cssi/SciSciGPT-SciSciNet huggingface dataset:
SU‐E‐T‐381: Evaluation of Calculated Dose Accuracy for Organs‐At‐Risk Located at Out‐Of‐Field in a Commercial Treatment Planning System for High Energy Photon Beams Produced From TrueBeam Accelerators

Purpose: Dose calculation accuracy for the out-of-field dose is important for predicting the dose to the organs-at-risk when they are located outside primary beams. The investigations on evaluating the calculation accuracy of treatment planning systems (TPS) on out-of-field dose in existing publications have focused on low energy (6MV) photon. This study evaluates out-of-field dose calculation accuracy of AAA algorithm for 15MV high energy photon beams. Methods: We used the EGSnrc Monte Carlo (MC) codes to evaluate the AAA algorithm in Varian Eclipse TPS (v.11). The incident beams start with validated Varian phase-space sources for a TrueBeam linac equipped with Millennium 120 MLC. Dose comparisons between using AAA and MC for CT based realistic patient treatment plans using VMAT techniques for prostate and lung were performed and uncertainties of organ dose predicted by AAA at out-of-field location were evaluated. Results: The results show that AAA calculations under-estimate doses at the dose level of 1% (or less) of prescribed dose for CT based patient treatment plans using VMAT techniques. In regions where dose is only 1% of prescribed dose, although AAA under-estimates the out-of-field dose by 30% relative to the local dose, it is only about 0.3% of prescribed dose. For example, the uncertainties of calculated organ dose to liver or kidney that is located out-of-field is <0.3% of prescribed dose. Conclusion: For 15MV high energy photon beams, very good agreements (<1%) in calculating dose distributions were obtained between AAA and MC. The uncertainty of out-of-field dose calculations predicted by the AAA algorithm for realistic patient VMAT plans is <0.3% of prescribed dose in regions where the dose relative to the prescribed dose is <1%, although the uncertainties can be much larger relative to local doses. For organs-at-risk located at out-of-field, the error of dose predicted by Eclipse using AAA is negligible. This work was conducted in part using the resources of Varian research grant VUMC40590-R.
Reinforcement Learning for Call Admission Control and Routing under Quality of Service Constraints in Multimedia Networks

In this paper, we solve the call admission control and routing problem in multimedia networks via reinforcement learning (RL). The problem requires that network revenue be maximized while simultaneously meeting quality of service constraints that forbid entry into certain states and use of certain actions. The problem can be formulated as a constrained semi-Markov decision process. We show that RL provides a solution to this problem and is able to earn significantly higher revenues than alternative heuristics.
Anomalous epr lineshapes for AsO4 4 center in NH4H2PO4-RbH2PO4 glasses: Strain VS dynamic effects

Abstract The temperature dependence of lineshapes of EPR signals of AsO4 4 center has been utilized as a probe of the slow dynamics of (NH4H2PO4)x-(RbH2PO4)1–x proton glass system over the whole composition range x. The EPR signals exhibit anomalous line-broadening as a function of x as well as temperature. A theoretical procedure was developed based on the formalism of modified Bloch equations, that enabled us to evaluate the broadening effect of motional dynamics, and, consequently, lattice strain. A comparison of the experimental and theoretical lineshapes revealed that strain broadening, and not exchange effects, makes a dominant contribution to the broadening of EPR signals in the proton glass.
Chapter 9 Conventionality of Simultaneity and Reality

Abstract An important epistemological lesson can be learned from the impossibility to determine the one-way velocity of light and the immediate implication that simultaneity is conventional. The vicious circle—to determine whether two distant events are simultaneous we need to know the one-way velocity of light between them, but to determine the one-way velocity of light we need to know that the two events are simultaneous—is an indication of the need for a profound change of our view on reality.
Methanol effects on the O2 reduction reaction

The present most advanced technology for direct methanol fuel cell systems is based on proton exchange membrane technology. The membrane/electrode assembly is normally comprised of a sulfonated perfluorinated hydrocarbon membrane that acts as both the electrolyte and mechanical support for the anode and cathode electrodes. The cathode is usually fabricated using Pt black or Pt supported on carbon as the electrocatalyst. The operating temperature is usually well below 100 °C, to minimize vaporization of fuel and water. While this construction offers many advantages, including an invariant, immobile high conductivity electrolyte and very compact cells and cell stacks, it presents disadvantages relating to high permeability of methanol through present available membranes. Methanol permeating through the membrane is usually reported as completely oxidized at the Pt-based cathode. Permeation of methanol occurs by a combination of thermal diffusion and osmosis and can be equivalent to upwards of 100 mA cm−2 of methanol oxidation current. From the practical point of view, methanol permeation is objectionable because it both wastes fuel and depresses the cathode potential. At the oxygen/air cathode, oxygen reduction and methanol oxidation occur simultaneously. For a simple “mixed potential” effect, the two partial currents would have the same magnitude at any potential as they would if fed to the electrode separately. That is, the cathodic overvoltage would increase to an extent corresponding to an increase in current density corresponding to the partial methanol oxidation current. In the actual practical situation, there is an additional increase in overvoltage of ∼50 mV that appears to correspond to poisoning of the electrocatalyst by methanol adsorbate. There are a number of approaches that have been pursued to reduce the “methanol effect”. Using dilute fuel and operating a fuel cell at high anodic current densities (causing some concentration polarization) can greatly reduce permeation, but with an increase in system complexity. A number of new or composite ion membranes have been explored. So far, reduced permeation has also been accompanied by lower conductivity, poorer mechanical strength or higher electrode polarization. Perhaps the most promising approach involves the development of methanol tolerant electrocatalysts, that are based on porphyrins, chevrel-phase compounds and other transition metal chalcogenides, some of which appear to approach the catalytic efficiency of Pt. Establishment of long-term chemical/electrochemical stability of such materials could provide the best solution to the problem of “methanol effects”. Keywords: adsorption; anions; current-potential characteristics; electrocatalysis; fuel cells; ions; methanol fuel cells; oxygen electrode; proton exchange membrane fuel cells; electrocatalysts
Use of a fuzzy gain tuner for improved control of a DC motor system with nonlinearities

