cssi/SciSciGPT-SciSciNet huggingface dataset:
Virtual Prototyping Process For Assessment of Medium Voltage Grid-Connected Solid State Transformer Implementations

This paper presents a unique Virtual Prototyping Process (VPP) that allows for metaheuristic optimization of the building block based Power Electronic Converter systems. The VPP allows for exploration of a range of design space variables, including voltage levels, power semiconductor device technology and thermal management approach against competing objectives such as power density, efficiency and specific cost given electrical and environmental constraints. A unique feature of proposed VPP is compilation of lower voltage building blocks into a much higher voltage rated system and inclusion of allocations for insulation systems, thermal management, accessibility, busing/interconnections and frame/structure/chassis. This approach enables understanding of these practical considerations on power density. This paper presents a use case of a Medium Voltage ac (MVac) to Low Voltage dc (LVdc) solid state transformer.
Determinants of Turnover Intent in Higher Education: The Case of International and U.S. Faculty

DETERMINANTS OF TURNOVER INTENT IN HIGHER EDUCATION: THE CASE OF INTERNATIONAL AND U.S. FACULTY By Jaehee Park, Ph.D. A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at Virginia Commonwealth University. Virginia Commonwealth University, 2015. Major Director: Dr. Myung Hun Jin, Ph.D Assistant Professor of Public Administration L. Douglas Wilder School of Government and Public Affairs In spite of the increase in the number of the international academic workforce and their potential benefits, international status has been relatively under-studied in Public Management and Higher Education literature in comparison with studies of age, gender, and race. Given these realities, the present study identifies characteristics of internal and external variables that influence international and U.S. faculty turnover intentions in a large public South Eastern research university. To understand the variations in short-term and long-term turnover levels while controlling for various demographic, structural, and external variables, eight Ordinary Least Square (OLS) regression analysis were performed using turnover intentions as the dependent variables. Distributive justice has the strongest negative effect on short-term turnover, and communication openness has the strongest negative effect on long-term turnover. After controlling for job satisfaction and organizational commitment, the effect of communication openness on short-term turnover and the effect of distributive justice on long-term turnover are not statistically significant. This suggests that communication openness and distributive justice might affect turnover through job satisfaction and/or organizational commitment. Job satisfaction has the strongest negative effect on short-term turnover and organizational commitment has the strongest negative effect on long-term turnover after controlling for internal and external variables. In addition, this study aims to analyze the differences in internal and external factors that impact faculty turnover by international status. In achieving this aim, international faculty were compared to the U.S. faculty on the afore-mentioned internal and external factors that were shown in the literature to impact turnover. The result shows that structural variables such as autonomy, communication openness, and procedural justice play a bigger part in how international faculty evaluate their career with the current university than it does for U.S. faculty. On the contrary, kinship ties and job opportunity have stronger effects on U.S. faculty turnover than international faculty turnover. The implications of this study and areas of future opportunities are discussed.
Suppressible insertion-induced mutations in Drosophila.

Publisher Summary This chapter provides a review of the basic elements of the origin and behavior of transposons and their relationship to their cellular hosts. It focuses on one specific aspect of the analysis of transposons in Drosophila: the molecular genetic analyses of suppressor/enhancer loci. In this case, the objective is to develop a new, detailed proposal for the role of suppressor/enhancer loci. Transposons carry on a life-style requiring very complex behaviors and decisions. In spite of this, transposons are very small (typically 3 to 10 kb in size), with limited amounts of genetic information. This paradoxical juxtaposition of genetic simplicity and a complex life-style is achieved by extensive parasitism of information produced by the cellular host. Equivalently, transposons carry only a tiny fraction of the genetic information necessary to their existence. This tiny fraction consists of a few functions idiosyncratic to transposition and whatever information is necessary to organize parasitized host functions and information. This latter “organizational” function is incompletely understood but certainly consists of cis-acting regulatory elements responsive to host regulatory information.
Myotonic muscular dystrophy: Calcium-dependent phosphatidate metabolism in the erythrocyte membrane

Abstract It has been suggested that the erythrocytes of myotonic dystrophy (MyD) patients have a decreased calcium-stimulated phosphatidic acid (PA) accumulation. This could be the result of a defect in the calcium-stimulated hydrolysis of the polyphosphoinositides (calcium-dependent phosphodiesterase) or in the subsequent formation of PA from its precursors (diacylglycerol kinase). In vitro assays were established for both enzymes in erythrocyte membranes. Calcium-dependent phosphodiesterase activity was assayed with both endogenous 32 P-labeled erythrocyte diphosphoinositide and triphosphoinositide and with the same phospholipids isolated from rat brain. No significant differences in activity were found between MyD patients and normal controls with either method of substrate preparation. No difference in diglyceride kinase activity was found between ghosts prepared from MyD patients and normal controls. Thus, there were no differences in either of the membrane-associated enzymes of phosphatidic acid metabolism.
Certificate Recocation: Mechanics and Meaning

Revocation of public key certificates is controversial in every aspect: methodology, mechanics, and even meaning. This isn't so surprising, though, when considered in the context of current public key infrastructure (PKI) implementations. PKIs are still immature; consumers, including application developers and end-users, are just beginning to understand the implications of large-scale, heterogeneous PKIs, let alone PKI subtleties such as revocation. In this paper, which is the product of a panel discussion at Financial Cryptography '98, we illustrate some of the semantic meanings possible with current certificate revocation technology and their impact on the process of determining trust relationships among public keys in the PKI. Further, we postulate that real-world financial applications provide analogous and appropriate models for certificate revocation.
Safety of spinal decompression using an ultrasonic bone curette compared with a high-speed drill: outcomes in 337 patients.

