cssi/SciSciGPT-SciSciNet huggingface dataset:
Unconstrained Inverse Electrocardiography: Epicardial Potentials

The inverse problem in electrocardiography is attacked via the development of a model appropriate for the computation of epicardial potentials from a knowledge of heart and torso geometry as well as surface potentials. The model takes the form of an integral equation of the first kind in which the kernel is interpreted as a Green's function. A theoretical investigation of system independence in the presence of error is developed, and two techniques for the theoretical consideration of system independence are examined. Application of these two techniques to concentric spherical systems indicates that spheres with ratios of inner-to-outer radii less than 0.5 contain less than twenty independent parameters in the presence of realistic noise levels. The number of independent parameters deteriorates rapidly as this ratio falls below 0.5. These results suggest that it is not feasible to determine epicardial potentials from torso potentials by using unconstrained solutions.
Assessment of left ventricular diastolic function in dilated cardiomyopathy with cine magnetic resonance imaging : effect of an angiotensin converting enzyme inhibitor, benazepril

The effects of angiotensin converting-enzyme inhibitor, benazepril, on diastolic function in patients with dilated cardiomyopathy, with (n = 4) or without (n = 11) mitral regurgitation, were examined with the time-volume curve of the left ventricle derived from cine magnetic resonance images. Peak filling rate/end-systolic volume and ejection fraction were increased in the group without regurgitation (p < 0.01) but not in the group with regurgitation after treatment. There was a strong correlation between peak filling rate/end-systolic volume and ejection fraction (r = 0.89) and between the change in peak filling rate/end-systolic volume and that in ejection fraction after treatment (r = 0.74) in the group without regurgitation. These findings suggest that in some patients with dilated cardiomyopathy benazepril has favorable effects on diastolic function, which seem to be related to improvement in systolic function. This drug may not be as beneficial in patients with dilated cardiomyopathy complicated by mitral regurgitation.
Contributions of surface and conceptual information to recognition memory

The present experiments were designed to determine whether memory for the voice in which a word is spoken is retained in a memory system that is separate from episodic memory or, instead, whether episodic memory represents both word and voice information. These two positions were evaluated by assessing the effects of study-to-test changes in voice on recognition memory after a variety of encoding tasks that varied in processing requirements. In three experiments, the subjects studied a list of words produced by six voices. The voice in which the word was spoken during a subsequent explicit recognition test was either the same as or different from the voice used in the study phase. The results showed that word recognition was affected by changes in voice after each encoding condition and that the magnitude of the voice effect was unaffected by the type of encoding task. The results suggest that spoken words are represented in long-term memory as episodic traces that contain talker-specific perceptual information.
Multiscale Nonlocal Thermo-Elastic Analysis of Graphene Nanoribbons

This paper investigates the effect of interfacial thermal characteristics and nonlocal effects on the overall effective thermal property of graphene nanoribbons embedded in low-density polyethylene matrix. It is widely known that apart from the thermal conductivity, the effect of interfacial thermal resistance is the most important factor that determines the thermal efficiency of nanostructures. In this work, we develop nonlocal thermo-elastic properties coupled with a multiscale strategy by means of properties derived from atomistic simulations. Atomistic based thermal properties of graphene nanoribbons are estimated from molecular dynamics (MD) simulations and the effect of inter-tubular spacing on the interfacial thermal characteristics are also studied. The paper also discusses the effect of the nonlocal parameter on the thermal conduction of the composite system using the developed nonlocal thermo-elastic model.
NASA science problems deeper than dollars

With little increase in funding at NASA over the last few years and a presidential mandate to go to the Moon and Mars, NASA science has suffered as funds have been redirected to the manned space program. However, the agency could make better use of its existing science funds, according to several witnesses who testified on 2 May before the U.S. House of Representatives Science and Technology Subcommittee on Space and Aeronautics. About $3–4 billion was removed from future spending plans for NASA's Science Mission Directorate following the implementation of the Vision for Space Exploration, which was announced in 2004. The recent hearing focused on how this loss of funding could be better managed by three of NASA's four science divisions.
A rapid extraction technique for atomic absorption determinations of kidney calcium

Abstract A simple method of extracting calcium from kidney tissue prior to atomic absorption measurements of calcium in experimental models of nephrocalcinosis is described. This technique results in substantial time savings over traditional ashing or acid-digestion techniques for monitoring the rate and extent of calcification of the kidney. Comparisons of calcium in the kidneys of mice maintained on regimens which produce both intra- and extracellular calcification by both extraction and ashing techniques produced statistically equivalent results. Brief sonication of the tissue in a butanol-HCl-lanthanum medium effectively extracted calcium allowing accurate determination of tissue calcium without ashing. This technique has proven very useful when numerous samples must be processed daily.
The Therapeutic Community: A Sociobiologic Study

†Revised version of “The Drug-free Therapeutic Community: A Biosocial Laboratory” presented at the Seventh World Conference of Therapeutic Communities, Chicago, May 10, 1983.
Intramural methotrexate therapy for the prevention of neointimal thickening after ballon angioplasty