Research in control systems has established the potential effectiveness of control techniques utilizing elements of artificial intelligence such as fuzzy logic. The majority of control systems which incorporate heuristic reasoning use fuzzy logic controllers to map sets of error information or system state histories to appropriate control outputs. In this paper, the authors show how a fuzzy gain tuner (FGT) consisting of a sparse set of fuzzy rules can be incorporated into a DC motor control system to improve system response. The general approach, analysis and experimental results obtained from an actual DC motor system under PI control are presented and the effectiveness of the FGT control technique is discussed. The smoothness of response, response times and disturbance rejection of the PI control system with and without the proposed FGT are analyzed. >
Crossover interactions among niches

Niching methods in genetic algorithms (GAs) strive to locate and maintain stable subpopulations or niches, within a single population. This paper explores the distribution of population elements among niches arising under deterministic crowding. Crossover interactions among niches are observed, isolated, and explained. Ideal behavior is compared with actual behavior on a variety of multimodal optimization problems, including a multimodal deceptive problem. >
ESTIMATION OF SAMPLE SIZES IN CASE-CONTROL STUDIES WITH MULTIPLE CONTROLS PER CASE: DICHOTOMOUS DATA

In planning case-control studies with matched sets, the calculation of exact sample sizes is difficult, because this calculation depends on some nuisance parameters that are usually unknown in practice. Using the Pitman efficiency of Miettinen's test relative to McNemar's test, Schlesselman and Stolley (Case-control studies: design, conduct, analysis. Oxford: Oxford University Press, 1982:144-70) derived an approximate sample size formula which requires the assumption that the difference in exposure rates between cases and controls is small. Furthermore, on the basis of an assumption similar to that used in Schlesselman and Stolley's approach, Taylor (Stat Med 1986;5:29-36) proposed another approximation formula. In this paper, an alternative and explicit formula that does not require the exposure difference to be small between case and control groups has been derived. Monte Carlo studies are given for comparing the accuracy of these three procedures. The results indicate that when odds ratios of exposure between cases and controls are small (less than or equal to 4) and there is more than one matched control per case, the formula derived in this paper seems to be the best. When odds ratios are large (greater than or equal to 5), however, Taylor's more conservative estimate is recommended, unless the exposure prevalence in the general population is large (0.9).
Effects of Acute Intravenous Iloprost on Right Ventricular Hemodynamics in Rats with Chronic Pulmonary Hypertension

AbstractThe inotropic effects of prostacyclins in chronic pulmonary arterial hypertension (PAH) are unclear and may be important in directing patient management in the acute setting. We sought to study the effects of an acute intravenous (IV) infusion of iloprost on right ventricular (RV) contractility in a rat model of chronic PAH. Rats were treated with monocrotaline, 60 mg/kg intraperitoneally, to induce PAH. Six weeks later, baseline hemodynamic assessment was performed with pressure-volume and Doppler flow measurements. In one group of animals, measurements were repeated 10–15 minutes after IV infusion of a fixed dose of iloprost (20 μg/kg). A separate group of rats underwent dose-response assessment. RV contractility and RV–pulmonary artery coupling were assessed by the end-systolic pressure-volume relationship (ESPVR) and end-systolic elastance/effective arterial elastance (Ees/Ea). RV cardiomyocytes were isolated, and intracellular cAMP (cyclic adenosine monophosphate) concentration was measured w...
A chaotic encryption scheme for real-time embedded systems: design and implementation

Chaotic encryption schemes are believed to provide greater level of security than conventional ciphers. In this paper, a chaotic stream cipher is first constructed and then its hardware implementation details over Xilinx Virtex-6 FPGA are provided. Logistic map is the simplest chaotic system and has high potential to be used to design a stream cipher for real-time embedded systems. Its simple construct and non-linear dynamics makes it a common choice for such applications. In this paper, we present a Modified Logistic Map (MLM) which improves the performance of Logistic Map in terms of higher Lyapunov exponent and uniformity of bifurcation map. It also avoids the stable orbits of logistic map giving a more chaotic behavior to the system. A stream cipher is built using MLM and random feedback scheme. The proposed cipher gives 16 bits of encrypted data per clock cycle. The hardware implementation results over Xilinx Virtex-6 FPGA give a synthesis clock frequency of 93 MHz and a throughput of 1.5 Gbps while using 16 hardware multipliers. This makes the cipher suitable for embedded devices which have tight constraints on power consumption, hardware resources and real-time parameters.
Pseudo-Underage Students' Access to Alcohol Surrounding Three College Campuses

