cssi/SciSciGPT-SciSciNet huggingface dataset:
Effect of prenatal cocaine on dopamine receptor-G protein coupling in mesocortical regions of the rabbit brain

The effects of in utero exposure to cocaine on dopamine receptors in the frontal and cingulate areas of the developing rabbit cortex were assessed by examining receptor-mediated stimulations in GTP binding to alpha-subunits of G proteins. Pregnant Dutch-belted rabbits received intravenous injections of 4 mg/kg of cocaine HCl twice a day on gestational days 8-29, cortical membranes were prepared from their progenies on postnatal days 10-100 and dopamine-stimulated [35S] guanosine-5'-[gamma-thio]triphosphate (GTP gamma S) binding to membrane G alpha proteins was measured. Dopamine increased [35S]GTP gamma S binding to G alpha s and G alpha i. These increases in [35S]GTP gamma S binding reflect the stimulation of D1- and D2-dopamine receptors, respectively. The ability of dopamine to stimulate the binding of [35S]GTP gamma S to G alpha s but not to G alpha i was reduced in both frontal and cingulate cortices obtained from cocaine-exposed animals when examined at 10, 50 or 100 days of age. Prenatal cocaine exposure was also shown to reduce dopamine-stimulated [alpha-32P]GTP binding to G alpha s without influencing binding to G alpha i. The muscarinic cholinergic receptor-evoked increases in [35S]GTP gamma S binding to G alpha i and G alpha o were not altered. Immunoblot analyses revealed no differences in the levels of these alpha subunits in membranes from cocaine-exposed animals vs controls. Furthermore, prenatal cocaine did not affect [3H]8-chloro-2,3,4,5-tetrahydro-3-methyl-5-phenyl-1H-3-benzazepin-7- olhemimaleate binding to cortical D1 dopamine receptors. The results suggest that prenatal exposure of rabbits to cocaine selectively uncouples the D1 dopamine receptor from its G protein in mesocortical brain areas and that this change persists through postnatal day 100.
Resolution of an infectious pseudoaneurysm in a cervical petrous carotid vein bypass graft after covered stent placement: case report.

OBJECTIVE AND IMPORTANCE: Covered stenting of the carotid artery has been used to treat aneurysms and dissections. We describe a unique case of covered stenting in the setting of an infected psuedoaneurysm in a previously placed cervical-to-petrous vein bypass graft. Operating in an infected field and reopening a surgical wound at the craniocervical junction that had previously been exposed to penetrating trauma created substantial risks to open surgical repair. We therefore chose an endovascular strategy to repair this lesion. CLINICAL PRESENTATION: A 57-year-old diabetic man with a previously placed cervical-to-petrous vein bypass graft presented with chronic otitis media and acute hemorrhage from his right external auditory meatus. Evaluation revealed an infectious pseudoaneurysm of the vein graft at the cranial base. INTERVENTION: The patient was treated with intravenous antibiotics and endovascular placement of an 8-mm x 25-mm polytetrafluoroethylene-covered stent across the pseudoaneurysm. Angiography obtained 8 months later confirmed successful obliteration of the lesion. CONCLUSION: The patient's clinical outcome was excellent. Despite the active infection, covered stenting of the pseudoaneurysm was an effective treatment strategy, obviating the need for open debridement and graft revision.
Recovering an optimal LP basis from an interior point solution

An important issue in the implementation of interior point algorithms for linear programming is the recovery of an optimal basic solution from an optimal interior point solution. In this paper we describe a method for recovering such a solution. Our implementation links a high-performance interior point code (OB1) with a high-performance simplex code (CPLEX). Results of our computational tests indicate that basis recovery can be done quickly and efficiently.
Modeling very large plastic flows at very large strain rates for large-scale computation

Abstract There are many important technological problems where accurate modeling of very large plastic deformations at very high strain rates is essential for effective and reliable design and manufacture of metal components. Examples are crashworthy vehicles, automated manufacturing, and automated metal forming and cutting. Another example is the understanding of the deformation field at the tip of a fast-running crack, where strain rates can easily exceed 10 5 s −1 with local strains of several hundred percent. This paper summarizes some of the recent efforts by the authors and coworkers at the University of California, San Diego to develop physically-based constitutive models for mono- and polycrystalline solids, and to implement these models in large-scale finite element codes in the form of constitutive modules with efficient and robust computer algorithms. In the case of single crystal viscoplasticity, the constitutive integration is complicated by the fact that the essential set of ordinary differential equations is highly stiff for realistic levels of instantaneous rate-sensitivity. The algorithm that was developed for the integration of these equations in an explicit finite element environment is presented. Two example finite element solutions are given to demonstrate features of the overall finite element code. Also, a phenomenological viscoplasticity model that includes noncoaxiality between the stress and the plastic deformation rate is presented. This model is thought to be appropriate for high-strain-rate problems involving polycrystalline metals. Since the essential equation in this model is a single ordinary differential equation, numerical stiffness is not a factor; however, the integration is still complicated by an abrupt transition from the elastic regime to the plastic flow regime. A simple, robust “predictor-corrector” algorithm for the integration of this equation is presented.
Initial processes in the cationic homo and copolyierization of trioxane

