cssi/SciSciGPT-SciSciNet huggingface dataset:
Imaging task-based optimal kV and mA selection for CT radiation dose reduction: from filtered backprojection (FBP) to statistical model based iterative reconstruction (MBIR)

Optimal selections of tube potential (kV) and tube current (mA) are essential in maximizing the diagnostic potential of a given CT technology while minimizing radiation dose. The use of a lower tube potential may improve image contrast, but may also require a significantly higher tube current to compensate for the rapid decrease of tube output at lower tube potentials. Therefore, the selection of kV and mA should take those kinds of constraints as well as the specific diagnostic imaging task in to consideration. For conventional quasi-linear CT systems employing linear filtered back-projection (FBP) image reconstruction algorithm, the optimization of kV-mA combinations are relatively straightforward, as neither spatial resolution nor noise texture has significant dependence on kV and mA settings. In these cases, zero-frequency analysis such as contrast-to-noise ratio (CNR) or normalized CNR by dose (CNRD) can be used for optimal kV-mA selection. The recently introduced statistical model-based iterative reconstruction (MBIR) method, however, has introduced new challenges to optimal kV and mA selection, as both spatial resolution and noise texture become closely correlated with kV and mA. In this work, a task-based approach based on modern signal detection theory and the corresponding frequency-dependent analysis has been proposed to perform the kV and mA optimization for both FBP and MBIR. By performing exhaustive measurements of task-based detectability index through the technically accessible kV-mA parameter space, iso-detectability contours were generated and overlaid on top of iso-dose contours, from which the kV-mA pair that minimize dose yet still achieving the desired detectability level can be identified.
Application of photon correlation to turbulent fluid mechanics

Application de la technique de correlation de photons a differents ecoulements turbulents: jet d'une tuyere rectangulaire, conduite d'entree d'un reacteur, ecoulement derriere un disque, sillage bidimensionnel, jet instationnaire
Docosahexaenoyl ethanolamide improves glucose uptake and alters endocannabinoid system gene expression in proliferating and differentiating C2C12 myoblasts

Skeletal muscle is a major storage site for glycogen and a focus for understanding insulin resistance and type-2-diabetes. New evidence indicates that overactivation of the peripheral endocannabinoid system (ECS) in skeletal muscle diminishes insulin sensitivity. Specific n-6 and n-3 polyunsaturated fatty acids (PUFA) are precursors for the biosynthesis of ligands that bind to and activate the cannabinoid receptors. The function of the ECS and action of PUFA in skeletal muscle glucose uptake was investigated in proliferating and differentiated C2C12 myoblasts treated with either 25 μM of arachidonate (AA) or docosahexaenoate (DHA), 25 μM of EC [anandamide (AEA), 2-arachidonoylglycerol (2-AG), docosahexaenoylethanolamide (DHEA)], 1 μM of CB1 antagonist NESS0327, and CB2 inverse agonist AM630. Compared to the BSA vehicle control cell cultures in both proliferating and differentiated myoblasts those treated with DHEA, the EC derived from the n-3 PUFA DHA, had higher 24 h glucose uptake, while AEA and 2-AG, the EC derived from the n-6 PUFA AA, had lower basal glucose uptake. Adenylyl cyclase mRNA was higher in myoblasts treated with DHA in both proliferating and differentiated states while those treated with AEA or 2-AG were lower compared to the control cell cultures. Western blot and qPCR analysis showed higher expression of the cannabinoid receptors in differentiated myoblasts treated with DHA while the opposite was observed with AA. These findings indicate a compensatory effect of DHA and DHEA compared to AA-derived ligands on the ECS and associated ECS gene expression and higher glucose uptake in myoblasts.
Emergent effects in multimodal feedback from virtual buttons

The continued advancement in computer interfaces to support 3D tasks requires a better understanding of how users will interact with 3D user interfaces in a virtual workspace. This article presents two studies that investigated the effect of visual, auditory, and haptic sensory feedback modalities presented by a virtual button in a 3D environment on task performance (time on task and task errors) and user rating. Although we expected task performance to improve for conditions that combined two or three feedback modalities over a single modality, we instead found a significant emergent behavior that decreased performance in the trimodal condition. We found a significant increase in the number of presses when a user released the button before closing the virtual switch, suggesting that the combined visual, auditory, and haptic feedback led participants to prematurely believe they actuated a button. This suggests that in the design of virtual buttons, considering the effect of each feedback modality independently is not sufficient to predict performance, and unexpected effects may emerge when feedback modalities are combined.
The effect of sulindac and sulindac metabolites on arachidonate-induced lethality in rabbits: Effect on human, guinea pig, dog, and rat platelet activity