Abstract Objectives. The study was performed to test the hypothesis that high local, intramural concentrations of antineoplastic agents at the site of balloon injury inhibit vascular smooth muscle cell proliferation without systemic toxicity. Background. The predominant mechanism for recurrent stenosis after coronary balloon angioplasty is neointimal thickening due to medial smooth muscle cell proliferation. The clinical use of potent antiproliferative agents to prevent restenosis has been limited by the potential for severe systemic side effects. Local therapy with these agents may be effective and free of systemic complications. Methods. After bilateral balloon angioplasty of the carotid arteries of 14 juvenile farm pigs, the dilated arterial segments were treated locally with methotrexate (6.25 mg/ml, total dose 25 mg) or 0.9% saline solution through a perforated balloon catheter. The animals were then killed 30 days after balloon injury to determine the effects of this therapy on neointimal thickness. In an additional six animals, tritium-labeled methotrexate was used to determine the concentration and duration of detectability of methotrexate in the wall of the treated arteries and in the systemic circulation. Results. Two hours after drug instillation the concentration of labeled drug was > 1,000-fold greater in the wall of the treated artery than in circulating blood, and this ratio remained between 50 and 100 for at least 7 days. Despite this difference, the mean intimal thickness 30 days after the procedure was similar in the 10 methotrexate-treated arteries and the 18 saline-treated arteries (59 ± 30 vs. 56 ± 25 μm, p = 0.6). The morphologic appearance of the neointima was similar in each group and suggested an important role for mural thrombus in the genesis of the intimal thickening. Conclusions. Treatment with intramural methotrexate, delivered through a perforated balloon catheter at the selected concentration and total dose, failed to prevent intimal thickening after balloon injury. Nonetheless, the perforated balloon catheter appears to be a promising means of delivering a high local concentration of drugs with potentially life-threatening systemic side effects. The optimal concentrations and combinations of candidate drug therapies warrant further evaluation.
The extraction of thulium(III), dysprosium(III) and samarium(III) by dioctylarsinic acid in chloroform

Abstract Dioctylarsinic acid, HDOAA, in chloroform (0.1 M ) extracts thulium(III), dysprosium(III) and samarium(III) from their aqueous solutions in the pH ranges 1–6.5, 2–7 and 4–8, respectively, with extraction coefficients of approximately 0.1 for the lowest and 10 for the highest pH. The extractability increased with increasing ionic strength for each ion and decreased in the order ClO 4 - > NO 3 - > Cl - > SO 4 2- > acetate for solutions of the same molarity. pH-Dependence curves had slopes ranging from 1.05 to 1.87. The reagent-dependence studies gave curves with slopes between 3.60 and 5.30. The general formula [MX n (DOAA) m (HDOAA) p (H 2 O) q ] (X = Cl - . NO 3 - , SO 4 2- /2, ClO 4 - , acetate, OH - ; n + m =3, m + p =4 or 5, q ⩾0)is suggested for the extracted species.
Race, Gender, and Social Support: A Study of Networks in a Financial Services Organization

A wealth of research indicates that social support improves employees' well-being and job performance. What is not well understood is how employees' race and gender influence the receipt of this type of support. I analyze qualitative and quantitative data to understand how race and gender influence the social support that workers receive. The results suggest that neither structural nor relational factors explain why blacks receive social support from fewer network members than whites. There is some evidence that relational factors contribute to gender differences in the receipt of social support, however. Interviews with workers suggest that gender schemata, the sex-typing of networks, reactions to racial discrimination, and differences in the value placed on social support contribute to race and gender differences in social support.
Static and structural properties of III–V zincblende semiconductors

Abstract The pseudopotential method within the local density approximation is used to investigate the static and structural properties of some III–V zincblende semiconductors. The results for lattice constants and bulk moduli are within a few percent of experiment. Comparisons of calculated total energies as a function of volume and structure yield information about solid-solid structural phase transformations. At high pressures, the results indicate that metallic rocksalt and β-Sn structures are lower in energy than zincblende. Other structures (e.g., CsCl and NiAs) are also investigated.
Educational indicators and occupational achievement

Abstract Many sociological and economic studies assume that the variable, Highest Grade Completed in School, is by itself an adequate measure of people's education for the purpose of explaining their occupational achievement. Use of Highest Grade Completed as the sole measure of education has at least two major shortcomings. It assumes people have (1) learned the same amount of (2) the same thing in an academic year. Supplementary education indicators are identified and tested to see if they have a substantial impact on occupational prestige or earnings. Background social statuses and Highest Grade Completed are controlled for in this test. Only measures of subject matter studied in high school or college have a statistically significant relationship with occupational achievement net of Highest Grade Completed and social background variables. Highest Grade Completed is quite adequate in measuring the impact of education on occupational achievement without help from the measures of subject matter studied.
Contraception and fertility awareness among women with solid organ transplants.