1H NMR in situ studies of the initial processes involved in the cationic bulk homo- and copolymerization of trioxane indicate that the historically termed “induction period” has a kinetic rather than thermodynamic origin. The generation of cyclic acetals takes place through a process kinetically equivalent to insertion rather than back-biting. The roles played by H2O, formaldehyde, tetraoxane and trioxepane have been further clarified.
Characterizations of monotone and 2-monotone capacities

Given a capacityc and a probability measurep on a finite set, there is a natural way to combinec andp to produce a measure. For fixedc, these measures are probability measures for allp precisely whenc is monotone, and dominatec for allp precisely whenc is 2-monotone.
ASYMPTOTIC EXPANSIONS APPLIED TO F‐TEST CRITERIA

Summary Using asymptotic expansions of the Kummer hypergeometric function, the sequential. F-test criterion is evaluated asymptotically in terms of the sample size. The continuation region inequalities for the test are inverted and expressed in terms of known test criteria. A rapidly converging algorithm for carrying out the sequential procedure is provided. This makes the F-test easier for the practitioner to use. Almost sure finite termination of the sequential. F-test is asserted by appealing to the continuation inequalities and a heuristic asymptotic expansion of the test criterion. Average stopping times of the sequential procedure for a variety of population means and population number configurations are tabulated. The computer symbolic manipulation program MAPLE was used to derive some formulae.
Exploiting Intrinsic Triangular Geometry in Relativistic He 3 + Au Collisions to Disentangle Medium Properties

Recent results in $d+\mathrm{Au}$ and $p+\mathrm{Pb}$ collisions at RHIC and the LHC provide evidence for collective expansion and flow of the created medium. We propose a control set of experiments to directly compare particle emission patterns from $p+\mathrm{Pb}$, $d+\mathrm{Au}$, and $^{3}\mathrm{He}+\mathrm{Au}$ or $t+\mathrm{Au}$ collisions at the same $\sqrt{{s}_{NN}}$ . Using a Monte Carlo Glauber simulation we find that a $^{3}\mathrm{He}$ or triton projectile, with a realistic wave function description, induces a significant intrinsic triangular shape to the initial medium. If the system lives long enough, this survives into a significant third-order flow moment ${v}_{3}$ even with viscous damping. By comparing systems with one, two, and three initial hot spots, one could disentangle the effects from the initial spatial distribution of the deposited energy and viscous damping. These are key tools for answering the question of how small a droplet of matter is necessary to form a quark-gluon plasma described by nearly inviscid hydrodynamics.
Prosthetic management of resected edentulous mandibles.

Abstract Edentulous patients with partially resected mandibles are best treated with uncomplicated appliances. Elaborate mechanical devices are unnecessary when fundamental principles of denture construction are followed. The ramp provided on the maxillary denture serves as a training device for returning the mandible to a functional position. Patients adjust well to these appliances. Through determination and practice, they learn adequate control of mandibular movements. Mastication generally is possible after a short period of accommodation.
Electron Paramagnetic Resonance Spectra Observed in Single Crystals of YBa2Cu3O7–δ

An electron paramagnetic resonance absorption study is conducted on four separately prepared single crystal groups of the superconductor YBa2Cu3O7–δ, each group consisting of from four to six crystalline platelets. This investigation confirms conclusions reached by other regarding the EPR silence of this superconducting oxide while demonstrating that EPR spectroscopy can be used to determine certain properties of superconducting oxides. Such determinations include detection of paramagnetic impurity phases, noninvasive means for determining Tc, and estimating the depth of penetration of a microwave radiation field in these materials. Some comments are provided on the nonresonant, zero field absorption in both, the powders and single crystal platelets. An vier getrennt hergestellten Einkristallgruppen des Supraleiters YBa2Cu3O7–δ werden Untersuchungen der elektronenparamagnetischen Resonanzabsorption durchgefuhrt, wobei jede Gruppe aus vier bis sechs Kristallplattchen besteht. Diese Untersuchung bestatigt fruher von anderen Autoren gemachte Schlusse uber das Fehlen der EPR an diesem supraleitenden Oxid, wahrend sie zeigt, das EPR-Spektroskopie benutzt werden kann, um gewisse Eigenschaften der supraleitenden Oxide zu bestimmen. Diese Bestimmungen schliesen den Nachweis von paramagnetischen Verunreinigungsphasen, nichtangreifende Mittel zur Bestimmung von Tc und die Abschatzung der Eindringtiefe des Mirkowellenstrahlungsfeldes in diesen Materialien ein. Einige Bemerkungen uber die nichtresonante Nullfeld-Absorption in Pulverproben und Einkristallplattchen werden gemacht.
Towards understanding the role of price in residential electricity choices: Evidence from a natural experiment☆

