cssi/SciSciGPT-SciSciNet huggingface dataset:
The Influence of Endocardial Electrode Fixation Status on Acute and Chronic Atrial Stimulation Threshold and Atrial Endocardial Electrogram Amplitude

UNLABELLED The endocardial atrial electrogram or "P wave amplitude" (PWA) and pacemaker atrial stimulation thresholds are important parameters determining correct pacing system function. Pacemaker lead fixation mechanism and lead age may negatively influence these parameters. Therefore, we compared acute and chronic PWA and atrial stimulation thresholds in 33 patients with permanent transvenous atrial screw-in leads, follow-up 647 days +/- 297 days; and in 31 patients with nonscrew leads, follow-up 855 days +/- 512 days (P = ns). RESULTS The PWA differed between the two lead types acutely (1.97 mV +/- 0.8 mV for screw-in versus 2.48 mV +/- 1.1 mV for nonscrew-in leads; P less than 0.05), but not chronically (2.21 mV +/- 0.8 mV vs 2.2 mV +/- 1.2 mV; P = ns). Acute and chronic atrial pacing thresholds did not differ between groups. We also analyzed an early interim PWA in a subgroup of patients (mean 31 days after implantation). The nonscrew fixation group interim PWA was 1.76 mV +/- 0.9 mV versus 2.7 mV +/- 1.2 mV at implant (P less than 0.001). The screw-in lead interim PWA was 2.04 mV +/- 0.9 mV versus 1.97 mV +/- 0.7 mV at implant (P = ns). CONCLUSIONS (1) A significantly higher endocardial PWA occurs at the time of lead implantation in nonscrew versus screw-in lead groups, but the chronic PWA does not differ between the two groups. (2) A transient but marked early (mean approximately 31 days) attenuation of the PWA occurs only with nonscrew-in leads. (3) Atrial threshold stimulation energies do not differ between the two lead groups acutely or during follow-up.
Disinfection of Contaminated Water by Ultraviolet Irradiation, with Emphasis on Whirling Disease (Myxosoma cerebralis) and Its Effect on Fish

Abstract Rainbow trout fry developed whirling disease upon exposure to water contaminated with Myxosoma cerebralis. When similarly contaminated water was irradiated with 2537 Angstrom units of ultraviolet light at dosages of 35,000, 43,000, and 112,000 microwatt sec/cm2, infection of fry was prevented. The minimum effective dosage was not determined in the present experiments. High mortality and a 61% growth inhibition of survivors occurred in the infected fry.
High-performance optoelectronic bus system

In order to utilize the high speed of optical interconnects and overcome the latencyproblem of a large bus structure, we proposed an architecture of optoelectronic hierarchical bus system. Waveguide hologram implementations, and its associated cache coherence problem are addressed. In our configuration, bus hierarchy is controlled with electronic programmable plates. Optical signals can be transmitted on all-optical paths without intermediate conversions.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
High-resolution chemical sensor for unattended underwater networks

Autonomous underwater sensors are the best solution for continuous detection of chemical species in aquatic systems. The Spectrophotometric Elemental Analysis System (SEAS), an in situ instrument that incorporates both fluorescence and colorimetric techniques, provides high-resolution time-series measurements of a wide variety of analytes. The use of Teflon AF2400 long-pathlength optical cells allows for sub-parts-per-billion detection limits. User-defined sampling frequencies up to 1 Hz facilitate measurements of chemical concentrations on highly resolved temporal and spatial scales. Due to its modular construction, SEAS can be adapted for operation in littoral or open ocean regions. We present a high-level overview of the instrument's design along with data from moored deployments and deep water casts.
Percent body fat measured by BIA and DEXA in obese, African-American adolescent girls.

To compare the estimation of body fat between bioelectrical impedance analysis (BIA) and dual energy X-ray absorptiometry (DEXA) in overweight, African-American female adolescents. In total, 54 African-American adolescent female subjects were recruited for Study 1. Each adolescent's body mass index was greater than the 85th percentile and their average body fat was 45% according to DEXA. A total of 26 African-American adolescent female subjects were available for Study 2, and had an average body fat of 26% according to DEXA. Percent body fat was measured by DEXA and BIA. Seven different BIA equations were tested. Both sets of data were analyzed using Bland–Altman regression analyses, utilizing percent body fat measured by DEXA as the criterion. The Kushner equation provided estimates that were unaffected by body fat in both studies. Estimates were unbiased when applied to the exclusively overweight sample and biased when utilized with the separate sample of normal weight and obese girls. The remaining equations were biased, provided inconsistent estimates across body weight, or were biased and provided inconsistent estimates. Ethnicity-specific and ethnicity-combined equations performed similarly in the obese sample, but became more disparate when applied to a sample encompassing a wider body weight range. The limits of agreement between all BIA equations and the DEXA estimates ranged from 6 to 9%. The study suggests that the Kushner BIA equation is appropriate for use with African-American female adolescents across the weight spectrum, while the majority of BIA equations underestimated percent body fat as body fat increased.
Nonmonotonic TC trends in bi-based ferroelectric perovskite solid solutions.

