cssi/SciSciGPT-SciSciNet huggingface dataset:
Development of a real time wind turbine emulator based on RTDS using advanced perturbation methods

This paper presents the development of a fixed speed wind turbine emulator using the Real Time Digital Simulator (RTDS). The wind turbine emulator consists of a wind turbine modeled in an RSCAD software environment. The software model for the wind turbine generates appropriate torque signals based on wind speed profiles using auto-regressive moving average and perturbation methods. These torque signals were fed to a servo motor emulating the wind turbine and were connected to an induction machine that emulated the generator. The response of the emulator shows that it closely matches the performance of the software model under various wind speed profiles. Thus, it can be used as an effective research and experimental tool in several wind energy based renewable energy projects.
Freeze-Dry Technique for Making Ultra-Fine Metal Powder

Ultra-fine particles can be made from soluble materials by freeze-drying their solutions. Reduction of homogeneous compounds can be used to produce homogeneous alloy powders of controlled composition.
Culture and Liberty

This Article considers the claim that free market legal rules subvert the stock of private virtues on whose survival free markets depend. This concern has been raised by Joseph Schumpeter and Daniel Bell, but has not heretofore been examined from a legal perspective. The "cultural contradictions" claim resonates deeply at a time when America's material capital increases exponentially but its social capital seems fragile. On close scrutiny, the virtues of doux commerce are incontestible. What remains an issue, however, is whether these virtues come at a price. Does living in a market society require one to sacrifice other ways of encountering the world, as Weber and Heidegger suggested. Nevertheless, this does not supply a reason to impeach individual choice, and this attack on free bargaining therefore fails. Moreover, the individual virtues that plausibly support free bargaining would appear to thrive under free markets.
A Freeze-Sectioning Method for Preparation of the Detergent-Resistant Cytoskeleton Identifies Stage-Specific Cytoskeleal Proteins and Associated mRNA in Xenopus Oocytes and Embryos. (Cytoskeleton/amphibian/mRNA)

Proteins of the detergent-resistant cytoskeleton fraction and the detergent-soluble fraction from Xenopus oocytes and embryos are examined using a procedure which allows rapid and uniform extraction of tissues and large, single cells. SDS-polyacrylamide gels reveal only a few prominent cytoskeletal proteins in the early embryo, however qualitatively different proteins begin to appear after gastrulation. Incorporation of [35S]-methionine into newly synthesized proteins indicates that there is synthesis and assembly of proteins into the cytoskeleton, but the amount remains low until after gastrulation. The use of nucleic acid probes for alpha-tubulin and actin mRNA indicates that about 80% of these mRNAs in the oocyte and meiotically mature egg are bound to the detergent-resistant cytoskeleton.
A Critique of Dosage Type Measures of Community Noise

A highway traffic noise simulator is employed to generate statistical descriptions of the A-weighted instantaneous sound levels at several observer positions. It is suggested that some kinds of noise impact are more appropriately described by instantaneous criteria than by cumulative criteria. It is shown that if such instantaneous criteria are assumed, one obtains a significantly different evaluation of the relative contributions of different noise sources than would be obtained from an evaluation based upon cumulative criteria. The actual quantification of the relative contributions of different noise sources is quite sensitive to the choice of instantaneous criterion.
Skin EffectNormal and Anomalous

This chapter contains sections titled: Introduction Low-frequency Resistance and Inductance of a Solid Round Wire Current Distribution in Solid Circular Wire with AC Excitation Surface Impedance of a Solid Circular Wire with AC Excitation Exact General Solution for Propagation Properties of a Wave between the Surfaces of Thick, Plane Strip-line Conductors Analysis of Assumptions used in Transmission-line Analyses Surface Impedance of a Thick, Plane Conductor Surface Impedance of a Plane Conductor of Any Thickness Plane Wave Incident Perpendicularly on a Thick, Plane Conductor Introduction to Anomalous Skin Effect Limitations of Ohm's Law-Local versus Nonlocal Theory Surface Impedance of a Semi-infinite Half-plane with Anomalous Skin Effect Extreme Anomalous Skin Effect-Ineffectiveness Concept Thin Conductors This chapter contains sections titled: Appendix 4A Problems References
Solar cycle dependence of ion cyclotron wave frequencies