OBJECTIVE:: To assess the contraception and fertility counseling provided to women with solid organ transplants. METHODS:: A telephone survey of 309 women aged 19-49 years who had received a solid organ transplant at the University of Nebraska Medical Center was performed. Of the 309 eligible women 183 responded. Patients were asked 19 questions regarding pretransplant and posttransplant fertility awareness and contraception counseling. Data were summarized using descriptive statistics. RESULTS:: Patients had undergone a variety of solid organ transplantations: 40% kidney (n=73); 32% liver (n=59); 6% pancreas (n=11); 5% heart (n=9); 3% intestine (n=5); and 14% multiple organs (n=26). Before their transplantations 79 women (44%) reported they were not aware that a woman could become pregnant after transplantation. Only 66 women aged 13 and older at the time of transplantation reported that a health care provider discussed contraception before transplantation. Approximately half of women surveyed were using a method of contraception. Oral contraceptive pills were the most commonly recommended method. Twenty-two of the 31 pregnancies after organ transplantation were planned which is higher than that of the general population. CONCLUSION:: Few women with transplants are educated regarding the effect of organ transplantation on fertility and are not routinely counseled about contraception or the potential for posttransplant pregnancy. Health care providers should incorporate contraceptive and fertility counseling as part of routine care for women with solid organ transplants. LEVEL OF EVIDENCE:: II.
African American Fathering in Violent Neighborhoods: What Role Does Spirituality Play?

The salience of spirituality in African American family life is well documented. However, less is known about the role of spirituality in the parenting styles and practices of African American fathers generally or among those fathers rearing children in under-resourced, high-violence neighborhoods. African American families are disproportionately represented in communities characterized by violence, crime, and drug activity. This study explores how fathers residing in these neighborhoods rear their preschool sons and daughters and how spirituality relates to their fathering practices and styles. Study participants included 61 African American fathers of preschoolers attending Head Start. Findings revealed that, regardless of their child’s sex, highly spiritual fathers were more likely to use proactive parenting practices to decrease their child’s exposure to violence. Further, highly spiritual fathers were significantly more likely to use an authoritative parenting style and less likely to use a permissive style with their sons than fathers who reported spirituality as less important. Implications for future research are discussed.
Thermally Induced Fluctuations below the Onset of Rayleigh-Bénard Convection

We report quantitative experimental results for the intensity of noise-induced fluctuations below the critical temperature difference {Delta}{ital T}{sub {ital c}} for Rayleigh-Benard convection. The structure factor of the fluctuating convection rolls is consistent with the expected rotational invariance of the system. In agreement with predictions based on stochastic hydrodynamic equations, the fluctuation intensity is found to be proportional to 1/{radical}{minus}{epsilon}, where {epsilon}{equivalent_to}{Delta}{ital T}/{Delta}{ital T}{sub {ital c}}{minus}1. The noise power necessary to explain the measurements agrees with the prediction for thermal noise.
Materials with structural hierarchy

The role of structural hierarchy in determining bulk material properties is examined. Dense hierarchical materials are discussed, including composites and polycrystals, polymers, and biological materials. Hierarchical cellular materials are considered, including cellular solids and the prediction of strength and stiffness in hierarchical cellular materials.
Bis(dialkylaminophosphino)ferrocenes: Reactivity and electrochemistry ☆

New compounds containing the 1,1′-bis(dialkylaminophosphino)ferrocene ligands 1,1′-bis(dimethylaminophosphino)ferrocene (dmapf) and 1,1′-bis(diethylaminophosphino)ferrocene (deapf) were prepared and characterized by NMR. The oxidative electrochemistries of these compounds were examined in methylene chloride. The transition metal compounds M n Cl 2 (P–P) (M = Pd or Pt, n = 1, P–P = dmapf or deapf; M = Au, n = 2, P–P = dmapf) displayed one-electron, Nernstian waves. The corresponding selenides were prepared and the oxidative electrochemistries, along with those of the previously prepared 1,1′-bis(alkylaminophosphine sulfide)ferrocene, were examined. The sulfides displayed one-electron, Nernstian oxidations. The selenides displayed electrochemically irreversible two-electron waves. The X-ray structures of the sulfides and selenides as well as that of the transition metal compounds [(AuCl) 2 (dmapf)] and [PtCl 2 (dmapf)] were determined.
Engineering service products: the case of mass-customising service agreements for heavy equipment industry

Service agreements are one of a kind, and commit the service providers to certain configuration, execution and delivery of their processes and resources over a long time. To improve productivity, the providers need a way to mass-customise the service they produce while the customers need to be able to evaluate and benchmark the service they obtain. The field lacks sufficient results to allow either party to construct the agreements with the efficiency and effectiveness they need. The mass customisation model of manufacturing can help solve the problem; however, to achieve this goal, new and comprehensive understanding of service production is required. Therefore, a reference model of service agreement engineering to help mass-customise and evaluate service agreements is developed for, first, manufacturing-based and, then, nonmanufacturing- based products. The reference model provides the static knowledge on the structuring of service processes and resources and the dynamic assessment of their costs and risks, useful for both providers and customers. The observer–participant method is used to develop and test the model with the Power Systems Division, Aircraft Engines Division and Transportation Systems Division of General Electric Corporation. Ongoing work generalises it for IT outsourcing and other non-manufacturing-based service agreements. The results hold promise for generalisation into other service products, such as facilitating the application service providers of ebusiness to host many different, custom processes provided to its clientele on a common base of resources.
Enhancement of replication of genetically engineered herpes simplex viruses by ionizing radiation: A new paradigm for destruction of therapeutically intractable tumors