We use first-principles density functional theory calculations to investigate the strongly nonlinear compositional trends in ferroelectric ${\mathrm{BiBO}}_{3}\mathrm{\text{\ensuremath{-}}}{\mathrm{PbTiO}}_{3}$ solid solutions for a variety of cations on the perovskite $B$ site. We demonstrate that previously tabulated crystal chemical parameters (extracted from other Pb-based perovskite alloys [Grinberg et al., J. Appl. Phys. 98, 094111 (2005)]) permit accurate prediction of cation displacements in these new Bi-Pb alloys. We find that observed transition temperatures in these materials are well correlated with computed polarization magnitudes. The presented model for coupling between compositional variation and cation displacements explains the highly nonlinear and often nonmonotonic dependence of the Curie temperature (${T}_{C}$) on composition observed in these solid solutions.
Time optimal control of coupled qubits under nonstationary interactions

In this paper, we give a characterization of all the unitary transformations that can be synthesized in a given time for a two-qubit system in the presence of general time varying coupling tensor. This characterization helps to compute the minimum time and the shortest pulse sequence for generating a general two-qubit transformation under nonstationary interactions. The methods presented here can be applied in design of time optimal pulse sequences for transferring coherence and polarization between coupled spins with time varying couplings as in solid-state NMR under magic angle spinning.
Investigation of steel containment buckling under dynamic loads

Abstract Buckling of freestanding nuclear steel containment buildings from dynamic base excitation was investigated in a combined experimental/numerical program. A polycarbonate scale model of a containment building was excited with scaled earthquake transients and single-frequency harmonic transients to determine the peak base acceleration levels required to induce buckling. Buckling was identified using recorded signals from strain gages and accelerometers, with high-speed video records, and by audibility. Experimental results are compared with numerical results obtained by using a freezing-in-time technique. The results are preliminary, since several more tests are to be performed. However, the limited data obtained indicate that the freezing-in-time technique approximates the required acceleration levels reasonably well, although not conservatively. Additional experiments are described that will take containment asymmetries into account, as well as use instrumentation that will provide more accurate measures of the occurrence of buckling.
A localization principle for multiplicative perturbations

Abstract A certain resolvent estimate implies point spectrum for discrete linear wave equations with random local propagation speed. The significance of point spectrum in this context is that scattering within a random medium produces only localized standing waves. The implication is derived from a general result about multiplicative perturbations of a self-adjoint operator. The estimate implies point spectrum for almost every value of the perturbation parameter.
The effects of propranolol on the electrophysiology of the heart.

The effects of propranolol on the electrical behavior of ventricular muscle fibers were investigated in the anesthetized dog by simultaneously recording surface and intracellular electrograms. After administration of propranolol during sinus rhythm, the RR, PQ and QT intervals were significantly prolonged, while the QRS duration remained unchanged. During electrically driven rhythm, propranolol caused a slight but insignificant prolongation of the QT interval. There were no changes in the QRS duration. Significant delay of the interatrial and atrioventricular conduction times was observed. There were no significant changes in the intraventricular conduction time. Propranolol principally affects the sinoatrial node, the atrioventricular node and the conduction time of the atria. Effects of propranolol on the intracellular electrograms from the ventricle were as follows. The duration of the membrane action potential was significantly prolonged. No changes were observed in the amplitudes of the membrane action potential, membrane resting potential and overshoot. The maximum upstroke velocity of the membrane action potential did not change. Propranolol has a quinidine-like action as well as a beta adrenergic blocking action. Both actions contribute to the effectiveness of the drug in the treatment of cardiac arrhythmias.
Integral Representation of Energy Release Rate in Graded Materials

It is well known that, for homogeneous materials, the pathindependent J contour integral is the (potential) energy release rate. For general nonhomogeneous, or graded materials, such a contour integral as the energy release rate does not exist. This work presents a rigorous derivation of the extended J integral for general graded materials from the potential energy variation with crack extension. Effects of crack shielding and amplification due to a graded interlayer in an elastic-plastic material system are discussed in terms of this integral.
Characteristics of tagging behavior in digitized humanities online collections

