cssi/SciSciGPT-SciSciNet huggingface dataset:
Influence of Prostate-Specific Antigen Testing on the Spectrum of Patients With Prostate Cancer Undergoing Radical Prostatectomy at a Large Referral Practice

Objective To analyze trends in the clinical stage and pathologic outcome of patients with prostate cancer who underwent radical prostatectomy at a large referral practice during the prostate-specific antigen (PSA) testing era. Material and Methods Between January 1987 and June 1995,5,568 patients with prostate cancer (4,774 with clinically localized disease of stage T2c or less) underwent pelvic lymphadenectomy and radical retropubic prostatectomy at our institution. Patient age, preoperative serum PSA level, clinical stage, pathologic stage, Gleason score, and tumor ploidy were assessed. Outcome was based on clinical and PSA (increases in PSA level of 0.2 ng/ mL or more) progression-free survival. Results Patient age (65 to 63 years old; P Conclusion Since the advent of PSA testing, patients referred to our institution for radical prostatectomy have shown a significant migration to lower-stage, lessnondiploid, more often organ-confined prostate cancer at the time of initial assessment. Cancer-free survival associated with PSA-detected cancer (cTlc) is superior to that with palpable tumors (cT2). Whether these trends translate into improved long-term cancer-specific survival remains to be confirmed with longer follow-up.
Hot from the laboratory

Publishers of newsletters have reacted swiftly to meet the demand for information on developments in high-temperature superconductivity. What have these publications got to offer?
Testing the homogeneity of a set of correlated variances

SUMMARY To test the equality of a set of p variances when the p variates are correlated with common correlation coefficient, four test procedures are proposed in this paper, namely, the asym- ptotic test, the modified Bartlett test, the multiple correlation test and the Flmax test. Comparisons among these four tests were made. A Monte Carlo study showed that, when p = 3, the sample size needed is about 40 in order that the asymptotic theory holds, while for p = 4 it needs about 50. the asymptotic test criterion, which can be shown to be asymptotically equivalent to the likelihood ratio test. A modification of the Bartlett test in large samples is given in ? 3. Section 4 deals with the multiple correlation test. Hartley (1950) considered the maximum F-ratio as a short-cut test for heterogeneity of variance in the independent case. A similar approach in the dependent case is given in ? 5. When p = 2, the four tests are equivalent. When p > 2, the asymptotic test is generally better than others for large samples. The relative efficiency of the modified Bartlett test to the asymptotic test is between 0-88 and 1 when p > 0, but is poor when p < 0. The multiple correlation test is an exact test for any size of sample. Unfortunately its relative efficiency to the asymptotic test is generally low. The Fmax test is worth considering for particular patterns of oj, e.g. one very large, one very small and the rest in the middle. The asymptotic test, the modified Bartlett test and the Fmax test were derived for large samples. A Monte Carlo study is given in ? 6 which showed that when p = 3, the sample size needed is about 40 in order that the asymptotic theory holds, while for p = 4 it needs about 50.
Purification and characterization of recombinant Pneumocystis carinii thymidylate synthase.

Abstract Gatalytically active Pneumocystis carinii thymidylate synthase is expressed to the extent of about 4% of the soluble protein in Escherichia coli χ2913 harboring plasmid pUETS-1.8 (U. Edman, J. C. Edman, B. Lundgren, and D. V. Santi, Proc. Natl. Acad. Sci. USA 86, 6503–6507, 1989). Ion-exchange, affinity, hydrophobic, and reactive dye agarose chromatography steps were explored to devise a large-scale purification protocol for P. carinii thymidylate synthase. Sequential DE52, Q-Sepharose, phenyl-Sepharose, and Cibacron Blue F3GA chromatography yielded enzyme that was homogeneous by SDS-PAGE in a yield of over 50%. The sequence of the first 10 amino acid residues of the purified protein was in accord with that predicted from the DNA sequence. Isoelectric focusing gave a pI of 6.2. Kinetic analysis of the purified enzyme revealed that the the K m values were 4.7 ± 1.3 μM for dUMP and 15.7 ± 4.3 μM for 5,10-methylenetetrahydrofolate, similar to those of many other thymidylate synthases; the κ cat of the most active preparation was 0.8 s −1 . The enzyme is stable for at least 2 months when stored at −80°C in the presence of 40% glycerol, Tris-HCl, and thiol.
The mass spectra of some metal carbonyl complexes of tris(dimethylamino)phosphine

Abstract Mass spectral data for several metal carbonyl complexes of tris(dimethylamino)phosphine have been obtained. These data include fragmentation patterns of the molecules (studied as a function of pressure, temperature and ionizing energy), and ionization and appearance potential measurements. From the latter information the average bond dissociation energies of the metal-carbonyl bond in these complexes were estimated. The results are compared to the semi-quantitative data for these phosphines reported by King. Studies of the fragmentation patterns as a function of energy (clastograms) indicate that several of the fragmentation reactions involve the production of more than one neutral fragment.
Selection on Gamete Recognition Proteins Depends on Sex, Density, and Genotype Frequency