Electromagnetic ion cyclotron (EMIC) waves have been studied for decades, though remain a fundamentally important topic in heliospheric physics. The connection of EMIC waves to the scattering of energetic particles from Earth's radiation belts is one of many topics that motivate the need for a deeper understanding of characteristics and occurrence distributions of the waves. In this study, we show that EMIC wave frequencies, as observed at Halley Station in Antarctica from 2008 through 2012, increase by approximately 60% from a minimum in 2009 to the end of 2012. Assuming that these waves are excited in the vicinity of the plasmapause, the change in Kp in going from solar minimum to near solar maximum would drive increased plasmapause erosion, potentially shifting the generation region of the EMIC to lower L and resulting in the higher frequencies. A numerical estimate of the change in plasmapause location, however, implies that it is not enough to account for the shift in EMIC frequencies that are observed at Halley Station. Another possible explanation for the frequency shift, however, is that the relative density of heavier ions in the magnetosphere (that would be associated with increased solar activity) could account for the change in frequencies. In terms of effects on radiation belt dynamics, the shift to higher frequencies tends to mean that these waves will interact with less energetic electrons, although the details involved in this process are complex and depend on the specific plasma and gyrofrequencies of all populations, including electrons. In addition, the change in location of the generation region to lower L shells means that the waves will have access to higher number fluxes of resonant electrons. Finally, we show that a sunlit ionosphere can inhibit ground observations of EMIC waves with frequencies higher than ∼0.5 Hz and note that the effect likely has resulted in an underestimate of the solar-cycle-driven frequency changes described here.
Professional competencies and training needs of professional social workers in integrated behavioral health in primary care

The Affordable Care Act has led to a widespread movement to integrate behavioral health services into primary care settings. Integrated behavioral health (IBH) holds promise for treating mild to moderate psychiatric disorders in a manner that more fully addresses the biopsychosocial spectrum of needs of individuals and families in primary care, and for reducing disparities in accessing behavioral health care. For behavioral health practitioners, IBH requires a shift to a brief, outcome-driven, and team-based model of care. Despite the fact that social workers comprise the majority of behavioral health providers in IBH settings, little research has been done to assess the extent to which social workers are prepared for effective practice in fast-paced primary care. We conducted a survey of social workers (N = 84) in IBH settings to assess the following: (1) Key competency areas for social work practice in IBH settings and (2) Self-rated preparedness for effective practice in IBH settings. Online snowball sampling methods were used over a period of 1 month. Results indicate that social workers feel prepared for general practice in IBH settings, but would benefit from additional training in IBH-specific competency areas identified in the survey. Findings can help guide social work training to improve workforce preparedness for practice in IBH settings in the wake of health care reform.
Molecular sieve based MRI contrast agents

Abstract The application of zeolite molecular sieves as magnetic resonance imaging contrast agents for the gastrointestinal tract is described. Results for the preparation and characterization of zeolite GdNaY, the principle component of Gadolite, are presented. Ion exchange studies suggest GdNaY is stable to relatively low pH values as well as in dilute NaCl solutions. Preliminary relaxivity (R) measurements of aqueous GdNaY suspensions at room temperature and 40 MHz indicate an increase in R with a decrease in zeolite gadolinium loading.
Mucosal immune dysfunction associated with alcoholic IgA nephropathy.

Abstract We investigated the hypothesis that alcohol-induced changes of the immune system result in IgA nephropathy (IAN). Wistar rats were infused with liquid diet containing alcohol: “alcoholics”. Control rats received an isocaloric diet with glucose instead of alcohol. IAN was diagnosed by mesangial IgA deposition. When compared to controls, serum IgA in alcoholic rats with IAN had a fourfold increase and a twofold increase in alcoholics without IAN. The intestinal lamina propria showed overall lymphocyte depletion in alcoholic rats. The decrease was not uniform for all the lymphocyte subgroups: it resulted in a relative increase in IgA-B cells in alcoholic rats with IAN but not in alcoholic rats without IAN. No significant differences were observed between alcoholic and control rats in the percentages of spleen lymphocyte subtypes. We suggest that dysfunction of the mucosal immune system may be related to the induction of IAN in chronic alcohol consumption.
Small-Scale Dynamics of Large-Scale Processes

IN HIS PROVOCATIVE ESSAY, David Brion Davis, to whom all of us who work on the history of slavery owe so much, has offered a glimpse of several pedagogical and conceptual strategies that can help overcome the tendency toward the compartmentalization of the study of slavery. He notes two axes along which slavery studies can expand: first, the rich and by now familiar field of comparative studies; and, second, what he sees as the less developed area of broadly systemic approaches. Some of the latter might be characterized by the term Atlantic Studies. Though rarely invoked as a recognized subfield for the purposes of job definition, Atlantic Studies has indeed emerged as an organizing principle under which multiple phenomena within and outside metropoles and colonies can be linked, often with slavery at the core.1 Davis's argument for the centrality of slavery, however, goes beyond the importance of the slave trade and slave labor in the construction of the Atlantic system, and invokes the powerful apparent contradiction between the New World as a place of opportunity and new beginnings, on the one hand, and a place of retrograde and exploitative labor relations embodied in slavery, on the other. It is from this vantage point that he asserts that "the Big Picture" is indispensable. Davis sketches a fascinating undergraduate course focused on the making and then the overthrow of New World slavery, encompassing themes as varied as biblical constructions of bondage and the life histories of the Italian bankers who
A theoretical investigation of bed-form shapes