The purpose of this study was to examine user tags that describe digitized archival collections in the field of humanities. A collection of 8,310 tags from a digital portal Nineteenth-Century Electronic Scholarship, NINES was analyzed to find out what attributes of primary historical resources users described with tags. Tags were categorized to identify which tags describe the content of the resource, the resource itself, and subjective aspects e.g., usage or emotion. The study's findings revealed that over half were content-related; tags representing opinion, usage context, or self-reference, however, reflected only a small percentage. The study further found that terms related to genre or physical format of a resource were frequently used in describing primary archival resources. It was also learned that nontextual resources had lower numbers of content-related tags and higher numbers of document-related tags than textual resources and bibliographic materials; moreover, textual resources tended to have more user-context-related tags than other resources. These findings help explain users' tagging behavior and resource interpretation in primary resources in the humanities. Such information provided through tags helps information professionals decide to what extent indexing archival and cultural resources should be done for resource description and discovery, and understand users' terminology.
Leukemia inhibitory factor, a cytokine at the interface between neurobiology and immunology

The growing appreciation of the active interface between the immune system and the nervous system includes recognition of the cell surface molecules and the transducing mechanisms that are shared between the two systems. Perhaps even more compelling is the identification of intercellular messengers that mediate active signaling between the two systems. Neurotransmitters and neuropeptides, well known for their role in the communication between neurons, are also capable of activating monocytes and macrophages and inducing chemotaxis in immune cells. Transmitters and neuropeptides released by local neuronal processes are, therefore, well suited for mediating the ability of neurons to participate in inflammatory reactions at sites of injury or infection, as discussed below. In addition, immune tissues such as the spleen and lymph nodes are innervated, and pharmacological manipulations indicate that transmitters and neuropeptides are likely to regulate immune functions (1, 2).
Granular impact cratering by liquid drops: Understanding raindrop imprints through an analogy to asteroid strikes

When a granular material is impacted by a sphere, its surface deforms like a liquid yet it preserves a circular crater like a solid. Although the mechanism of granular impact cratering by solid spheres is well explored, our knowledge on granular impact cratering by liquid drops is still very limited. Here, by combining high-speed photography with high-precision laser profilometry, we investigate liquid-drop impact dynamics on granular surface and monitor the morphology of resulting impact craters. Surprisingly, we find that despite the enormous energy and length difference, granular impact cratering by liquid drops follows the same energy scaling and reproduces the same crater morphology as that of asteroid impact craters. Inspired by this similarity, we integrate the physical insight from planetary sciences, the liquid marble model from fluid mechanics, and the concept of jamming transition from granular physics into a simple theoretical framework that quantitatively describes all of the main features of liquid-drop imprints in granular media. Our study sheds light on the mechanisms governing raindrop impacts on granular surfaces and reveals a remarkable analogy between familiar phenomena of raining and catastrophic asteroid strikes.
Synthesis and activity of substituted heteroaromatics as positive allosteric modulators for α4β2α5 nicotinic acetylcholine receptors.

Abstract The design and synthesis of a series of substituted heteroaromatic α4β2α5 positive allosteric modulators is reported. The optimization and development of the heteroaromatic series was carried out from NS9283, and several potent analogues, such as 3-(5-(pyridin-3-yl)-2H-tetrazol-2-yl)benzonitrile (5k) and 3,3′-(2H-tetrazole-2,5-diyl)dipyridine (12h) with good in vitro efficacy were discovered.
Autoxidation of Turkey Lipidsa

SUMMARY Autoxidation of lipids in raw, ground turkey tissues was studied with the 2-thiobarbituric acid (TBA) method. Samples prepared immediately post-mortem and held at 4°C for approximately one week showed significant differences between the rates of autoxidation for certain of these tissues, notably red and white muscle. Failure to detect other differences, as between skin and white muscle, reflects variation in both lipid and fatty acid composition. A significant delay of autoxidation was achieved by the addition of 1% egg albumen solids (w/w), 0.04% butylated hyldroxyanisole, or 0.35% phosphates to the ground tissue; 1% gelatin exhibited no beneficial effect. Possible mechanisms by which these materials delay oxidative changes are discussed.
Validation of the Salmonella (SV50)/arabinose-resistant forward mutation assay system with 26 compounds.