The objective of this study was to determine underage college students' ability to purchase alcohol in their immediate campus environment. Approximately 25% of off-site (e.g., liquor stores) and on-site (e.g., bars) outlets surrounding 3 college campuses were selected for this study. At each campus, one male and one female auditor, age 21 or 22 years, conducted alcohol access audits (audits) by attempting to purchase alcohol without identification. Audits resulted in the purchase of alcohol without identification at 2 to 15 off-site outlets (5%–13.9%) and 0 to 19 of on-site outlets (0%–21.6%), with no significant differences among campuses (P = .36 and P = .16), respectively. This is the first report of alcohol access in the college environment. The rate of successful purchase was lower than previously reported for other environments (range 26%–73%).
Amino-acid uptake compared in motor neurons, spinal cord grey matter, muscle and liver.

Abstract White male rats were injected intravenously with either [ 3 H]lysine, [ 3 H]tyrosine or [ 14 C]glutamine. Uptake of labeled materials into ventral horn motor neurons dissected from the spinal cord grey matter, the spinal cord grey matter as a whole, liver and muscle was determined by liquid scintillation counting methods and the nature of the radioactive material present in the tissues was determined by ascending paper chromatography. The percentage of the injected dose of labeled material present per gram of dry tissue was always found to be highest in the ventral horn motor neurons. Muscle and spinal cord grey matter uptakes were much lower than liver, with muscle uptake being higher in lysine- and glutamine-injected rats and lower when tyrosine was the injected amino-acid. In all instances, some of the injected amino-acid was detected in the neural tissue by ascending paper chromatography. Following lysine injection, only lysine was present, while after glutamine and tyrosine, the various metabolites of these amino-acids were also detected. The high uptake in motor neurons relative to the low uptake in an area of spinal cord grey matter comparable to that from which such neurons were dissected is discussed in relation to the ‘blood-brain barrier’. This comparison indicates the importance of comparing amino-acid uptakes between cell types rather than between organs of heterogenous structure.
A peptide-linkage deletion procedure for estimate of energetic contributions of individual peptide groups in a complex environment: Application to parallel β-Sheets

A peptide-linkage deletion procedure is introduced for extracting the quantum mechanical (QM) interaction energies of individual groups in a complex environment and applied for the determination of the energetic contributions of the individual hydrogen bond acceptors (C=O’s) and donors (N-H’s) in parallel β-sheets. For the β-sheets studied here, the results show that the contributions from the H-bond acceptors (C=O) can be significantly greater than the contributions from the donors (N-H). It is suggested that this imbalance may be induced, at least in part, by the inter-strand Cα-H⋯O=C interactions which may play an important role in stabilizing β-sheets. The results demonstrate the usefulness of the approach proposed in this paper to study interactions in complex protein environments.
Pollen tube growth and guidance is regulated by POP2, an Arabidopsis gene that controls GABA levels.

Abstract During angiosperm reproduction, pollen grains form a tube that navigates through female tissues to the micropyle, delivering sperm to the egg; the signals that mediate this process are poorly understood. Here, we describe a role for γ-amino butyric acid (GABA) in pollen tube growth and guidance. In vitro, GABA stimulates pollen tube growth, although vast excesses are inhibitory. The Arabidopsis POP2 gene encodes a transaminase that degrades GABA and contributes to the formation of a gradient leading up to the micropyle. pop2 flowers accumulate GABA, and the growth of many pop2 pollen tubes is arrested, consistent with their in vitro GABA hypersensitivity. Some pop2 tubes continue to grow toward ovules, yet they are misguided, presumably because they target ectopic GABA on the ovule surface. Interestingly, wild-type tubes exhibit normal growth and guidance in pop2 pistils, perhaps by degrading excess GABA and sharpening the gradient leading to the micropyle.
Pentium PC-based craniofacial 3D imaging and analysis system

PC-based computing is now ubiquitous in common consumer applications. Although PCs have equalled or surpassed engineering workstations in basic computing power and economy, there is still strong workstation dependency for imaging applications. In this paper, we demonstrate that a complete system, based on a Pentium PC and readily available inexpensive software, can be built very economically for effective execution of most of the commonly used 3D imaging operations. For the craniofacial application, the Pentium system offers a twofold speed advantage over a Sparc 20 system, allowing interactive fuzzy volume rendering of complex hard and soft tissue structures.
NMR reaction monitoring during the development of an active pharmaceutical ingredient

We show the use of NMR spectroscopy to develop detailed understanding of a reaction mechanism during development of a manufacturing process for an active pharmaceutical ingredient (API). This includes structural elucidation of reaction starting materials, intermediates and products. The method is able to generate an immediate mass balance through quantitative profiling of all materials involved in the reaction. A straightforward reaction monitoring methodology was employed using existing laboratory based equipment.
Objective and subjective outcomes in surgery for chronic sinusitis.