The deformation of movable boundaries under the action of an applied turbulent shear stress is well known. The resulting bed forms often are highly organized and nearly two-dimensional, which makes them an intriguing focus of study considering that they are generated in both steady and oscillatory turbulent flows. Many past studies share a common approach in which an infinitesimal perturbation is prescribed and the resulting growth or decay patterns are examined. In this approach, the bed forms are usually sinusoidal and the perturbation analysis does not provide a theoretical prediction of equilibrium bed-form geometry. An alternative approach is suggested here in which the forcing terms (pressure and stress) are prescribed parametrically and the governing equations are solved for the flow velocity and the associated boundary deformation. Using a multilayered approach, in which the bottom boundary layer is divided into a discrete, yet, arbitrary number of finite layers, analytical solutions for the horizontal current and bed profile are derived. The derivations identify two nondimensional parameters, p 0/u 0 2 and Δτ0/k h 0 u 0 2, which modulate the amplitude of the velocity fluctuations and boundary deformation. For the case of combined pressure and stress divergence anomalies, the magnitude of the front face and lee slopes exhibit an asymmetry that is consistent with observed bed forms in steady two-dimensional flows.
Micro-fabricated perforated polymer devices for long-term drug delivery

Fabrication techniques have been developed to produce a perforated polymer microtube as a drug delivery device. The technique consists of first forming a silicon platform with trenches and alignment marks to hold the tubes for subsequent processing. Photolithography and reactive ion etching with an inductively coupled plasma source were used to fabricate micro holes on the surface of polyimide tubes. Several materials have been used to form the etching mask, including titanium film deposited by e-beam evaporation and SiO2 and SiNx films deposited by high-density plasma chemical vapor deposition (HDPCVD). Three equidistant holes of 20 μm in diameter were fabricated on polyimide tubes (I.D. = 125 μm). The perforated tubes were loaded with ethinyl estradiol and tested for drug release in phosphate buffered saline (pH = 7.1) at 37°C. Zero order release was observed over a period of 30 days with a potential to be extended to 4 years.
Spinning Tops in External Fields: Nonadiabatic Alignment in Complex Systems

Short, intense laser pulses can be used to excite rotationally-broad, aligned wavepackets with fascinating properties. We extend the alignment concept to dissipative media and propose applications in quantum information, molecular switches, and guided molecular assembly.
Periodic reflecting paths in right triangles

A reflecting path in a Jordan curve has the ready physical analogies of a billiards ball bouncing off the cushions of a custom billiards table and of a laser beam reflecting off the mirrored boundary of a thin cavity. What does the curve tell us about the possible reflecting paths? Two types of reflecting paths are of perennial interest — periodic paths and dense paths.
Decay of thermally emitted n-p states: A means to measure their lifetime.

The evaporation and subsequent decay of n-p states (especially /sup 2/H(: the singlet deuteron) from compound nuclei is examined theoretically. The energy difference between a proton and neutron observed in coincidence provides information about the time interval between the thermal emission and the breakup of the n-p state. It thus offers the opportunity for measuring a lifetime of the order of 10/sup -21/ seconds, without recourse to the relation ..delta..t = h/GAMMA. Thermal emission of both singlet and triplet deuterons is considered. The subsequent decay through the natural mode and polarization mode is calculated. Results of Monte Carlo calculations are presented for both coincidence and singles spectra, and the feasibility of direct lifetime measurement is discussed.
A decompression core for powerPC

Code size efficiency is a critical parameter in the design of computer systems for embedded applications. This paper describes a method for improving code size efficiency involving the use of compression techniques to reduce the size of the stored code, and on-the-fly hardware decompression at full processor speed for execution. A simple frequency-based encoding scheme for PowerPC® code achieves a typical code size reduction to 60% of the original size. A corresponding decompression core has been implemented for an embedded microprocessor, such as the PowerPC 401TM. The compression/decompression scheme operates in a manner transparent to the processor and requires no changes to such tools as compilers, linkers, and loaders.
Alteration of uracil-DNA glycosylase activity by uracil dimers in DNA.

— The effects of UV irradiation on double-stranded PBS-2 phage DNA, which contains uracil in place of thymine, were studied. Irradiation by 254 nm light, or by 313 nm light in the presence of the triplet sensitizer acetophenone, resulted in production of uracil-containing pyrimidine photodimers. DNA chain breaks were also produced under both conditions. Uracil-DNA glycosylase released free uracil, but no uracil-containing dimers from such irradiated DNA. The rate of enzymatic release of uracil from irradiated PBS-2 DNA was decreased as the number of photodimers per DNA molecule was increased.
Thrombolytic efficacy and enzymatic activity of rt-PA-loaded echogenic liposomes