Gamete recognition proteins can evolve at astonishing rates and lie at the heart of reproductive isolation and speciation in diverse taxa. However, the source of selection driving this evolution remains unknown. We report on how the sperm bindin genotype influences reproductive success under natural conditions. An interaction between genotype frequency and spawning density determines how sperm bindin genotype influences reproductive success. Common genotypes are selected under sperm-limited conditions, whereas rare genotypes are selected under conditions of intense sperm competition and sexual conflict. Variation in the evolutionary rates of bindin may reflect historic differences in sperm availability.
The Safety and Efficacy of the Calcium Channel Blocker (CCB) Amlodipine in the Treatment of Secondary Hypertension in Children † 1806

The Safety and Efficacy of the Calcium Channel Blocker (CCB) Amlodipine in the Treatment of Secondary Hypertension in Children † 1806
High signal intensity soft tissue masses on T1 weighted pulsing sequences

On T1 weighted pulsing sequences, the majority of soft tissue masses are of low signal intensity and show high intensity signals on T2 weighting. There however is a subset of soft tissue masses of varied histology that shows high signal intensity on T1 weighted pulsing sequences. These masses have either fat or blood in their substance. Lipomatous and hemangiomatous lesions that did not show high-signal intensity on T1 weighting were also encountered and are discussed. Present experience with MRI of soft tissue masses suggests that there is a limited spectrum of entities that produce high-signal intensity T1 weighted soft tissue masses.
High resistivity Co and Ti silicide formation on silicon-on-insulator substrates

Abstract Under the condition of excess metal deposition, the formation of Co and Ti silicides on (001) silicon-on-insulator (SOI) substrates was investigated. In the Co silicide case, a high-resistivity Co silicide film was formed after a high temperature anneal (100 °C for 30 s). Transmission electron microscopy (TEM) revealed that the phase formed was CoSi. The phenomenon of CoSi being the most stable phase, instead of CoSi2, at high temperatures can be understood from both kinetics and thermodynamics. In the Ti silicide case, the most dominant phase was C49-TiSi2, therefore the film resistance was high even after high temperature annealing (900 °C for 20 s). The film morphology was thermally stable on further annealing and the resistance decreased gradually by means of partial transformation of C49-TiSi2 to the C54-TiSi2 phase. For device applications, high resistance silicide films are not desirable, therefore the metal thickness and consequent silicide thickness have to be controlled precisely.
Solubility of Oxygen in Rubber and Its Effect on Rate of Oxidation

Abstract It is apparent that an artificial aging test must consider the concentration of oxygen existing in the rubber. The concentration of oxygen in rubber suspended in air at 70° C. will be less than that required for normal oxidation at the maximum rate. This should limit the use of an air atmosphere to the highest quality of rubber in which the rate of oxidation is extremely small in comparison with the rate of diffusion of oxygen, and in this case tests should be confined to thin slabs. The solubility of oxygen in rubber suspended in oxygen at 70° C. and atmospheric pressure appears to be slightly greater than that required for uniform oxidation. Under these conditions thin slabs of good or medium-quality rubber should oxidize in a satisfactory manner. The fact that strips 4 mm. square of a rubber extremely sensitive to oxidation, when tested in an oxygen atmosphere at 26° C., produce deviation from a straight line would make doubtful the accuracy of tests conducted on easily oxidized rubber under t...
Ischemically Mediated Sustained Monomorphic Ventricular Tachycardia: Resolution With Anti-ischemic Therapy

We describe a patient with ischemically mediated sustained monomorphic ventricular tachycardia occurring at rest and resistant to treatment with intravenously administered procainamide. Percutaneous transluminal coronary angioplasty was initially successful, but rest angina and ventricular tachycardia, resistant to procainamide therapy, recurred 2 weeks later and responded to aggressive anti-ischemic medical therapy. We suggest that anti-ischemic medication may be of benefit in patients with malignant ventricular arrhythmias precipitated by spontaneous myocardial ischemia.
Immobilization of aptamers onto unmodified glass surfaces for affordable biosensors

Silicon dioxide surfaces are commonly used in photonic microsensors for bioreceptor attachment. Functionalization of sensor surface with aptamer receptors provides the opportunity to develop low cost, robust, field deployable sensors. Most aptamer sensors are constructed by covalently linking modified aptamers to a derivatized surface. There have been reports of using UV crosslinking to directly immobilize DNA with sequences that end with poly(T)10-poly(C)10 on an unmodified glass surface for hybridization. We have expanded this strategy using thrombin-binding aptamers (TBAs) with three different tail modifications. TBA with PolyT20 tail showed the best performance in terms of sensitivity and dynamic range. PolyTC tailed aptamers did not bind thrombin well, which may be due to that the interactions between the C bases and G-quadruplex affect their target binding capability. When compared to biotinylated aptamer immobilized on a streptavidin surface, polyT aptamer printed directly on plain glass showed comparable affinity. Direct immobilization of TBA on nonfunctionalized silicon dioxide wafer and its binding towards thrombin has also been demonstrated. Our results showed that using polyT-tagged aptamer probes directly immobilized on unmodified glass and SiO 2 surface is a robust, very straightforward, and inexpensive method for preparing biosensors.
An Equilibrium Model of Quits under Optimal Contracting

