cssi/SciSciGPT-SciSciNet huggingface dataset:
MO-AB-BRA-02: A Novel Scatter Imaging Modality for Real-Time Image Guidance During Lung SBRT

Purpose: A novel scatter imaging modality is developed and its feasibility for image-guided radiation therapy (IGRT) during stereotactic body radiation therapy (SBRT) for lung cancer patients is assessed using analytic and Monte Carlo models as well as experimental testing. Methods: During treatment, incident radiation interacts and scatters from within the patient. The presented methodology forms an image of patient anatomy from the scattered radiation for real-time localization of the treatment target. A radiographic flat panel-based pinhole camera provides spatial information regarding the origin of detected scattered radiation. An analytical model is developed, which provides a mathematical formalism for describing the scatter imaging system. Experimental scatter images are acquired by irradiating an object using a Varian TrueBeam accelerator. The differentiation between tissue types is investigated by imaging simple objects of known compositions (water, lung, and cortical bone equivalent). A lung tumor phantom, simulating materials and geometry encountered during lung SBRT treatments, is fabricated and imaged to investigate image quality for various quantities of delivered radiation. Monte Carlo N-Particle (MCNP) code is used for validation and testing by simulating scatter image formation using the experimental pinhole camera setup. Results: Analytical calculations, MCNP simulations, and experimental results when imaging the water, lung, and cortical bone equivalent objects show close agreement, thus validating the proposed models and demonstrating that scatter imaging differentiates these materials well. Lung tumor phantom images have sufficient contrast-to-noise ratio (CNR) to clearly distinguish tumor from surrounding lung tissue. CNR=4.1 and CNR=29.1 for 10MU and 5000MU images (equivalent to 0.5 and 250 second images), respectively. Conclusion: Lung SBRT provides favorable treatment outcomes, but depends on accurate target localization. A comprehensive approach, employing multiple simulation techniques and experiments, is taken to demonstrate the feasibility of a novel scatter imaging modality for the necessary real-time image guidance.
Multicolor immunophenotyping: human mature immune system.

Publisher Summary The ability to measure many markers simultaneously results in identification of multiple new cellular subsets and reveals new levels of complexity of the immune system. One major advantage of multicolor flow cytometry is the ability to combine markers that precisely identify cellular subsets with additional markers that access function. This allows obtaining functional information at the single-cell level for cells that are characterized by surface marker expression. The chapter focuses on T cells and discusses some of the markers used to identify and classify T-cell subsets. Most of these are cell-surface markers, but some intracellular markers as additional phenotyping markers and markers that provide information about function are also discussed. T cells can be characterized and subdivided in different ways. For classification of these subsets, cells at different stages of differentiation or maturation are identified. The choice of fluorochrome (or dye) to use with marker and the choice of the combinations of markers to use for each staining panel are very important for all flow cytometric experiments. The choice of the combinations of markers to include in a panel depends on the subsets that need to be identified. The characteristics of fluorescent dyes relevant to flow cytometry are brightness; measurement error and compensation requirement; dyes used for intracellular staining; and characteristic of the cell-associated marker to be examined.
Bioavailability of Soil-borne Chemicals: A Regulatory Perspective

ABSTRACT U.S. Environmental Protection Agency (USEPA) risk assessment guidance documents dating back to 1989 have articulated the principles for incorporating information on bioavailability into the risk assessment process. However, in the interim period both the methods for obtaining media or route specific measures of bioavailability and the corresponding guidance to incorporate these data have languished. Presently, USEPA is developing guidance to address both of these concerns. This article outlines the broad framework for systematically evaluating the role of bioavailability in site-specific risk assessment from a regulatory perspective. At the same time, in appreciation of the vast horizon of uncharted territory ahead, the focus of USEPA's draft guidance, and consequently this report, is on bioavailability adjustments for soil-borne metals. The article describes a two-stage process. The first stage outlines a paradigm for screening sites to determine if generating site-specific data on the bioavaila...
4-Hydroxylated Metabolites of the Antiestrogens Tamoxifen and Toremifene Are Metabolized to Unusually Stable Quinone Methides

Tamoxifen is widely prescribed for the treatment of hormone-dependent breast cancer, and it has recently been approved by the Food and Drug Administration for the chemoprevention of this disease. However, long-term usage of tamoxifen has been linked to increased risk of developing endometrial cancer in women. One of the suggested pathways leading to the potential toxicity of tamoxifen involves its oxidative metabolism to 4-hydroxytamoxifen, which may be further oxidized to an electrophilic quinone methide. The resulting quinone methide has the potential to alkylate DNA and may initiate the carcinogenic process. To further probe the chemical reactivity and toxicity of such an electrophilic species, we have prepared the 4-hydroxytamoxifen quinone methide chemically and enzymatically, examined its reactivity under physiological conditions, and quantified its reactivity with GSH. Interestingly, this quinone methide is unusually stable; its half-life under physiological conditions is approximately 3 h, and its...
Distributions of Weekly Averages of Diurnal Temperature Means and Ranges about Harmonic CURVES1

Abstract The distributions of weekly averages of diurnal temperature maxima, minima, means, and ranges are found to be non-normal, although the errors in using the normal distribution do not impair the usefulness of derived estimates of probability. The central tendency and the variance are estimated by harmonic regression. This enables the estimation of probabilities for any week from as few as five parameters. A three-term harmonic curve fitted to individual years is adequate to describe the course of temperature.
Immunization practices of Washington State pediatricians--1989.