Human U-87 malignant glioma xenografts in mice were exposed to ionizing radiation, inoculated with a herpes simplex virus 1 mutant R3616 lacking both copies of the gamma 34.5 gene, or received both virus and radiation. Dual treatment caused a significantly greater reduction in volume or total regression of tumors than either radiation or infection alone. The significantly enhanced oncolytic effects of the combined treatment correlate with two-to five-fold enhanced replication in irradiated tumor cells than in tumors receiving virus only. In addition, in situ hybridization with viral DNA probes showed that infected tumor cells were the dominant landscape of irradiated tumors and much less apparent in the nonirradiated tumors administered this virus.
Environmental effects in the MO treatment of the trimethylamine-trimethylboron addition reaction

An attempt has been made to estimate charge redistribution effects in the Lipscomb MO treatment of the trimethylamine-trimethylboron addition reaction. The zeroth-order results which show substantial electron shifts and features suggesting charge imbalance in the amine and alkylboron accompanying reaction are modified by a self-consistent, linear α-upon-orbital charge adjustment method. The form and parametrization are derived from known atom behavior upon charging and from attempts at separation of charge effects in limited SCF calculations for simpler molecules. Whereas the charge imbalances appear to be satisfactorily remedied, the method as presently parametrized does not simultaneously improve correlations with the limited set of experimental observables for this reaction system.
Telomere dysfunction and chromosome instability

The ends of chromosomes are composed of a short repeat sequence and associated proteins that together form a cap, called a telomere, that keeps the ends from appearing as double-strand breaks (DSBs) and prevents chromosome fusion. The loss of telomeric repeat sequences or deficiencies in telomeric proteins can result in chromosome fusion and lead to chromosome instability. The similarity between chromosome rearrangements resulting from telomere loss and those found in cancer cells implicates telomere loss as an important mechanism for the chromosome instability contributing to human cancer. Telomere loss in cancer cells can occur through gradual shortening due to insufficient telomerase, the protein that maintains telomeres. However, cancer cells often have a high rate of spontaneous telomere loss despite the expression of telomerase, which has been proposed to result from a combination of oncogene-mediated replication stress and a deficiency in DSB repair in telomeric regions. Chromosome fusion in mammalian cells primarily involves nonhomologous end joining (NHEJ), which is the major form of DSB repair. Chromosome fusion initiates chromosome instability involving breakage-fusion-bridge (B/F/B) cycles, in which dicentric chromosomes form bridges and break as the cell attempts to divide, repeating the process in subsequent cell cycles. Fusion between sister chromatids results in large inverted repeats on the end of the chromosome, which amplify further following additional B/F/B cycles. B/F/B cycles continue until the chromosome acquires a new telomere, most often by translocation of the end of another chromosome. The instability is not confined to a chromosome that loses its telomere, because the instability is transferred to the chromosome donating a translocation. Moreover, the amplified regions are unstable and form extrachromosomal DNA that can reintegrate at new locations. Knowledge concerning the factors promoting telomere loss and its consequences is therefore important for understanding chromosome instability in human cancer.
Abstract 707: MK1775-mediated gemcitabine sensitization correlates with prolonged DNA damage signaling in S-phase cells.

Pancreatic cancer remains among the most lethal cancers with an overall 5-year survival of Citation Format: Leslie A. Parsels, Joshua D. Parsels, Meredith A. Morgan, Theodore S. Lawrence, Jonathan Maybaum. MK1775-mediated gemcitabine sensitization correlates with prolonged DNA damage signaling in S-phase cells. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 707. doi:10.1158/1538-7445.AM2013-707
Noncontact measurement of nerve displacement during action potential with a dual-beam low-coherence interferometer.

We have used a novel phase-referenced heterodyne dual-beam low-coherence interferometer to perform what we believe are the first noncontact measurements of surface motion in a nerve bundle during the action potential. Nerve displacements of ∼5-nm amplitude and ∼10-ms duration are measured without signal averaging. This interferometer may find general application in measurement of small motion in cells and other weakly scattering samples.
Comparison of Frequency of New-Onset Atrial Fibrillation or Flutter in Patients on Statins Versus Not on Statins Presenting With Suspected Acute Coronary Syndrome