Abstract We examine a choice setting in which residential electricity consumers may respond to non-financial incentives in addition to prices. Using data from a natural field experiment that exposed some households to a change in their electricity rates, we find that households reduced electricity usage in response to a contemporaneous decrease in electricity prices. This provides clear evidence that other factors – potentially encompassing non-monetary and dynamic considerations – can influence consumer choice, and even dominate the static price response in some cases. A comprehensive understanding of household behavior in energy markets is essential for the effective implementation of market-based energy and environmental policies. The documentation of our result and others like it is a necessary step in achieving such an understanding.
Strained AlGaInP quantum wire lasers

Abstract We report on the fabrication of strained separate-confinement heterostructure AlGaInP visible laser diodes with multiple quantum wire active regions formed in situ during gas source molecular beam epitaxy. Lateral composition modulation with a period on the order of 100 A perpendicular to the growth direction occurs spontaneously during the growth of the (GaP)2/(InP)2 short-period superlattice active region by the strain-induced lateral-layer ordering (SILO) process. Individual laser diodes fabricated from the same wafer but emitting parallel and normal to the wire axis exhibit highly anisotropic properties, including large difference in threshold current, emission wavelength, and opposite polarizations. These effects are explained in terms of the strained quantum wire potential. The additional degree of quantum confinement in quantum wire structure reduces the threshold current density by a factor of > 2.7 when compared with an otherwise identical quantum well laser.
Preliminary assessment of the temporal subtraction of tomosynthesis images for improved detection of pulmonary nodules

Digital tomosynthesis is an imaging technique which reconstructs tomographic planes in an object from a set of projection images taken over a fixed angle (1). Results from our initial pilot study show that tomosynthesis increases the detectability of lung nodules; while only 50% of CT confirmed nodules were found on typical chest radiographs, 81% were found on tomosynthesis image sets (2). Temporal subtraction is a method which takes two sequential images and subtracts one from another, emphasizing the appearance of interval change (3-6). As an addition to conventional chest radiography, it has been shown in several studies to significantly increase observer performance in detecting newly developed abnormalities (7-10). Thus the combination of temporal subtraction and tomosynthesis may yield improved sensitivity of detection over either method alone. For this preliminary evaluation into the combination of these techniques, images were taken of an anthropomorphic chest phantom in different orientations and subtle lung nodules were simulated in order to emulate temporal discrepancies in anatomy. An automated method of segmentation, registration, and image warping was employed to align corresponding lung regions of each image set. The visibility of temporal change of simulated nodules was more apparent in the subtraction image. By our subjective analysis, tomosynthesis substantially improved the visibility of nodules relative to conventional chest radiography; and tomosynthesis augmented by temporal subtraction even further enhanced the conspicuity of difficultly placed subtle nodules.
A prospective study of the clinical outcome of femoral pseudoaneurysma and arteriovenous fistuals induced by arterial puncture

Abstract Purpose: Although spontaneous thrombosis of femoral false aneurysms (FAs) and arteriovenous fistulas (AVFs) has been reported, the frequency of this occurrence is unknown. This prospective study was designed to establish the natural history of FA and AVF and to evaluate factors that might predict eventual thrombosis of these lesions. Methods: Twenty-two patients with either femoral FAs ( n = 16) or AVFs ( n = 6) induced by percutaneous arterial punctures were evaluated prospectively. After an initial duplex scan, all patients were monitored with serial scans, either in hospital or weekly as outpatients, depending on the stability of the process. Operative repair was performed for the following indications: (1) a greater than 100% increase in size of a FA by duplex scan, (2) the development of symptoms, or (3) continued patency of the lesion after 2 months of observation. Results: Nine of 16 FAs and four of six AVFs closed spontaneously; FAs greater than 6 cm 3 (1.8 cm in diameter) required repair more often ( p = 0.065). However, size was not an absolute predictor of the need for repair because two small aneurysms (1.6 and 0.7 cm 3 ) remained patent, although both patients were discharged safely from the hospital, and two large aneurysms (13.2 and 10.7 cm 3 ) thrombosed spontaneously. Three of seven patients whose aneurysms required repair received anticoagulation continuously from the time of catheterization until repair became necessary. None of the patients whose FAs closed spontaneously were receiving anticoagulants at the time of thrombosis ( p = 0.02). Neither length of the FA neck, velocity in the FA cavity, size of original arterial puncture, nor velocity in the AVF correlated with thrombosis. Conclusions: We conclude that (1) all FAs do not thrombose spontaneously and at least one third require surgical repair, (2) patients receiving continuous anticoagulation should undergo aneurysm repair, (3) discharge of patients with FAs less than 6 cm 3 is safe (the majority of these FAs will eventually thrombose spontaneously), and (4) many AVFs close spontaneously and repair is not required unless symptoms or signs of progressive enlargement develop. (J VASC SURG 1993;17:125-33.)
On the Significance of Motion Degradation in High-Resolution 3D μMRI of Trabecular Bone