Endoscopic and radiological findings in patients with chronic sinusitis do not always correlate with symptoms. Studies suggest that postoperative endoscopic examination of the sinonasal cavity provides prognostic information regarding the potential for future episodes of sinusitis and the need for revision surgery. It is recommended that findings on nasal endoscopy be included in future outcomes studies on sinusitis.
Silvertop of Bluegrass and Bentgrass Produced by Anaphothrips obscurus

Anaphothrips obscurus (Muller) produced a distinct type of silvertop in bluegrass and bentgrass by feeding on the developing inflorescence while the grass was in the hoot stage. Thrips failed to produce the withered inner stem above the terminal node that is characteristic of silverlop produced by plant bugs. Thrips were frequently associated with silvertop produced by plant bugs but were considered secondary invaders of injured culms. About 16% of the seed was destroyed by the silvertop that resulted from the feeding of thrips in a field of ‘Emerald’ bentgrass.
Depreciation Patterns for Agricultural Machinery

A flexible functional form model is used to estimate remaining-value equations for eleven major types of farm machinery. Data used in estimation were obtained from ten years of machinery auctions. Remaining values were found to be influenced by machinery condition, use, manufacturer, and age. Macroeconomic variables were significant explanatory variables for most types of machinery. Estimated depreciation patterns varied by machinery type, demonstrating the need for updated machinery-specific remaining-value equations. Reduced-form equations are presented for use in applied economic analysis.
Patterns of Heroin, Cocaine and Speedball Injection Among Bronx (Usa) Methadone Maintenance Patients: 1978-1988

(1996). Patterns of Heroin, Cocaine and Speedball Injection Among Bronx (Usa) Methadone Maintenance Patients: 1978-1988. Addiction Research: Vol. 3, No. 4, pp. 323-340.
Latino Immigrant Acculturation and Crime

Recent debate on the future of immigration policy in the United States has spawned much discussion on social costs and consequences for immigrants, such as employment, education, health care, and most notably, crime. Although recent Latino immigrants are often portrayed as outsiders in popular media, their successful accul- turation into the American way of life may present more crime-related risk rather than less. This study examines arrest records for Latinos in two southwestern American cities to determine the extent to which Latino acculturation is related to arrests and convictions for both misdemeanors and felonies after controlling for certain legal and extra-legal factors. Results indicate that acculturation is consistently and positively associated with all four crime-related outcomes in this sample. Implications for policy and future research are discussed.
Molecular characterization of mutations of nit-4, the pathway-specific regulatory gene which controls nitrate assimilation in Neurospora crassa.

Summary The nit-4 genes of three conventional Neurospora crassa mutations and of the closely related species, Neurospora intermedia, have been isolated by amplifying the genomic DNA with the polymerase chain reaction. Nucleotide sequencing has revealed that the three nit-4 mutants, alleles 15,1214, and 2994, are the result of a missense mutation, a nonsense mutation and a frameshift mutation, respectively. The nucleotide sequence of the NIT4 protein coding region of a nit-4 mutant (allele 2994) and of N. intermedia have been determined and compared with that of wild-type N. crassa. The molecular characteristics confirm that the mutated gene of 2994 originated from N. intermedia and was introgressed into N. crassa. The polyglutamine domains of the N. crassa wild type, the 2994 mutant, or N. intermedia cannot replace an upstream glutamine-rich domain which is essential for nit-4 function.
Actin Polymerization Serves as a Membrane Domain Switch in Model Lipid Bilayers

The ability of cells to mount localized responses to external or internal stimuli is critically dependent on organization of lipids and proteins in the plasma membrane. Involvement of the actin cytoskeleton in membrane organization has been documented, but an active role for actin networks that directly links internal organization of the cytoskeleton with membrane organization has not yet been identified. Here we show that branched actin networks formed on model lipid membranes enriched with the lipid second messenger PIP2 trigger both temporal and spatial rearrangement of membrane components. Using giant unilamellar vesicles able to separate into two coexisting liquid phases, we demonstrate that polymerization of dendritic actin networks on the membrane induces phase separation of initially homogenous vesicles. This switch-like behavior depends only on the PIP2-N-WASP link between the membrane and actin network, and we find that the presence of a preexisting actin network spatially biases the location of phase separation. These results show that dynamic, membrane-bound actin networks alone can control when and where membrane domains form and may actively contribute to membrane organization during cell signaling.
Comparing Nutrient Availability in Low-Fertility Soils using Ion Exchange Resin Capsules

Assessing the nutrient status of low-input, low-fertility desert soils poses some unique challenges. Commonly used soil analysis procedures and resin capsules generally assess nutrient status of fertile agricultural soils. Ion-exchange resin capsules (Unibest Company, Bozeman, Mont.) provide a viable alternative. A study was conducted to determine effectiveness of resin capsules to extract low levels of nutrients applied to native soils. Loamy sand and sandy clay loam desert soils from Utah were treated with combinations of four rates of nitrogen (N) as ammonium nitrate (34–0–0), three rates of phosphorus (P) as phosphoric acid (0–72–0), and two rates of iron sulfate (FeSO4·7H2O) and zinc sulfate (ZnSO4·7H2O) (include an untreated control). Each soil treatment was implanted with a resin capsule placed into either 250 or 1000 cm3 of soil after addition of water equivalent to 50% field capacity and incubated for either 60 or 120 days at 25 °C. After the appropriate incubation time, capsules were washed and ...
In vitro recording of raphe unit activity: evidence for endogenous rhythms in presumed serotonergic neurons.