Echogenic liposomes (ELIP), that can encapsulate both recombinant tissue-type plasminogen activator (rt-PA) and microbubbles, are under development to improve the treatment of thrombo-occlusive disease. However, the enzymatic activity, thrombolytic efficacy, and stable cavitation activity generated by this agent has yet to be evaluated and compared to another established ultrasound-enhanced thrombolytic scheme. A spectrophotometric method was used to compare the enzymatic activity of the rt-PA incorporated into ELIP (t-ELIP) to that of rt-PA. An in vitro flow model was employed to measure the thrombolytic efficacy and dose of ultraharmonic emissions from stable cavitation for 120-kHz ultrasound exposure of three treatment schemes: rt-PA, rt-PA and the perfluorocarbon-filled microbubble Definity®, and t-ELIP. The enzymatic activity of rt-PA incorporated into t-ELIP was 28 % that of rt-PA. Thrombolytic efficacy of t-ELIP or rt-PA and Definity® was equivalent when the dose of t-ELIP was adjusted to produce comparable enzymatic activity. Sustained bubble activity was nucleated from Definity but not from t-ELIP exposed to 120-kHz ultrasound. These results emphasize the advantages of encapsulating a thrombolytic and the importance of incorporating an insoluble gas required to promote sustained, stable cavitation activity.
Suppression of virulence factors of Pseudomonas aeruginosa by erythromycin

The effects of erythromycin stearate over a concentration range of 0.1-10 mg/l on production of elastase, protease and leucocidin by clinical isolates of Pseudomonas aeruginosa were investigated. Growth of P. aeruginosa N42 in broth was not affected significantly during 24 h culture with erythromycin (0.1-10 mg/l), although extracellular protein contents were reduced by erythromycin at concentrations of 0.1-1.0 mg/l. Production of elastase and protease by strain N42 was significantly suppressed by erythromycin with a maximum inhibition at 0.5 mg/l, but the complete inhibition of enzyme production was not achieved. In contrast, leucocidin production by strain N42 was completely impaired by erythromycin at concentrations of 0.1-5.0 mg/l. Although the leucotoxic activity, as determined by vital staining, was not detected, the leucocidin fraction prepared from the autolysate of strain N42 cultured with 10 mg/l of erythromycin induced morphological changes in human leucocytes, resulting in release of elastase. Erythromycin exerted similar effects on other clinical isolates of P. aeruginosa. These findings indicate that erythromycin might have a role in P. aeruginosa infection, although it has no direct antibacterial activity.
Integral Gummel relation for single- and double-heterojunction graded-base HBTs

Integral Gummel charge-control relation for both linearly graded- and non-graded-base and for single or double-heterojunction bipolar transistors has been derived. In addition to modeling the collector current density for different heterojunction biopolar transistor with and without graded energy gap in the base. Comparisons with numerical and experimental data show excellent agreement.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Suhl-Nakamura interaction and inhomogeneous broadening

Abstract The effect of microscopic inhomogeneities on the Suhl-Nakamura indirect interaction between nuclear spins is shown to alter the NMR line shapes in the direction observed experimentally. Two simple models for exploring these effects are proposed.
Surreptitious self-administration of epinephrine resulting in 'pheochromocytoma'.

SELECTED CASE A 35-YEAR-OLD woman with a possible pheochromocytoma was referred to the National Institutes of Health (NIH) from Pittsburgh, Pa. Her symptoms started in December 1987, when she developed headache, tremor, tachycardia, and mild hypertension after an injection of novocaine and epinephrine. Soon the episodes began to occur spontaneously. She often went to a local emergency department, where her blood pressure was as high as 160/100 mm Hg and her heart rate as high as 140 beats per minute. Her urinary epinephrine output was 1600 nmol/d (normal,
A Krasovskii-LaSalle function based recurrence principle for a class of stochastic hybrid systems

We characterize the sets to which bounded random solutions generated by a class of stochastic hybrid systems converge under the existence of a Lyapunov-like function that is non-increasing almost surely during flows and on average during jumps. In particular, we establish that we get almost sure convergence to the largest weakly totally recurrent in probability set that is contained in a level set of this function. We also apply this result to establish weak sufficient conditions for uniform global asymptotic stability in probability of compact sets and uniform global recurrence of open, bounded sets for a class of stochastic hybrid systems.
Magnetically enhanced protection of bone marrow from beta particles emitted by bone-seeking radionuclides: theory of application.

Utilization of radiopharmaceuticals that directly target radioactivity to tumors for treatment has a great deal of promise. Ideally, lethal doses of radiation could be delivered precisely to areas of disease, while, for the most part, sparing normal tissues. This potential, however, has not yet been fully realized. Current limitations of this approach are low tumor uptake of radiopharmaceuticals and dose‐limiting radiotoxicity. In an effort to offset low uptake, radionuclides that emit high average‐energy electrons have been proposed. Unfortunately, use of these radionuclides increases myelosuppression on a per decay basis. In order to allow for the utilization of high doses of this class of high‐energy beta emitters, we propose the application of a strong static homogeneous magnetic field to constrain the beta particles.Monte Carlo computer simulations indicate that application of a 10 T magnetic field can decrease the total radiationdose from bone‐avid tracers to marrow located in shafts of human long bones by 14%. More significantly, however, the penetration depth of high‐energy electrons from the bone surface into the marrow can be reduced by up to 74.6%. Preservation of marrow in areas distal to the bone has previously been shown to facilitate relatively rapid recovery from pancytopenia produced by radiation damage to trabecular marrow (without marrow transplantation). Magnetically enhanced protection of bone marrow, therefore, may allow administered doses of high‐energy beta‐emitting radionuclides to be increased. By raising the limits on injected quantities of such highly ionizing radionuclides, amounts of the radiationdose absorbed by both soft and calcified tissuetumors will be increased, compared to conventional treatments. Hence, it is possible that this technique will, in part, aid in the realization of the promise of radionuclide therapy by permitting the delivery of therapeutic levels of radiation exposure to tumors.
Management of Obliterated Urinary Segments Using a Laser Fiber for Access