Abstract This article develops an equilibrium model of quits in a labor market and examines the effect of contracting under asymmetric information, when compared with symmetric information and noncontractual base lines. We demonstrate that quits increase in periods of high output, without postulating exogenous price rigidity.
Scotophobin a causes dark avoidance in goldfish by elevating pineal N-acetylserotonin

Abstract We had shown that synthetic rat scotophobin A caused several effects upon goldfish, apparently mediated by the pineal gland. Here we report that norepinephrine decreased goldfish dark avoidance in a manner that was blocked by scotophobin or pinealectomy. Increased dark avoidance was caused by either propranolol or scotophobin alone. Certain components of the pineal melatonin pathway also affected goldfish light-dark preference: serotonin, and especially N-acetylserotonin, increased dark avoidance, as did the hydroxyindole-O-methyl-transferase (HIOMT) product inhibitor, S-adenosyl-homocysteine. Melatonin and S-adenosyl-methionine were without effect in this regard. Pinealectomy prevented the dark avoidance increase caused by serotonin and N-acetylserotonin. These data suggested that increased dark avoidance behavior in goldfish was correlated with N-acetylserotonin buildup in the pineal, and that scotophobin could cause this, if it were to inhibit pineal HIOMT. To test this hypothesis the effect of various agents upon pineal melatonin levels was determined. Scotophobin was found to both reduce pineal melatonin and to block the melatonin-increasing effect of N-acetylserotonin. This led to the discovery that, indeed, scotophobin was an effective inhibitor (K I 50 , 6×10 −7 M) of purified bovine HIOMT.
Resolving the heterogeneity of psychiatric disorders: Clinical and statistical approaches

Abstract Despite some progress, the overwhelming majority of susceptibility genes that likely play an important role in psychiatric disorders remain undiscovered. This may be due to the fact that the etiologies of psychiatric disorders are complex and involve multiple genes of small effect acting independently and interactively. We review promising new strategies that utilize clinical information to facilitate the search for these susceptibility genes. We discuss family studies methods that can be used to assess whether a clinical feature reflects the underlying genetic heterogeneity of psychiatric disorders. We then review approaches for incorporating clinical covariates into linkage and association analyses for gene mapping. Finally, we discuss some considerations for assessing the significance of findings that emerge from the exploration of clinical data. The strategy of using clinical information to resolve the genetic heterogeneity of complex disorders has been successfully used in the past. We believe the wider application of this strategy in the study of psychiatric disorders may yield considerable benefits in the future.
Ten Steps to Create an Innovative Community-Based Pediatric Experience as Part of a Clinical Practicum: A Model

Innovative and alternative learning experiences are needed for students to obtain essential parts of the pediatric nursing clinical experience. This article presents a Ten Step approach guide for nurse educators to develop and implement a community-based pediatric primary health care model in a clinical practicum. The community pediatric primary health care experience is part of the San Jose State University School of Nursing's Nurse Managed Centers. Our approach focuses on providing community-based primary health care by faculty and nursing students to culturally diverse, underserved children and families in community settings in and around the university.
Effect of interfacial shear and entrainment models on flooding predictions

The counter-current annular flow in vertical pipes and its limitation, namely flooding, is important for the operation of Emergency Core Cooling Systems in LWR Nuclear Reactors, as well as in other physical situations. In this paper an analysis has been developed for adiabatic, steady-state, one-dimensional, air-water flow to predict flooding phenomenon. The formulation consists of separated flow analysis of the film and gas-droplet mixture in the pipe. The droplet phase of the pipe core is treated with a drift-flux model. Many correlations for interfacial shear, entrainment inception and rate, available in the literature, have been used in this analysis. Futhermore, recent versions of TRAC-PF1 and RELAP5/MOD1, along with the present analysis, have been applied to model University of Houston counter-current flow tests. The effects of various constitutive relationships have been compared. Some suggestions for model improvement have also been given.
Pteropod abduction as a chemical defence in a pelagic antarctic amphipod