Abstract Mutagenic sensitivity of the Salmonella/arabinose-resistant (Arar) assay system using the tester strain SV50 was evaluated with 26 compounds both by the preincubation and the standard plate incorporation tests. The mutagenic activity of all 26 compounds was also tested with TA98 and/or TA100 of the Ames Salmonella/microsome assay system. The results indicate that 13 and 10 of 26 compounds were mutagenic and nonmutagenic, respectively, in both assay systems. PR toxin and hydrogen peroxide were mutagenic only in the Arar assay, while 2-nitrofluorene was mutagenic only in the Ames assay. The results also show that the mutagenic response of SV50 to 13 of 15 mutagenic compounds was much higher (2.1–154-fold) if the compounds were tested with the preincubation rather than the plate incorporation test. The mutagenic activity of 4 compounds (diethyl sulfate, niridazole, PR toxin and hydrogen peroxide) in the Arar assay was detected only with the preincubation test. Since the Arar assay using tester strain SV50 has similar mutagenic sensitivity as the Ames assay to chemicals with different modes of action and since it requires only one tester strain, we find this assay system to be useful for screening environmental mutagens. Based on the effectiveness of the preincubation test in this study, it is recommended that the preincubation test instead of the plate incorporation test be used for the Arar assay system with tester strain SV50.
Conditioned aversion to a taste perceived while grooming.

Abstract Four experiments were conducted to determine how the characteristics of conditioned taste aversion (CTA), as described from studies conducted in the drinking and feeding contexts, applied in the grooming context. In Experiment 1, sodium saccharin was mixed with a “neutral-tasting” jelly and applied to the fur of male Sprague-Dawley® rats. Rats injected with LiCl after the applications strongly avoided saccharin solutions in subsequent 1-hr, 2-choice (saccharin solution vs water) drinking tests, whereas rats injected with NaCl or given plain jelly on the fur showed only an initial neophobic response to the saccharin solution. Thus, the taste of saccharin was perceived while grooming and the CTA formed in the grooming context generalized to drinking. In Experiments 2–4, we obtained evidence that: (a) rats discriminated between one intensity of saccharin applied to the fur and another used in the test solution; and (b) rats differentiated between qualities of the two tastants applied to the fur in that saccharin overshadowed NaCl; and (c) taste qualities were more important than toxic properties when two stimuli (saccharin, LiCl) were used (saccharin overshadowed NaCl in subsequent drinking tests). We speculate that taste while grooming might play a role in social communication in some vertebrates. Further, CTA and grooming might have uses in rodent control (e.g., in agricultural situations) not previously considered such as in delivering a non-attractive, low-salience toxin so that the taste of the crop overshadows that of the bait, and induces crop aversion.
Transformational leadership theory: Using levels of analysis to determine boundary conditions.

The purpose of this study was to refine understanding of transformational leadership theory by a specification and test of boundary conditions. Multiple levels of analysis (individual, dyad, and group) were used to identify conceptually and assess empirically the potential bounds on transformational leadership theory. Multi-source data were collected from a sample of 105 salespersons and their 33 sales supervisors, and within and between analysis (WABA) procedures were conducted. Contrary to higher-level (dyad, group) and cross-level assertions in the literature, transformational leadership results were based solely on individual differences. That is, in this sales setting, transformational leadership theory was determined to be an individual-level theory bounded by individuals' (superiors' and subordinates') perceptions and not holding at higher levels of analysis. Implications of the findings for future leadership research and practice are discussed.
Language Structure Is Partly Determined by Social Structure

Author(s): Lupyan, Gary; Dale, Rick | Abstract: BackgroundLanguages differ greatly both in their syntactic and morphological systems and in the social environments in which they exist. We challenge the view that language grammars are unrelated to social environments in which they are learned and used.Methodology/principal findingsWe conducted a statistical analysis of g2,000 languages using a combination of demographic sources and the World Atlas of Language Structures--a database of structural language properties. We found strong relationships between linguistic factors related to morphological complexity, and demographic/socio-historical factors such as the number of language users, geographic spread, and degree of language contact. The analyses suggest that languages spoken by large groups have simpler inflectional morphology than languages spoken by smaller groups as measured on a variety of factors such as case systems and complexity of conjugations. Additionally, languages spoken by large groups are much more likely to use lexical strategies in place of inflectional morphology to encode evidentiality, negation, aspect, and possession. Our findings indicate that just as biological organisms are shaped by ecological niches, language structures appear to adapt to the environment (niche) in which they are being learned and used. As adults learn a language, features that are difficult for them to acquire, are less likely to be passed on to subsequent learners. Languages used for communication in large groups that include adult learners appear to have been subjected to such selection. Conversely, the morphological complexity common to languages used in small groups increases redundancy which may facilitate language learning by infants.Conclusions/significanceWe hypothesize that language structures are subjected to different evolutionary pressures in different social environments. Just as biological organisms are shaped by ecological niches, language structures appear to adapt to the environment (niche) in which they are being learned and used. The proposed Linguistic Niche Hypothesis has implications for answering the broad question of why languages differ in the way they do and makes empirical predictions regarding language acquisition capacities of children versus adults.
Anomalous temperature dependence of electrical transport in quantum Hall multilayers