• Administration of immunizations has become complicated by issues about consent, cost, and liability. To determine if these issues have changed the immunization practices of pediatricians, we surveyed pediatricians in private practice in Washington State. The survey results show that about one half of vaccines administered in pediatricians' offices are provided by the Washington State Health Department. The mean charge for administration of each parenteral vaccine was $7.02. Respondents strongly agreed that they would administer vaccine supplied by the Washington State Health Department if it was available. They also agreed that they referred patients to Health Department clinics for vaccination because of inability to pay and not because of concern about liability. ( AJDC . 1992;146:1033-1036)
Enzymatic total synthesis of enterocin polyketides

Polyketides are clinically important natural products that often require elaborate organic syntheses owing to their complex chemical structures. Here we report the multienzyme total synthesis of the Streptomyces maritimus enterocin and wailupemycin bacteriostatic agents in a single reaction vessel from simple benzoate and malonate substrates. To our knowledge, our results represent the first in vitro assembly of a complete type II polyketide synthase enzymatic pathway to natural products.
VHL loss of function and its impact on oncogenic signaling networks in clear cell renal cell carcinoma

Loss of von Hippel-Lindau tumor suppressor gene function occurs in familial and most sporadic clear cell renal cell carcinoma, resulting in the aberrant expression of genes that control cell proliferation, metabolism, invasion and angiogenesis. The molecular mechanisms by which loss of function leads to tumorigenesis are not yet fully defined. The von Hippel-Lindau gene product is part of an ubiquitin ligase complex that targets hypoxia inducible factors for polyubiquitination and proteasomal degradation, linking hypoxia response genes to renal cell carcinoma oncogenesis. Loss von Hippel-Lindau gene function also promotes cell invasiveness in response to hepatocyte growth factor, an important regulator of kidney development and renal homeostasis. Increased cell invasiveness is mediated by another ubiquitin ligase target with relevance to the molecular pathogenesis of renal cell carcinoma: β-catenin. This discovery and other recent insights into kidney cancer oncogenesis implicate convergent developmental and homeostatic signaling pathways in tumorigenesis, tumor invasiveness and metastasis.
Role of Oxygen in the Quenching of Liquid Scintillators

The quenching effects of oxygen on the light outputs of several organic liquid scintillators have been compared under conditions of high-energy gamma irradiation and direct light excitation of the solute. The reduction by oxygen of the light output has been found to be primarily due to solute quenching. Results are obtained which support the collision-transfer mechanism proposed by Kallmann.
Angiotensin II AT1 Receptor Blockade Prolongs the Lifespan of Spontaneously Hypertensive Rats and Reduces Stress-Induced Release of Catecholamines, Glucocorticoids, and Vasopressin

A 2-week pretreatment with an Angiotensin II AT(1) antagonist prevented the adrenomedullary and hormonal response to isolation stress. We studied the effect of life-long treatment with the AT(1) receptor antagonist candesartan, 10 mg/kg/day, or vehicle administered orally in the drinking water from 8 weeks of age on the response to stress of stress-sensitive spontaneously hypertensive rats (SHRs) and their normotensive controls, the Wistar Kyoto (WKY). Rats were submitted to 24-h isolation stress at different times during the treatment. Treatment with candesartan extended the lifespan of SHRs. AT(1) receptor blockade retained its capacity to blunt the response to isolation stress over a long period of treatment. The AT(1) antagonist inhibited epinephrine release in SHR but not in WKY rats during the first 3 months, corticosterone release in SHR and WKY rats during 10 months, and vasopressin release in SHR rats during 18 months of treatment when rats were submitted to isolation stress. There were no changes in vasopressin release in WKY rats during stress or after AT(1) receptor blockade. We conclude that the blockade of the stress response by the AT(1) receptor antagonist is long lasting and differs between stress-prone SHR and WKY rats and that the specific components of the stress response (sympathoadrenal activity, hypothalamic-pituitary-adrenal axis activation, and vasopressin release) react differently to AT(1) receptor blockade. The long-term protective effects of AT(1) receptor blockade can be important in animals vulnerable to stress and, in conjunction with the normalization of blood pressure, can prolong lifespan through end-organ protection.
School culture audits: making a difference in school improvement plans:

The United States census data report that the nation is becoming more diverse at a rapid rate. Schools reflect these demographical changes by representing multiracial and multiethnic groups whose languages, religions, economics, and abilities are equally diverse. Educational systems often struggle in their efforts to support the needs of culturally different students. Consequently, these students often do not fare well academically. This article examines those factors which contribute to the achievement gap between culturally different and majority students, and describes how the cultural audit process can serve as a mechanism for addressing academic disparities.
Ion-exclusion chromatography of aliphatic car☐ylic acids on a cation-exchange resin by elution with polyvinyl alcohol