THIS study documents an example of an invertebrate that cannot defend itself chemically (an amphipod) increasing its chances of survival by capturing and carrying a species that can (a pteropod). Although chemical defences are found in a wide variety of marine invertebrates1–4, few studies have established the extent to which these chemicals will deter predators5–7, and even fewer have investigated how one organism might exploit another's chemical defence to protect itself8–10. These chemicals are usually ingested or sequestered in the host's tissue8,9. Several species indiscriminately decorate themselves with potentially toxic organisms or are passively fouled with chemically defended organisms11,12. These seem to be commensalisms or sometimes mutualisms. Our example has benefits and costs for the carrier, but only costs to the captive. The antarctic marine food web not only has a variety of chemically defended organisms13–16, contrary to earlier predictions17–19, but has at least one unusual symbiosis that makes use of noxiousness.
Control of dopant incorporation in InAs/GaAs quantum dots for infrared photodetection with low dark current

To reduce dark current in quantum-dot infrared photodetectors, different InAs/GaAs quantum-dot doping conditions, i.e. concentration and modulation- vs. delta-doping, have been investigated by the comparison of temperature-dependent dark current and corresponding activation energies vs. bias.
University faculty and administrator responses to job strains

This study reports the relationships between job strain and several quality of life (QOL) indicators for a group of university faculty and administrators. The QOL indicators were in the domain of job satisfaction, life satisfaction, and health. Variables presumed to moderate the relationship between job strain and QOL were tested for their ability to buffer the strain effects. Analyses were carried out on faculty's and administrators' responses. The strong correlations obtained have both theoretical and practical consequences. Intervention strategies are discussed.
Peak power reduction in MIMO OFDM via active channel extension

High peak to average power ratio (PAR), a major drawback in single-input-single-output (SISO) systems using orthogonal frequency division multiplexing (OFDM), has already found many methods of reduction. The active channel extension (ACE) method reduces analog PAR by as much as 3.5 dB with no reduction in data rate by altering constellation points. We present an extension of this original method for PAR reduction for multi-input-multi-output (MIMO) systems in general. This new scheme, compatible with variable power allocation, minimizes PAR on each antenna in a similar manner as in the SISO system. It also supports any number of unique constellations and number of antennas by moving outer constellation points appropriately depending on the constellation for the particular channel and antenna. Simulations with 4 antennas at both transmitter and receiver show analog peak reductions of more than 3 dB overall for all 4 antennas.
Brook trout use individual recognition and transitive inference to determine social rank

Transitive inference (TI) occurs when information about known relationships is used to construct novel associations, for example, when an individual infers the order of 3 conspecifics in a linear dominance hierarchy (A > B > C) by watching 2 dyads (A > B and B > C). TI has been demonstrated for several species, but never for organisms with hierarchies involving many individuals whose rank order changes often. Under these circumstances, theory predicts natural selection may favor use of explicit cues to rank conspecifics, rather than TI. Here we show that brook trout (Salvelinus fontinalis), a species that exhibits complex, shifting dominance hierarchies, can combine individual recognition and TI to rank individuals within a hierarchy without use of explicit cues. Subjects that were allowed to directly interact with rivals were able to identify the social rank of each individual. In addition, we found that a subject, whose rank was C within a 5-fish hierarchy (A > B > C > D > E), could use TI to correctly infer the ranks of A and E after first interacting with B and D and then watching dyads involving A > B and D > E. This demonstration of TI in brook trout contributes to the understanding of stream trout population dynamics as TI could lower the energetic costs associated with movement. Key wor ds: brook trout, individual recognition, social learning, transitive inference. [Behav Ecol]
Vibrio vulnificus: Disease and Pathogenesis

Vibrio vulnificus is an opportunistic human pathogen that is highly lethal and is responsible for the overwhelming majority of reported seafood-related deaths in the United States ([30][1], [117][2]). This bacterium is a part of the natural flora of coastal marine environments worldwide and has been
Generating Driver Population for the Microscopic Simulation Model (CORSIM)

This paper deals with the CORSIM (Corridor Simulator) interval-based simulation model and its application to traffic operations analysis. It explains how with CORSIM, each vehicle is a distinct object moving every second and how its kinematic properties as well as status are updated every second. The authors propose that the driving behavior represented by speed distributions over different driver types should be built in CORSIM in order to reflect more realistic patterns of driving behavior. Simulation analysis is used to demonstrate the impact of the driver distribution to freeway capacity.
Active vision-based robot localization and navigation in a visual memory

We present a new strategy for active vision-based localization and navigation of a mobile robot in a visual memory, i.e., within a previously-visited area represented as a large collection of images. Vision-based localization in such a large and dynamic visual map is intrinsically ambiguous, since more than one map-locations can exhibit the same visual appearance as the current image observed by the robot. Most existing approaches are passive, i.e., they do not devise any strategy to resolve this ambiguity. In this work, we present an active vision-based localization and navigation strategy that can disambiguate the true initial location among possible hypotheses by controlling the mobile observer across a sequence of highly distinctive images, while concurrently navigating towards the target image. The performance of our active localization and navigation algorithm is demonstrated experimentally on a robot moving within a large outdoor environment.
Silvicultural intensification for tropical forest conservation: a response to Sist and Brown