The effect of statins on the incidence of new-onset atrial fibrillation (AF) in patients presenting with suspicion of acute coronary syndrome (ACS) is unknown. Our study population consisted of patients admitted to a tertiary care Veterans Administration hospital with suspicion of ACS between November 2001 and January 2006. All patients had an electrocardiogram on admission that was compared with a previous electrocardiogram to confirm new-onset AF or atrial flutter. Of 1,526 patients, 164 (10.8%) had new-onset AF and 601 (39.4%) were on a statin on admission. Patients with AF were significantly more likely to be older, Caucasian, have renal insufficiency and anemia, and less likely to be diabetic, on a statin or angiotensin-converting enzyme inhibitor on admission, or have chest pain as a presenting complaint. In univariate analysis, patients on statins were significantly less likely to have new-onset AF (odds ratio 0.40, 95% confidence interval 0.33 to 0.69, p <0.01). This relation persisted in the multivariate model (odds ratio 0.57, 95% confidence interval 0.39 to 0.83, p <0.01) after correcting for age, race, diabetes mellitus, chest pain, and use of angiotensin-converting enzyme inhibitor. In conclusion, patients presenting with suspicion of ACS were much less likely to have newonset AF if they were on a statin at time of presentation.
POPULATION EXTINCTION IN DETERMINISTICAND STOCHASTIC DISCRETE‐TIME EPIDEMIC MODELS WITH PERIODIC COEFFICIENTS WITH APPLICATIONS TO AMPHIBIAN POPULATIONS

. Discrete-time deterministic and stochastic epidemic models are formulated for the spread of disease in a structured host population. The models have applications to a fungal pathogen affecting amphibian populations. The host population is structured according to two developmental stages, juveniles and adults. The juvenile stage is a post-metamorphic, nonreproductive stage, whereas the adult stage is reproductive. Each developmental stage is further subdivided according to disease status, either susceptible or infected. There is no recovery from disease. Each year is divided into a fixed number of periods, the first period represents a time of births and the remaining time periods there are no births, only survival within a stage, transition to another stage or transmission of infection. Conditions are derived for population extinction and for local stability of the disease-free equilibrium and the endemic equilibrium. It is shown that high transmission rates can destabilize the disease-free equilibrium and low survival probabilities can lead to population extinction. Numerical simulations illustrate the dynamics of the deterministic and stochastic models.
Vascular Disease, Hypertension, and Prevention

There were 411 presentations related to vascular disease, hypertension, and prevention during the American College of Cardiology 2006 Scientific Sessions, including the results of the Study to Evaluate the Effect of Rosuvastatin on Intravascular Ultrasound-Derived Coronary Atheroma Burden (ASTEROID
Finding homes for orphan cytochrome P450s: CYP4V2 and CYP4F22 in disease states.

Genetic analyses have identified a wide spectrum of mutations in the CYP4V2 gene from patients suffering from Bietti’s crystalline corneoretinal dystrophy, and mutations in the CYP4F22 gene have been linked to lamellar ichthyosis. These strong gene–disease associations will be better understood if we can elucidate the substrate specificity of the heretofore “orphan” P450s and unravel the biochemical pathways that go awry in disease states. The complex biotransformations that underlie eicosanoid signaling, however, pose great challenges for the enzymologist seeking to assign specific metabolic roles to these members of the CYP4 family. Inductive reasoning and modeling are crucial tools for designing the experiments that will define disease progression in terms of CYP function.
Simplified and Revalidated Score for Neonatal Acute Physiology (SNAP-II) Maintains Excellent Predictive Performance • 1326

Background: SNAP is used for describing populations, stratifying risk in epidemiology and clinical trials and projecting resource use. We sought to simplify and revalidate it empirically.
A big-O experiment: which function is it?

This paper describes an assignment given to students who are first studying runtime analysis and big-O notation. It requires them to identify code based on its running time.
Lipid and carbohydrate utilization during flight of the migratory moth, Agrotis ipsilon (Lepidoptera: Noctuidae)

Male black cutworm, Agrotis ipsilon (Hufnagel) moths, were attached to laboratory flight mills on the third night after emergence. Individuals were classified according to their longest uninterrupted flight during the night. There were not enough non-fliers or trivial fliers (flight < 1 h) to make meaningful comparisons, so only short-fliers (flight ≥ 1 h but ≤ 5 h) and long-fliers (flights ≥ 5 h) were further tested. After a day of rest, short- and long-fliers were tethered to a stationary pin and forced to fly 0, 10, 20, 30, 60, 120, or 180 min, after which hemolymph was sampled and lipid and carbohydrate concentrations determined. Concentrations in samples taken at intervals after cessation of a 60-min flight indicated that both energy sources were being utilized during flight. Neck-ligation experiments indicated that a handling-induced hyperlipemic response occurs 15 min after the beginning of the sampling procedure, and that the hormone triggering does not come from the head. Resting concentration of lipid in long-fliers is about half that of short-fliers, but it increases threefold in the first 20 min of flight, whereas that of short-fliers remains unchanged. In-flight lipid concentration in controls, which experienced their first and only flight on day 5, was greater than the concentration in both short- and long-fliers. Between 10 and 20 min, carbohydrate concentrations decrease about twofold in long-fliers but drop only slightly in short-fliers. These data suggest that long-fliers may have a lower basal metabolic rate and depend more on carbohydrate when at rest than short-fliers and that long-fliers may utilize more carbohydrate than lipid during the initial period of flight. In addition, previous flight on the flight mills has a greater influence on lipid mobilization and usage in short-fliers than it does on long-fliers. Patterns of lipid mobilization during flight seem to differ between migrant and non-migrant species and to vary among migrants depending on the flight strategy used, but there are no major differences in patterns of carbohydrate usgaeg. © 1995 Wiley-Liss, Inc.
Thin-film synthesis of the orthorhombic phase of SnO 2