Object Unintended durotomies are a common complication of spine surgery and are often correlated with increased postoperative morbidity. Recently, ultrasonic bone curettes have been introduced in spine surgery as a possible alternative to the conventional high-speed drill, offering the potential for greater bone-cutting precision and less damage to surrounding soft tissues. To date, however, few studies have investigated the safety and efficacy of the ultrasonic bone curette in reducing the rates of incidental durotomy compared with the high-speed drill. Methods The authors retrospectively reviewed the records of 337 consecutive patients who underwent posterior cervical or thoracic decompression at a single institution between January 2009 and September 2011. Preoperative pathologies, the location and extent of spinal decompression, and the use of an ultrasonic bone curette versus the high-speed drill were noted. The rates of incidental durotomy, as well as hospital length of stay (LOS) and perioperative ...
Alternating magnetic anisotropy of Li2(Li1–xTx)N (T = Mn, Fe, Co, and Ni)

Substantial amounts of the transition metals Mn, Fe, Co, and Ni can be substituted for Li in single crystalline Li2(Li1–xTx)N. Isothermal and temperature-dependent magnetization measurements reveal local magnetic moments with magnitudes significantly exceeding the spin-only value. The additional contributions stem from unquenched orbital moments that lead to rare-earth-like behavior of the magnetic properties. Accordingly, extremely large magnetic anisotropies have been found. Most notably, the magnetic anisotropy alternates as easy plane→easy axis→easy plane→easy axis when progressing from T = Mn → Fe → Co → Ni. This behavior can be understood based on a perturbation approach in an analytical, single-ion model. As a result, the calculated magnetic anisotropies show surprisingly good agreement with the experiment and capture the basic features observed for the different transition metals.
Promoting Leadership in Doctoral Programs in Mathematics Education

Mathematics educators have many different opportunities to reflect leadership throughout their careers. High quality doctoral programs provide a rich and stimulating environment that supports the development of leadership qualities. This paper describes some ways that leadership can be fostered in doctoral programs in mathematics education.
Mitomycin C and Temperature Induction of Colicin B in the Absence of Deoxyribonucleic Acid Synthesis

An Escherichia coli K-12 strain and its mutant, temperature-sensitive in deoxyribonucleic acid (DNA) synthesis, were used as hosts for two different ColB factors (ColB3-K166 and ColB4-K98). Induction of either colicin occurred in both hosts in the presence of mitomycin C at 42 C. Induction of the temperature-sensitive colicinogenic hosts also occurred without mitomycin C at 42 C at which temperature no DNA synthesis was observed. Colicin synthesis was a nonlethal event in ColB4-K98+ cultures, whereas in cultures of ColB3-K166+ induction led to death of a large fraction of the population.
Generalized effective stiffness theory for nonelastic laminated composites

Abstract Effective stiffness theory of the N th order is derived for the modeling of the 3-dimensional dynamic motion of a laminated medium made of elastic-viscoplastic work-hardening constituents. The resulting theory represents the composite as a higher order homogeneous continuum with microstructure, whose motion is governed by higher order displacements and stresses. The derivation is systematic and can be applied to other types of nonelastic laminated media to the desired degree of accuracy.
A Note on Relative Perturbation Bounds

In this paper we provide an actual bound for the distance between the original and the perturbed right singular vector subspaces of a general matrix with full column rank. We also provide actual relative componentwise bounds for perturbed eigenvectors of a positive definite matrix.
The accuracy of financial report projections of future environmental capital expenditures: a research note