Abstract Sulindac, an indene sulfoxide, and its sulfide and sulfone metabolites were compared to aspirin and indomethacin as potential antithrombotic agents. Sulindac itself had no effect in vitro on guinea pig or human platelet aggregation but the sulfide metabolite was β times more potent than aspirin. The sulfone metabolite had little or no activity in this test or others. Sulindac and its sulfide metabolite when given orally to guinea pigs, dogs, or rats were consistent antagonists of platelet aggregation. A correlation existed between plasma levels of the sulfide and reduction of platelet activity. The sulfide metabolite was a more potent platelet aggregation inhibitor than aspirin in guinea pigs, equal to aspirin in dogs, and less potent than aspirin in rats. Sulindac and the sulfide metabolite both protected rabbits against arachidonate-induced lethality; sulindac was less potent than aspirin but the sulfide metabolite was not different in potency from aspirin in protecting rabbits.
Solvent-catalyzed cis-trans isomerization of halosilacyclo-butanes and -pentanes. Evidence for cationic intermediates with expanded coordination

Abstract 1-Chloro-l,2,-dimethylsilacyclo-butane (IV)and-pentane (V) undergo cis-trans isomerization catalyzed by a variety of nucleophilic species, including polar aprotic solvents. Kinetics of the process have been investigated for HMPT in CCl4. Rate laws and the observation of HMPT-catalyzed halogen exchange between bromo- and chloro-silanes lead to the conclusion that 5-coordinate siliconium ions are intermediates in this process. Evidence is also presented that pentacoordinate species formed from V (but not from IV) undergo rapid pseudorotations.
Diode-pumped, single-frequency Nd:YLF laser for 60-beam OMEGA laser pulse-shaping system

The operational conditions of the OMEGA pulse-shaping require an extremely reliable and low-maintenance master oscillator. We have developed a diode-pumped, single- frequency, pulsed Nd:YLF laser for this application. The laser generates Q-switched pulses of approximately 160-ns duration and approximately 10 (mu) J energy content at the 1053-nm wavelength with low amplitude fluctuations and low temporal jitter. Amplitude and frequency feedback stabilization systems have been used for high long-term amplitude and frequency stability.
Analyzing Civil Unrest through Social Media

Mining and analyzing data from social networks such as Twitter can reveal new insights into the causes of civil disturbances, including trigger events and the role of political entrepreneurs and organizations in galvanizing public opinion.
Multiparameter singular perturbations of linear systems with multiple time scales

A joint multitime scale-multiparameter singular perturbation is formulated and resolved in the context of linear time-varying systems. An interesting feature of the solution procedure is a hierarchial scheme of aggregating and arranging of the groups of small parameters according to their order. The scheme provides a suitable framework for establishing qualitative properties of multitime scale systems.
Assessing competence in the use of motivational interviewing

This report presents reliability, validity and sensitivity indices for the Motivational Interviewing Treatment Integrity (MITI) scale. Factor analysis of MI treatment sessions coded with the Motivational Interviewing Skills Code (MISC) was used to derive 10 elements of MI practice, forming the MITI. Canonical correlation revealed that the MITI captured 59% of the variability in the MISC. Reliability estimates for the MITI were derived using three masked, independent coders. Intra-class coefficients ranged from .5 to .9 and were generally in the good to excellent range. Comparison of MITI scores before and after MI workshops indicate good sensitivity for detecting improvement in clinical practice as result of training. Implications for the use of this instrument in research and supervision are discussed.
Open-field behavior in mice: selection response and situational generality.

The response to selection for open-field activity in each of six lines of mice (two selected for high activity, two selected for low activity and two controls) is presented. Change in activity as a function of selection during the last five generations was found to be somewhat less than that during the first five generations, although the correlated response in open-field defecation has continued. The realized heritability of open-field activity was estimated to be 0.13±.02 and the realized genetic correlation between open-field activity and defecation was −0.80±.13. During the tenth generation of selection, second litters were obtained so that full-sibs ofS 10 subjects could be tested in an extensive activity battery and thus assessed for the situational generality of the response to selection. In general, selection for open-field activity has produced lines which differ markedly in both activity and defecation in apparatus which have some elements in common with the open field. Apparatus which result in significant differences between the high-and low-active lines are boxlike and illuminated, but do not necessarily possess the “openness” of the open field. However, significant differences were not observed in more confining apparatus nor in exercise wheels.
A Review of Sex Determining Mechanisms in Geckos (Gekkota: Squamata)

Geckos are a species-rich clade of reptiles possessing diverse sex determining mechanisms. Some species possess genetic sex determination, with both male and female heterogamety, while other species have temperature-dependent sex determination. I compiled information from the literature on the taxonomic distribution of these sex determining mechanisms in geckos. Using phylogenetic data from the literature, I reconstructed the minimum number of transitions among these sex determining mechanisms with parsimony-based ancestral state reconstruction. While only a small number of gecko species have been characterized, numerous changes among sex determining mechanisms were inferred. This diversity, coupled with the high frequency of transitions, makes geckos excellent candidates as a model clade for the study of vertebrate sex determination and evolution.
The effect of gun ownership rates on homicide rates: a state-level analysis

The purpose of the present study is to examine the link between gun ownership rates and homicide rates. Using a very large cross-sectional survey dataset in order to obtain estimates for household-level gun ownership rates, and state-level data on homicides, the results indicate that gun ownership rates have a statistically significant and positive effect on the homicide rates at the 10% significance level. This result suggests that efforts to restrict access to firearms may reduce murders.
Hybrid competitive Lotka–Volterra ecosystems with a hidden Markov chain