Rationale and Objectives Subtle subject movement during high-resolution three-dimensional micro–magnetic resonance imaging of trabecular bone (TB) causes blurring, thereby rendering the data unreliable for quantitative analysis. In this work, the effects of translational and rotational motion displacements were evaluated qualitatively and quantitatively. Materials and Methods In experiment 1, motion was induced by applying various simulated and previously observed in vivo trajectories as phase shifts to k-space or rotation angles to k-space segments of a virtually motion-free data set. In experiment 2, images that were visually free of motion artifacts from two groups of 10 healthy individuals, differing in age, were selected to probe the effects of motion on TB parameters. In both experiments, images were rated for motion severity, and the scores were compared to a focus criterion, the normalized gradient squared. Results Strong correlations were observed between the motion quality scores and the corresponding normalized gradient squared values ( R 2 = 0.52–0.64, P Conclusions Quantitative TB structural measures are highly sensitive to subtle motion-induced degradation, which adversely affects precision and statistical power. The results underscore the influence of subject movement in high-resolution three-dimensional micro–magnetic resonance imaging and its correction for TB structure analysis.
Confirming suboptimal adherence to HPV cotesting guidelines in an academic center in Vermont.

To the Editor We read with interest the report by Tatsas et al1 documenting practice patterns of cervical cancer screening and human papillomavirus (HPV) cotesting. The authors noticed a trend of increased adoption of age-appropriate cotesting in women 30 years and older, and a persistence of age-inappropriate cotesting in women younger than 30 years. We performed a comparable study at our institution, a rural practice with a low incidence of cervical cancer, and found disappointing, yet similar, results. We evaluated the ordering practices of providers by analyzing the number of Papanicolaou (Pap) tests performed with and without accompanying HPV orders for 2 age groups: women younger than …
The experience of pain and emergent osteoarthritis of the knee

Conclusions: Joint pain in AA women was more likely to be associated with radiographic OAK as compared with CA women. This suggests differences in these two groups in both how pain is experienced in the OAK process and in the prevalence of non-OAK related pain in knee joints. © 2001 OsteoArthritis Research Society International
Identification and quantitation of phenylethylene glycol in human and rat urine, and its elevation in phenylketonuria.

Abstract Phenylethylene glycol has been identified in rat and human urine using gas chromatography/chemical ionization/mass spectrometry. A method was developed for the quantitative analysis in urine of this phenylalanine metabolite and of p-hydroxyphenylethanol, a metabolite of tyrosine, by converting them to the pentafluoropropionyl derivatives and measuring them by selected ion monitoring. In human urine, about 90% of the phenylethylene glycol was present in a conjugated form (releasable by glusulase), but the reverse was true for rat urine, with about 90% being present in the unconjugated form. The excretion of free phenylethylene glycol (expressed as ng/mg creatinine) was 2.7-fold higher in a group of untreated phenylketonuric patients than in the control group, but the phenylketonuric patients excreted abnormally low amounts of 3-methoxy-4-hydroxyphenylethylene glycol. Intraperitoneal injections of l -phenylalanine in rats resulted in a small increase in the excretion of phenylethylene glycol. On the other hand, the injection of phenylethanolamine resulted in an 82-fold increase in the excretion of phenylethylene glycol, but phenylethylamine had no effect. These results indicate that the conversion of phenylethylamine to phenylethanolamine is the rate limiting step in this metabolic pathway.
WEALTH ACCUMULATION OF BLACK AND WHITE MEN: THE CASE OF HOUSING EQUITY*

This paper looks at racial differences in how male workers accumulate housing equity. Findings from a national sample suggest major differences favoring whites in the payoff to such characteristics as earnings, age, marital status, and area of current residence. Blacks and whites also differ in the form of the relationship between years of schooling and housing equity. When the analysis is confined to homeowners only, many of these racial differences remain. The findings provide evidence concerning racial inequity in the United States housing markets and thus allow inferences concerning discrimination in housing. The findings also dramatize racial differences in a key form of wealth accumulation as a complement to other reports of racial differences in socio-economic outcomes.
The Monitoring Core: A framework for sensor security application development

Wireless sensor networks (WSNs) are used for the monitoring of physical and environmental phenomena, and applicable in a range of different domains (e.g., health care, military, critical infrastructure). When using WSNs in a variety of real-world applications, security is a vital problem that should be considered by developers. As the development of security applications (SAs) for WSNs require meticulous procedures and operations, the software implementation process can be more challenging than regular applications. Hence, in an effort to facilitate the design, development and implementation of WSN security applications, we introduce the Monitoring Core (M-Core). The M-Core is a modular, lightweight, and extensible software layer that gathers necessary data including the internal and the external status of the sensor (e.g., information about ongoing communications, neighbors, and sensing), and provides relevant information for the development of new SAs. Similar to other software development tools, the M-Core was developed to facilitate the design and development of new WSN SAs on different platforms. Moreover, a new user-friendly domain-specific language, the M-Core Control Language (MCL), was developed to further facilitate the use of the M-Core and reduce the developer's coding time. With the MCL, a user can implement new SAs without the overhead of learning the details of the underlying sensor software architecture (e.g., TinyOS). The M-Core has been implemented in TinyOS-2.x and tested on real sensors (Tmote Sky and MicaZ). Using the M-Core architecture, we implemented several SAs to show that the M-Core allows easy and rapid development of security programs efficiently and effectively.
Ceramide Changes the Mediator of Flow-Induced Vasodilation From Nitric Oxide to Hydrogen Peroxide in the Human Microcirculation