ABSTRACTPurpose: We describe a modification of the cut to the light and core-through procedures using a laser fiber to gain through and through access for treatment of complete occlusion of the ureter or urethra.Materials and Methods: Three patients presented with complete obliteration of the ureter (2) and vesicourethral anastomosis (1). In each case the laser fiber was advanced through the obliterated segment under direct vision and then exchanged for a standard guide wire using an open ended catheter.Results: Through and through access was obtained in all 3 cases and allowed subsequent incision for repair. In all 3 patients the area of incision was stented and urinary continuity was restored.Conclusions: Loss of access can lead to complications and termination of any endoscopic procedure. Use of the laser fiber to incise through the obliterated segment and subsequently act as a guide wire in our experience minimized the possibility for loss of access. The disadvantage is the cost of the laser fiber, wh...
The Resonance Energy of Benzene: A Revisit

Zielinski and van Lenthe recently extended the block-localized wave function (BLW) method by introducing the resonating BLW (RBLW) method and performed test calculations on hexagonal H(6) and benzene [J. Phys. Chem. A 2008, 112, 13197]. However, the Pauling's resonance energies from their RBLW and ab initio valence bond (VB) calculations were greatly underestimated largely due to the imperfect use of either one-electron orbitals (method = delocal) or resonance structures (method = local). Whereas it has been well recognized that electronic resonance within a molecular system plays a stabilizing role, there are many indirect experimental evidences available to evaluate the resonance energy and, thus, to justify computational results. Here we used the BLW method, which can be regarded as the simplest variant of modern ab initio VB theory, to re-evaluate the resonance energy of benzene at the B3LYP level, following the original definition by Pauling and Wheland, who obtained the resonance energy "by subtracting the actual energy of the molecule in question from that of the most stable contributing structure". The computed vertical resonance energy (or quantum mechanical resonance energy) in benzene is 88.8, 92.2, or 87.9 kcal/mol with the basis sets of 6-31G(d), 6-311+G(d,p), or cc-pVTZ, respectively, while the adiabatic resonance energy (or theoretical resonance energy) is 61.4, 63.2, or 62.4 kcal/mol, exhibiting insignificant basis set dependency for moderate basis sets. In line with predictions, the geometry optimization of the elusive cyclohexatriene (i.e., the Kekule structure) with the BLW method also resulted in carbon-carbon bond lengths (e.g., 1.322 and 1.523 A with the cc-pVTZ basis set) comparable to those in ethylene or ethane.
Impact of a Common Clinical Pathway on Length of Hospital Stay in Patients Undergoing Open and Minimally Invasive Kidney Surgery

Purpose: Clinical pathways are designed to reduce variability in patient care practices and improve clinical outcomes. We evaluated the effect of implementing a clinical care pathway on length of stay in patients undergoing kidney surgery.Materials and Methods: After receiving institutional review board approval we evaluated prospective data on consecutive cases of partial and radical nephrectomy performed at our institution from 2000 to 2011. We identified 1,775 partial nephrectomies (1,449 open and 326 minimally invasive) and 1,025 radical nephrectomies (857 open and 168 minimally invasive). We used multivariate linear regression to test for an interaction between procedure type and surgery before vs after the clinical pathway was begun.Results: Median length of stay decreased 40% (from 5 to 3 days) for open surgery and 33% (from 3 to 2 days) for minimally invasive surgery after clinical pathway implementation. Length of stay in patients treated with minimally invasive or open partial nephrectomy and op...
Halothane, enflurane, and isoflurane do not affect the basal or agonist-stimulated activity of partially isolated soluble and particulate guanylyl cyclases of rat brain.

Background : Evidence suggests that inhalational anesthetics interact with the nitric oxide-guanylyl cyclase signaling pathway in the central nervous system and that the inhibition of this pathway in brain may result in an anesthetic, analgesic, or sedative effect. The mechanism of the effects of inhalational anesthetics on this signaling pathway is not clear. This study attempted to determine whether inhalational anesthetics directly affect soluble or particulate guanylyl cyclase activity in a partially isolated enzyme system. Methods : The effects of halothane (0.44-4.4%), enflurane (1.34-6.7%), and isoflurane (0.6-5.0%) on basal or stimulated soluble or particulate guanylyl cyclase activity were examined. Soluble guanylyl cyclase was isolated from whole rat brain and was stimulated by sodium nitroprusside or nitric oxide. Particulate guanylyl cyclase was isolated from rat olfactory bulb and was stimulated by rat atrial natriuretic peptide 1-28 ). Cyclic guanosine monophosphate content was measured by radioimmunoassay. The concentrations of anesthetics in the incubation solution were confirmed by gas chromatography methods. Results : None of the three anesthetics affected the activity of basal or stimulated soluble or particulate guanylyl cyclase at the concentrations examined in the current experimental conditions. Conclusions : These results suggest that halothane, enflurane, and isoflurane do not directly interact with soluble or particulate guanylyl cyclases of rat brain.
A design of expert system architecture for communications engineering simulation