We demonstrate the formation of an ${\mathrm{SnO}}_{2}$ thin film in an orthorhombic phase which has previously been found in high-pressure experiments. Our starting point was the pulsed-laser deposition of an amorphous film of SnO on Si [001] substrates. During a series of subsequent heat treatments in air, the film crystallized in a sequence of three phases. First, after heating to $300\ifmmode^\circ\else\textdegree\fi{}\mathrm{C},$ the litharge phase of SnO was formed. Next, while heating to $700\ifmmode^\circ\else\textdegree\fi{}\mathrm{C},$ the film absorbed oxygen and formed the high-pressure orthorhombic phase of ${\mathrm{SnO}}_{2}.$ Eventually, after heating to $1150\ifmmode^\circ\else\textdegree\fi{}\mathrm{C},$ the film was fully converted to the stable cassiterite phase of ${\mathrm{SnO}}_{2}.$ The experiments performed to date are not conclusive, but indirect evidence indicates that the litharge structure is important as an intermediary in the formation of the orthorhombic phase, in contrast to the transformation route at high pressure.
Progress in demonstrating homochiral selection in prebiotic RNA synthesis

Abstract The dual properties of RNA as an enzyme catalyst (ribozyme) and its ability to store genetic information suggest that early life could have been based on RNA. We have synthesized RNA oligomers up to 50-mer chain lengths by Na + -montmorillonite catalyzed reactions of 5′-activated mononucleotides. For studying chiral selectivity, the reactions of racemic mixtures of D, L-ImpA and D, L-ImpU were carried out on Na + -montmorillonite. The dimer, trimer, tetramer and pentamer fractions (yields 43.3%, 14.5%, 5.8% and 3.0%, respectively) were investigated for homochiral selection. These products were collected via ion exchange HPLC, their terminal 5′-phosphate was cleaved by alkaline phosphatase and further analyzed by reverse phase HPLC. Twelve linear and three cyclic dimers were isolated and characterized. The homochirality of dimers was 63.5 ± 0.8%. Out of the sixteen trimers isolated, ten were homochiral with an overall homochirality of 74.2 ± 1.6%. The tetramers and pentamers were separated into 24 and 20 isomers, respectively. Their co-elution with those formed in the binary reactions of D-ImpA with D-ImpU on Na + -montmorillonite revealed 92.7 ± 2.0% and 97.2 ± 0.5% homochirality, respectively. These results suggest that Na + -montmorillonite not only catalyzes the prebiotic synthesis of RNA but it also facilitates homochiral selection. Work is in progress to determine chiral selectivity in the reaction mixtures of activated nucleotides of racemic A, U, G and C on Na + -montmorillonite.
Emulation of biological networks in reconfigurable hardware

Models of biological networks have been studied through simulations using a number of software tools. However, the intrinsic disparity between the sequential nature of microprocessor architecture used in software-based simulations and the highly parallel nature of biological systems may result in prohibitively long simulation times. In this work, we adopt an alternative approach to simulation of biological systems using hardware-based emulation. Our results on Boolean network models show that such an approach can provide speedup of 17,000X when compared to existing software simulation approaches.
Considerations for the use of the Beck Depression Inventory in the Assessment of Weight-Loss Surgery Seeking Patients

The Beck Depression Inventory (BDI) is an assessment frequently used in pre-surgical evaluation for patients seeking bariatric surgery. Items on the BDI reflect both cognitive and somatic symptoms associated with depression. However, many patients seeking bariatric surgery have medical symptomatology and health concerns independent of the syndrome of depression, and thus scores on the BDI may inflate their actual level of depression.With depression viewed by some clinicians as contraindicated for bariatric surgery, clarification of the BDI items is necessary. Pre-surgical BDIs of 259 bariatric patients were reviewed. An exploratory factor analysis was conducted to examine the factor structure of the BDI in this population. Independent sample t-tests compared the means of the cognitive and somatic items. A clear two-factor solution emerged on the BDI, indicating items mapped on to either a cognitive or a somatic domain. The patients in the present sample also were more likely to endorse somatic and health-related symptoms on the BDI. The factor structure of the BDI in this population is similar to that in other non weight-loss surgery populations. However, this population is more likely to endorse somatic complaints that may not be indicative of depression, rather an acknowledgement of actual medical complaints. Thus, assessors should be mindful of specific symptom endorsement, rather than a total depression score when utilizing the BDI to help determine surgery suitability.
Calving location selection patterns of saiga antelope in Mongolia