Rationale: Mitochondrial-derived hydrogen peroxide (H 2 O 2 ) regulates flow-induced dilation (FID) in microvessels from patients with coronary artery disease. The relationship between ceramide, an independent risk factor for coronary artery disease and a known inducer of mitochondrial reactive oxygen species, and FID is unknown. Objective: We examined the hypothesis that exogenous ceramide induces a switch in the mediator of FID from nitric oxide to H 2 O 2 . Methods and Results: Internal diameter changes of resistance arterioles from human adipose and atrial tissue were measured by video microscopy. Mitochondrial H 2 O 2 production was assayed in arterioles using mito peroxy yellow 1. Polyethylene glycol–catalase, rotenone, and Mito-TEMPO impaired FID in healthy adipose arterioles pretreated with ceramide, whereas N ω -nitro-l-arginine methyl ester had no effect. Mitochondrial H 2 O 2 production was induced in response to flow in healthy adipose vessels pretreated with ceramide, and this was abolished in the presence of polyethylene glycol–catalase. Immunohistochemistry demonstrated ceramide accumulation in arterioles from both healthy patients and patients with coronary artery disease. N ω -nitro-l-arginine methyl ester reduced vasodilation to flow in adipose as well as atrial vessels from patients with coronary artery disease incubated with GW4869, a neutral sphingomyelinase inhibitor, whereas polyethylene glycol–catalase had no effect. Conclusions: Our data indicate that ceramide has an integral role in the transition of the mediator of FID from nitric oxide to mitochondrial-derived H 2 O 2 and that inhibition of ceramide production can revert the mechanism of dilation back to nitric oxide. Ceramide may be an important target for preventing and treating vascular dysfunction associated with atherosclerosis.
Resonance nature of the magnetosphere

Abstract A new approach toward an understanding of the nature of low frequency e.m. waves ( f⪡, B ) ( f B is the ion gyrofrequency) observed in the magnetosphere is given in this essay. It is based on detailed studies of Fourier spectra of magnetic field records obtained at 14 observation points, with L =2.6–13, around the world: in Antarctica, Canada, Italy, Iceland, Russia, and the USA in the frequency band f ≈1–250 mHz. It overlaps the frequency band of so-called Pc2–Pc5 micropulsations. Repetitive and non-repetitive single Pc1 micropulsations at f ≈0.4–2.2 Hz are also briefly discussed here. Under different conditions they should be created, respectively, by interaction of a non-linear and/or only linear gyro-resonance instability mechanism. The oscillations considered exist at any time both in quiet (QC) and disturbed (DC) conditions. Their spectra possess a line structure . The background is composed of resonance oscillations, and weaker oscillations caused by noise. The resonance oscillations may occur in the entire magnetosphere or in its parts. In the frequency range examined 12, 20–25, and more resonance frequencies f s ,res were accordingly found in the spectra of the NP and SP observation points ( L ≃13) and in the Tuckerton and Point Arena ( L ≃2.6) data. The higher-order resonance maxima are overlapped by the noise oscillations. All these oscillations can be set swinging , producing strong non-repetitive wave packets with durations τ 0 ≈20–300 s and longer. The conditions for producing the swinging background can be impulse/shock excitations of the magnetospheric plasma, a gyro-resonance instability, etc. Thus, the well-known multiple manifestations of hydromagnetic wave packets observed in our research in the magnetosphere at f Hz are considered to be the result of a single physical phenomenon : the fundamental resonance e.m. oscillatory nature of the background magnetospheric plasma environment. It is shown that the observed waves and the spectral resonance oscillations are temporally modulated by extra-low-frequency oscillations f mod ≃1.8– 2.0 mHz and⪡ f s ,res . We believe that these oscillations are of Solar origin and were transferred to the Earth by the Solar wind. By analyzing calculated Fourier spectra of different kinds of wave packets – signals F ( t ) – we have found that any continuum of spectral maxima f s ,max of these F ( t ) is characterized by a quasi-constant quantity – the spectral shape characteristic . It estimates the general image of the envelope of the signals and their duration.
Dexmedetomidine: Antiarrhythmic Effects in the Pediatric Cardiac Patient

This report aims to provide a general description of the cardiovascular effects of dexmedetomidine, emphasizing its effects on conduction, and to give an evidence-based review of the literature regarding the use of dexmedetomidine to treat and prevent tachyarrhythmias in infants and children. A computerized bibliographic search of the literature on the use of dexmedetomidine to treat and prevent arrhythmias in infants and children was conducted. The cardiovascular effects of dexmedetomidine have been well studied in animal and adult human models. Growing experience, mostly in the pediatric population, has demonstrated the potential therapeutic applications of dexmedetomidine in the acute treatment of arrhythmias. Additionally, its use during cardiac surgery has been associated with a decreased incidence of postoperative ventricular and supraventricular tachyarrhythmias. Although dexmedetomidine is not currently approved by the Food and Drug Administration for the pediatric population, findings have shown it to be effective in various clinical scenarios for sedation. In addition, recent studies show that dexmedetomidine may have promising properties for the acute treatment and prevention of tachyarrhythmias.
Alkyltransition metal compounds II. n-alkylchromium systems: olefin isomerization