Abstract Financial report environmental disclosure has been widely criticized because the extent of disclosure both varies in response to exposures facing the firm and because it is not an accurate measure of firm environmental performance. This study suggests there are at least two potential problems that need to be addressed before this disclosure can be completely condemned as meaningless. A first potential problem is the earlier studies' focus on broad measures of environmental disclosure. Hidden within those broader measures may be pieces of meaningful information. Second, while the disclosure examined previously may not correspond well with past environmental performance, it, or at least parts of it, may still provide meaningful information for assessing future environmental action. This study attempts to address these shortcomings by examining one specific, but potentially useful, category of environmental disclosure: projections of future spending for pollution abatement and control equipment. Based on 355 sets of projected/actual spending drawn from 10K reports filed with the US's Security and Exchange Commission between 1993 and 2002, inclusive, results suggest that the projections may be more misleading than meaningful. Actual spending was lower than the projected amount for more than 75% of the observations, and the mean projection error (the difference adjusted for the size of the projection) was a negative 16.4%. Analysis of projection errors for a 2-year, rather than a 1-year window revealed a similar distribution. In contrast to the accuracy of the environmental capital expenditure projections, the actual/projection difference for total capital expenditures was very small, suggesting that it is not a difficulty in estimating future capital spending that is driving the error results. The projection errors also did not appear to be a function of changes in company revenues or profitability. Overall, therefore, it appears that, similar to broader measures of corporate environmental disclosure, projections of future spending on environmental control lack value.
Cluster Analysis Techniques to Separate Air Motion and Hydrometeors in Vertical Incident Profiler Observations

Abstract Profilers operating in the UHF range are sensitive to both Bragg scattering from radio refractive index structure and to Rayleigh scattering from small point targets. Identification of the scattering process is critical for proper interpretation of these observations, especially the data collected from the vertical incident beam. This study evaluates the performance of Doppler velocity thresholds as a means to separate air motions from hydrometeor motions in vertical incident profiler observations. This evaluation consists of three different steps. First, using two collocated profilers operating at different frequencies, the observations are unambiguously identified as Bragg or Rayleigh scattering processes. Second, the observations are separated into either air or hydrometeor motion using only the data from one profiler. The third step quantitatively evaluates the performance of the single profiler separation techniques by counting the number of correct classifications and adjusting the count by...
WITNESSING: THE PROCESS OF HOPE

Abstract In this article, Weingarten's (2000) ideas about witnessing are applied to the events and aftermath of September 11, 2001. A discussion that occurred among marriage and family therapy faculty, supervisors, and students about the events of September 11 is examined from a systemic perspective. Structure, process, and patterns are identified through participants' responses on a questionnaire as well as the author's experience. Witnessing is seen as a collaborative, systemic process of creating hope, affected by structure and social context. Implications and reflections are also discussed.
Assessment of the patient in heart failure

Abstract Heart failure is the inability of the heart to act as a pump to supply the body with adequate circulating blood. If the heart suddenly becomes damaged in any way, its pumping ability decreases. Therefore the home care provider must be alert to the clues indicating heart failure so that early interventions can be initiated. This article briefly reviews the basic principles of cardiac function and the classifications of heart failure, basic assessment of the heart failure patient, and assessment for heart failure complications.
Sidewall Covalent Functionalization of Single Wall Carbon Nanotubes Through Reactions of Fluoronanotubes with Urea, Guanidine, and Thiourea

Sidewall covalent functionalization of carbon nanotubes is necessary to achieve smaller bundles and individuals, link to other functional moieties, and aid in better dispersion in composites. In the present study, we developed a one-step functionalization method which uses fluorinated single wall carbon nanotubes (F-SWNTs) as starting materials in the reactions with urea, thiourea, or guanidine. Through these reactions, the derivatives with terminal amide and heteroamide groups on the nanotube sidewalls have been prepared. The nanotubes also contain some residual fluorine generating bifunctional derivatives. These derivatives were characterized by Raman spectroscopy, Fourier Transform infrared (FTIR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and atomic force microscopy (AFM). Compared to fluorinated nanotubes, the urea-functionalized SWNTs (U-F-SWNTs) have shown among the three derivatives the high...
A homogeneously dispersed silica dopant for control of the textural and structural evolution of an alumina aerogel

Abstract We have prepared pure alumina and silica-doped alumina (9:1 Al:Si atom ratio) aerogels by supercritical drying of monolithic alcogels formed by slow, sub-stoichiometric (H2O:Al=2.2) hydrolysis of solutions of alkoxide precursors (aluminum s-butoxide and tetraethyl orthosilicate) in s-butanol. Both aerogels were X-ray indifferent over a large temperature range, first ordering as the η transition form upon calcination at 1173 K. The silica dopant retarded sintering of the aerogel, thereby enhancing its surface area and delaying crystallization of α-alumina from 1373–1473 K. Silica did not, however, affect the surface-chemical properties of the X-ray amorphous alumina; both aerogels were inert to pyridine adsorption and butene isomerization probes at 523 K. Stabilization of structure and texture without alteration of surface-chemical properties is a result of the high dispersion of the silica dopant throughout the aerogel's bulk. Incorporation of silicon atoms into the growing pre-alumina network facilitates their insertion into vacancies in the transition alumina structure, thereby restricting lattice diffusion as a route for crystallization of the α phase.
Processing of Mars Exploration Rover Imagery for Science and Operations Planning