Ion-exclusion chromatography of aliphatic car☐ylic acids of different acidity (pKa) and hydrophobicity was investigated on a polystyrene-divinylbenzene (PS-DVB) based strongly acidic cation-exchange resin in the H+ form and conductivity detection by elution with polyvinyl alcohol (PVA). When water was used as an eluent, the resolution of the car☐ylic acids was very low and the peak accompanied a fronting depending on their hydrophobicities. Therefore, to improve the peak shape and the peak resolution, aqueous eluents containing PVAs (degrees of polymerization, n=500, 1500and2000) with many OH groups were tested for the ion-exclusion chromatographic separation of the car☐ylic acids. When aqueous eluents containing PVA were used, the fronting was decreased dramatically by the effect of increased hydrophilicity of the PS-DVB cation-exchange resin surface due to adsorption of OH group in PVA. The high resolution ion-exclusion chromatographic separation without the fronting and highly sensitive conductimetric detection of the car☐ylic acids was accomplished successfully by elution with a 0.2% PVA (n=1500)-10% methanol-water.
Intestinal Subepithelial Myofibroblasts Support the Growth of Intestinal Epithelial Stem Cells

Intestinal epithelial stem cells (ISCs) are the focus of recent intense study. Current in vitro models rely on supplementation with the Wnt agonist R-spondin1 to support robust growth, ISC self-renewal, and differentiation. Intestinal subepithelial myofibroblasts (ISEMFs) are important supportive cells within the ISC niche. We hypothesized that co-culture with ISEMF enhances the growth of ISCs in vitro and allows for their successful in vivo implantation and engraftment. ISC-containing small intestinal crypts, FACS-sorted single ISCs, and ISEMFs were procured from C57BL/6 mice. Crypts and single ISCs were grown in vitro into enteroids, in the presence or absence of ISEMFs. ISEMFs enhanced the growth of intestinal epithelium in vitro in a proximity-dependent fashion, with co-cultures giving rise to larger enteroids than monocultures. Co-culture of ISCs with supportive ISEMFs relinquished the requirement of exogenous R-spondin1 to sustain long-term growth and differentiation of ISCs. Mono- and co-cultures were implanted subcutaneously in syngeneic mice. Co-culture with ISEMFs proved necessary for successful in vivo engraftment and proliferation of enteroids; implants without ISEMFs did not survive. ISEMF whole transcriptome sequencing and qPCR demonstrated high expression of specific R-spondins, well-described Wnt agonists that supports ISC growth. Specific non-supportive ISEMF populations had reduced expression of R-spondins. The addition of ISEMFs in intestinal epithelial culture therefore recapitulates a critical element of the intestinal stem cell niche and allows for its experimental interrogation and biodesign-driven manipulation.
Investigation of damage mechanisms of KTiOPO 4 crystals by use of a continuous-wave argon laser

We have developed a simple method that uses cw irradiation from an argon laser to measure the damage threshold of KTP crystals. Our experimental results show that there are two types of damage in KTP crystal, depending on the polarization of the incident laser beam. One type of optical damage is the appearance of gray tracks, including both dark tracks and orange dots, when the pump polarization is perpendicular to the z axis. The other type is invisible damage when the polarization is parallel to the z axis. In addition, we have also observed weak photorefractive two-wave mixing in KTP crystals in each of these polarization states. After a systematic analysis we have concluded that the first type of damage is due to the formation and absorption of Ti3+ and Fe3+ centers and the second is due to the drift of K+ ions. The weak photorefractive effect is the result of screening of the electric field by the drifted K+ ions.
THE SECRETORY PATHWAY OF PLASMODIUM FALCIPARUM REGULATES TRANSPORT OF P82/RAP-1 TO THE RHOPTRIES

The rhoptries of Plasmodium falciparum are formed during a restricted period in the asexual erythrocytic cycle. The steps required for rhoptry biogenesis and the pathway for targeting proteins to the rhoptries have not been elucidated. Using the maturation of the Rhoptry-Associated Protein 1 (RAP-1) gene product to study these steps, it is reported here that a secretory pathway controls transport of protein complexes containing RAP-1 products to the rhoptries. Both brefeldin A (BFA) and low temperature reversibly block the processing of an 86-kDa precursor (Pr86) to the mature 82-kDa RAP-1 product (p82). Furthermore, the points of action of BFA and low temperature appear to overlap since their sequential application reversibly prevents Pr86 processing. Treatment of intact cells with N-ethylmaleimide, which prevents the fusion of transport vesicles with Golgi membranes in other eukaryotic cells, irreversibly blocks processing of Pr86. The role of the secretory pathway in targeting p82 protein complexes to the rhoptries is further supported by the observed co-translational translocation into canine microsomes of the in vitro translation product of RAP-1. These in vitro results also reveal that the RAP-1 product contains a cleavable N-terminal signal molecular weight from the in vivo precursor Pr86. Our results suggest that rhoptry biogenesis is controlled in part peptide and appears to be initially synthesized as an 84-kDa protein. The above data indicate that transport of p82 to the rhoptries is regulated by the secretory pathway and that the RAP-1 primary translation product differs in apparent by the secretory pathway and that the RAP-1 gene product acquires a previously undetected protein modification during its maturation.
Propionic acidemia in patients with ketotic hyperglycinemia.