We study the temperature dependence of vertical transport through the chiral sheath of surface states that exists near the sidewalls of $\mathrm{GaAs}∕{\mathrm{Al}}_{0.01}{\mathrm{Ga}}_{0.09}\mathrm{As}$ multilayer structures in the regime of the integer quantum Hall effect. Because variable-range hopping through the bulk provides a parallel conduction channel, we design our experiment to extend the temperature range of sheath-dominated transport. To do so, we increase device perimeter by using fractal-perimeter mesas. We report on the nearly linear increase of the sheath conductivity with temperature, a result not predicted by existing theories for the edge state sheath.
AXONIN-1, NR-CAM, AND NG-CAM PLAY DIFFERENT ROLES IN THE IN VIVO GUIDANCE OF CHICK COMMISSURAL NEURONS

Immunoglobulin/fibronectin type III-like cell adhesion molecules have been implicated in axon pathfinding based on their expression pattern in the developing nervous system and on their complex interactions described in vitro. The present in vivo study demonstrates that interactions by two of these molecules, axonin-1 on commissural growth cones and Nr-CAM on floor plate cells, are required for accurate pathfinding at the midline. When axonin-1 or Nr-CAM interactions were perturbed, many commissural axons failed to cross the midline and turned instead along the ipsilateral floor plate border. In contrast, though perturbation of Ng-CAM produced a defasciculation of the commissural neurites, it did not affect their guidance across the floor plate.
A rabbit model of abdominal aortic aneurysms (AAA)

Abstract Introduction: The rat elastase model of AAA is well established and useful for studying the early events in AAA formation. Development of a physiologic large animal model that reliably produces AAA expansion will allow in vivo testing of endovascular devices. Methods: Adult male New Zealand white rabbits (3.0–3.5 kg) were anesthetized and the terminal aorta exposed through a midline incision. Nine animals were divided into three groups: (I) saline controls, (II) elastase (100u/ml), or (III) elastase (100 μ/mL) and collagenase (50 μ/mL). A 2 cm segment of infrarenal aorta was isolated and was infused with one of the solutions for 5 minutes. Peak pressures were maintained between 300–400 mmHg. The aortic diameter was measured directly and by angiography before infusion, after infusion and at 8 weeks, when the animals were humanly killed. Results: Both treatment groups had significant increases in the size of the aorta at the end of the experiment compared to controls (p = 0.013). Animals treated with elastase and collagenase had a significantly greater change in mean aortic diameter, 2.7mm increased to 6.1mm, at 8-weeks compared to elastase alone, 2.8mm increased to 4.3 mm (p = 0.018). Conclusions: Infusion of an isolated segment of rabbit aorta with elastase and collagenase may provide a reproducible large animal model of AAA. Further work is required to determine if this could lead to a physiologic model with reproducible rupture that will allow in vivo testing of endovascular devices.
An analysis of the role of microfilaments in the establishment and maintenance of asymmetry in Caenorhabditis elegans zygotes

Microfilaments are needed to generate asymmetry during the first cell cycle in Caenorhabditis elegans zygotes. To investigate when and how microfilaments participate in this process, we have "pulsed" zygotes with the microfilament inhibitor cytochalasin D (CD) at different times during the cell cycle. We have shown that microfilaments are only required during a narrow time interval approximately three-quarters of the way through the first cell cycle for the manifestations of asymmetry that occur during and subsequent to this interval. When CD treatment spans this critical time interval, pseudocleavage, pronuclear migration, germ-granule segregation (all of which occur during the interval), and movement of the mitotic spindle to an asymmetric position (which occurs later in the cell cycle) are perturbed. In contrast, embryos briefly treated with CD before or after the critical time interval manifest normal asymmetry. Our results suggest that in C. elegans microfilaments participate in the generation of zygotic asymmetry by providing spatial cues and/or serving as a part of the necessary machinery only during a brief period in the first cell cycle, and are not required to maintain asymmetries that have already been established.
Cancer information seeking and awareness of cancer information sources among Korean Americans.

Many Korean Americans (KAs) suffer high cancer incidence levels and have low cancer screening rates. A significant number of KAs lack adequate information about cancer screening tests. However, little is known about the health information seeking behaviors of KAs. This study examines the types of cancer information searched for, the cancer information seeking experiences, and the awareness of major cancer information sources, such as the National Cancer Institutes (NCI) and the NCI’s Cancer Information Service, among KAs. It also examines associations with demographic characteristics and media use influencing variations in the awareness of cancer information sources. Data for this study were gathered with a cross-sectional, community-based survey (254 KAs). The survey results indicated that KA’s involvement in cancer information seeking is relatively low, and they have somewhat negative experiences in seeking cancer information. In addition, their awareness of cancer information sources was limited. Despite of the heavy use of Korean ethnic media, it did not connect to cancer information source awareness. Rather, use of US mainstream media was significantly related with awareness. Campaigns using the Korean language through partnerships with Korean ethnic media to inform KAs about credible sources of health information appear to be warranted by our findings.
Surgical diseases of the feline stifle joint.