Simulation expert system architecture for communications simulation including the features of common data structure, top- down information driven technique, optimization, and expert system approach is addressed. The concepts can be combined to implement a very user-friendly simulation system for either a novice or experienced user. The architecture block diagram of the simulator is discussed to highlight the important functions. Complete or partial features addressed can be adopted in any simulator design.
The Effect of Vortex Formation on Left Ventricular Filling and Mitral Valve Efficiency

A new mechanism for quantifying the filling energetics in the left ventricle (LV) and past mechanical heart valves (MHV) is identified and presented. This mechanism is attributed to vortex formation dynamics past MHV leaflets. Recent studies support the conjecture that the natural healthy left ventricle (LV) performs in an optimum, energy-preserving manner by redirecting the flow with high efficiency. Yet to date, no quantitative proof has been presented. The present work provides quantitative results and validation of a theory based on the dynamics of vortex ring formation, which is governed by a critical formation number (FN) that corresponds to the dimensionless time at which the vortex ring has reached its maximum circulation content, in support of this hypothesis. Herein, several parameters (vortex ring circulation, vortex ring energy, critical FN, hydrodynamic efficiencies, vortex ring propagation speed) have been quantified and presented as a means of bridging the physics of vortex formation in the LV. In fact, the diastolic hydrodynamic efficiencies were found to be 60, 41, and 29%, respectively, for the porcine, anti-anatomical, and anatomical valve configurations. This assessment provides quantitative proof of vortex formation, which is dependent of valve design and orientation, being an important flow characteristic and associated to LV energetics. Time resolved digital particle image velocimetry with kilohertz sampling rate was used to study the ejection of fluid into the LV and resolve the spatiotemporal evolution of the flow. The clinical significance of this study is quantifying vortex formation and the critical FN that can potentially serve as a parameter to quantify the LV filling process and the performance of heart valves.
New Hybrid Runge-Kutta Methods for Unsteady Reactive Flow Simulation: Applications

The applicability is examined of the new hybrid Runge-Kutta methods derived in the companion paper by specifically analyzing both nonstiff and stiff system of equations that represent multidimensional reactive flows. In a reactive flow simulation, the standard explicit calculation is prohibitively expensive because of the small time steps needed to address the stiffness of a governing differential system. The new hybrid Runge-Kutta schemes are suitable for this task because the time-step size is controlled by the Courant condition, whereas the stiffness is treated by an unconditionally stable method. This set of methods also meets the modern computing needs of high-order accuracy and low-storage requirement. A representative scheme is used to simulate a series of combustion problems that include model equations with stiff sources and multidimensional detonations with complex chemical kinetics
Determination of a dynamical model for time-lag systems using a second-order method

Abstract A computational scheme is presented to determine the parameters in a time-lag system. A mathematical form for the system is assumed, and the unknown parameters, including those in the time lag, are determined by applying the method of least-squares fit to the observed discrete-time data. The algorithm is constructed by means of second- order terms. Examples using digital simulation are presented to demonstrate the applicability of the method.
NOAA Ship Okeanos Explorer: Telepresence in the Service of Science, Education and Outreach

The National Oceanic and Atmospheric Administration's (NOAA's) Ocean Exploration (OE) Program dedicates 10% of its annual budget to education and public outreach. As exciting expeditions are the core of the OE program, education and outreach efforts are typically focused around these missions. Since the program's inception five years ago, education and outreach activities have been implemented mainly through NOAA's award-winning Web site (oceanexplorer.noaa.gov) and through a variety of direct and indirect efforts. Through these various initiatives, as well as others more specifically tailored to individual needs, OE works with traditional and non-traditional educational institutions to provide exciting programs and products to enhance ocean literacy across the U.S. The OE program is now poised to initiate a major ongoing satellite-based education and public outreach program from its new dedicated research vessel, the Okeanos Explorer that will become operational in 2008. Through telepresence technology designed by the Institute for Exploration (IFE) in Mystic, CT, expeditions can be managed `virtually' by scientists working from Science Command Centers on land, and live education broadcasts can be produced in real-time through collaborations with groups such as IFE, the JASON Foundation for Education, and Immersion Presents. Three pilot programs were successfully completed in the past three years demonstrating the potential for this new technology to allow for unlimited access to data, including video, from expeditions in real-time, sharing the excitement of discovery through multiple virtual pathways at once.
Born to lose. I. Measures of tissue loss and regeneration by the brittlestar Microphiopholis gracillima (Echinodermata: Ophiuroidea)