The twin Mars Exploration Rovers (MER) delivered an unprecedented array of image sensors to the Mars surface. These cameras were essential for operations, science, and public engagement. The Multimission Image Processing Laboratory (MIPL) at the Jet Propulsion Laboratory was responsible for the first-order processing of all of the images returned by these cameras. This processing included reconstruction of the original images, systematic and ad hoc generation of a wide variety of products derived from those images, and delivery of the data to a variety of customers, within tight time constraints. A combination of automated and manual processes was developed to meet these requirements, with significant inheritance from prior missions. This paper describes the image products generated by MIPL for MER and the processes used to produce and deliver them.
Joint moment and muscle power output characteristics of below knee amputees during running: The influence of energy storing prosthetic feet

Stance phase joint moments, muscle power outputs and mechanical energy characteristics were determined in five normal and five below knee amputee subjects running at 2.8 m s-1. The amputees were studied sequentially on three different prosthetic feet: the SACH foot (solid ankle cushion heel), and two energy storing feet, Seattle and Flex. While wearing the SACH foot, the amputees exhibited major alterations in the distribution and magnitude of muscle power output and muscle work: (1) the total work done by the lower extremity was reduced; (2) the hip extensors became the main source of energy absorption and generation, while in normal subjects the ankle plantarflexors were the major energy generators and the knee extensors the major energy absorbers; (3) the eccentric and concentric knee extensor power outputs were reduced and an abnormal concentric knee flexor power output was noted immediately after heel contact. In four of the amputees, energy storing feet resulted in improvements in the power output and mechanical work characteristics of the lower extremity: (1) the energy storing prosthetic feet generated 2-3 times greater energy than the SACH foot; (2) with the Flex foot the amputees exhibited a more normal pattern and magnitude of hip and knee extensor muscle work. One of the subjects, however, exhibited increased abnormalities with the energy storing prosthetic feet. The amount of energy restored relative to the amount of energy absorbed by each of the prosthetic feet was greater with the energy storing feet than the SACH foot (Flex 84%, Seattle 52%, SACH 31%).
On-Line Monitoring Of Products Generated In The Combustion Of Polymeric Materials Using Fourier Transform Infrared Spectroscopy

The distribution of products which evolve during the course of a fire is sensitive to prevailing conditions of temperature, fuel composition, and oxygen availability. The dynamic nature of the combustion process has implications for the design and safe operation of controlled burning units such as municipal and hazardous waste incinerators. Spectroscopic measurements provide a means for obtaining a continuous signature of the incineration process which is suitable for input into a servo-mechanism which is designed to achieve optimal combustion efficiency. We have designed and constructed a facility for making time-resolved concentration measurements of combustion effluents. The setup consists of an FTIR spectrometer interfaced to an oxygen consumption calorimeter through a heated sample line. The gases which are evolved during the combustion of bulk materials, typically wood and plastics, are pulled through the sample line into a thermostatted gas cell at a rate of≈ 30 e/min. Interferograms are co-added over 30 second intervals and processed into absorbance spectra with a resolution of = 0.5 cm-1. The concentrations for a small number of target compounds are determined from numerically robust curve-fitting techniques which make use of predetermined analytical windows and the derivative spectra obtained from a representative spectral data base. The details of our methodology and spectral data collected during the combustion of representative materials will be presented. The possibility of integrating this information into a useful model of incinerator performance will also be discussed.
The impact of selected abatement strategies on transnational pollution, the terms of trade, and factor rewards: A general equilibrium approach

Abstract Widespread publicity of international conflict over transfrontier pollutants, such as acid deposition and the November 1986 chemical spill in the Rhine River, has increased the public's awareness of the need to devise abatement strategies appropriate for transnational pollution. This article develops a general equilibrium approach for analyzing the economic impacts of selected abatement strategies. The model includes internationally mobile goods, capital and pollution flows, and flexible output and factor prices. The general equilibrium approach provides policymakers with important information which is usually not revealed by a partial equilibrium approach. That is demonstrated by applying the model to the North American acid deposition issue.
Inactive complex formation between E. coli RNA polymerase and inhibitor protein purified from T7 phage infected cells

THE “host shut-off” function of T7 phage has been thought to result from an inhibition of the host Escherichia coli RNA polymerase, which transcribes host RNA and T7 early mRNA, by an early T7 protein presumably the product of gene 0.7, or the “host shut-off” gene1–4. When T7 infection proceeds, early mRNA synthesis is shut off and the T7-specific RNA polymerase5, the product of an early gene of T7 (gene 1), transcribes late mRNA. Thus, “host shut-off” is another control factor involved in the early–late switch of T7 gene expression in addition to the switch of two RNA polymerases from the host to the phage-coded enzyme transcribing early mRNA and late mRNA, respectively, at different times of infection3.
Transient Global Ischemia Triggers Expression of the DNA Damage-Inducible Gene GADD45 in the Rat Brain:

Using in situ hybridization, Northern blot analysis, Western blot analysis, and immunocytochemistry, mRNA and protein expression of the novel DNA damage-inducible gene GADD45 was examined in the rat brain at 0.5, 2, 4, 8, 16, 24, 48, and 72 hours after 15 minutes of transient global ischemia. Transient ischemia produced by the four-vessel occlusion method resulted in DNA double-strand breaks and delayed neuronal cell death in vulnerable neurons of the hippocampal CA1 sector, the hilus, dorsal caudate-putamen, and thalamus, as shown by in situ DNA nick end-labeling and histologic staining. GADD45 mRNA was transiently increased in less-vulnerable regions such as the parietal cortex (up to 8 hours after ischemia) and dentate granule cells (up to 24 hours after ischemia) but was persistently increased in vulnerable neurons such as CA1 pyramidal neurons (up to 48 hours). GADD45 immunoreactivity was increased in both vulnerable and less-vulnerable regions at earlier reperfusion periods (4 to 16 hours), but thereafter immunoreactivity was decreased below control levels in most vulnerable regions before delayed cell death and DNA double-strand breaks. At 72 hours after transient ischemia, a moderate increase in GADD45 immunoreactivity was still detectable in some CA3 neurons and in a few surviving neurons in the CA1 region. Double staining performed at 16 to 72 hours after ischemia revealed that GADD45 immunoreactivity was persistently increased in neurons that did not develop DNA damage. Because GADD45 protein may participate in the DNA excision repair process and because it has been shown that this protein is also overexpressed in neurons that survive focal ischemia and kainate-induced epileptic seizures, the results reported here support the hypothesis that GADD45 could have a protective role in neuronal injury.
Discussion of “A hypothesis of formation of mountains and continents”

The authors have attempted to demonstrate mathematically that the cooling Earth suffered elastic failure primarily by “buckling rather than cracking” and that the resultant depressions localized the oceans while the humps formed the continents and mountains. This conclusion ignores the few certain facts we know about the Earth's crust. It is readily observed that the continental crust has been repeatedly deformed by shortening accomplished by folding, faulting and loss of volume due to metamorphism. The oceanic crust shows no such tectonic pattern. It is profoundly different from the continental crust in strength, petrography, thickness, and elevation (reflecting its greater density).
Ligand Conjugation to Bimodal Poly(ethylene glycol) Brush Layers on Microbubbles

Using microbubbles as model systems, we examined molecular diffusion and binding to colloidal surfaces in a bimodal PEG brush layers. A microbubble is a gaseous colloidal particle with diameter less than 10 μm, of which the surface comprises amphiphilic phospholipids self-assembled to form a lipid monolayer shell. Due to the compressible gas core, microbubbles provide a sensitive acoustic response and are currently used as ultrasound contrast agents. Similar to the design of long circulating liposomes, poly(ethylene glycol) (PEG) chains are typically incorporated into the shell of microbubbles to form a steric barrier against coalescence and adsorption of macromolecules to the microbubble surface. We introduced a buried-ligand architecture (BLA) design where the microbubble surface was coated with a bimodal PEG brush. After microbubbles were generated, fluorescent ligands with different molecular weights were conjugated to the tethered functional groups on the shorter PEG chains, while the longer PEG chains served as a shield to protect these ligands from exposure to the surrounding environment. BLA microbubbles reduced the binding of macromolecules (>10 kDa) to the tethers due to the steric hindrance of the PEG overbrush, while allowing the uninhibited attachment of small molecules (<1 kDa). Roughly 40% less fluorescein-conjugated streptavidin (SA-FITC) bound to BLA microbubbles compared to exposed-ligand architecture (ELA) microbubbles. The binding of SA-FITC to BLA microbubbles suggested a possible phase separation between the lipid species on the surface leading to populations of revealed and concealed ligands. Ligand conjugation kinetics was independent of microbubble size, regardless of ligand size or microbubble architecture. We observed, for the first time, streptavidin-induced surface structure formation for ELA microbubbles, and proposed that this phenomenon may be correlated to flow cytometry scattering measurements. We therefore demonstrated the feasibility of post-labeling for small-molecule ligands to BLA microbubbles to generate stealth targeted ultrasound contrast agents.
Experimental Characterization of Single and Multiple Droplet Impingement on Surfaces Subject to Constant Heat Flux Conditions

Spray cooling is one of the most promising technologies in applications which require large heat removal capacity in very small areas. Previous experimental studies have suggested that one of the main mechanisms of heat removal in spray cooling is forced convection with strong mixing due to droplet impingement. These mechanisms have not been completely understood mainly due to the large number of physical variables, and the inability to modulate and control variables such as droplet frequency and size. Our approach consists of minimizing the number of experimental variables by controlling variables such as droplet direction, velocity and diameter. An experimental study of single and multiple droplet impingements using HFE 7100 as the cooling fluid under constant heat flux conditions is presented. A monosized droplet train is produced using a piezoelectric droplet generator with the ability to adjust droplet frequency, diameter and velocity. In this study, heaters consisting of a layer of Indium Tin Oxide (ITO) as heating element, and silicon substrates are used. Film morphology was characterized using a Laser Induced Fluorescence (LIF) technique with a focus on the droplet impact zone by measuring variables such as film thickness and diameter of the impact zone. Infrared thermography was used to measure surface temperature at the liquid-solid interface. The IR thermography technique was also used to characterize temperature gradients at the droplet impact zone. The results and effects of droplet frequency, fluid flow rate, and fluid temperature on heat flux are also presented.Copyright © 2010 by ASME
Comments on the symmetry relations in the hyperon radiative decays

Abstract We demonstrate that in general Hara's theorem which gives various symmetry relations for the hyperon radiative decays is not valid. The new relations we derive are different from those given by Hara. But for the Σ + →P γ decay, the asymmetry parameter is still zero in the exact SU(3) limit.
Valvular heart disease: focus on women.