We welcome the comments by Sist and Brown (henceforth S & B) about our suggestion that in some tropical forests, silvicultural interventions need to be intensified to promote regeneration of some commercially valuable species and to otherwise sustain timber yields. Although there is nothing particularly new about this suggestion, it is often lost in campaigns to minimize the deleterious environmental impacts of logging. We also applaud S & B’s efforts to promote reduced-impact logging (RIL) and agree that for forests well stocked with advanced regeneration of commercial species, maintaining pre-intervention forest structure by using RIL techniques represents a major step towards the goal of sustainable forest management. Given how difficult it is to improve logging practices (e.g., Putz et al. 2000; Blate et al. 2001), even when application of RIL techniques would be to the loggers’ short-term financial advantage (e.g., Holmes et al. 2002), S & B’s emphasis on logging to the exclusion of other silvicultural interventions seems justified. Also, if we had actually made a blanket endorsement of the creation of extremely large felling gaps, which was apparently S & B’s interpretation, we would share their concern about proliferation of vines and other weeds. Instead, we argued that there are conditions under which any of a number of silvicultural treatments, such as gap enlargement, vine cutting, liberation of future crop trees, and soil scarification, can be justified if they promote the regeneration and growth of commercial species. Ultimately, maintaining the value of forests for timber production may be the best incentive for keeping forests from being converted to other land uses.
Application of Groebner Basis Methodology to Nonlinear Mechanics Problems

The application of the Groebner basis methodology to four nonlinear mechanics problems is discussed. The MAPLE software package is used in all cases to implement the Groebner basis calculation which converts a set of coupled polynomial algebraic equations into an equivalent set of uncoupled polynomial algebraic equations (the reduced Groebner basis). Observations concerning implementation of Groebner basis methodology are reported.
Endogenous nitric oxide inhibits chloride transport in the thick ascending limb

Nitric oxide (NO) inhibits transport in various nephron segments, and the thick ascending limb of the loop of Henle (TALH) expresses NO synthase (NOS). However, the effects of NO on TALH transport have not been extensively studied. We hypothesized that endogenously produced NO directly decreases NaCl transport by the TALH. We first determined the effect of exogenously added NO on net chloride flux (JCl). The NO donor spermine NONOate (SPM; 10 microM) decreased JCl from 101.2 +/- 9.6 to 65.0 +/- 7.7 pmol. mm-1. min-1, a reduction of 35.5 +/- 6.4%, whereas controls did not decrease over time. To determine whether endogenous NO affects cortical TALH transport, we measured the effect of adding the NOS inhibitor NG-nitro-L-arginine methyl ester (L-NAME), the substrate L-arginine (L-Arg), or its enantiomer D-arginine (D-Arg) on JCl. L-NAME and D-Arg did not alter JCl; in contrast, addition of 0.5 mM L-Arg decreased JCl by 40.2 +/- 10.4% from control. The inhibition of chloride flux by 0.5 mM L-Arg was abolished by pretreatment with L-NAME, indicating that cortical TALH NOS is active, but production of NO is substrate-limited in our preparation. Furthermore, cortical TALH chloride flux increased following removal of 0.5 mM L-Arg from the bath, indicating that the reductions in chloride flux observed in response to L-Arg are not the result of NO-mediated cytotoxicity. We conclude that 1) exogenous NO decreases cortical TALH JCl; 2) cortical TALHs produce NO in the presence of L-Arg, which decreases JCl; and 3) the response of cortical TALHs to L-Arg is reversible in vitro. These data suggest an important role for locally produced NO, which may act via an autocrine mechanism to directly affect TALH sodium chloride transport. Thus TALH NO synthesis and inhibition of chloride transport may contribute to the diuretic and natriuretic effects of NO observed in vivo.
Apical and basolateral CO2-HCO-3 permeability in cultured bovine corneal endothelial cells

Corneal endothelial function is dependent on HCO 3 − transport. However, the relative HCO 3 − permeabilities of the apical and basolateral membranes are unknown. Using changes in intracellular pH s...
Development of a nonlinear wind-turbine simulator for LPV control design

It is challenging to design a controller for a wind turbine system because of its nonlinear time-varying dynamics. To solve this issue, linear parameter-varying (LPV) control theory has been applied in the recent ten years to deal with nonlinear and wind-speed-dependent dynamics. Before applying the LPV control method, it is required to transform the nonlinear model of the system to an LPV model. The main objectives of this research are to model a 5-MW Reference Wind Turbine for Offshore System as an LPV system, develop a nonlinear wind turbine simulator using MATLAB/Simulink to validate the LPV model, and conduct a preliminary study on LPV control design to test the simulator, which will be used in the future research for applying different LPV control techniques, such as switching LPV control, LPV antiwindup control, etc.
What is the potential role of transcutaneous carbon dioxide in guiding acute noninvasive ventilation

Transcutaneous monitoring has been used in the clinical setting to assess both oxygenation (PtcO2) and ventilation (PtcCO2). Because pulse oximetry is considered to be the standard of care for assessing oxygenation noninvasively, much of the more recent focus on transcutaneous monitoring has been on
Reduction of urinary sodium and potassium of diabetic rats produced by hypophyseal growth hormone.