To measure amounts of tissue lost in natural populations of the burrowing amphiurid ophiuroid Microphiopholis gracillima (Stimpson), individuals were collected from subtidal mud flats in North Inlet, South Carolina, USA, at monthly intervals between February 1985–February 1987 and December 1989–November 1990. Between 20 and 70% of all individuals were regenerating the disc, and 85% of the 2045 arms examined had regeneration scars; >50% had one scar and some arms had up to 4 scars. Fewer individuals were regenerating discs in warmer months, but there was no seasonality in arm-loss frequency. To quantify rates of arm regeneration in the field, individuals which had 1, 2, or 3 arms removed were placed in mud-filled cores in the field in late July and November 1988 and in March and May 1989, and recovered after periods of about one month. Another set of cores was held in a running seawater laboratory during the May 1989 experiment. No regeneration occurred during the cooler times of year (November and March), and rates of regeneration were slower in May (total: 0.13 mg/d; tissue: 0.03 mg/d) than July (total: 0.17 mg/d; tissue: 0.05 mg/d). These rates indicate complete replacement of lost tissue in 100 to 120 d during the growth season. Within experiments, per arm regeneration rates were similar regardless of the number of arms removed. This finding is complicated by small sample size, high variability and low statistical power, but in general individuals which lost 2 or 3 arms regenerated proportionally more tissue than individuals which lost 1 arm. Individuals held in the laboratory regenerated the same amount of tissue but 30% less skeleton than individuals in the field. Sublethal tissue loss is common in this population, and M. gracillima is capable of regenerating at least 50% (each arm=17% of total body weight x 3) of its standing crop in a single growing season. Burrowing brittlestars probably constitute a significant renewable energy source for higher trophic levels in areas where they occur in dense populations.
Entry and exit by new versus existing firms

Abstract Firms relocating across industries or product lines are empirically relevant in industry dynamics: they account for 22% of exit; and two-thirds of surviving firms alter their product mix every 5 years. Yet, existing theories of industry dynamics focus exclusively on new entrants and assume that firm exit is synonymous with failure. This paper proposes a model that incorporates entry and exit by both new and existing firms into a standard framework of industry dynamics. There are two forms of exit: a firm may shut down by selling its assets to earn their salvage value, or reallocate its assets at a cost to enter another industry or product line. In equilibrium, a low-skill firm shuts down from and a high-skill firm transfers out of an industry with a low state of demand. We show the model is consistent with a series of stylized facts pertaining to the entry and exit patterns of new versus existing firms.
The precision of positron emission tomography: theory and measurement.

The limits of quantitation with positron emission tomography (PET) are examined with respect to the noise propagation resulting from radioactive decay and other sources of random error
DNA synthesis in promastigotes of Leishmania major and L. donovani.

Abstract The requirement of protozoan parasites for pre-formed purines affords the opportunity for quantitation of nucleic acid synthesis from incorporation of radioactively labeled purines into DNA and RNA. We have developed rapid and simple assays to quantitate DNA and RNA synthesis in promastigotes of Leishmania major and L. donovani from the incorporation of [ 3 H]hypoxanthine. DNA but not RNA synthesis in L. major or L. donovani promastigotes was inhibited by aphidicolin (50% inhibition by 0.2–0.3 μM) and by hydroxyurea (50% inhibition by 0.3–0.5 mM). The inhibition of DNA synthesis by aphidicolin or hydroxyurea was reversible when the inhibitor was removed 2, 4 or 24 h after its addition. Several well-characterized agents that inhibit DNA synthesis in mammalian cells, 1-β- d -arabinofuranosylcytosine (araC), 9-β- d -arabinofuranosyladenine (araA), phosphonoacetic acid, novobiocin and N 2 -( p - n -butylphenyl)guanine (BuPG), failed to inhibit DNA synthesis in promastigotes of L. major even when used at very high concentrations, demonstrating differences between DNA replication components of parasite and host.
Intensified therapy for infants with acute lymphoblastic leukemia: results from the Dana-Farber Cancer Institute Consortium.

BACKGROUND Infants with acute lymphoblastic leukemia (ALL) have a very poor prognosis. Since 1985, we have intensified therapy for infants with ALL by including a month of high dose multiagent chemotherapy after remission induction. METHODS Between 1985 and 1995, we treated 23 infants (age < 12 months). We compared the presenting characteristics and outcomes of these infants with the 11 infants treated on our protocols between 1973 and 1985, an era prior to the intensification of therapy. Available bone marrow samples from infants treated since 1985 were analyzed for the presence of MLL gene rearrangements by Southern blot analyses and for TEL-AML1 gene fusion by reverse transcriptase-polymerase chain reaction. RESULTS With a median follow-up of 5.6 years, the 50-month event free survival (EFS) (± standard error) for the 23 infants was 54 ± 11%, a significant improvement (P = 0.001) compared with the outcome for the 11 infants treated on our protocols prior to 1985 (EFS = 9 ± 9%). Of the seven infants found to have a rearranged MLL gene, three (43%) remained in first complete remission. None of the nine infant bone marrow specimens tested had evidence of TEL-AML1 gene fusion. The intensified therapy was complicated by a high incidence of infections, including septicemia in 52% of patients and Pneumocystis carinii pneumonitis in 22% of patients. Late effects identified in the 13 long term survivors (median age, 6 years) included developmental delay and learning disabilities of varying severity (82% of evaluable patients), asymptomatic cataracts (67%), asymptomatic echocardiographic abnormalities (30%), obesity (27%), and short stature (18%). CONCLUSIONS Intensification of therapy significantly improved the EFS of infants with ALL compared with previous, less intensive regimens and with the experience of other investigators. Future treatment for infants should attempt to improve efficacy while minimizing toxicity. Cancer 1997; 80:2285-95. © 1997 American Cancer Society.
Delineation of mafic intrusions near Bedford (Virginia, USA) using geological and geophysical methods