Abstract: Calcific aortic stenosis is a disease of the elderly and aortic valve replacement should always be considered for severe symptomatic disease; comorbidities, not age, determine surgical risk. Aortic regurgitation imposes a pressure and volume load on the left ventricle so that close monitoring is needed to identify patients at risk for irreversible left ventricular dysfunction, although symptoms are the most common indication for valve replacement. Early intervention now is recommended for rheumatic mitral stenosis due to the effectiveness of percutaneous balloon valvotomy. Earlier intervention also may be considered in selected patients with mitral regurgitation at experienced centers when valve anatomy is favorable for a successful repair. Semiquantitative descriptors of regurgitation as mild, moderate, or severe are no longer adequate; management of adults with chronic valve disease requires quantitation of both the severity of valve disease and of left ventricular size and systolic function.
Receiving information at Korean and Taiwanese universities, industry, and GRIs

This article examines the incentive structure underlying information transfers received by the three key players of the Triple Helix paradigm: universities, industry, and government research institutes (GRIs). For Korea and Taiwan, which are the cases under analysis here, such an empirical examination has not yet been conducted on a quantitative level. Using a unique dataset of survey responses from a maximum of 325 researchers based in Korean and Taiwanese universities, industry, and GRIs, this article shows that there are some significant differences between and within countries. Most importantly, policy interventions to promote university-industry-GRI interactions impact the degree to which specific information transfers are considered useful. In Korea, formal transfers are emphasized, while both formal and, in particular, informal transfers are emphasized in Taiwan.
Apoptosis during spermatogenesis: The thrill of being alive

Emerging clues about the apoptotic molecular mechanisms operating during spermatogenesis indicate that the activation mechanism of executioner caspases may diverge from the traditional signaling operating in the immune system. Two issues are now been debated: (1) Whether the massive apoptosis of spermatogenic cells observed during the first spermatogenic wave represents a mechanism for ensuring the steady state sperm output in a given segment of a seminiferous tubule. (2) Whether apoptosis just represents a local remodeling process commanded by the Sertoli cell constraints to satisfy the differentiation needs of a juxtaposed cellular domain of spermatogonial, spermatocyte, and spermatid cohorts in the adult testis.
Dabigatran in atrial fibrillation: pharmacology and clinical trials

The central pharmacologic approach to stroke prevention in atrial fibrillation has recently changed with the approval of dabigatran by the US Food and Drug Administration (FDA). Dabigatran is an oral anticoagulant that belongs to the class of direct thrombin inhibitors. Dabigatran has predictable pharmacokinetics, without significant drug and food interactions, rapid onset, and requires twice-daily administration without the need for monitoring. The only drug contraindicated with dabigatran is rifampin. In the Randomized Evaluation of Long-Term Anticoagulation Therapy (RE-LY) trial, dabigatran at a dose of 150 mg bid is statistically superior to warfarin in preventing strokes and systemic embolism in patients with atrial fibrillation and has a lower non-statistically significant rate of major bleeding. There is significantly lower rate of intracranial bleeding. The FDA recently approved the 150-mg bid dose for patients with a creatinine clearance above 30 mL/min and 75 mg bid for use in patients with a creatinine clearance of 15 to 30 mL/min. A prespecified subanalysis in both warfarin-experienced and warfarin-naive subgroups mirrored the main results. For cardioversions, a post hoc analysis showed that the rate of thromboembolism and major bleeding within 30 days of cardioversion for dabigatran 150 mg bid was low and comparable to that of warfarin, with or without transesophageal echocardiography guidance. Dabigatran, therefore, is the first novel anticoagulant to offer an alternative to warfarin.
Preparing for the revolution--pharmacogenomics and the clinical lab.

Pharmacogenomics seeks to apply the field of genomics to improve the efficacy and safety of therapeutics. Simply put, pharmacogenomics is genetic-based testing to determine patient therapy. Interestingly, the clinical lab has rarely been discussed within the context of pharmacogenomics. Since clinical labs fill a key role in drug development, it is important that they are included in pharmacogenomic discussions. Currently, clinical labs assist pharmaceutical sponsors in preclinical pharmacogenetic testing. In the future, clinical labs will be looked to for genetic test development and validation, and high-throughput genotyping of patients in clinical trials and routine testing. Clinical labs are an essential link in the chain of pharmacogenomic drug development, a fact which must be recognised by both the labs themselves and the industry as a whole.
Radical polymerization initiated by primary radicals with similar structure to the end radical on the polymer