ConclusionThe administration of growth hormone to partially depancreatized diabetic rats produces a reduction in urinary nitrogen, sodium and potassium excretion, although there may be a concomitant increase in glycosuria.
The viscerovertebral angle. The surgical avenue of the neck.

The viscerovertebral angle is the realization surgically of an anatomic abstraction that permits the surgeon to proceed in a logical and competent manner while operating in the neck. It provides an avenue of access to vital structures in a predictable and reproducible manner.
Integration of vinorelbine into chemotherapy strategies for non-small-cell lung cancer.

Meta-analyses of randomized clinical studies comparing combination chemotherapy versus "best supportive care" for advanced non-small-cell lung cancer have revealed a small, but statistically significant survival
Perineal Urethrostomy to Facilitate Gaining Ureterorenoscopic Length

AbstractA simple method of gaining ureterorenoscopic length via a perineal urethrostomy and its use in an obese, 6-foot, 6-inch man with a suspected renal pathological condition is described.
CHAPTER 266 – Attractive and Repulsive Signaling in Nerve Growth Cone Navigation

The function of the nervous system depends on complex and precise connections between nerve cells. The formation of specific connections during development often requires the growing axon to navigate over considerable distances to reach their final target cells. This long-range navigation is achieved by guidance factors within the developing tissue that regulate the motility or directionality of the growing tip of the axon, the growth cone. During the last decade several families of guidance factors have been identified, including netrins, semaphorins, ephrins, and slits. In addition, inhibitory factors associated with the myelin that exert repulsive actions on the navigation of regenerating axons have also been discovered. Different classes of membrane receptors for these factors have been identified and their intracellular signal transduction mechanisms are beginning to be elucidated. Two types of guidance signals may be distinguished: signals that convey a "stop or go" command regulating growth cone motility and signals that provide directional instructions to the growing axon, triggering turning responses of the growth cone. This chapter summarizes some of the putative signaling pathways that have been shown to participate in growth cone navigation.
Anesthesia Techniques for Endovascular Surgery

In the United States each year there are about 15,000 deaths directly related to abdominal aortic aneurysms (AAA) [1]; 62% may die outside the hospital from rupture of their aneurysms; the overall mortality is 90% [2]. In the year 1984 in patients with ruptured aneurysms, hospitals lost some $24,000 per patient [3]. If repaired electively, 2,000 patients were saved per year and annual costs were $50 million in 1984 [4]. Elective repair is indicated when aneurysms are 5 cm in diameter or greater and may lead up to 20% mortality if the patients have comorbid diseases [5, 6], Now add thoracic aneurysms, aortic dissections, and transections to the picture and the same as stated previously can be staggering.
Wanted: toolsmiths

Seeking to use software, hardware, and algorithmic ingenuity to create unique domain-independent instruments.
Dynamic flow stress of fine grain material processed using equal channel angular pressing

Abstract The dynamic deformation of a fine grained aluminum alloy generated using equal channel pressing techniques is examined using a split Hopkinson pressure bar at strain rates of 10 2 –10 4 s −1 and temperature levels 20, 50, 100 and 200 °C. A constitutive dynamic flow relationship has been formulated and its parameters are generated as an explicit function of strain, strain rate and temperature as well as the grain size. This relationship is derived by considering the flow stress to be composed of two physically based components; athermal and thermal, each of which is associated with a different set of dislocations barriers. The athermal component of stress is shown to be related to grain size through the typical Hall-Petch relationship while also relating the hardening parameter to the grain size. The thermal component of the flow stress is shown to be increasingly dependent on the grain size due to the transition in deformation mechanisms from coarse-grain regime into the ultra-fine grain. The material studied is shown to exist in the fine grain regime, in which competing deformation mechanisms exists. The constitutive model has been used to obtain the true stress-strain relationship for the fine grain material at different strain, strain rate, temperature and grain size. Results of the model simulation compared well with the experimentally generated curves.
Finding Evidence for Effectual Application Development on Digital Platforms

The development of novel software applications on digital platforms differs from traditional software development and provides unique challenges to software development managers and teams. Platform-based applications must achieve application-platform match, application-market match, value propositions exceeding platform’s core value propositions, and novelty. These desired properties support a new vision of the software development team as entrepreneurs with a goal of developing novel applications on digital platforms. In this research study, we look for evidence on an open-source software development project – Apache Cordova – that development teams use effectual thinking. Over one thousand user stories are analyzed for the use of constructs from a proposed effectual software development research model. The findings provide an initial confirmation that effectual development methods hold promise for the definition of new process models that better support application development on digital platforms. We conclude with a discussion on the implications of our results, research contributions, and future directions.
Wall stress on ascending thoracic aortic aneurysms with bicuspid compared with tricuspid aortic valve