This work concerns Lotka–Volterra models that are formulated using stochastic differential equations with regime-switching. Distinct from the existing formulations, the Markov chain that models random environments is unobservable. For such partially observed systems, we use Wonham’s filter to estimate the Markov chain from the observable evolution of the population, and convert the original system to a completely observable one. We then show that the positive solution of our model does not explode in finite time with probability 1. Several properties including stochastic boundedness, finite moments, sample path continuity and large-time asymptotic behaviour are also obtained. Moreover, stochastic permanence, extinction and feedback controls are also investigated.
WE-D-304A-06: The Characterization of Iodinated-Contrast Kinetics Using a Dynamic Breast Phantom

Purpose: To demonstrate the effectiveness of contrast‐enhanced dual energy mammography (CEDEM) in characterizing the contrast kinetic curve. Method and Materials: The acquisition of CEDEM was performed using a dedicated cone‐beam breast CT scanner in our laboratory, with the system operating in stationary imaging mode. CEDEM images were acquired with a filter combination of 0.2 mm Cu and 0.2 mm Sn at the same kVp. Previous studies in our group have shown that 55 kVp is the optimal technique factor to acquire high‐quality CEDEM images when imaging a 6‐cm, anatomical‐complex breast phantom. As an addition to the static breast phantom, a tumor perfusion chamber was designed and fabricated to simulate the contrast kinetics of breast tumors. The chamber is composed of a “leaky” vessel (soaker hose) and the tumor interstitial space (foam). The contrast kinetics was controlled by two peristaltic pumps, the “leakiness” of the soaker hose, and the permeability of the foam. When imaged experimentally, the tumor perfusion chamber was fixed in the middle of the static breast phantom. A sequence of CEDEM images were acquired with an initial bolus injection of 100 ml Visipaque®. The contrast kinetics was determined by evaluating the signal‐to‐noise ratio of each dual‐energy subtracted image as a function of time. Results: The CEDEM image sequence of the dynamic breast phantom was acquired at 55 kVp. The contrast kinetic curve was found to follow closely that of human subjects. The influence of the phantom parameters on the kinetic curve will be presented. The contrast kinetic curve modeling benign and malignant tumors using this phantom will be presented. Conclusion: The contrast kinetic curve was evaluated using a dynamic breast phantom. CEDEM was found to be effective in characterizing the contrast kinetic curve around breast tumors.
The intimacies of power: rethinking violence and affinity in the Bolivian Andes

In the Bolivian Andes although violence between spouses is more frequent, violence also erupts between women who are affines. By examining events of violence through the discourses and practices that sustain asymmetries of power among affines, I demonstrate that kinship and violence in the highland Andean region of'Sullk'ata are shaped by multiple inequalities and embedded in, yet extend beyond, the domestic arena. Incorporating violence into an analysis of kinship further highlights the lived interactions of individuals rather than static structures of kinship. [gender, power, domestic violence, marriage, kinship, Andes, Latin America]
Detection of dual-gene expression in arteries using an optical imaging method

We evaluate the in vivo use of an optical imaging method to detect the vascular expression of green fluorescent protein (GFP) or red fluorescent protein (RFP), and to detect the simultaneous expression of GFP and RFP after transduction into arteries by a dual-promoter lentiviral vector driving their concurrent expression. This method involves using a charge-coupled device camera to detect fluorescence, a fiber optic probe to transmit light, and optical filters to distinguish each marker. In animal models, these vectors are locally delivered to target arteries, whereas the gene for a nonfluorescent cell-surface protein is transduced into contralateral arteries as the sham control. The images show distinct areas of bright fluorescence from GFP and RFP along the target arteries on excitation; no exogenous fluorescence is observed in the controls. Measured signal intensities from arteries transduced with the single- and dual-promoter vectors exceed the autofluorescence signal from the controls. Transgene expression of GFP and RFP in vivo is confirmed with confocal microscopy. We demonstrate the use of an optical imaging method to concurrently detect two distinct fluorescent proteins, potentially permitting the expression of multiple transgenes and their localization in the vasculature to be monitored.
Cognitive-behavior modification: A conceptual review

Abstract Conceptual issues regarding cognitive-behavior modification are presented, beginning with an analysis of the basic terms of cognition, behavior modification, and behaviorism. Five controversies in the relevant literature that stimulated increased interest in cognitive factors among behavior therapists are reviewed: (a) symbolic control in classical and operant conditioning; (b) Breger and McGaugh's (1965) critique of behavior therapy; (c) cognitive factors in systematic desensitization; (d) the debate regarding cognition in the first issue of Behavior Therapy (1970); and (e) Ledwidge's (1978) Psychological Bulletin critique of cognitive-behavior modification. An analysis of several conceptual issues emerging from the literature results in the following conclusions: cognitive-behavior modification is a “revolutionary” development only insofar as it extends beyond mediational behaviorism to a truly cognitive view that includes internal cognitive structures; cognitions are not behaviors, but can be studied in their effects on behaviors as is done with drugs and genetics; a unifiedinteractive approach that incorporates cognition, behavior, and affect represents the logical future development in psychotherapy research and practice.
Fractal classifications of trajectories in a nonlinear mass-spring system