Plasma concentrations of propionic acid were determined in 3 patients with ketotic hyperglycinemia and in control individuals. The patients were all in remission. Only 2 had elevated concentrations of glycine in the blood at the time of the study. Propionic acidemia was found in all 3 patients. The concentrations of propionic acid were 10 to 20 times the median of control subjects. It is concluded that propionic acidemia may be a more consistent feature of this disorder than hyperglycinemia. This conclusion is consistent with the presence of a defect in the enzyme propionyl-CoA carboxylase.
Asymptotic analysis of steady dynamic crack growth in an elastic-plastic material

Abstract A ttention is focussed on the asymptotic stress and deformation fields near the edge of a mode I crack propagating steadily in an elastic-perfectly plastic incompressible material under plane strain conditions. Features of previously reported results on this problem are reviewed, with a view toward establishing discriminating characteristics. An asymptotic solution valid for all crack speeds is constructed. This solution has the properties that the angular variation of stress and particle velocity around the crack tip are continuous and the plastic strains are bounded at the crack tip. The construction depends on the boundedness of hydrostatic stress at the crack tip, and the conditions under which this stress measure is bounded are discussed in an Appendix. The possibility of an asymptotic field with logarithmically singular plastic strain at the crack edge is examined. While fields with this feature can be constructed by admitting discontinuities in stress and particle velocity, it is shown that the sequence of mechanical states experienced in the discontinuities is inconsistent with the principle of maximum plastic work. The dynamic asymptotic field does not reduce to the generally accepted quasi-static asymptotic field in the limit as the crack speed goes to zero. It has been established for the equivalent case of mode III elastic-plastic crack growth that the domain of validity of the dynamic asymptotic field vanishes as the crack speed vanishes, and the implication is that the mode I result has the same property.
Isolation and properties of carboxypeptidase from leaves of wounded tomato plants

Abstract A carboxypeptidase was purified to homogeneity from upper, unwounded leaves of tomato plants in which carboxypeptidase activity had been induced to increase over three-fold by severely wounding the lower leaves. The carboxypeptidase was purified by ammonium sulfate precipitation, affinity chromatography, and finally by gel permeation chromatography. Electrophoresis at pH 4.3 and isoelectric focusing showed only a single band. The isoelectric point was 5.2 and the MW 105 000. Tomato carboxypeptidase possessed both peptidase and esterase activities and it sequentially hydrolysed amino acids from the carboxyl-terminal end of insulin chain B. It was optimally active at pH 6–7 on peptidase substrates, and at pH 8 on esterase substrates. The enzyme was inhibited by diisopropylfluorophosphate and incorporated 1 mol of DFP-[3H]. per mol of enzyme. Both peptidase and esterase activities were strongly inhibited by HgCl2 but not by p-hydroxymercuribenzoate or iodoacetamide. Carboxypeptidase inhibitor from potatoes did not inhibit the enzyme.
Theory of laser-simulated surface processes

Abstract Theoretical techniques for describing laser-stimulated surface processes in a vacuum and at a gas-surface interface are presented. For adspecies-surface systems, the laser excitation of vibrational degrees of freedom is considered, and quantum-mechanical and classical models and also an “almost first-principles” treatment of the competition between multiphoton absorption and multiphonon relaxation are discussed. The laser excitation of electronic degrees of freedom is considered with respect to surface states of semiconductors and metals, for the predissociation of diatomic adspecies on metal substrates, for ionization, and for resonance fluorescence of a gaseous atom near a metal. In connection with gas-surface interactions, the influence of laser radiation on diffraction patterns and energy transfer in atom-surface scattering is explored. Collisional ionization and ion neutralization in the presence of laser radiation are discussed. The roles of partial pressure and surface coverage in laser-stimulated surface processes are analyzed. Finally, some ideas on surface waves and annealing are presented.
Anesthesia-related cardiac arrest in children with heart disease: data from the Pediatric Perioperative Cardiac Arrest (POCA) registry.

BACKGROUND:From 1994 to 2005, the Pediatric Perioperative Cardiac Arrest Registry collected data on 373 anesthesia-related cardiac arrests (CAs) in children, 34% of whom had congenital or acquired heart disease (HD).METHODS:Nearly 80 North American institutions that provide anesthesia for children v
Effect of heat-treatment temperature of vapor-grown graphite fibers. I - Properties of their bromine intercalation compounds

Vapor-grown graphite fibers were heat treated at 2000, 2200, 2400, 2600, 2800, and 3000 C, brominated at room temperature for two days, and then characterized by X-ray diffraction analysis, differential scanning calorimetry, and resistivity measurements. Fibers greater than 13 microns in diameter had low resistivities (50 microohms or less) irrespective of the heat treatment temperature. An analysis of the results obtained suggests that resistivities below 6 microohms cannot be achieved through a further reduction in defect level unless the amount of bromine is increased.
Potassium channel blockade induces action potential generation in guinea-pig airway vagal afferent neurones.