Abstract Objective Guidelines for repair of bicuspid aortic valve–associated ascending thoracic aortic aneurysms have been changing, most recently to the same criteria as tricuspid aortic valve-ascending thoracic aortic aneurysms. Rupture/dissection occurs when wall stress exceeds wall strength. Recent studies suggest similar strength of bicuspid aortic valve versus tricuspid aortic valve-ascending thoracic aortic aneurysms; thus, comparative wall stress may better predict dissection in bicuspid aortic valve versus tricuspid aortic valve-ascending thoracic aortic aneurysms. Our aim was to determine whether bicuspid aortic valve-ascending thoracic aortic aneurysms had higher wall stresses than their tricuspid aortic valve counterparts. Methods Patients with bicuspid aortic valve- and tricuspid aortic valve-ascending thoracic aortic aneurysms (bicuspid aortic valve = 17, tricuspid aortic valve = 19) greater than 4.5 cm underwent electrocardiogram-gated computed tomography angiography. Patient-specific 3-dimensional geometry was reconstructed and loaded to systemic pressure after accounting for prestress geometry. Finite element analyses were performed using the LS-DYNA solver (LSTC Inc, Livermore, Calif) with user-defined fiber-embedded material model to determine ascending thoracic aortic aneurysm wall stress. Results Bicuspid aortic valve-ascending thoracic aortic aneurysms 99th-percentile longitudinal stresses were 280 kPa versus 242 kPa ( P = .028) for tricuspid aortic valve-ascending thoracic aortic aneurysms in systole. These stresses did not correlate to diameter for bicuspid aortic valve-ascending thoracic aortic aneurysms ( r = −0.004) but had better correlation to tricuspid aortic valve-ascending thoracic aortic aneurysms diameter ( r = 0.677). Longitudinal stresses on sinotubular junction were significantly higher in bicuspid aortic valve-ascending thoracic aortic aneurysms than in tricuspid aortic valve-ascending thoracic aortic aneurysms (405 vs 329 kPa, P = .023). Bicuspid aortic valve-ascending thoracic aortic aneurysm 99th-percentile circumferential stresses were 548 kPa versus 462 kPa ( P = .033) for tricuspid aortic valve-ascending thoracic aortic aneurysms, which also did not correlate to bicuspid aortic valve-ascending thoracic aortic aneurysm diameter ( r = 0.007). Conclusions Circumferential and longitudinal stresses were greater in bicuspid aortic valve- than tricuspid aortic valve-ascending thoracic aortic aneurysms and were more pronounced in the sinotubular junction. Peak wall stress did not correlate with bicuspid aortic valve-ascending thoracic aortic aneurysm diameter, suggesting diameter alone in this population may be a poor predictor of dissection risk. Our results highlight the need for patient-specific aneurysm wall stress analysis for accurate dissection risk prediction.
Estuarine Classification — A Help or a Hindrance

It is likely that a number of the participants at this conference wonder why such an old subject as estuarine classification should be included in a symposium intended to provide a forum for the discussion of our up-to-date knowledge of the circulation patterns in estuaries, and of the manner in which the physical transport processes affect the living resources, geological processes, and other aspects of the marine environment. There is no short and simple answer to this question, since a number of factors concerning the use and misuse of the various estuarine classification schemes came together in the forefront of my consciousness at about the time I chose a subject for this meeting.
STR Genotypes: Heterozygote Balance, Stochastic Thresholds, Allele, and Concordance Studies

Abstract Individual alleles are amplified using the polymerase chain reaction (PCR) and measured following capillary electrophoresis (CE) separation and detection. However, because humans are diploid, with one allele coming from an individual’s mother and one allele coming from an individual’s father, it is the genotype – the specific allele pair – that matters in human DNA profiles at each short tandem repeat (STR) locus tested. To determine whether two measured alleles can be associated into a genotype, validation data are collected from single-source samples to determine expected heterozygote peak height balance ranges. This information can then inform DNA mixture interpretation efforts.
Thermodynamics of carbonaceous mesophase: II. General theory for nonideal solutions

Abstract Carbonaceous mesophase is a discotic liquid crystal (LC) that forms as an intermediate during the fluid state carbonization of many organic precursors. The literature contains two distinct conceptual approaches to the description of carbonaceous mesophase formation: one based on orientational molecular potentials with ideal mixing (LC theory) and one based on nonideal mixing and finite solubility of pitch fractions of differing molecular weight and chemical composition (solubility theory). The present paper proposes the first general theory of liquid phase behavior in mesophase-containing pitches that integrates these two approaches. Submodels are developed for the individual terms in the general theory, drawing from regular solution theory, Flory–Huggins theory, and statistical theories of the liquid crystalline state. The resulting hybrid, integrated model is capable of describing the essential features of three separate literature data sets on pitch phase behavior. Sensitivity studies with the model indicate the importance of two distinct driving forces for mesophase formation: (a) poor solubility of high molecular weight aromatic molecules in the lower molecular weight fractions, and (b) reduction in the system free energy by molecular orientation of the larger, disk-like molecules accompanied by expulsion of some of the smaller, less oriented molecules to a separate isotropic phase. For the cases examined here, both contributions (orientational and excess mixing free energies) are significant and must be considered.
Parenting advice books about child sleep : Cosleeping and crying it out