Abstract 1,1′-Azobisethyl-1-phenylethane and dimethyl-2,2′-azobisisobutylate decompose to yield 1-phenylethyl radical (PER) with a similar structure to the end radical on polystyrene (ST) and 1-methyl-1-methylcarboxylate ethyl radicals with that of poly(methylmethacrylate) (MMA). The data on the polymerizations of ST and MMA initiated by the above primary radicals at 60°C are treated by using some equations obtained before. Rate constants of termination between small polymeric radicals such as the primary radicals are estimated to be k tST : ST = 5.2 × 10 8 l mol −1 s −1 and k tMMA : MMA = 1.1 × 10 8 . A rate constant of primary radical termination between PER and polyMMA radical is also estimated to be k ti = 3.1 × 10 8 ( ⋍ k tST : MMA ). From these values, k tST : MMA ( k tST : ST k tMMA : MMA ) 1 2 is calculated to be 1.3, which is close to unity. However, it differs from o ⋍ 13 obtained before for cross-termination in polymerization between ST and MMA.
Chromatography on lipophilic dextran gels for fractionation of low molecular weight compounds I: steroid digitonides.

Abstract A method for the separation of 3β‐hydroxysterols from other sterols is presented. The method involves precipitating 3β‐hydroxysterols as the digitonides. The digitonide is then decomposed and separated into components using chromatography on highly cross‐linked lipophilic polysaccharide gels. The digitonin in the mother liquor is separated from other sterols using the same chromatographic procedure.
The role of the pilot's night vision system (PNVS) and the integrated helmet and display sighting system (IHADSS) in AH-64 Apache accidents

Helmet-mounted displays (HMDs), while not new, are a unique method of providing pilotage and targeting imagery to aviators. Although there are a number of HMDs in various phases of design, the AH-64s Integrated Helmet and Display Sighting System (IHADSS) is currently the Army's only fielded integrated HMD. A number of studies have investigated the visual and perceptual issues associated with the monocular optical design of the IHADSS in combination with the AH-64s forward looking infrared (FLIR) thermal sensor (Pilots Night Vision System - PNVS). While these systems have greatly enhanced the operational effectiveness of the AH-64, they have resulted in reports of physiological complaints, degraded visual cues, and both static and dynamic illusions. This study investigated the possible role the IHADSS HMD and PNVS may have played in AH-64 Apache accidents. A total of 217 AH-64 accidents (FY85-02) were analyzed and assigned causal factors associated with the use of the IHADSS and PNVS. The resulting analysis failed to identify any significant role between these systems and flight-related accidents.
Disease burden at the progenitor level is a feature of primary myelofibrosis: a multivariable analysis of 164 JAK2 V617F-positive myeloproliferative neoplasm patients.

Objective Suppression of normal hematopoiesis by the neoplastic clone (clonal dominance) is a feature of the myeloproliferative neoplasms, but the determinants that predict clonal dominance are unknown. The objective of this study was to identify clinical and laboratory variables that associate with the JAK2 V617F CD34 + progenitor allele burden and clonal dominance, which was defined by congruence of the JAK2 V617F CD34 + progenitor and neutrophil allele burdens. Materials and Methods A cross-sectional analysis was performed on 164 consecutive JAK2 V617F-positive patients: 30 with essential thrombocytosis (ET), 100 with polycythemia vera (PV), and 34 with myelofibrosis (MF), including 8 post-ET MF and 3 post-PV MF. The JAK2 V617F CD34 + progenitor and neutrophil allele burdens were measured using an allele-specific, quantitative real-time polymerase chain reaction assay. Results After adjusting for genotype, sex, age at diagnosis, and disease duration, disease type was the strongest predictor of clonal dominance, with the odds ratio being nearly 61.9 times higher for MF patients when compared with ET patients ( p p = 0.002). Additionally, clonal dominance was associated with a clinical phenotype of an increased spleen size ( p = 0.006), increased white blood cell count ( p = 0.009), and lower hemoglobin ( p Conclusions These data indicate that loss of wild-type clones at the progenitor level is a feature of MF (primary MF, post-ET MF, and post-PV MF), presumably due to expansion of the JAK2 V617F clone and that this characteristic is surprisingly independent of JAK2 V617F homozygosity, suggesting that additional genomic lesions may contribute to this unique molecular process that distinguishes MF from ET and PV.
Looming crisis in graduate science education: Where are America's top science students?

Only 750 physics doctorates were awarded to American students during 1990–1991 from a population base of over 248 million people. Even institutions such as MIT are having difficulty attracting enough top American students to its graduate programs in the sciences. We discuss some of the reasons for the decline in domestic student participation in the sciences and offer several nuts-and-bolts methods to reverse this trend. Key ingredients include graduate student recruiting, motivational activities to promote the excitement of being a professional scientist, and a reeducation of employers to look more favorably toward hiring students from the basic sciences. The methods have resulted in dramatic changes in the composition of recent graduate classes; at Auburn University we now admit an incoming class composed of over 70% domestic students.
Protection of parathyroid function using carbon nanoparticles during thyroid surgery.