Abstract A series of experiments with the trimethyl-, triethyl-, tri-n-butyl-, tri-n-decyl- and tri-p-tolylchromium systems with various terminal olefins, internal olefins and 1,5-cyclooctadiene under a variety of conditions have been carried out. The results indicate that the activity of the catalyst (probably a hydrido-chromium species) and the rate of isomerization of added olefin are temperature dependent. The consistent isomerization of terminal olefins to trans- and cis-2-olefins as major product and of 1,5-cyclooctadiene to the 1,4- then the 1,3-diene is in keeping with a mechanism involving the cis-addition/elimination of a metal hydride species.
PULSE NITROGEN MUSTARD TREATMENT OF CHILDHOOD IDIOPATHIC NEPHROTIC SYNDROME (INS.)

As an alternative to long-term administration of oral cytotoxic agents, pulse intravenous nitrogen mustard (HN2) has been used in 5 patients with steroid-resistant INS (all had “early resistance”) and one patient with steroid responsive INS. The dose of HN2 was 0.1 mg/kg/day × 4 days. All patients had minimal-lesion histology. The patient with steroid-responsive INS had a frequently relapsing course (4.8 relapses/year) despite treatment with cyclophosphamide (2 courses) and chlorambucil. Since HN2, she has had no further relapses. The current status of 5 patients with steroid-resistant INS is: 3 have persistent mild proteinuria, normal excretory function and absence of overt nephrotic syndrome; 2 have persistent INS despite HN2 but subsequently remitted after cyclophosphamide and both have since had a steroid-responsive, relapsing course. No toxicity attributable to HN2 was noted. This preliminary experience suggests that HN2 may ameliorate INS in some patients with steroid-resistance. HN2 may also be a useful adjunct in the management of some patients with steroid-responsive, frequently-relapsing INS, in whom oral cytotoxic therapy may not be warranted. A controlled therapeutic trial to better assess the usefulness of HN2 is planned.
Computer-controlled laboratory experiments

Inexpensive, safe, computer-controlled laboratory experiments which use modern sensors, digital storage oscilloscopes, and data acquisition units were developed for National Science Foundation Faculty Enhancement Workshops offered at Bucknell University. Although the experiments are simple in construction, rather complex data analysis using MATLAB or Excel applies. Detailed descriptions of the experiments will be available on the Internet.© 1996 John Wiley & Sons, Inc..
Preform design for forging and extrusion processes based on geometrical resemblance

AbstractPreform design in multi-stage forging processes is critical to ensure the production of defect-free parts. Moreover, owing to the geometry and material-flow complexities in forging processes, finding the optimal preform shapes could be difficult and time consuming. This paper proposes an efficient preform design methodology based on geometrical resemblance, which requires several finite element analysis simulation iterations to obtain a good preform shape. The initial and subsequent simulations are carried out by constructing a slightly larger part that geometrically resembles the desired part. Initial finite element analysis simulation of the larger part is performed with a reasonably guessed preform shape, whose forming defects or flash formation would be corrected in subsequent steps. Then a series of intermediate parts of similar shape and between the largest part and the desired part in size are constructed. The undeformed shape corresponding to an intermediate part can be obtained by backwar...
pO2-dependent NO production determines OPPC activity in macrophages

Stimulated macrophages produce nitric oxide (NO) via inducible nitric oxide synthase (iNOS) using molecular O(2), L-arginine, and NADPH. Exposure of macrophages to hypoxia decreases NO production within seconds, suggesting substrate limitation as the mechanism. Conflicting data exist regarding the effect of pO(2) on NADPH production via the oxidative pentose phosphate cycle (OPPC). Therefore, the present studies were developed to determine whether NADPH could be limiting for NO production under hypoxia. Production of NO metabolites (NOx) and OPPC activity by RAW 264.7 cells was significantly increased by stimulation with lipopolysaccharide (LPS) and interferon gamma (IFNgamma) at pO(2) ranging from 0.07 to 50%. OPPC activity correlated linearly with NOx production at pO(2)>0.13%. Increased OPPC activity by stimulated RAW 264.7 cells was significantly reduced by 1400 W, an iNOS inhibitor. OPPC activity was significantly increased by concomitant treatment of stimulated RAW 264.7 cells with chemical oxidants such as hydroxyethyldisulfide or pimonidazole, at 0.07 and 50% O(2), without decreasing NOx production. These results are the first to investigate the effect of pO(2) on the relationship between NO production and OPPC activity, and to rule out limitations in OPPC activity as a mechanism by which NO production is decreased under hypoxia.
The role of percutaneous aortic balloon valvuloplasty in patients with cardiogenic shock and critical aortic stenosis