Habitat selection for calving by ungulates is an important behavioral trait because it affects neonate survival. Generally, ungulate calving site selection varies by vulnerability to predators, local topography, habitat quality and level of human disturbance. The Mongolian saiga (Saiga tatarica mongolica) is endemic to Mongolia where a threatened population of ∼7000 exists in the northern Gobi Desert. We analyzed factors that could affect selection of saiga calving locations in the Sharga Nature Reserve, western Mongolia, using data obtained from ground surveys over 4 years between 2008 and 2012. Multiple factors explain calving location selection by saiga antelopes, based on the results of a generalized linear mixed model within a use availability framework. Individual saiga females preferred calving locations that were away from settlements and closer to water sources and avoided steeper slopes in comparison with random locations. These results demonstrate that the choice of calving locations for saiga antelope is driven by both internal and external factors. Understanding which factors influence calving location selection for saiga provides insights to protect important habitats.
Causality violations in cascade models of nuclear collisions

Transport models have successfully described many aspects of intermediate energy heavy-ion collision dynamics. As the energies increase in these models to the ultrarelativistic regime, Lorentz covariance and causality are not strictly respected. The standard argument is that such effects are not important to final results; but they have not been seriously considered at high energies. We point out how and why these happen, how serious of a problem they may be and suggest ways of reducing or eliminating the undesirable effects.
Investigation of sub-monolayer, monolayer, and multilayer self-assembled semifluorinated alkylsilane films

Semifluorinated self-assembled (FAS SA) films fabricated from trifunctional precursors are frequently used in myriad applications, yet an understanding of the effects of fabrication conditions, including deposition time, on adsorption mechanisms and molecular architectures is still being developed. In this work we prepared SA films based on the F(CF2)8(CH2)2SiCl3 (FAS-17) precursor and characterized these films using a suite of surface analytical techniques. Contact angle, sum frequency generation (SFG) spectroscopy, X-ray photoelectron spectroscopy (XPS), and ellipsometry results are consistent with the formation of disordered sub-monolayer structures at short deposition times, well-ordered monolayers at intermediate deposition times, and inhomogeneous multilayers at long deposition times. Correlation of SFG and XPS results demonstrates a change in FAS-17 chain orientation as the deposition time increases from 2 s to 5min. Group theory-based calculations, SFG studies, and Fourier-transform infrared (FTIR) results also afford additional evidence in support of the assignment of the SFG signals at ∼1345 and ∼1370cm-1 to the asymmetric stretching mode of the semifluorinated silane chain's terminal CF3 group rather than to its axial CF2 stretches. To our knowledge, this is the first report of SFG studies on semifluoroalkyl silane self-assembled films in the C-F stretching frequency region.
Refractory grain destruction in low-velocity shocks.

Recent abundance determinations in intermediate-velocity clouds near the Orion association have shown that silicon abundances may be nearly cosmic even in clouds with a velocity as low as 40 to 50 km/sec. It is argued that grain destruction in radiative shocks traveling perpendicular to the magnetic field may be much more effective than was previously considered. The destruction mechanism consists of acceleration of the gyromotion of the grains about their drift center owing to magnetic field compression, followed by sputtering of the high-velocity grains by He and (CNO) atoms. It is found that MgSiO3 grains may be almost fully destroyed in shocks of velocity greater than 80 km/sec and graphite grains substantially destroyed at shock velocities of 100 km/sec.
An Investigation of the Steady-State Performance of a Wave Aerodynamic Thrust Bearing for High Speed Applications

The steady-state performance of an aerodynamic double thrust wave bearing was investigated. The investigation showed that a double thrust wave bearing with an inner diameter of 15 mm and an outer diameter of 45 mm can support axial loads of 200 N at 100,000 rpm for a minimum film thickness of 3 microns. The influence of the wave bearing parameters on the bearing performance was also analyzed. The theoretical analysis was validated by experimentally testing one side of the thrust bearing. A special test rig was built for this purpose. The experimental data were close to the numerical predictions, validating the computer codes.Copyright © 2012 by ASME
Cardiovascular Consequences of Pulmonary Hypertension

Pulmonary hypertension occurs when pulmonary vascular pressures are elevated. Pulmonary arterial hypertension is associated with occlusion of the pulmonary arterial tree, while pulmonary venous hypertension is seen when pulmonary vein outflow is impeded. Cardiovascular consequences are common with pulmonary hypertension, regardless of the underlying pathogenesis and whether management is complex. However, there are a number of interventions that may improve quality of life and survival of pulmonary hypertension. This article discusses current recommendations for diagnosis and management.
VENTILATION BY FLOATING LEAVES IN NUPHAR