Abnormalities of the feline stifle joint typically cause hind limb lameness, joint swelling, and pain. They occur less frequently in cats than in dogs and are often the result of trauma, such as vehicular trauma, a fall from height, or an altercation with another animal. Cruciate ligament rupture, patellar luxation, stifle dislocation, fractures of the patella and distal femur, and septic arthritis caused by bite wounds are common traumatic causes of stifle lameness in cats. Fortunately, stifle injuries in cats can often be managed more conservatively than in dogs, and the prognosis for adequate return of joint function is generally good. Nontraumatic causes of stifle lameness in the cat include congenital patellar luxation and immune-mediated arthropathies. Although immunemediated joint diseases are not treated surgically, they are important in the differential diagnosis for stifle lameness in cats. They typically cause polyarthritis with an acute or insidious onset of lameness and shifting leg lameness. Feline chronic progressive polyarthritis and caliciviral arthritis are two types of immune-mediated joint disease seen in cats. Feline chronic progressive polyarthritis usually occurs in male cats between the ages of 1 and 5 years of age. It is an erosive arthritis that most commonly affects the carpi and tarsi, although other joints may be involved. The antigen responsible for the immune response is unconfirmed, but the disease is linked to serologic evidence of exposure to feline syncytium-forming virus and feline leukemia virus [1–3]. Caliciviral arthritis is a transient self-limiting polyarthritis associated with calicivirus, and it is acquired by natural infection or vaccination. It is typically seen in kittens and usually resolves within 1 week without treatment [2,4]. Mycoplasma species and Lyme disease are also possible causes of polyarthritis in cats [2]. A thorough physical examination, complete understanding of the patient’s history, and knowledge of common feline diseases are needed to Vet Clin Small Anim 32 (2002) 963–982
Inhibition of Glucagon Secretion by Diazoxide In Vitro

The effect of diazoxide on the secretion of glucagon and insulin was studied using the isolated perfused rat pancreas. The perfusate concentration of D-glucose was kept constant at 5.6 mM. Five secretagogues of both glucagon and insulin—10 mM L-arginine, 5 mM L-leucine, 1.4 μM prostaglandin F 2α , 100 nM bovine growth hormone, and 10 mM theophylline—were administered individually in the presence or absence of 325 μM diazoxide. Basal secretion of glucagon or insulin was not discernibly affected by diazoxide. With diazoxide the secretion of glucagon was (a) abolished completely in response to L-arginine or L-leucine; (b) inhibited partially in response to prostaglandin F 2α ; (c) unaltered in response to growth hormone; and (d) unchanged or, at times, enhanced in response to theophylline. On the other hand, the secretion of insulin induced by each of these agents was inhibited effectively by diazoxide. Conclusions: (a) Diazoxide inhibits the secretion of glucagon as well as insulin in response to certain secretagogues independent of any changes in prevailing levels of glucose, (b) At the concentration tested, diazoxide is a more potent and consistent inhibitor of the release of insulin than of glucagon.
ON THE DYNAMICAL FORMATION OF VERY YOUNG, X-RAY EMITTING BLACK HOLE BINARIES IN DENSE STAR CLUSTERS

We recently discovered a population of very young ({tau} {approx}< 6-8 Myr), X-ray emitting black hole binaries (BHBs) in the nearby starburst galaxy NGC 4449. These BHBs are located within or near to very young star clusters, indicating that they form within the clusters, but that some fraction are dynamically ejected. Here we present results from a suite of N-body simulations of N = 16,384 ({approx}6000 M{sub Sun }) star clusters, similar to the masses of BHB hosts in NGC 4449, through the first 10 Myr of their lives. Our goal is to determine whether dynamical interactions are responsible for the observed population of BHBs in NGC 4449. Our simulations span a wide range of initial size and density profiles, both with and without primordial mass segregation, testing both realistic initial conditions and extreme ones. We find that clusters without primordial mass segregation only dynamically produce BHBs within 10 Myr when they are extremely compact and centrally concentrated. Preliminary results that include primordial binaries support this conclusion. The introduction of strong primordial mass segregation, however, greatly increases the rapidity with which the binaries form, although these are still not tight enough that they will emit X-rays. We conclude that X-raymore » emitting BHBs are unlikely to form dynamically in clusters of this mass under realistic conditions. Instead, they probably originate from binaries that contain two massive stars with small orbital separations, which are present from the cluster's birth.« less
DOES POLITICS REALLY MATTER? Policy and Government's Equalizing Influence in the United States