Abstract Electrophysiological studies of vagal sensory nerves with cell bodies in the nodose ganglion and mechanically sensitive receptive fields in the guinea-pig trachea/bronchus, were performed. Exposure of the mechanically sensitive receptive fields to 4-aminopyridine (100 μM–1 mM) caused pronounced action potential discharge in all fibres studied. Action potential generation was also produced by α-dendrotoxin, and in a subset of fibres, by barium. By contrast, neither iberiotoxin, tetraethyl ammonium, glybenclamide, BDS-II, nor apamin caused action potential generation in the vagal afferent nerve fibres. Tetramethylrhodamine dextran was instilled into the trachea to retrogradely label cell bodies within the nodose ganglion. In these cells, 4-aminopyridine caused a large depolarization of the resting membrane potential, concomitant with an increase in input impedance. The data suggest 4-aminopyridine- and α-dendrotoxin-sensitive ion channels within the airway afferent nerve membrane hold the resting membrane potential below the threshold for action potential generation. Mechanisms that lead to an inhibition of these channels will likely lead to an increase in excitability of the airway afferent neurones.
Social Workers and Battered Women: The Need to Study Client Violence in the Domestic Violence Field

Domestic violence is a significant issue for the United States and internationally. Although many social workers may desire to work in the domestic violence field, such work is far more difficult and challenging than many social workers would expect. In fact, many domestic violence workers are abused by their clients or their clients' family members in the course of their work. The purpose of this article is to clarify why examining client violence toward workers in the domestic violence field is critically important, describe the current state of the research, and discuss recommendations for future research in this area.
National security and sustainability

Despite the expenditure of $1 trillion per year, the USA is less secure than ever before. Beyond conventional threats are those attributable to rapid climate destabilization and unpredictable high-consequence events with long-term global consequences. The paper discusses one response to such threats that promotes local and regional resilience as a coordinated network of sites, cities, and projects.
Amino acid biosynthesis and sodium‐dependent transport in Methanococcus voltae, as revealed by 13C NMR

Of several methanogenic bacteria examined only Methanococcus voltae readily incorporated exogenous amino acids into cell protein. This was easily shown, since growth in the presence of exogenous amino acids resulted in a loss of signal intensities from those carbon atoms normally labelled by [13C]acetate during biosynthesis. From 80% to 95% of the Ser, Lys, Pro or Val incorporated into protein could be supplied directly from the growth medium. In contrast, Asp and Glu, if supplied to the medium, accounted for only a small percentage of the total acidic amino acid used in protein synthesis. Constitutive transport systems took up a wide range of amino acids at rates of 0.1-4.1 nmol min-1 mg-1. The transport systems required Na+, with the possible exception of the basic amino acid lysine, and were inhibited by N-ethylmaleimide or 3,3',4',5-tetrachlorosalicylanilide. No interconversion of Ile to other amino acids was detected when cells were given [13C]Ile during growth, whereas the expected labelling of the Asp and Glu families of amino acids resulted when [13C]Asp was provided to the culture. Mc. voltae synthesized its amino acids from acetate via routes fully consistent with those found in Methanospirillum hungatei [Ekiel, I., Smith, I.C.P. & Sprott, G.D. (1983) J. Bacteriol. 156, 316-326]. Propionate could substitute for an auxotrophic requirement for Ile, resulting in the synthesis of Ile with the beta-carbon originating from the carboxyl of acetate and the alpha-carbon from the carboxyl of propionate. No labelling of Ile from [13C]acetate could occur without the fatty acid. These results provide strong evidence for the carboxylation of propionate to form 2-oxobutyrate as intermediate in Ile biosynthesis, and show that the metabolic defect in Ile biosynthesis occurs prior to 2-oxobutyrate synthesis. The presence of constitutive amino acid transport systems and multiple routes for ile biosynthesis make Methanococcus voltae an attractive methanogen for genetic studies.
Three Approaches to Diagnosis and Educational Planning for Children with Learning Disabilities

Three approaches to educational diagnosis - etiological, diagnostic-remedial, and task-analysis - are examined, showing the unique emphases of each.
Budd-chiari syndrome, mediastinal mass and recalcitrant leg ulcers, an unlikely trio