Study Objectives: To identify the book sources of parenting advice about child sleep and then characterize those sources with respect to their authorship and the content of advice about cosleeping and cry-it-out sleep training. Setting: Availability in the United States market. Sample: Forty currently available parenting advice books about sleep were identified. Intervention: N/A. Measurement and Results: Most books were accessible regarding price and reading grade level. Most authors either had a medical background or no professional credentials. With regard to cosleeping, 28% of books endorsed it, 32% took no position, and 40% opposed it. Those that endorsed cosleeping generally recommended long-term bed sharing, but a few suggested room sharing only during the first few months after birth. With regard to crying it out, 61% of books endorsed it, 8% took no position, and 31% opposed it. Most of those that endorsed crying it out recommended scheduled checking, but a few suggested a cold-turkey method. More than half of the books presented advice that explicitly supported either cosleeping or crying it out and rejected the other. Conclusions: A medical perspective on sleep predominates in parenting advice in this area. That perspective is typically opposed to cosleeping and supportive of sleep training. However, a substantial minority present an opposite position.
Linking Cigarette Smoking/Tobacco Exposure and Cluster Headache: A Pathogenesis Theory

Introduction To propose a hypothesis theory to establish a linkage between cigarette smoking and cluster headache pathogenesis. Background Cluster headache is a primary headache syndrome grouped under the trigeminal autonomic cephalalgias. What distinguishes cluster headache from all other primary headache conditions is its inherent connection to cigarette smoking. It is undeniable that tobacco exposure is in some manner related to cluster headache. The connection to tobacco exposure for cluster headache is so strong that even if an individual sufferer never smoked, then that individual typically had significant secondary smoke exposure as a child from parental smoking behavior and in many instances both scenarios exist. The manner by which cigarette smoking is connected to cluster headache pathogenesis is unknown at present. If this could be determined this may contribute to advancing our understanding of cluster headache pathophysiology. Methods/results Hypothesis statement. Conclusion The hypothesis theory will include several principles: (1) the need of double lifetime tobacco exposure, (2) that cadmium is possibly the primary agent in cigarette smoke that leads to hypothalamic-pituitary-gonadal axis toxicity promoting cluster headache, (3) that the estrogenization of the brain and its specific sexually dimorphic nuclei is necessary to develop cluster headache with tobacco exposure, and (4) that the chronic effects of smoking and its toxic metabolites including cadmium and nicotine on the cortex are contributing to the morphometric and orexin alterations that have been previously attributed to the primary headache disorder itself.
An Integrative Approach to Neuroinflammation in Psychiatric disorders and Neuropathic Pain

Neuroinflammation is a complex process involving both the peripheral circulation and the Central Nervous System (CNS) and is considered to underlie many CNS disorders including depression, anxiety, schizophrenia, and pain. Stressors including early-life adversity, psychosocial stress, and infection appear to prime microglia toward a pro-inflammatory phenotype. Subsequent inflammatory challenges then drive an exaggerated neuroinflammatory response involving the upregulation of pro-inflammatory mediators that is associated with CNS dysfunction. Several pharmacologic inhibitors of pro-inflammatory cytokines including TNF-α and IL-1β show good clinical efficacy in terms of ameliorating neuroinflammatory processes. Mind/body and plant-based interventions such as yoga, breathing exercises, meditation, and herbs/spices have also been demonstrated to reduce pro-inflammatory cytokines and have a positive impact on depression, anxiety, cognition, and pain. As the intricate connections between the immune system and the nervous system continue to be elucidated, successful therapies for reducing neuroinflammation will likely involve an integrated approach combining drug therapy with nonpharmacologic interventions.
Reverse engineering the ultrasound contrast agent

Abstract In this review, a brief history and current state-of-the-art is given to stimulate the rational design of new microbubbles through the reverse engineering of current ultrasound contrast agents (UCAs). It is shown that an effective microbubble should be biocompatible, echogenic and stable. Physical mechanisms and engineering calculations have been provided to illustrate these properties and how they can be achieved. The reverse-engineering design paradigm is applied to study current FDA-approved and commercially available UCAs. Given the sophistication of microbubble designs reported in the literature, rapid development and adoption of ultrasound device hardware and techniques, and the growing number of revolutionary biomedical applications moving toward the clinic, the field of Microbubble Engineering is fertile for breakthroughs in next-generation UCA technology. It is up to current and future microbubble engineers and clinicians to push forward with regulatory approval and clinical adoption of advanced UCA technologies in the years to come.