Abstract Objectives. The goal of this study was to evaluate the role of percutaneous aortic valvuloplasty in patients with cardiogenic shock due to severe aortic stenosis and associated major comorbid conditions and to establish predictors of survival. Background. The prognosis for patients in cardiogenic shock with severe aortic stenosis is poor. Aortic valve replacement can be lifesaving but the presence of multiorgan failure precludes these patients from operation. Percutaneous aortic balloon valvuloplasty has been used in these patients with short-term improvement and could be an alternative therapeutic option. Methods. Of 310 patients undergoing percutaneous aortic balloon valvuloplasty, 21 were in cardiogenic shock and were included in this study. All 21 patients had associated major comorbid conditions at the time of presentation. Results. After percutaneous aortic balloon valvuloplasty, systolic aortic pressure increased from 77 ± 3 (mean ± SEM) to 116 ± 8 mm Hg (p = 0.0001); aortic valve area increased from 0.48 ± 0.04 to 0.84 ± 0.06 cm2(p = 0.0001); and cardiac index increased from 1.84 ± 0.13 to 2.24 ± 0.15 liters/min per m2(p = 0.06). Nine patients died in the hospital, two during the procedure and seven after successful percutaneous aortic balloon valvuloplasty (five from multiorgan failure). Five patients had vascular complications. Stroke, cholesterol emboli and aortic regurgitation requiring aortic valve replacement occurred in one patient each. Twelve patients (57%) survived and were followed up for 15 ± 6 months; five patients subsequently died. The Kaplan-Meier survival curve showed a 38 ± 11% survival rate at 27 months. The only predictor for longer survival rate was the postprocedure cardiac index. Conclusions. 1) Emergency percutaneous aortic balloon valvuloplasty can be performed successfully as a lifesaving procedure. 2) Morbidity and mortality remain high despite successful percutaneous aortic balloon valvuloplasty. 3) For nonsurgical candidates, percutaneous aortic balloon valvuloplasty may be the only therapeutic alternative.
Supervisory control of multiple robots in dynamic tasking environments

A military targeting environment was simulated to examine the effects of an intelligent route-planning agent RoboLeader, which could support dynamic robot re-tasking based on battlefield developments, on the performance of robotics operators. We manipulated the level of assistance (LOAs) provided by RoboLeader as well as the presence of a visualisation tool that provided feedback to the participants on their primary task (target encapsulation) performance. Results showed that the participants’ primary task benefited from RoboLeader on all LOAs conditions compared to manual performance; however, visualisation had little effect. Frequent video gamers demonstrated significantly better situation awareness of the mission environment than did infrequent gamers. Those participants with higher spatial ability performed better on a secondary target detection task than did those with lower spatial ability. Finally, participants’ workload assessments were significantly lower when they were assisted by RoboLeader tha...
Target identification performance as a function of low spatial frequency image content

Current imaging system performance models use either the minimum resolvable temperature difference or the minimum resolvable contrast concepts to predict target identification performance. Both of these performance functions describe the limiting frequency that can be viewed through the imaging system at a particular contrast. No credit is given to the system for the amount of low frequency (lower than the limiting frequency) information that is passed through the system. We determine whether the low spatial frequency information is important in the target identification task. Previous experiments show that no degradation is seen on character recognition if a high-pass, edge enhancing filter is applied to character images. This is not the case in target identification performance, where the targets of interest are military tanks. A number of filters (six levels of blur at four bandwidth configurations) are applied to tank imagery including high-pass filters to reduce the low frequency image content. A perception experiment is performed to determine whether target identification performance was degraded with a reduced amount of low spatial frequency image content. The probability of target identification is calculated from the observer responses and the identification performance is evaluated as a function of low spatial frequency image content. Low frequency information is shown to contribute to the overall system performance.
The Effects Of The Coverage Gap On Drug Spending: A Closer Look At Medicare Part D

We calculated prescription drug usage in two groups of Medicare beneficia- ries: employer group with no coverage gap, and individual Part D group with no coverage or some generic drug coverage in the coverage gap. Among those with employer coverage, 40 percent reached the doughnut hole, compared with 25 percent of those without such cover- age. Overall, 5 percent went through the doughnut hole to reach the catastrophic coverage level. Those lacking coverage in the doughnut hole reduced their drug use by 14 percent; those with generic coverage reduced their use by 3 percent. Coverage of generic drugs with a $0-$10 copayment in the doughnut hole could be financed by, at most, a six-to-nine- percentage-point increase in initial coinsurance. (Health Affairs 28, no. 2 (2009): w317-
Variation in fiber number of a male-specific muscle between Drosophila species: a genetic and developmental analysis.

SUMMARY We characterize a newly discovered morphological difference between species of the Drosophila melanogaster subgroup. The muscle of Lawrence (MOL) contains about four to five fibers in D. melanogaster and Drosophila simulans and six to seven fibers in Drosophila mauritiana and Drosophila sechellia. The same number of nuclei per fiber is present in these species but their total number of MOL nuclei differs. This suggests that the number of muscle precursor cells has changed during evolution. Our comparison of MOL development indicates that the species difference appears during metamorphosis. We mapped the quantitative trait loci responsible for the change in muscle fiber number between D. sechellia and D. simulans to two genomic regions on chromosome 2. Our data eliminate the possibility of evolving mutations in the fruitless gene and suggest that a change in the twist might be partly responsible for this evolutionary change.
Is Contingent Reciprocity A Fourth Governance Mode Applicable To Market Entry And Operation