Analyses of the U.S. governing system indicate that national policy is influenced by public opinion, and this is interpreted as representation. Not as much is known about whether policy systematically influences societal outcomes. In fact, some analyses suggest that there is little connection between policies and the outcomes these policies seek to produce. This article seeks to determine whether such a connection exists for income inequality. Although connections should exist, various views of the policymaking process cast doubt on the prospect. Measures of government’s equalizing influence and aggregate policy are created for 1979-1996, and time series regression is used to test the connection between the two. Even in the presence of controls for economic and demographic factors, policy liberalism produces greater government redistribution. When assessed in light of earlier research, these results indicate that shifts in public opinion lead to important changes in the way government influences society.
Lattice relaxation around substitutional defects in semiconductors

The tight-binding theory of total energies in semiconductors, based upon universal parameters, is modified following the findings on the overlap repulsion by van Schilfgaarde and Sher. The nonorthogonality S of neighboring orbitals is thus taken to vary as 1/d rather than 1/${d}^{2}$, giving a repulsion proportional to 1/${d}^{3}$. An additional repulsion due to nonorthogonality of valence orbitals with neighboring cores is taken to vary as 1/${d}^{12}$. The two coefficients are chosen to give the observed equilibrium spacing and bulk modulus of the homopolar materials. The fit gives nonorthogonalities S near the expected value of 0.5. A natural generalization of the repulsion to polar materials predicts spacings and bulk moduli in reasonable accord with experiment in the compounds. The method is then applied to the prediction of lattice distortion around substitutional impurities and energies of substitution. The results are in excellent agreement with the known experimental values.
Microscopic theory of liquid 4He

Abstract A finite temperature theory is given of the temperature variation of the sound velocity and of the structure factor of liquid helium. The sound velocity is found to decrease slightly as the temperature is increased from absolute zero. The first peak of the structure factor is higher for higher temperature below the λ point. The internal energy is characterized by the quasiparticle distribution function with the Bogoliubov-Zubarev type excitation energy. The structure factor and the energy are determined by the effective interaction which depends on the average density, the density of the excited particles, and temperature in addition to the interaction potential.
Activation of Aldehyde Dehydrogenase-2 Reduces Ischemic Damage to the Heart

There is substantial interest in the development of drugs that limit the extent of ischemia-induced cardiac damage caused by myocardial infarction or by certain surgical procedures. Here, using an unbiased proteomic search, we identified mitochondrial aldehyde dehydrogenase 2 (ALDH2) as an enzyme whose activation correlates with reduced ischemic heart damage in rodent models. A high-throughput screen yielded a small-molecule activator of ALDH2 (Alda-1) that, when administered to rats before an ischemic event, reduced infarct size by 60%, most likely through its inhibitory effect on the formation of cytotoxic aldehydes. In vitro, Alda-1 was a particularly effective activator of ALDH2*2, an inactive mutant form of the enzyme that is found in 40% of East Asian populations. Thus, pharmacologic enhancement of ALDH2 activity may be useful for patients with wild-type or mutant ALDH2 who are subjected to cardiac ischemia, such as during coronary bypass surgery.
Synchronization in weighted uncorrelated complex networks in a noisy environment: optimization and connections with transport efficiency.

Motivated by synchronization problems in noisy environments, we study the Edwards-Wilkinson process on weighted uncorrelated scale-free networks. We consider a specific form of the weights, where the strength (and the associated cost) of a link is proportional to $({k}_{i}{k}_{j}{)}^{\ensuremath{\beta}}$ with ${k}_{i}$ and ${k}_{j}$ being the degrees of the nodes connected by the link. Subject to the constraint that the total edge cost is fixed, we find that in the mean-field approximation on uncorrelated scale-free graphs, synchronization is optimal at ${\ensuremath{\beta}}^{*}=\ensuremath{-}1$. Numerical results, based on exact numerical diagonalization of the corresponding network Laplacian, confirm the mean-field results, with small corrections to the optimal value of ${\ensuremath{\beta}}^{*}$. Employing our recent connections between the Edwards-Wilkinson process and resistor networks, and some well-known connections between random walks and resistor networks, we also pursue a naturally related problem of optimizing performance in queue-limited communication networks utilizing local weighted routing schemes.
Chronic toxicity of S-(trans-1,2-dichlorovinyl)-L-cysteine in mice

