dislocations (TDs) for { 1 ¯ 0 1 1 } and { 1 ¯ 0 1 3 } twins by fully characterizing their structure for an Mg crystal. For both { 1 ¯ 0 1 1 } and { 1 ¯ 0 1 3 } twins, we conclude that the 2-layer TD, not the 4-layer TD, is the active TD in twinning. The 4-layer TD can be considered as the combination of two 2-layer TDs with opposite-sign screw components. Molecular statics simulations of the Peierls energy show why the TDs of both twinning modes (for c/a ratios > 1.5) are only activated when the c-axis experiences a compressive strain. The simulations predict that 2-layer TDs are more mobile than 4-layer TDs and that the mobility of these twinning dislocations depends strongly on dislocation character. Correspondingly, the influence of TDs involved in deformation twinning processes on deformation twins is discussed.
Direct Synthesis of Gallium Oxide Tubes, Nanowires, and Nanopaintbrushes

We demonstrate bulk synthesis of highly crystalline β-gallium oxide tubes, nanowires, and nanopaintbrushes using molten gallium and microwave plasma containing a mixture of monatomic oxygen and hydrogen. Gallium oxide nanowires were 20−100 nm thick and tens to hundreds of micrometers long. Transmission electron microscopy (TEM) revealed the nanowires to be highly crystalline and devoid of any structural defects. Results showed that multiple nucleation and growth of gallium oxide nanostructures could easily occur directly out of molten gallium exposed to an appropriate composition of hydrogen and oxygen in the gas phase. These gallium oxide nanostructures should be of particular interest for optoelectronic devices and catalytic applications.
Double Jeopardy: Race/Ethnicity and Sexual Harassment in the U.S. Military

Our research examines a sample of respondents from a Department of Defense (DoD) survey in an attempt to determine the incidence of sexual harassment in the military by race/ethnic category and to determine whether or not women's experiences differ based on race and ethnic membership. Logistic regression is used to test whether racial and ethnic minorities face double risks of victimization with respect to sexual Results do not support an adverse interaction of race and gender with respect to sexual harassment in the military for Black women; however, findings varied depending on type of harassment for Hispanic and Other Race women. The biggest surprise is that the males report a higher incidence of harassment in 2002. Replicating an earlier finding, when no environmental harassment is reported individual harassment is very rare. Overall, this finding supports the importance of organizational context in producing different levels of harassment. Keywords: Sexual harassment, Race, Ethnicity, Sex, Military
Validating the human resource system structure: A levels-based strategic HRM approach

Abstract Despite considerable empirical evidence that human resource systems are related to firm performance, significant conceptual and methodological issues remain. We argue that progress along these lines requires basic development of the validity of the HR system construct. To help accomplish this, we draw on previous strategic HRM literature and insights from organizational levels of analysis literature to explicate a levels-based HR systems approach for validating the HR systems structure. We propose that conceptual and levels-based distinctions between HR system structure components can shed light on current methodological debates in the field, and offer an expanded strategic HRM research agenda.
The application of ground-penetrating radar to a coastal prehistoric archaeological site, Cape Henlopen, Delaware, USA

Cape Henlopen, Delaware is a coastal spit complex located at the confluence of Delaware Bay and the Atlantic Ocean. This region was occupied by prehistoric peoples throughout the evolution of ancestral Cape Henlopen. A ground-penetrating radar (GPR) survey was conducted at one of the prehistoric archaeological sites (7S-D-30B) located within the Cape Henlopen Archaeological District. The site was in a remote location in the center of a tide dominated back-barrier marsh. Ground-penetrating radar waves penetrated to depths of 7 m, and four major sets of reflections were observed. Three sets were interpreted to be GPR images of geomorphic units associated with the spit complex, and the fourth was identified as the GPR image of a shell midden deposit. The GPR survey was used to determine the approximate dimensions of the shell midden, including its depth below ground surface (up to 2.1 m) and horzontal extent (∼250 m2), and to establish the paleoenvironmental setting and antecedent topography of the site prior to occupation. The GPR data suggests that the shell midden was initially deposited upon an aeolian dune surface and the antecedent topography at the site included an up to 1 m deep trough located 5 m to the north of, and trending parallel to, the axis of a present-day topographic high. This survey illustrates that GPR is a useful, noninvasive, tool that may be implemented at archaeological sites in coastal areas. It provides constraints on the environmental setting and topography of the terrain which prehistoric peoples inhabited, and it can be used in planning excavations at sites in coastal geomorphic settings. © 2000 John Wiley & Sons, Inc.
The effect of sex on certain properties of the very low density lipoprotein secreted by the liver.

Summary Livers from normal fed male and female rats were perfused with a diluted blood-buffer medium containing various amounts of oleic acid as the complex with bovine serum albumin. Livers from female rats secreted greater quantities of triglyceride into the perfusate, over a wide range of concentration of free fatty acid, than did livers from male animals. The very low density lipoprotein (VLDL) carrier for triglyceride, which was secreted by livers from female animals, was a larger particle and contained fewer moles phospholipid and sterol per mole triglyceride than the VLDL secreted by livers from male rats. Since plasma concentrations of triglyceride in female rats are similar to or less than those in male animals, but yet hepatic output of VLDL triglyceride is greater in the female, it can be postulated that extrahepatic uptake and metabolism of VLDL triglyceride is also more rapid in the female than in the male; the more rapid rate of utilization of VLDL triglyceride may also apply to phospholipid and cholesterol, and, in part, result from the differences in properties and composition of the VLDL secreted by livers from male and female animals, respectively.
Edinger-Westphal neurons that project to spinal cord contain substance P

Combined retrograde transport and immunocytochemical methods were used to determine whether Edinger-Westphal neurons projecting to spinal cord also demonstrate substance P-like immunoreactivity (SPLI). Large injections of horseradish peroxidase (HRP) into cervical and lumbar enlargements retrogradely labeled cells throughout the length of the Edinger-Westphal complex (EW). Nearly all HRP-labeled EW neurons also stained for SPLI, evidence that EW is the origin of a direct substance P pathway linking rostral mesencephalon with spinal cord.