Abstract The spontaneous activity of single neurons in the nucleus raphe dorsalis was recorded in vitro in mouse brain slices. The neurons displayed the slow and regular discharge pattern characteristics of raphe neurons recorded in vivo . When magnesium ion was added to increase the medium concentration to 20–30 mM for the purpose of inhibiting all synaptic transmission, raphe neurons continued to display the same discharge pattern and rate. The data suggest that the steady rhythmic firing of nucleus raphe dorsalis neurons is generated by an intracellular pacemaker mechanism.
Thinking about one's gender group's privileges or disadvantages: Consequences for well‐being in women and men

Thoughts about group-based privileges or disadvantages were expected to have different consequences for personal and group well-being, depending on whether the individual is a member of a high- or low-status group. To test this hypothesis, women and men were randomly assigned to consider the ways that their gender group membership has resulted in either beneficial or detrimental outcomes in their lives. For men, thinking about their gender group's privileges resulted in lower scores on the group-related well-being measures compared to women, and thinking about their group's disadvantages resulted in higher personal self-esteem scores in men compared to women. It is suggested that among high-status group members, thinking about privilege can evoke guilt and taint one's group image, whereas thinking about disadvantage can augment personal internal attributions for the positive outcomes received. Discussion focuses on the implications that the operation of two types of mechanisms—group-based emotions and the undermining or augmenting of attributions—has for the responses of high- and low-status group members when their groups are portrayed as exerting either negative or positive effects on their lives.
Laparoscopic Partial Nephrectomy: Contemporary Technique and Outcomes

Abstract Objectives Laparoscopic partial nephrectomy has emerged as a viable alternative to open partial nephrectomy while minimizing patient morbidity. In this article and accompanying video we describe our current technique of LPN and review our outcomes in specific patient sub-sets. Methods Since September 1999 more than 500 laparoscopic partial nephrectomies have been performed by the senior author. Data were collected prospectively. All patients underwent a three-dimensional CT scan prior to the operation. Our established technique involves preoperative ureteral catheterization, laparoscopic renal ultrasonography to delineate the tumor, en bloc clamping of the renal hilar vascular pedicle, tumor excision with cold endoshears, pelvicaliceal suture repair and parenchymal closure over Surgicel bolsters with biologic hemostatic agent. Renal hypothermia was achieved laparoscopically with ice slush in selected cases with anticipated long warm ischemia time. Results Mean tumor size was 2.9cm (1–10.3cm), 31% of the tumors were greater than 3cm, 5% occurred in a solitary kidney, and tumor location was central in 40% and hilar in 6% of patients. Transperitoneal approach was employed in 65% of the cases. Mean warm ischemia time was 32min. Intraoperative complications occurred in 5.5%. Pathology confirmed renal cell carcinoma in 75% of the tumors. In the initial 100 patients with a 3 years minimum follow-up, overall survival was 86% and cancer-specific survival was 100%. Conclusions Laparoscopic partial nephrectomy is a technically challenging procedure. Adequate prior experience with laparoscopy is necessary. Long-term functional and oncological outcomes are being confirmed currently.
Nonlinear optics in photonic crystal nanocavities: from light sources to quantum photonic interfaces

We demonstrate photonic interfaces between infrared and visible wavelength ranges by employing enhanced nonlinear frequency conversion in photonic crystal cavities in GaP or GaAs. We first show resonantly enhanced second harmonic and sum frequency generation in GaP photonic crystal cavities. We then integrate these nonlinear frequency conversion elements with a single InAs quantum dot to produce a fast single photon source that is optically triggered at telecommunications wavelength. These frequency conversion techniques are critical for applications including light sources at wavelengths that are difficult to access with existing lasers, IR upconversion-based detectors, and photonic quantum interfaces between the fiber-optic networks and quantum emitters.
Alcohol Preference in the Rat: Reduction Following Depletion of Brain Serotonin

Preference for ethyl alcohol was significantly reduced or totally abolished in rats given orally p- chlorophenylalanine, a tryptophan hydroxylase inhibitor that selectively depletes brain serotonin. Some aversion to alcohol was observed while p- chlorophenylalanine was administered, but the rats9 rejection of alcohol was even more marked after the drug was discontinued. Oral administration of α-methyl -p- tyrosine, a tyrosine hydroxylase inhibitor that depletes brain catecholamines, slightly reduced selection of alcohol, but preference returned to normal as soon as α-methyl -p- tyrosine was terminated.
Glycosaminoglycan content of small intestinal submucosa: a bioscaffold for tissue replacement.