A 59 year old non-smoker male presented with a long history of recalcitrant lower extremity ulcers. Forty years ago, he underwent splenectomy for a nonmalignant reason. Shortly after his surgery, he developed multiple collateral veins over his abdomen with extensive lower extremities venous varicosities. He was ultimately diagnosed with Budd-Chiari syndrome (BCS), classified as Budd-Chiari type I whereby the thrombus was limited to the intrahepatic inferior vena cava, not directly compromising the hepatic veins [1, 2]. He was initially treated with warfarin but due to bleeding complications, this medication was discontinued. More recently, he has been plagued with chronic recurrent lower extremity ulcers. Although healing promptly with compression therapy, his clinical course was marked by frequent ulcer recurrence. He otherwise denied dyspnea or recent weight changes. Physical examination revealed a 10 cm ulcer involving the medial foreleg of the right lower extremity with hemosiderin staining and dermal sclerosis. Multiple large varices were evident on the inspection of his extremities. There was no evidence of lower extremity deep vein thrombosis on venous Doppler ultrasound. His ECHO revealed a normal left ventricular ejection fraction (68%) and normal right ventricular systolic pressure. Laboratory evaluation was negative for lupus anticoagulant, factor V Leiden and PT 20210 mutation. He had normal levels of protein C and S and there was no evidence of myelodysplasia. His initial evaluation however, also included a chest X-ray that revealed a soft-tissue prominence in the right tracheobronchial angle (Fig. 1) worrisome for malignancy.
Elastic Wrinkling of a Tensioned Circular Plate Using von Kármán Plate Theory

A circular elastic plate, with a uniform tension field applied at its outer edge, is acted upon by a centrally applied transverse force. As the force is increased, the tension state as determined from von Karman plate theory, changes. In particular for sufficiently large values of the transverse force or displacement, the plate can develop a compressive circumferential membrane stress. When this compressive stress becomes sufficiently large, wrinkling can result. The corresponding value of the transverse displacement is determined by investigating an eigenvalue problem in which wrinkling is indicated by the vanishing of the lowest eigenvalue. The results are the values of the central transverse deflection which induces wrinkling for a range of in-plane tensions and are sensitive to the in-plane boundary support conditions at the outer edge.
PROPERTIES OF LITHIUM HYDRIDE. I. SINGLE CRYSTALS

Abstract Single crystals of optical quality LiH have been prepared by slow crystallization of the melt under hydrogen gas at moderate pressure. Measured and reported values of the physical, thermal, chemical, and optical properties of LiH and LiD are compared to those of LiF and NaCl. These properties bear out the predominantly ionic nature of crystalline LiH. The optical properties of LiH differ from those expected by a comparison with the properties of the alkali halides or the other alkali hydrides. This difference is related to distortion and polarization effects on the hydride ion in the LiH crystal lattice. There is a tendency toward covalency which may contribute to the binding energy of crystalline LiH, and this also may be responsible for its somewhat anomalous behavior.
Core Excitons and the Soft-X-Ray Threshold of Silicon

The photoabsorption coefficient in crystalline Si is computed in the 100-eV region (${L}_{\mathrm{II}},{L}_{\mathrm{III}}$) on the basis of core excitons, using an adaptation of the effective-mass theory. The line shape is in good agreement with experiment, and, using experimental evidence from the phosphorus impurity in Si as to the central-cell correction, we find the absolute value to be compatible with experiment.
Communication Processes for Virtual Organizations

Communication is fundamental to any form of organizing but is preeminent in virtual organizations. Virtual organizations are characterized by (a) highly dynamic processes, (b) contractual relationships among entities, (c) edgeless, permeable boundaries, and (d) reconfigurable structures. Relative to more traditional settings, communication processes that occur in virtual contexts are expected to be rapid, customized, temporary, greater in volume, more formal, and more relationship-based. To glean insight into communication processes for virtual organizations, we draw on the rich body of literature on synchronous and asynchronous electronic organizational communication. The vast set of empirical findings regarding mediated communication can foreshadow how communication will change as firms “go virtual.” Six areas of electronic communication research provide implications for the major aspects of virtual organization design: (1) communication volume and efficiency, (2) message understanding, (3) virtual tasks, (4) lateral communication, (5) norms of technology use, and (6) evolutionary effects.
A historical survey with success and maturity estimates of launch systems with RL10 upper stage engines

Pratt & Whitney's RL10 engine line has a long and rich history, beginning in 1958 and continuing today. This paper provides a historical summary of launch vehicles using RL10 engine derivatives dating from 1962 - 2005. The historical launch data is used to derive baseline launch success rates and growth curves for vehicles configured with RL10 engines in the upper stage.Because it was the first liquid hydrogen fueled rocket engine, the RL10 engine launch history provides a unique opportunity to investigate the maturity trends for revolutionary new complex systems. All of the data used in this survey was acquired through publicly-available sources. In all, 190 vehicles configured with RL10 upper stage engines were launched between 1962 and 2005. There were 12 upper stage failures that either failed to reach orbit, or reached a lower, unintended orbit. The early failures were dominated by knowledge gaps in system interactions and operational flight conditions. There is a clear trend of early development growth with an eventual plateau as system knowledge improved as a result of flight experience and more thorough test programs. Failures due to process-based issues (fabrication techniques, quality control, etc.), however, do not appear to exhibit maturity growth. Eventually, as the knowledge-based failures are removed, these process-based failures become the dominant risk driver. Vehicles that use mature, highly-reliable components are still vulnerable to process or functional changes, and failures of this type occur fairly uniformly with flight experience. In order to improve future reliability estimates for such systems, it is important to understand the trends and relationship between the knowledge-based and process-based issues, and determine which class of issues currently dominates. It should be noted that of the 12 upper stage failures, only one was caused by a defective part.
Photochemical activity of iron pentacarbonyl on Ag(111): photofragmentation, quenching and wavelength-dependent effects