Abstract Nonlinear continuous dynamical systems can exhibit extremely complicated behavior. We investigate a physical system consisting of a single mass anchored to two fixed points in the plane by two ideal linear springs. Though the spring forces used in the system are linear, their interactions in two dimensions create a nonlinear system, which forms the basis for more sophisticated dynamical systems used in physics and computer animation. This paper uses a numerical solution to investigate the dynamics of the trajectories in this system, and to quantify specific characteristics. We find a complicated space of trajectories which gives rise to a class of intricate fractal shapes in the system's four-dimensional phase space. We investigate the fractal properties of these shapes that help quantify and classify features of the system's trajectories, and enable visualization of the structure of its four-dimensional phase space.
Adhesion of spores of Bacillus thuringiensis on a planar surface.

Adhesion of spores of Bacillus thuringiensis (Bt) and spherical silica particles on surfaces was experimentally and theoretically investigated in this study. Topography analysis via atomic force mi...
Proposal for two model undergraduate curricula in entrepreneurship

This paper takes three important preliminary steps towards the development of undergraduate curricula in entrepreneurship. First, it provides one of the first analyses comparing the entrepreneurship education standards proposed by the Consortium for Entrepreneurship Education and the European Commission’s Education and Training in Entrepreneurship initiative. Next, it presents an analysis of results of a workshop of entrepreneurship educators regarding development of an undergraduate entrepreneurship standard for business schools. With these two elements in place, the paper makes recommendations for model undergraduate entrepreneurship curricula for majors and concentrations, and concludes with a discussion of the issues in developing and implementing model curricula in a manner consistent with emerging standards in US business schools.
Pronounced Isotope Effect in the Superconductivity of HfV 2 Containing Hydrogen (Deuterium)

Superconducting transition temperatures of $\mathrm{Hf}{\mathrm{V}}_{2}{\mathrm{H}}_{x}$ and $\mathrm{Hf}{\mathrm{V}}_{2}{\mathrm{D}}_{x}$ have been measured in the composition ranges $x=0\ensuremath{-}1.5$ and $x=0\ensuremath{-}1.0$, respectively. Hydrogen or deuterium absorption is found to decrease ${T}_{c}$ of ${\mathrm{HfV}}_{2}$. Pronounced isotope effects have been observed. At $x=1$, hydrogen absorption reduces ${T}_{c}$ by 4.8 K while deuterium absorption reduces ${T}_{c}$ by 6.9 K with respect to ${\mathrm{HfV}}_{2}$.
The persistent puzzle of the geographic patterning of cardiovascular disease

It has long been known that health is geographically patterned (Jones and Moon, 1987). In fact, “place” has been a key dimension of epidemiology since its origins. Descriptive epidemiology emphasizes differences in disease distribution across places because it may provide important etiologic clues. Cardiovascular disease mortality, and in particular coronary heart disease (CHD) and stroke, vary markedly across and within countries (Lloyd-Jones et al., 2009). In the United States, there are up to two-fold differences in stroke and CHD mortality across states (Lloyd-Jones et al., 2009). Yet our ignorance about the reasons for these differences is surprising, especially given our knowledge of major heart disease and stroke risk factors. Together with the causes of trends over time – topic of debate and research in itself – the causes of geographic variations remain one of the big unanswered questions in cardiovascular disease epidemiology. In this issue of Preventive Medicine, Howard et al. (G.C.M. Howard, Prineas R., Howard VJ., Moy CS, Sullivan LM, D'Agistino RB, McLure LA, Pulley LV, Safford MM) use unique data collected as part of the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study, a national study of geographic variations in stroke, to investigate the extent to which established heart disease and stroke risk factors explain geographic variations in stroke and heart disease mortality. They construct summary aggregate measures of the Framingham Coronary Heart Disease Risk Score and the Framingham Stroke Risk Score for US states and investigate correlations between scores and corresponding mortality rates, between stroke and heart disease scores, and between stroke and heart disease mortality rates. As expected, each of these scores is positively associated with the corresponding mortality rate at the state level, with stronger correlations observed for CHD than for stroke. They find that CHD and stroke mortality rates are not correlated, suggesting that the etiologic processes leading to each outcome are distinct and could involve different sets of factors. In contrast the Framingham heart and stroke risk scores are positively correlated with each other. From this pattern of results (weak associations between CHD and stroke mortality but strong associations between scores) the authors infer that the risk factor components of the FRS do not explain the geographic variation in store and CHD mortality rates. The correlational results reported by Howard et al. are compatible with the possibility that geographic differences are not explained by risk factors, but they also have limitations. If risk factors are important contributors tomortality differences, the geographic patterning of risk factor scores should mirror the geographic patterning of mortality
Mesenchymal stem cell differentiation and roles in regenerative medicine