Small intestinal submucosa (SIS) is a resorbable biomaterial that induces tissue remodeling when used as a xenogeneic tissue graft in animal models of vascular, urologic, dermatologic, neurologic, and orthopedic injury. Determination of the composition and structure of naturally occurring biomaterials such as SIS that promote tissue remodeling is necessary for the greater understanding of their role in wound healing. Since glycosaminoglycans (GAGs) are important components of extracellular matrix (ECM) and SIS is primarily an ECM-based material, studies were performed to identify the species of glycosaminoglycans present in SIS. Porcine SIS was chemically extracted and the extracts were analyzed for uronic acid. The extractable uronic acid content was determined to be 47.7 µmol/g (approximately 21 µg GAG/mg) of the dry weight of the SIS tissue. Using electrophoretic separation of GAGs on cellulose acetate membranes, hyaluronic acid, heparin, heparan sulfate, chondroitin sulfate A, and dermatan sulfate wer...
CARDIOVASCULAR PERFORMANCE IN SICKLE CELL DISEASE

Cardiopulmonary studies including clinical evaluation, ECG, echo, nuclear imaging, and exercise responses were performed on 156 patients (mean age 21 years, range 5 to 60) with homozygous sickle cell (SS) disease (mean hemoglobin 8.2±1.2 gm/dl). LVH by ECG criteria was present in 45% but in only 25% by echo measurements. LV dilatation was also noted in 20% (echo). Left atrial enlargement by ECG criteria was evident in 5% but left atrial dilatation by echo was noted in 26%. With graded bicycle exercise (n=110) only 40% reached 50% of predicted maximal work load (Wmax) with no patients reaching Wmax. The level of work completed was inversely related to age with 54% of the patients under 20 years of age achieving 50% of Wmax while no patients over 40 years of age were able to reach this level of work. Maximal levels of VO2 achieved were decreased at 19.5±7.9 ml/kg/min while the respiratory quotient was greater than 1 at less than 50% of Wmax in all patients exercised. An ischemic response (ST depression) to exercise was noted in 39%. Again, this was inversely related to age with only 19% of patients under 20 and 80% of patients over 40 showing ST depression. The left ventricular ejection fraction response to exercise was abnormal in 25%. In patients under 20 years of age the abnormal response was present in only 4% and in patients over 40 this was present in 40%. All patients with SS disease thus evidenced decreased exercise performance primarily on the basis of decreased O2 carrying capacity. This may be associated with decreased pump function and myocardial ischemia in some patients.
Morphine stimulates nitric oxide release from invertebrate microglia.

Abstract Morphine stimulates nitric oxide (NO) release in human endothelial cells. To determine whether this mechanism also occurs in invertebrates, the mussel Mytilus edulis was studied. Exposure of excised ganglia to morphine for 24 h resulted in a significant dose-dependent decrease in rnicroglial egress that was naloxone sensitive. In coincubating the excised ganglia with morphine and the nitric oxide synthase inhibitor, N omega-nitro- l -arginine methyl ester ( l -NAME), an increase in microglial egress was observed, suggesting that morphine may stimulate microglia to release NO. Morphine exposure to these cells in vitro resulted in NO release (39.4 ± 4.9 nM), a phenomenon found to be naloxone sensitive (10 −6 M; NO level = 5.9 ± 2.6 nM) and l -NAME sensitive (10 −4 M; NO level = 2.8 ± 1.8 nM). Opioid peptides did not stimulate NO release, indicating that the process was mediated by the opiate alkaloid selective μ 3 receptor. Coincubation of microglia with l -arginine or the superoxide scavenger, superoxide dismutase, resulted in significantly higher NO levels observed following morphine stimulation. Taken together, the data demonstrate that morphine can stimulate NO release in cells obtained from an invertebrate that represents an animal 500 million years divergent in evolution from man, underscoring the significance of this process and further substantiating the critical importance of morphine as a naturally occurring signal molecule.
Psychoanalytic education in the united states

Editor's Note. This article is a review oJ a book, Psychoanalytic Education in the United States by Bertram D. Lewr and Helen Ross ( N e w York: IV. W. Norton & Company, Inc., 1960, 478 pp., $10.00). In February we published an editorial by Sexvard Hiltner on "The Cost of Keeping Up," a statemerit analyzing the expenditures of the average psychologist for the indispensable professional journals of his profession. In this article Dr. Hiltner continues with a discussion of wha t it "takes" to become a psychoanalyst. In view of the many erroneous notions held by some people, among them ministers, on this subject, we believe that both of these statements by Dr. Hilther serve an important purpose.
Exposed High-Voltage Source Effect on the Potential of an Ionospheric Satellite

A pulsed, high-voltage source, which is able to draw a current from the surrounding plasma, is seen to induce large changes in the potential of an ionospheric satellite (the Iowa Plasma Diagnostics Package flown on Space Shuttle flight STS-51F). This, in turn, may affect the operation of other instruments that use the chassis of the satellite as a ground for electrical circuits. The magnitude of the change in satellite potential is dependent upon both the orientation of the high-voltage source, relative to the plasma flow, and the characteristics of the high-voltage source. When the satellite is grounded to the Shuttle Orbiter, this effect is sufficient to change the potential of the Orbiter by a small, but noticeable, amount.
An Integrated Electrically Driven Coherent Source of Surface Plasmon Polaritons