Several recent publications have identified a fourth means of getting the intermediate products a firm needs when entering a market – namely, by plying a supplier with gifts or exercising power ove...
Superconducting AC/DC power coversion using high-temperature superconducting components

The trend towards DC transmission of power, especially when using superconductors, has made the conversion of power from AC to DC and DC to AC a critical element of many electrical systems. We designed and tested an AC to DC and DC to AC converter which used HTS cryotron switches. The superconducting elements were made from yttrium barium copper oxide, and the converter was operated at 77 Kelvin. Both AC to DC and DC to AC conversion has been demonstrated, and the conversion has been shown to be relatively independent of frequency over a wide range. The converter was tested with a current of a few amperes, but is upwardly scalable to thousands of amperes, At larger currents the converter is more efficient as much of the power loss occurs in a separate control circuit which carries a current that does not scale with the amount of current controlled. Significant sources of inefficiencies remain which make the initial device impractical for actual use; however, the proposed improvements in material and design should allow the converter to be used in practical applications and outperform conventional methods of conversion such as thyristors.
A Coherent Grid Traversal Approach to Visualizing Particle-Based Simulation Data

We present an approach to visualizing particle-based simulation data using interactive ray tracing and describe an algorithmic enhancement that exploits the properties of these data sets to provide highly interactive performance and reduced storage requirements. This algorithm for fast packet-based ray tracing of multilevel grids enables the interactive visualization of large time-varying data sets with millions of particles and incorporates advanced features like soft shadows. We compare the performance of our approach with two recent particle visualization systems: one based on an optimized single ray grid traversal algorithm and the other on programmable graphics hardware. This comparison demonstrates that the new algorithm offers an attractive alternative for interactive particle visualization.
Single-pot enzymatic synthesis of Dicer-substrate siRNAs

We describe an inexpensive and efficient method for generating functional pools of Dicer-substrate small interfering RNAs (siRNAs) in a single reaction tube. The method exploits a highly active form of the enzyme Dicer from Giardia lamblia, which is capable of accurately processing double-stranded RNA (dsRNA) into 25–27nt RNA pools during in vitro transcription. The small RNAs produced function as substrates of human Dicer in vitro and induce gene silencing with potency equivalent to traditional siRNAs when introduced into mammalian cells. The overall reaction is simple, can be carried out in any laboratory with access to a PCR machine, and is amenable to high-throughput processes.
Novel real-time R-wave detection algorithm based on the vectorcardiogram for accurate gated magnetic resonance acquisitions.

Electrocardiograph (ECG) triggered or gated magnetic resonance methods are used in many imaging applications. Therefore, a reliable trigger signal derived from to the R-wave of the ECG is essential, especially in cardiac imaging. However, currently available methods often fail mainly due to the artifacts in the ECG generated by the MR scanner itself, such as the magnetohydrodynamic effect and gradient switching noise. The purpose this study was to characterize the accuracy of selected R-wave detection algorithms in an MR environment, and to develop novel approaches to eliminate imprecise triggering. Vectorcardiograms (VCG) in 12 healthy volunteers exposed to 1.5 T magnetic field were digitized and used as a reference data set including manually corrected onsets of R-waves. To define the magnetohydrodynamic effect, the VCGs were characterized in time, frequency, and spatial domains. The selected real-time R-wave detection algorithms, and a new "target-distance" VCG-based algorithm were applied either to standard surface leads calculated from the recorded VCG or to the VCG directly. The flow related artifact was higher in amplitude than the R-wave in 28% of the investigated VCGs which yielded up to 9-16%false positive detected QRS complexes for traditional algorithms. The "target-distance" R-wave detection algorithm yielded a score of 100% for detection with 0.2% false positives and was superior to all the other selected methods. Thus, the VCG of subjects exposed to a strong magnetic field can be use to separate the magnetohydrodynamic artifact and the actual R-wave, and markedly improves the trigger accuracy in gated magnetic resonance scans. Magn Reson Med 42:361-370, 1999.
Nerve-released acetylcholine contracts urinary bladder smooth muscle by inducing action potentials independently of IP3-mediated calcium release

Nerve-released ACh is the main stimulus for contraction of urinary bladder smooth muscle (UBSM). Here, the mechanisms by which ACh contracts UBSM are explored by determining Ca2+ and electrical sig...
Gratitude and depressive symptoms: The role of positive reframing and positive emotion

Eight studies (N=2,973) tested the theory that gratitude is related to fewer depressive symptoms through positive reframing and positive emotion. Study 1 found a direct path between gratitude and depressive symptoms. Studies 2-5 demonstrated that positive reframing mediated the relationship between gratitude and depressive symptoms. Studies 6-7 showed that positive emotion mediated the relationship between gratitude and depressive symptoms. Study 8 found that positive reframing and positive emotion simultaneously mediated the relationship between gratitude and depressive symptoms. In sum, these eight studies demonstrate that gratitude is related to fewer depressive symptoms, with positive reframing and positive emotion serving as mechanisms that account for this relationship.