Adult stem cells with multi or unipotent differentiation potential are present in almost all tissues of adult organisms. The main function of these stem cells is to support normal repair and rejuvenation of diseased and aging tissues. Mesenchymal stem cells (MSCs) isolated from the bone marrow have the potential to differentiate into multiple connective tissues. Advancements in understanding tissue specific differentiation of MSCs in conjunction with global genomic and proteomic profiling of MSCs have not only provided insights into their biology but also made MSC based clinical trials a reality for treating various debilitating diseases and genetic disorders. The emerging evidence that MSCs are immunosuppressive makes them an even more attractive candidate for regenerative medicine as rejections of transplants by the recipient could be a limiting step for moving the stem cells based therapies from "bedside to bed side." To a large extent the therapeutic potential of MSCs is attributed to their differentiation ability. The fate and commitment of MSCs are regulated by various instructive signals from their immediate vicinity or microenvironment, which comprises many biological molecules (soluble and insoluble) and biomechanical forces. These biochemical and biophysical factors play a pivotal role in determining the efficacy of MSC differentiation and their contribution to the repair process. In this review, we discuss the characteristics of MSCs, their differentiation potential toward different skeletal tissues (cartilage and bone), and their emerging role in regenerative medicine.
A large lightweight mirror for use in cherenkov counters

Abstract The construction is described of Cherenkov counter mirrors of dimensions 120 cm × 120 cm, presenting on average 0.7 g/cm 2 to penetrating particles, yet with optical qualities adequet to allow a simplelight collection system.
Intradiscal treatment of back pain

Since sciatica was first recognized as having a common and clearly defined cause, lumbar disc herniation, there has been speculation that the disc may be a possible primary cause of low back pain (LBP) without any radicular component. Similarly, when percutaneous intradiscal injection of chymopapain was found to be unequivocally effective in treating sciatica, many investigators have searched for an effective percutaneous treatment of nonradicular LBP syndromes. At times anecdotal or case series reports have suggested some percutaneous interventions for LBP that have been extraordinarily effective or even at times unbelievably effective. Treatment strategies, such as percutaneous routertype nucleotomy, intradiscal injection of sclerosing agents or intradiscal lubricating agents, and so on, have come and gone. Interventions such as intradiscal electrothermal annuloplasty (IDET) reported spectacular and decidedly less than spectacular outcomes in nearly simultaneous publications. Remarkably, even controlled trials have proven terribly misleading. For instance, Karasek and Bogduk [1] reported an eye-popping five-point improvement in pain intensity (median, 10-point pain scale) in an IDET-treated group compared with worsening pain scores in the controls. They reported that 80% of the IDET group had greater than 66%
Binding of Matrix Proteins to Developing Enamel Crystals: An Atomic Force Microscopy Study

The control of hydroxyapatite crystal initiation and growth during enamel development is thought to be mediated by the proteins of the extracellular matrix. However, the precise nature of these critical mineral−protein interactions remains obscure. In this study, fluid tapping mode atomic force microscopy was used to image, for the first time, the binding of extracellular proteins found in enamel matrix (amelogenin and albumin) to developing enamel crystals. Both albumin and amelogenin were found to be associated with the crystal surfaces under conditions close to physiological; however, the binding of the two proteins was distinctly different. Albumin appeared to bind as a monomer, whereas amelogenin was bound as aggregates resembling previously described “nanosphere” structures. Both proteins were arrayed on the crystal surface in a distinctive banding pattern, perpendicular to the c-axis. This pattern was coincident with recently identified positively charged domains on the crystal surface, suggesting ...
Thermal substitution reactions of the heterodinuclear complex CpFe(CO)2Co(CO)4 with phosphorus ligands

Abstract The thermal reactions of CpFe(CO) 2 Co(CO) 4 with phosphorus ligands (L = P( n -Bu) 3 , P( c -Hx) 3 , PPh 3 , P(OPh) 3 , PMePh 2 ) lead to formation of both ionic disproportionation products, [CpFe(CO) 2 L] + [Co(CO) 4 ] − , via a radical chain path, and neutral monosubstitution products, CpFe(CO) 2 Co(CO) 3 L, via a CO-dissociative pathway. Reaction with PPh( o -CH 3 Ph) 2 results in forming only the monosubstituted product and no reactions were observed with the two bulkiest ligands, P( o -CH 3 Ph) 3 and P(C 6 F 5 ) 3 . The slow CO-dissociative pathway is always in effect in these reactions, and the product distribution is therefore determined by the rate of radical chain process. The steric and electronic requirements on the ligand for the radical chain process to dominate are much milder than that for other homodinuclear and heterodinuclear complexes that have been studied.
Stiffness and Fatigue Study for Surface Mounted Module/Lead/Card Systems

Modules attached to circuit cards by peripheral J- and gullwing leads were studied for their behavior under flexure. Three aspects of mechanical behavior were focused upon: the stiffness of the system, the forces arising in the leads, and the fatigue strength of the latter. The effective stiffness of a module-reinforced circuit card was measured experimentally in several configurations (load on card and load-on-module, double-sided and stacked). The leaded attachments were in two parallel rows. Analytical modeling of these tests were performed considering the leads as a continuous elastic foundation connecting the module and the card; test results were corroborated. Experiments were also conducted to establish the elastic and elastoplastic range of lead stiffness in three perpendicular directions: in two shearing planes and axially. The latter was the stiffest and most significant direction, motivating much of the present analysis. For lead force, the analytical procedure yielded values which were confirmed by finite element computation methods described previously by Engel (1990). Fatigue tests were performed on both J- and gullwing leads. Solder joints failed in the former, while lead failures occurred in the latter.
REVERSING ENDOTHELIAL DYSFUNCTION WITH ACE INHIBITORS : A NEW TREND ?