We demonstrate a versatile electrically-driven source of coherent SPPs by end-coupling a quantum-well laser to an integrated plasmonic waveguide with coupling efficiency of ?36%. The SPP peak power generated at room temperature is 36 mW.
Is timing to delivery of treatment a reliable measure of quality of care for patients with colorectal adenocarcinoma

Background Among patients with colorectal adenocarcinoma, patient race has been associated with differences in colorectal cancer survival. Survival disparities between ethnic groups may be related to treatment delays, treating hospital, or other patient factors. We hypothesized that prolonged interval to delivery of cancer therapy negatively impacts survival. Study Design We designed a retrospective cohort study using tumor registry and clinical database information from two academically affiliated hospitals. We examined factors associated with interval to treatment and associations between interval and overall survival. Results Among 592 patients treated by a cohort of physicians, we found no differences in cancer stage related to race or treating hospital. Interval to treatment differed between different hospitals (29 vs 16 days; P Conclusion Differences exist related to the timing of definitive care for patients in this series; however, these differences do not translate directly into differences in overall survival. We must deliver quality health care in an efficient and timely manner; however, the metric of interval to treatment may not measure reliably the quality of care received.
3D range image resampling using B-spline surface fitting

Many optical range sensors use an Equal Angle Increment (EAI) sampling. This type of sensors uses rotating mirrors with constant angular velocity for radar and triangulation techniques, where the sensor sends and receives modulated coherent light through the mirror. Such an EAI model generates data for surface geometrical description that has to be converted, in many applications, into data which meet the desired Equal Distance Increment orthographic projection model. For an accurate analysis in 3D images, an interpolation scheme is needed to resample the range data into spatially equally-distance sampling data that emulate the Cartesian orthographic projection model. In this paper, a resampling approach using a B-Spline surface fitting is proposed. The first step is to select a new scale for all X, Y, Z directions based on the 3D Cartesian coordinates of range data obtained from the sensor parameters. The size of the new range image and the new coordinates of each point are then computed. The new range value is obtained using a B-Spline surface fitting based on the new Cartesian coordinates. The experiments show that this resampling approach provides a geometrically accurate solution for many industrial applications which deploy the EAI sampling sensors.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Intersubunit electrostatic complementarity in the RecA nucleoprotein filament regulates nucleotide substrate specificity and conformational activation.

The Escherichia coli RecA protein is the prototypical member of a family of molecular motors that transduces ATP binding and hydrolysis for mechanical function. While many general mechanistic features of RecA action are known, specific structural and functional insights into the molecular basis of RecA activation remain elusive. Toward a more complete understanding of the interdependence between ATP and DNA binding by RecA, we report the characterization of a mutant RecA protein wherein the aspartate residue at position 100 within the ATP binding site is replaced by arginine. Physiologically, D100R RecA was characterized by an inducible, albeit reduced, activation of the SOS response and a diminished ability to promote cellular survival after UV irradiation. Biochemically, the D100R substitution caused a surprisingly modest perturbation of RecA-ATP interactions and an unexpected and significant decrease in the affinity of RecA for ssDNA. Moreover, in vitro assays of RecA activities requiring the coordinated processing of ATP and DNA revealed (1) a 2-5-fold decrease in steady-state turnover of ATP; (2) no formation of mixed nucleoprotein filaments when wild-type and D100R RecA compete for limiting ssDNA; and (3) no formation of strand exchange reaction products. Taken together, these results suggest that the D100R mutational effects on isolated RecA activities combine synergistically to perturb its higher-order functions. We conclude that the replacement of Asp 100 resulted in a change in the electrostatic complementarity between RecA monomers during active filament assembly that prevents the protein from fully accessing the active multimeric state.
Mapping of base sequence heterologies between genomes from different adenovirus serotypes.

Abstract An electron microscopic heteroduplex technique was used to physically map sequence heterologies between genomes from different human adenovirus serotypes. When DNA from serotypes was mixed, denatured, and renatured, characteristic heteroduplex molecules were formed. These molecules, composed of one strand from one serotype and one strand from the other serotype, contained one or more detectable regions of strand separation (or heterology), depending upon denaturing conditions and the combination of type-specific DNA preparations. By increasing denaturing conditions, regions of partial homology could be demonstrated in all interserotypic heteroduplexes. The heterology patterns in heteroduplexes constructed with DNA from nononcogenic serotypes (Ad 1,2, and 5) were relatively simple and nearly similar, whereas both simple and complex patterns were seen in heteroduplexes prepared with DNA from weakly oncogenic serotypes (Ad3,7, and 21). Only complex heterology patterns were found in heteroduplexes prepared with DNA from highly oncogenic serotypes (Ad 12, 18, and 31). As expected, the most extensive heterologies were observed in heteroduplexes prepared with DNA from serotypes belonging to the different serologic groups. Within groups, heteroduplex molecules contained two specific regions in which heterologies were most marked. These regions appeared to map at similar locations among heteroduplexes from all groups. It was found that the integrated SV40 virus DNA in an Ad 7-SV40 hybrid genome was situated in one of these regions.
Diabatic initialization for improvement in the tropical analysis of divergence and moisture using satellite radiometric imagery data