Abstract The UV photon induced decomposition of Fe(CO) 5 on Ag(111) was examined with temperature programmed desorption (TPD), Auger electron spectroscopy (AES), and low-energy electron diffraction (LEED). In the absence of UV irradiation, Fe(CO) 5 thermally desorbed from Ag(111) with minimal decomposition. The temperature difference between the monolayer and multilayer states (12 K) suggests that the monolayer was physisorbed. Photodecomposition of adsorbed Fe(CO) 5 with 256 or 365 nm light produced unidentified surface species, presumably Fe x (CO) y clusters, which thermally decomposed near 330 K in TPD, evolving gas-phase CO and depositing a pure Fe film on the Ag surface. The photochemical properties of monolayer and multilayer Fe(CO) 5 were investigated separately by isolating multilayers of Fe(CO) 5 from the Ag(111) surface with a chemically and photolytically inert buffer layer (n-decane). Photodecomposition near the threshold energy (3.4 eV) was five times as efficient for monolayer Fe(CO) 5 as for multilayer Fe(CO) 5 , presumably due to a red-shifted absorption threshold for the monolayer. The Photodecomposition cross sections with 4.8 eV light were similar to gas-phase values, suggesting that the excited Fe(CO) 5 species were not significantly quenched by the surface. Quenching of energetic Fe x (CO) y fragments was more pronounced in the monolayer than for Fe(CO) 5 as inferred by the low cross section for Fe x CO x Photodecomposition.
40Ar/39Ar laser probe evidence concerning the age and associated hazards of the Lake Nyos Maar, Cameroon

The waters of Lake Nyos are impounded by a fragile natural dam composed of pyroclastic rocks ejected during the formation of the lake crater (maar). Lateral erosion of this dam has reduced its width from over 500 m to only 45 m. Published whole-rock K-Ar ages of about 100 ka on juvenile basalt from the dam suggests that erosion has been slow and that the dam poses no imminent threat. New apparent 40Ar/39Ar ages of 1.4 to 232 Ma on xenocrystic K-feldspar contained in the basalt show that the xenocrysts, whose source is the 528-Ma crystalline basement, are carriers of inherited radiogenic 40Ar and would cause the whole-rock K-Ar ages to be too old. The best estimate for the age of the maar is provided by a 14C age of 400 ± 100 yr BP on charcoal from the base of the dam. This young age indicates that the dam is eroding at a relatively rapid rate; its failure, perhaps within a few decades, would result in a major flood and imperil thousands of people living downstream in Cameroon and eastern Nigeria.
Using Industrial Trade Shows to improve New Product Development

Considers how research carried out during trade shows can help industrial firms to manage the new product development process. Discusses the NPD process and offers a scheme for classifying trade fairs, thus making the selection of appropriate events easier for the industrial marketer. Develops recommendations for the conducting of new product research at trade shows and concludes that while not a substitute for traditional NPD research methods due to cost limitations and the different types of attendees present at various events, good opportunities exist for industrial exhibitors to use NPD stages such as idea generation, screening and testing at trade shows rather than concentrating on the commercialization of new products.
Thin and small form factor cells: Simulated behavior

Thin and small form factor cells have been researched lately by several research groups around the world due to possible lower assembly costs and reduced material consumption with higher efficiencies. Given the popularity of these devices, it is important to have detailed information about the behavior of these devices. Simulation of fabrication processes and device performance reveals some of the advantages and behavior of solar cells that are thin and small. Three main effects were studied: the effect of surface recombination on the optimum thickness, efficiency, and current density, the effect of contact distance on the efficiency for thin cells, and lastly the effect of surface recombination on the grams per Watt-peak. Results show that high efficiency can be obtained in thin devices if they are well-passivated and the distance between contacts is short. Furthermore, the ratio of grams per Watt-peak is greatly reduced as the device is thinned.
Children Exposed to Community Violence or War/Terrorism: Current Status and Research Directions—Introduction

This issue of Clinical Child and Family Psychology Review, “Children Exposed to Community Violence or War/Terrorism: Current Status and Research Directions,” addresses the current status of our knowledge as well as critical research needs in the area of children exposed to violence outside the family. Although much has been learned in recent years about children exposed to violence, significant research gaps remain, the identification of which may help to build a more complete and rigorous science base in this area. This journal issue represents the distillation of a 3-day workshop on children exposed to violence, held in July of 2002, that identified what is known about children exposed to violence and what this information tells us about future research directions. Although many federal agencies have supported some research in this area, there is a need for more targeted attention on the topic, particularly with regard to measurement, sampling, and interventions/services. The papers in this issue were selected with these themes in mind. Although no single issue could cover the entire field, we intend to offer a representative sample of where we are and where we need to go with the hope of stimulating additional thought, collaboration, and research in this important area.
A cross-species analysis of carnivore, primate, and hominid behaviour