ObjectiveTo investigate the hypothesis that injected carbon nanoparticle (CN) suspension helps identify parathyroid glands (PGs) during thyroid cancer surgery, thereby reducing PG injury.Study Desi...
Probabilistic models of verb-argument structure

We evaluate probabilistic models of verb argument structure trained on a corpus of verbs and their syntactic arguments. Models designed to represent patterns of verb alternation behavior are compared with generic clustering models in terms of the perplexity assigned to held-out test data. While the specialized models of alternation do not perform as well, closer examination reveals alternation behavior represented implicitly in the generic models.
cDNA copies of the testis-specific lactate dehydrogenase (LDH-C) mRNA are present in spermatogenic cells in mice, but processed pseudogenes are not derived from mRNAs that are expressed in haploid and late meiotic spermatogenic cells.

Retroposons are a class of genes created by reverse transcribing a processed mRNA and inserting the DNA copy into genomic DNA in germ-line cells. The present study concerns the question: Are retroposons created in meiotic and haploid spermatogenic cells? We demonstrate that polymerase chain reaction amplifies cytoplasmic DNAs with the expected intronless-structure of endogenous reverse transcriptase copies of the processed lactate dehydrogenase C mRNA encoding the testis-specific isoform of lactate dehydrogenase. Quantification of cytoplasmic LDH-C mRNA and endogenous cDNA by competitive RT-PCR and PCR, respectively, indicates that the level of LDH-C cDNA is lower by a factor of about 107 than the level of LDH-C mRNA in the cytoplasmic nucleic acids extracted from the testes of 14-day-old mice, and that about 1 in 105 meiotic cells contains an endogenous cDNA copy of LDH-C mRNA. A review of the literature reveals that a large number of genes including the LDH-C gene, whose expression is restricted to spermatogenic cells, are always single copy. Collectively, these observations suggest that reverse transcriptase cDNA copies of mRNAs are present in meiotic and haploid spermatogenic cells, but these cDNAs are not integrated into genomic DNA.
An analysis of six greedy selection rules on a class of zero‐one integer programming models

Six greedy primal selection rules are evaluated on a class of generalized set packing models. The evaluation is conducted in accordance with experimental design methodologies proposed by Lin and Rardin. Results indicate that the simplest of rules performs best, except when the model constraints exhibit “mixed” slackness. In this case, the rule proposed earlier by Fox and Scudder performs best. The results clarify and add detail to previous work by Fox and Scudder.
Caste-Specific Tyramides from Myrmicine Ants†

Analysis of the extracts of male ants of Monomorium minimum and Monomorium ebeninum by GC−MS and GC−FTIR revealed the presence of tyramides 2 and 4c, for which the structures were established by comparison with synthetic samples. These compounds and their analogues 1 and 3 were also found in males of other Monomorium species, males of Myrmicaria opaciventris, and males of several Solenopsis (Diplorhoptrum) species. Vapor-phase FTIR spectra revealed critically important structural clues to two of the tyramides, which had methyl branching in the tyramide acyl moiety. Tyramide 4c exhibited a strong intramolecular amide NH hydrogen bond where an α-keto group was deduced to be present in the acyl moiety and also showed the overlap of this ketone group frequency with that of the amide νC═O. The biological function of these compounds is uncertain; however, their role in ant-mating behavior may be suggested by a large body of evidence.
The Meaning of 21 in the MicroRNA World: Perfection Rather than Destruction?

In this issue of Cancer Cell, Hatley et al., by using several tour-de-force in vivo approaches, reported a miR-21 -mediated oncogenic pathway through inhibition of negative regulators of the Ras/MEK/ERK pathway and inhibition of apoptosis in lung cancers models. Targeting miR-21 could be a promising therapeutic strategy in lung cancers.
Hybrid molecular dynamics: an approach to low density simulations

Abstract A new molecular dynamics technique is described which addresses the special problems intrinsic to low density simulations, particularly fluids in the gas phase. This technique incorporates aspects of both the conventional hard spheres and continouos potential molecular dynamics algorithms. The difficulties inherent in low density simulations are discussed and the synthesis of existing molecular dynamics techniques into a new, hybrid algorithm is described in detail, including optimization and vectorization modifications. Finally, benchmarks for the new code are reported which show a speedup of up to a factor of 7 over a traditional molecular dynamics program.
Copulas of bivariate Rayleigh and log-normal distributions

The intrinsic relations between multivariate distributions and their marginal distributions can be clearly characterised by copulas. The bivariate Rayleigh and bivariate log-normal distributions play important roles in both signal processing and digital communications. In this reported work, the formula of bivariate Rayleigh copula is improved and the formula of bivariate log-normal copula is derived. These formulas are in terms of the Marcum Q-function or the Gaussian Q-function, both being supported by Matlab. Thus the copula evaluation process can be expedited both analytically and numerically.