To improve the quality of horizontal divergence and moisture analyses in the tropics, a diabatic initialization scheme is developed to incorporate information on convective activity and the proxy data of precipitation obtained from satellite radiometric imagery data. The tropical precipitation rates are estimated by developing a relationship between the pentad precipitation data of the Global Precipitation Climatology Project with daily outgoing longwave radiation data. The tropical belt from 35°S to 25°N (for January 1988) is divided into 3 parts: convective, convective fringe, and downward-motion (clear-air) areas. In the convective region, the algorithm adjusts the horizontal divergence and humidity fields such that a version of the Kuo cumulus parameterization will yield the precipitation rates closest to the proxy data. The temperature in the planetary boundary layer is also adjusted, if necessary, to ensure the initiation of cumulus convection. In the downward-motion region, the divergence field is adjusted to yield descending motion expected from the thermodynamic balance between radiative cooling and adiabatic warming. In the convective fringe region, where convective criteria are not met, the divergence field is adjusted only to satisfy the global conservation of divergence. The humidity field is left intact in both the downward-motion and convective fringe regions. This adjustment scheme will ameliorate problems associated with spinup of precipitation in a numerical prediction model with the same cumulus parameterization as used in the initialization. This initialization scheme may be used as a method of quality control for first-guess fields in four-dimensional data assimilation by means of satellite radiometric imagery data. DOI: 10.1034/j.1600-0870.1994.t01-2-00002.x
Increasing the conformational entropy of the Ω-loop lid domain in phosphoenolpyruvate carboxykinase impairs catalysis and decreases catalytic fidelity

Many studies have shown that the dynamic motions of individual protein segments can play an important role in enzyme function. Recent structural studies of the gluconeogenic enzyme phosphoenolpyruvate carboxykinase (PEPCK) demonstrate that PEPCK contains a 10-residue Ω-loop domain that acts as an active site lid. On the basis of these structural studies, we have previously proposed a model for the mechanism of PEPCK catalysis in which the conformation of this mobile lid domain is energetically coupled to ligand binding, resulting in the closed conformation of the lid, necessary for correct substrate positioning, becoming more energetically favorable as ligands associate with the enzyme. Here we test this model by introducing a point mutation (A467G) into the center of the Ω-loop lid that is designed to increase the entropic penalty for lid closure. Structural and kinetic characterization of this mutant enzyme demonstrates that the mutation has decreased the favorability of the enzyme adapting the closed l...
Pre-operative imaging with CA125 is a poor predictor for granulosa cell tumors

Abstract Objective To determine the radiographic characteristics of ovarian granulosa cell tumors (GCTs) and to evaluate the use of CA125 levels >35 in combination with imaging as an algorithm for preoperative diagnosis. Methods A retrospective analysis of women from two academic medical centers who were diagnosed with ovarian GCT between January 1998 and August 2012 was conducted. Clinical data included tumor appearance on pre-operative imaging and CA125 levels. Ovarian cysts were defined as complex if imaging exhibited multicystic areas, hemorrhagic, solid, or cystic and solid components. A CA125 level >35 was abnormal. Results One hundred and fifteen women were diagnosed with GCTs, of whom 63 underwent pre-operative imaging. Median age at surgery was 46years (12–87). Forty women had preoperative ultrasounds, 43 had CT scans and 20 underwent both modalities. GCTs were almost exclusively classified as complex cysts in 62 (98%) cases. The most common morphology was solid and cystic (n=44 (70%)). Forty-four (70%) patients had tumors >10cm. Forty-two patients had a pre-operative CA125 performed. Eighteen (43%) patients had complex masses and CA125 >35. Twenty-three (55%) had CA125 35. Conclusions In this study, there was a near equal distribution of patients with complex masses and CA125 levels > or
Pregnancy and inherited metabolic disorders: maternal and fetal complications.

Some inherited metabolic disorders (IMDs) can cause significant complications during pregnancy, affecting the mother and/or the fetus. Although it appears that only a minority of IMDs have these effects, experience is still being acquired. For some disorders, patients will not have reached child-bearing age. Pregnancies in this group of patients will increase as the management of IMDs in childhood and adolescence improves. Clinicians should be aware of potential complications and consider carefully how best to manage these conditions. Ideally, patients should be followed up in adult life by a specialized clinical team, which can implement a planned approach to conception and pregnancy, but often this is not possible. For disorders where the risk of complications is well established (e.g. phenyl-ketonuria), optimal treatment may lead to a good fetal and maternal outcome. It is important also to consider the possibility of an IMD being present in fetuses of pregnancies that are affected by non-immune hydrops, maternal HELLP syndrome (haemolysis, elevated liver enzymes and low platelets) or acute fatty liver of pregnancy.