During the past 15 years, it has become apparent that the vascular endothelium plays a crucial role in modulating vasomotor tone. The endothelium accomplishes this by synthesizing and releasing several vasoactive substances, including prostacyclin, adenine nucleotides, kinins, NO·, an as-yet-unidentified hyperpolarizing factor, and vasoconstrictor substances such as endothelin, vasoconstrictor prostanoids such as PGH2, and the superoxide anion (·O2−).1 2 3 Among the best characterized and likely the most important of these is NO·, which was previously known as EDRF.4 NO is produced by the endothelium when a variety of neurohumoral, paracrine, and pharmacological stimuli act on endothelial cell receptors to increase intracellular calcium, which ultimately activates endothelial cell NO synthase. This enzyme catalyzes the complex oxidation of one of the guanidino nitrogens of arginine to NO·.5 There is substantial evidence that NO· may be transported attached to other molecules, such as nitrosothiols, both between cells and in the plasma.6 7 Vascular smooth muscle cells possess receptors to many of the same agonists that activate NO· release from the endothelium. Thus, the ultimate effect of any given stimulus for NO· release is a balance between the vasodilator effect of NO· versus the direct vasoconstrictive effect of the stimulus on the vascular smooth muscle. A clinically important aspect of this important role of the endothelium is that it is impaired in a variety of diseases and conditions. These include hypertension, hypercholesterolemia, diabetes, transplant atherosclerosis, congestive heart failure, and cigarette smoking. NO· has a variety of beneficial, potentially antiatherogenic effects in the vessel wall. These include inhibition of platelet aggregation, leukocyte adhesion, and inhibition of adhesion molecule expression. It is conceivable, therefore, that loss of an NO· effect in various disease conditions could contribute to the atherosclerotic process. On the basis of these considerations, …
The effects of psychological stress on plasma interleukin-6 activity in rats.

Abstract The purpose of this study was to determine the effects of a particular psychological stress, exposure to an open-field, on plasma IL-6 activity in rats. Plasma IL-6 activity was 40.6±7.2 units/ml in control rats, 105±6.8 units/ml after 30 minutes exposure to an open-field, and 221±17 units/ml after 60 minutes of exposure ( p =0.0003). There was a positive correlation (r=.71, p =0.043) between the change in plasma IL-6 activity and body temperature. However, we conclude, based on earlier data relating plasma IL-6 activity to body temperature changes following injection of lipopolysaccharide, that the plasma levels of IL-6 following exposure to an open-field are not high enough to account for the rise in body temperature observed in rats during this stress. In conclusion, these experiments indicate that exposure to psychological stress can elevate the plasma concentration of IL-6, a known mediator of the acute phase response.
Flat-Bottom Strategy for Improved Accuracy in Protein Side-Chain Placements.

We present a new strategy for protein side-chain placement that uses flat-bottom potentials for rotamer scoring. The extent of the flat bottom depends on the coarseness of the rotamer library and is optimized for libraries ranging from diversities of 0.2 A to 5.0 A. The parameters reported here were optimized for forcefields using Lennard-Jones 12-6 van der Waals potential with DREIDING parameters but are expected to be similar for AMBER, CHARMM, and other forcefields. This Side-Chain Rotamer Excitation Analysis Method is implemented in the SCREAM software package. Similar scoring function strategies should be useful for ligand docking, virtual ligand screening, and protein folding applications.
Ethanol production by recombinant Escherichia coli KO11 using crude yeast autolysate as a nutrient supplement

Crude yeast autolysate (10 g/l; 5.8 g solubles/l) supplemented with minerals and vitamins served as a nutrient supplement for ethanol production by the recombinant bacterium, Escherichia coli KO11. Ethanol production in this medium (46±1.7 g ethanol/l) was equivalent to that obtained using 5–15 g/l of purified, soluble, commercial protein hydrolysates (44–48 g ethanol/l). On site production of autolysates from spent yeast offers the potential for synergy between grain-based and lignocellulose-based ethanol plants.
An ensemble approach to microarray data-based gene prioritization after missing value imputation