The network of internal gas spaces in the yellow waterlily constitutes a pressurized flowthrough system which forces oxygen to the rhizome buried in anaerobic sediment. This ventilation has been documented previously in a subspecies of Nuphar luteum with aerial leaves, and appeared to occur only during daylight when the leaves are warmed by the sun's radiation. In this study we have found the ventilation system operating in two different subspecies of N. luteum growing in Alaska and in Massachusetts. These plants have floating leaves so that during certain times of the year the leaves are warmed not only by the sun in daylight but also by lake water at night, allowing the ventilation to continue during darkness.
The effect of age of second language acquisition on the representation and processing of second language words

Abstract In this study, the effects of second language (i.e., L2) proficiency and age of second language acquisition are assessed. Three types of bilinguals are compared: Early L2 learners, Late highly proficient L2 learners, and Late less proficient L2 learners. A lexical decision priming paradigm is used in which the critical trials consist of first language (i.e., L1) Spanish targets preceded by English (L2) primes. Three types of L2–L1 priming conditions were used: Semantic primes [e.g., prime=nail; target=TORNILLO (‘screw’)], Mediated Form primes [e.g., prime=bull (‘toro’); target=TORNILLO], and Form primes (e.g., prime=torture; target=TORNILLO). Semantic and Mediated Form primes produced facilitative priming effects for the Early group, but not for either of the Late groups. Highly proficient Late learners showed inhibitory effects of Form primes, whereas the less proficient group produced no priming effects of any type. The pattern of priming effects is consistent with an interactive activation architecture in which the semantic/conceptual level is shared by L1 and L2 for Early learners, versus a shared lexical level for proficient Late learners. The implication is that age of L2 acquisition has a major influence on how bilinguals represent and access words in their second language.
Role of collagen and fibronectin in neural crest cell adhesion and migration

Abstract Cultured neural crest cells which are freshly trypsinized require serum or purified fibronectin to attach to collagen substrates of types I–V. Furthermore, neural crest cells migrate in a Boyden chamber in response to fibronectin, and a “checkerboard” analysis demonstrates that fibronectin is both chemotactic and chemokinetic for these cells. It is proposed that collagen serves as a substrate for neural crest cells as they migrate in the early embryo. By mediating the cells' attachment to collagen, fibronectin may influence the movement of the cells. Local differences in fibronectin concentration or availability in the matrix could affect the degree of attachment of the cells to the collagen substrate and could also direct their migration by serving as a chemoattractant.
Exact Results for Casimir Interactions between Dielectric Bodies : The Weak-Coupling or van der Waals Limit

In earlier papers, we have applied multiple-scattering techniques to calculate Casimir forces due to scalar fields between different bodies described by delta function potentials. When the coupling to the potentials became weak, closed-form results were obtained. We simplify this weak-coupling technique and apply it to the case of tenuous dielectric bodies, in which case the method involves the summation of van der Waals (Casimir-Polder) interactions. Once again, exact results for finite bodies can be obtained. We present closed formulas describing the interaction between spheres, between cylinders, and between an infinite plate and a rectangular slab of finite size. For such a slab, we consider the torque acting on it and find that nontrivial equilibrium points can occur.
The New York Angler Cohort Study: Exposure Characterization and Reproductive and Developmental Health

The New York State Angler Study will evaluate the association between past and current consumption of contaminated fish from Lake Ontario and both short- and long-term health effects in a population-based cohort. It will measure fish consumption and reproductive and developmental health among 10,518 male anglers and 6,651 of their wives or partners, as well as among 913 female anglers. To characterize exposure among subgroups of the cohort, further analytical methods were developed and implemented to measure specific polychlorinated biphenyls (PCB) congeners, methylmercury, and other substances in biological samples. Exposure assessment has been completed for a stratified random sample of 321 anglers. In addition, analyses for 79 congeners of PCBs are complete for 177 anglers. A special study of duck andturtle consumers currently is underway. Telephone interviews have been completed with 2,454 of the 2,999 women who planned a pregnancy between 1991 and 1994. The entire cohort of male anglers, partners of ...
Ozone's Effects on UV documented

For the first time, scientists have recorded increases in ultraviolet irradiance through the Antarctic ozone hole. The measurements confirm the predicted effects of severe stratospheric ozone depletion on Earth. During last year's austral spring, when ozone declined about 15% over Antarctica, mid-October ultraviolet (UV) levels were as high as those of summer two months later. Because ozone levels during the period of most severe depletion in 1988 were still twice those of 1987, when nearly half the ozone over some areas was destroyed, even greater UV levels than measured last year may occur in Antarctica this coming austral spring, when the ozone layer is expected by some atmospheric scientists to thin as much as in 1987.
Spatial electron density and electric field strength measurements in microwave cavity experiments

Measurements of electron density and electric field strength have been made in an argon plasma contained in a resonant microwave cavity at 2.45 GHz. Spatial measurements of electron density, n sub e, are correlated with fluorescence observations of the discharge. Measurements of n sub e were made with Stark broadening and compared with n sub 3 calculated from measured plasma conductivity. Additional measurements of n sub 3 as a function of pressure and in mixtures of argon and oxygen are presented for pressures from 10 Torr to 1 atm. Measurements in flowing gases and in static systems are presented. In addition, limitations of these measurements are identified.