Abstract The traditional assumption that the origin of human behavior is found within the higher primates rather than the social carnivores is based on failure to adequately define primate and carnivore behavior. Phyletic classification takes no account of convergence and divergence; the behavior of a species is not necessarily characteristic of its order. Of 8 behavior variables that distinguish the order primates from the order carnivora, preagricultural man resembles the carnivores on 7 items: food sharing, food storing, cannibalism, surplus killing, interspecies intolerance, feeding of young, and division of labor; resembling the order primates only in group defense. The original form of much human behavior is found within the carnivores.
Improvement in rail-wheel adhesion by spark-discharge

Abstract Although the elimination of rail-wheel contaminants by an electrical discharge method is not a new concept, there is evidence that it provides the most consistent and satisfactory improvement in adhesion and tractive capability. A brief outline is given of research conducted at Battelle-Geneva over the last ten years on the spark method of increasing adhesion between a locomotive wheel and rail. The results of laboratory and field tests carried out in France, Switzerland and England show a remarkable agreement and consistent improvement in the adhesion values obtained for a variety of contaminants. An important feature is the memory capability of sparked rail sections, which, it is hoped, may lead to improved adhesion values by routine sparking. The speed of testing for all experiments conducted so far has been confined to the range 0–5 km/h, where power requirements are minimal. Further development of the method of spark-cleaning at much higher test velocities is necessary so that it may be available for practical railway application.
Aerodynamic interference for supersonic low-aspect-ratio missiles

and K for low-aspect-ratio, cruciform wingbodies with clipped delta fins for Mach numbers from 3 to 4 and angles of attack up to 20 deg. The ratios of fin span to body radius (S/R) range from 1.3 to 2, so that aspect ratios vary from 0.05 to 4 and taper ratios vary from 0 to 0.975. Euler results compare well with experimental data. At low angle of attack KW(B) is of the order of 1.5 for low-aspect-ratio fins. KW(B) decreases as the angle of attack increases and can be less than 1 at large angles of attack. Shock and expansion waves from the fin interact with the body and strongly influence ##(w> The afterbody length beyond the fin trailing edge also contributes to KB(W)* As the aspect ratio decreases from 4 to 0.05, KB(\Y) increases to a maximum value and then 1) decreases for small angles of attack and 2) remains fairly constant for large angles of attack. K^ is calculated for sideslip angles of ±3 deg. Euler predictions of K are larger than slender-body predictions, because of vortex effects. K^ is also influenced by shock and expansion waves from adjacent fins. At small angles of attack K^ is larger for negative sideslip than it is for positive sideslip. At large angles of attack K^ becomes independent of the sign of sideslip angle.
A fuzzy-algorithmic approach to the definition of complex or imprecise concepts

It may be argued, rather persuasively, that most of the concepts encountered in various domains of human knowledge are, in reality, much too complex to admit of simple or precise definition. This is true, for example, of the concepts of recession and utility in economics; schizophrenia and arthritis in medicine; stability and adaptivity in system theory; sparseness and stiffness in numerical analysis; grammaticality and meaning in linguistics; performance measurement and correctness in computer science; truth and causality in philosophy; intelligence and creativity in psychology; and obscenity and insanity in law.
An enhanced vegetation index time series for the Amazon based on combined gap-filling approaches and quality datasets

Vegetation indices from MODIS data are subject to residual atmospheric noise, affecting processes requiring data continuity and analyses. This work reconstructed a time series of MODIS EVI mosaics for the Amazon using a novel combination of curve-fitting and spatiotemporal gap-filling. TIMESAT was used for initial curve fitting and gap filling, using a Double Logistic method and MODIS Usefulness values as weights. Pixels with large temporal gaps were handled by a spatiotemporal gap filling approach. The method scans Julian Days before and after the image being gap filled, searching for a good quality pixel (Pg) at the location of the pixel to be replaced. If Pg is found, a window is defined around it and a search for good quality pixels (Px) with spectral characteristics similar to Pg is performed. Window size increases during processing and pixel similarity uses Euclidean distance based on MOD13A2 reflectances. A good quality EVI value for the image being gap filled and at the location analogous to the minimum distance Px replaces the low quality pixel. Results from the spatiotemporal gap filling were then used in TIMESAT for smoothing. An evaluation strategy of the spatiotemporal approach involved flagging 5,000 randomly selected good-quality pixels as low-quality, running the algorithm and regressing the results with the original EVI values (R 2 = 0.62). The combined strategy was able to find replacement pixels and reduce spikes for images with high cloud cover and was used to rebuild a time series of EVI over the Amazon region for the period 2000-2010.
Democracy, Confusion, or Chaos: Political Conditionality in Kenya

We argue that the policy of conditioning all economic development aid on a process of democratization is a mistake. Good economic policy should be rewarded for its own sake. The process of democratization is costly to participants, and forcing it prematurely can lead to institutional collapse rather than development. Unclear definition of political conditionality has made donor policies inconsistent and capricious. We make these arguments conceptually and then review the experience of one of the most explicit cases of conditionality-induced “democratization”—Kenya. An aid cutoff stimulated the government to hold multiparty elections for the first time in many years. Despite the apparent success, the human and economic costs have been high, and the political changes less than donors hoped.