Motivation: Microarrays have been widely used to discover novel disease related genes. Some types of microarray, such as cDNA arrays, usually contain a considerable portion of missing values. When missing value imputation and gene prioritization are sequentially conducted, it is necessary to consider the distribution space of prioritization scores due to the existence of missing values. We propose an ensemble approach to address this issue. A bootstrap procedure enables us to generate a resample multivariate distribution of the prioritization scores and then to obtain the expected prioritization scores. Results: We used a published microarray two-sample data set to illustrate our approach. We focused on the following issues after missing value imputation: (i) concordance of gene prioritization and (ii) control of true and false positives. We compared our approach with the traditional non-ensemble approach to missing value imputation. We also evaluated the performance of non-imputation approach when the theoretical test distribution was available. The results showed that the ensemble imputation approach provided clearly improved performances in the concordance of gene prioritization and the control of true/false positives, especially when sample sizes were about 5--10 per group and missing rates were about 10--20%, which was a common situation for cDNA microarray studies. Availability: The Matlab codes are freely available at http://home.gwu.edu/~ylai/research/Missing. Contact: [email protected]
SPIDER WEBS AS HABITAT PATCHES—THE DISTRIBUTION OF KLEPTOPARASITES (ARGYRODES, THERIDIIDAE) AMONG HOST WEBS (NEPHILA, TETRAGNATHIDAE)

Abstract Most adult golden orb weavers (Nephila clavipes) have kleptoparasites of the genus Argyrodes in their webs. The kleptoparasitic load correlates positively with web size. Clustered (interconnected) webs have a more predictable number of kleptoparasites than do solitary webs, but there is no difference in the mean number of kleptoparasites between the two. From the view of the kleptoparasite, host webs are habitat patches or islands. Isolated webs show characteristics of small patches, where web size is a poor indicator of kleptoparasite number and variation is high. The distribution of kleptoparasites in clustered webs, on the other hand, seems to fit the “ideal free distribution” where web size nearly entirely predicts kleptoparasitic load. Thus clustered webs, as a habitat patch, are more than merely the combination of their parts. The predictability of kleptoparasite load in clustered webs may be a function of the stability (longevity) of those habitat patches, and ease of colonization, as neig...
Incident angle and polarization effects on the dye-doped cholesteric liquid crystal laser

Polarization effect of the pulsed pumping laser on the lasing characteristics of the dye-doped right-handed cholesteric liquid crystal (CLC) is studied at different incident angles. At a small incident angle (<18°), the CLC laser performance is independent of the polarization state of the pumping laser. As the incident angle exceeds 18°, the CLC laser emission strongly depends on the polarization state of the pumping laser. As the incident angle increases, the lasing efficiency of the CLC laser is dramatically decreased for those excited by the right-handed circularly polarized or linearly polarized laser, but barely affected by the left-handed circularly polarized laser. As the incident angle exceeds ∼31°, lasing phenomenon diminishes under the excitation of the right-handed circularly polarized laser. The lasing threshold pumped by the linearly polarized laser is ∼2× higher than that pumped by the left-handed circularly polarized laser.
'That Man Behind the Curtain': Atheism and Belief in The Wizard of Oz

While The Wizard of Oz (1939) constructs an elaborate mythic world filled with witches, wizards, and magic, this essay argues that Victor Fleming's classic film also carries with it a message that is profoundly atheistic. The film persistently deconstructs ostensibly supernatural experiences by revealing their materialist underpinnings. Further, this essay interrogates Oz's epistemology by connecting it with Slavoj Žižek's concept of decaffeinated belief, as well as Daniel Dennett's notion of belief in belief.
Reliability of assessing change with sequential coronary angiography

Abstract Data are presented from a study evaluating the reliability of sequential angiography in estimating changes in coronary lesions. Three panels of three expert anglographers each read on two separate, independent occasions 18 sets of paired angiograms taken 24 months apart. All readers were blinded to the temporal sequence of the films, clinical data, and ventriculography information. The need for simultaneous viewing and reading of the two films, for training sessions, and for allowance to be made for apparent differences arising from boundary definitions prior to final analysis was demonstrated. Under stringent conditions (determination of change based on agreement of at least two out of three panels of physicians) it was possible to ascertain change in coronary atherosclerosis from sequential sets of coronary angiograms with good reliability. However, single-panel readings ylelded an unacceptable overestimate of the number of patients with lesion changes.
Microwave photonic applications of slab-coupled optical waveguide devices

The semiconductor slab-coupled optical waveguide (SCOW) concept is a versatile device platform that has enabled new classes of high-power, low-noise single-frequency lasers, mode-locked lasers, optical amplifiers, and photodiodes for analog optical links and photonic analog-to-digital converters.
Technical Note: Anomalies Accompanying the Cathodic Charging of Some bcc Metals

That the diffusion of hydrogen can be slowed down considerably in iron alloys, in Pd-Ni, and in iron, has been known for a long time, and this is believed to be caused by interactions between the diffusing solute and pre-existing structural and chemical conditions in the lattice. This ''trapping'' phenomenon may be regarded as a type of diffusion with chemical reaction, of which internal oxidation accompanying the diffusion of oxygen, and hydride formation accompanying the diffusion of hydrogen are well-known examples. In all these cases the further inward flux of the diffusing species is decreased by its consumption by the reaction. Another less familiar case is the recombination of atomically dissolved hydrogen at internal interfaces of microvoids and cracks in iron and steel. If the hydrogen is cathodically generated at high fugacity at the input surface, the internally produced molecular hydrogen can develop pressures large enough to expand the original microvoids by plastic deformation. The voids and the dislocation structure that result effectively prevent the penetration of hydrogen beyond a shallow layer below the input surface. The single-phase bcc alloy, Ti-30 Mo, can dissolve a large concentration of hydrogen without the formation of hydride; Gerberich, et al., have measured approximatelymore » 11,000 ppm introduced by cathodic charging without observing any evidence of hydrides. Therefore, normal Fickian diffusion of dissolved hydrogen is expected. This is not observed, however, and this note is a preliminary report and tentative explanation of the very large deviation from normal behavior of the diffusion of hydrogen cathodically charged into Ti-30 Mo.« less
Treatment of oropharyngeal candidiasis in HIV-positive patients†