In the present work, geological and geophysical methods were used to delineate the locations of multiple mafic intrusions at the Claytor Nature Study Center (CNSC) near Bedford, VA. An investigation of the groundwater hydrology of CNSC was launched in 2007. As a first step in that project a preliminary geological survey revealed sparse evidence of a number of diabase intrusions in the area. While diabase intrusions are not particularly permeable features, contact metamorphism of the host rock could provide conduits for groundwater due to stress fractures and joints and high-temperature recrystallization of the rock matrix. Following the geological survey, geophysical surveys including seismic refraction, ground penetrating radar, and magnetic ground measurements were conducted to determine the location and extent of these multiple igneous intrusions. Seismic and radar surveys proved to be inconclusive, but the magnetic surveys showed strong magnetic anomalies. The magnetic data were obtained using a Geometrics G-856 proton precession magnetometer and were interpreted using the Mag2dc algorithm and SGeMS geostatistical software. The results show that the intrusions are dikes that cut across nearly perpendicular to the regional metamorphic structures and trend generally north–south with a dip of approximately 75°–90° to the west. These findings are consistent with one of the general directions of stresses associated with the North Atlantic seafloor spreading in late Triassic or early Jurassic period. Subsequent hydrologic testing and groundwater modeling confirm the role of the dikes in the overall hydrogeology of the site.
Sylow-like theorems in geometry and algebra

The notion of congruence provides a means to extend the Sylow theorems from group theory to a class of geometric structures called congruence spaces and to their corresponding loops. The extension of these results depends on the existence of a group acting transitively on the congruence space and preserving congruence. A partial ordering on the congruence spaces suggests a means to form all of these spaces from groups.
REMOVING GOLD COATING FROM SEM SAMPLES

Abstract: An essential tool in micropalaeontological studies is analysis and imaging using a scanning electron microscope (SEM). It is commonly necessary to coat the sample with a thin layer of gold or gold-palladium alloy in order to prevent charging of the surface, to promote the emission of secondary electrons so that the specimen conducts evenly, and to provide a homogeneous surface for analysis and imaging. However, coating a specimen with gold is a semi-destructive process that masks the surface of specimens, and a common curatorial practice is to prohibit coating of important specimens. We describe a non-destructive, simple and inexpensive technique that uses KCN (or NaCN), a glass jar, paper towels, cardboard and a fume hood for the removal of gold coatings from SEM samples. This technique requires little additional handling of the specimen, and there is no need to place the specimen in a solution.
Characterisation of Al/AlInAs/GaInAs heterostructures

The paper is concerned with the characterisation of Al/AlInAs/GaInAs hetrostructures. A band model is presented for the metal/semiconductor barrier, and the electrical studies are shown to be consistent with this model. Preliminary studies are reported on a DLTS investigation of the hetrostructure and a deep level situated 0.41 eV below the conduction band of the AlInAs.
Men's and women's knowledge and perceptions of breast cancer and mammography screening.

Background. Although most men are not directly affected by breast cancer, they participate in decisions influencing breast cancer screening and contribute to shaping the social norm on mammography screening. This study tested the hypothesis that men may be less knowledgeable than women about breast cancer and mammography and have less favorable perceptions of mammography screening. Methods. A survey was mailed to 952 women and 370 men aged 40 to 80 years, randomly selected from the general population of Geneva, Switzerland. Information collected included knowledge and perceptions about breast cancer and mammography, familiarity with screening recommendations, and perceived usefulness of an organized screening program. Results. Men were almost as knowledgeable as women about breast cancer (difference in z-scores: −0.12; 95% CI: −0.25, 0.02; P = 0.10) and breast cancer screening (difference: −0.12; 95% CI: −0.25, 0.02; P = 0.09). Both men and women perceived mammography screening to be useful, but men had significantly higher z-scores of positive attitude toward mammography than women (difference: 0.28; 95% CI: 0.14, 0.42; P < 0.001). Younger and more educated respondents of either sex were both more knowledgeable and more favorably inclined toward screening. Conclusion. Men were as knowledgeable about breast cancer and mammography screening as women but had more favorable attitudes toward breast cancer screening than women. Actions to strengthen community support for mammography screening programs should primarily target older and less educated persons of either sex.