Most HIV-positive patients develop some form of oral candidiasis, most commonly pseudomembranous candidiasis, erythematous candidiasis, or angular cheilitis, at some point in their disease. All these manifestations are important risk markers for disease progression. Oral candidiasis is generally caused by Candida albicans. Although oral candidiasis can occur at any stage of HIV infection, it is most common in patients with low CD4 counts. Numerous oral and systemic therapies are used to treat oral candidiasis, the most popular of which are nystatin (topical), clotrimazole (topical), ketoconazole (systemic), fluconazole (systemic), and itraconazole (systemic). The topical agents are available in assorted dosage forms with varying degrees of efficacy and patient acceptability. The limited data currently available suggest an advantage for the systemic agents, although problems with resistance may limit the usefulness of fluconazole. The efficacy, safety, and cost effectiveness of a given agent must be considered when prescribing a specific agent for the treatment of oral candidiasis.
Computational Fluency Performance Profile of High School Students With Mathematics Disabilities

The purpose of this descriptive study was to develop a computational fluency performance profile of 224 high school (Grades 9—12) students with mathematics disabilities (MD). Computational fluency performance was examined by grade-level expectancy (Grades 2—6) and skill area (whole numbers: addition, subtraction, multiplication, division; rational numbers: fractions, decimals) using the Mathematics Operations Test— Revised (MOT-R). The findings indicated that these high school students with MD were fluent only in computational skills at the second- and third-grade levels. Computational fluency was found with most whole number basic facts in addition, subtraction, multiplication, and division. Lack of computational fluency was demonstrated on many items dealing with subtraction of multiple digits or items requiring regrouping, most multiplication and division items, and rational number items involving fractions and decimals. The results are discussed in regard to instructional programs and curriculum organ...
A new multimodal imaging strategy for integrating fMRI with EEG.

For the multimodal functional neuroimaging combining fMRI and EEG, it is of significance to correct the distortion due to the fMRI-EEG mismatches, which arise from the fundamental difference between brain electric and hemodynamic activities. In the present study, we proposed a novel two-step approach (referred to as "Twomey algorithm") for the fMRI-constrained cortical source imaging. In the first step, a "hard" spatial prior derived from the fMRI was imposed to solve the EEG inverse problem with a reduced source space; in the second step, the fMRI constraint was removed and the source estimate from the first step was re-entered as the initial guess of the desired solution into an EEG least squares fitting procedure with Twomey regularization. We evaluated the performance of Twomey algorithm in comparison with the well- known 90% fMRI-constrained Wiener filter and the EEG-alone weighted minimum norm methods in a randomized computer simulation setting. We examined the effects of invalid fMRI priors including fMRI invisible sources, fMRI extra regions and fMRI displacement. The present results in terms of the point spread function (PSF) and the localization error (LE), demonstrated that 1) relative to the EEG-alone solution, a higher spatial resolution can be achieved by using the fMRI priors in cortical source imaging; 2) the occurrence of fMRI invisible sources is the most problematic factor responsible for the error of the fMRI-EEG integrated cortical source imaging; and 3) the Twomey algorithm is more robust than the Wiener filter approach under invalid fMRI priors. The proposed Twomey approach may make an important contribution to the multimodal neuroimaging integrating fMRI with EEG.
The Surreals and the Reals

There have always been problems about our comprehension of the collection of all real numbers. Things became clearer by 1900 when the logicists had succeeded in the project of defining the reals in purely set-theoretical terms. Let us briefly summarise the approach that has now become traditional.
Consequences of Exchange in Low-Dimensional Compounds: High Temperature Spin Dynamics as Sampled by Magnetic Resonance

The isotropic exchange interaction 2JSi·Sj between a pair of spins i and j has several consequences as it forms the dominant “glue” of interaction which makes the system of 1022 or so spins a strongly coupled one rather than a collection of independent paramagnetic particles. One may roughly divide the effects of J into static and dynamic ones, as can be seen from a simple consideration of two spins only, each with S = ½. For antiferromagnetic coupling (J > 0 in our notation) the antiparallel (singlet) arrangement is lower in energy then the parallel (triplet) alignment by an amount 2J(1/4) − 2J(−3/4) = 2J. As a consequence the spins will tend to align antiparallel at a sufficiently low temperature T ~ 2J/kB. This effect is the root of static properties such as the magnetic susceptibility which will be discussed by Professor Gerstein in subsequent lectures.