S-(trans-1,2-Dichlorovinyl)-L-cysteine (DCVC) exposure causes acute renal tubular cytotoxicity. To further characterize the effects of DCVC, a chronic study was undertaken. Male Swiss-Webster mice received DCVC dissolved in their drinking water at 0.01, 0.05 and 0.1 mg ml-1. At 4, 8, 21 and 37 weeks, animals were terminated. Bladders, spleens, livers, kidneys and eyes were removed for histopathological examination. At 0.05 and 0.1 mg ml-1 DCVC, growth retardation was evident by 21 weeks. By 26 weeks, all animals in the 0.1 mg ml-1 group had developed cortical cataracts. Cytomegaly, nuclear hyperchromatism and multiple nucleoli were noted in the cells of the pars recta region of the kidney by 4 weeks and correlated to time and dose. At later time points, renal tubular atrophy and early interstitial fibrosis were evident. The epithelial cytological cellular abnormalities appear to be dose-related. Minor pathological changes were noted in the spleen, while there was no effect on the liver or bladder. Chronic ingestion of DCVC results in severe kidney injury.
Peroxomolybdate mediated oxidation of thioanisole in cationic and anionic microemulsions. Direct and indirect oxygen transfer

Abstract The reaction of the tetraperoxomolybdate dianion, Mo(O2)42−, with thioanisole, PhSMe, in reverse micelles of cetylpyridinium chloride (CPyCl), in CHCl3 is initially first-order in each reactant, indicating that this reaction involves direct oxygen transfer, and is faster than interconversion of the tri- and tetra-peroxomolybdates. Reaction is probably in the interfacial region surrounding the aqueous microdroplet. Direct oxygen transfer is very slow in anionic water-in-oil (w/o) microemulsions of AOT in hexane, or sodium dodecylsulfate (SDS) and n-butyl alcohol (n-BuOH) in CHCl3. There is oxidation involving singlet oxygen which escapes into the organic solvent and is trapped by PhSMe. This reaction is slower than the direct oxygen transfer from Mo(O2)42− in the cationic microemulsion.
Superficial suppurative thrombophlebitis in children, caused by anaerobic bacteria

Abstract Objective: The purpose of this study was to present the microbiology and clinical features of six children with superficial suppurative thrombophlebitis (SST) caused by anaerobic bacteria. Methods: A retrospective review of microbiological and clinical data was undertaken. Results: Anaerobic bacteria alone were recovered in four instances, and they were mixed with facultative bacteria in two. There were 12 bacterial isolates (10 anaerobic and 2 facultatives). The bacteria were Peptostreptococcus species (four isolates), Prevotella species (three), and one isolate each of Fusobacterium nucleatum, Propionibacterium acnes, Staphylococcus aureus , and Staphylococcus epidermidis . SST at an intravenous infusion site developed in all but one patient. One patient sustained trauma to the leg, and cellulitis developed. Anaerobes of oral origin ( Prevotella and Fusobacterium species) were recovered in scalp vein SST, and of gastrointestinal origin ( Bacteroides fragilis ) in a lower extremity SST. Conclusion: This study highlights the potential importance of anaerobic bacteria in children with SST.
Mitigating denial-of-service attacks in MANET by distributed packet filtering: a game-theoretic approach

Defending against denial-of-service (DoS) in a mobile ad hoc network (MANET) is challenging because the network topology is dynamic and nodes are selfish. In this paper, we propose a DoS mitigation technique that uses digital signatures to verify legitimate packets, and drop packets that do not pass the verification. Since nodes are selfish, they may not perform the verification so that they can avoid paying the overhead. A bad packet that escapes verification along the whole network path will bring a penalty to all its forwarders. A network game can be formulated in which nodes along a network path, in optimizing their own benefits, are encouraged to act collectively to filter out bad packets. Analytical results show that Nash equilibrium can be attained for players in the proposed game, in which significant benefits can be provided to forwarders such that many of the bad packets will be eliminated by verification.
Hydrodesulfurization over model sulfide cluster-derived catalysts

There is growing interest in the use of organometallic clusters as precursors to model heterogeneous catalysts. This interest is partially derived from the expectation that “solid-state metal complex catalysts” will be uniform in composition and structure thus more amenable to characterization than catalysts prepared using conventional techniques. This research used a series of sulfide clusters as precursors to model heterogeneous catalysts in an effort to enhance our understanding of the active sites in hydrodesulfurization catalysts. Alumina supported catalysts derived from the sulfide clusters Cp,Moz(pSH12(p-S),, Cp,Mo,Co,(~~-S),(~~-S) (Cold, and Cp,MozFe,(~,-S),(CO), (Cp=cyclopentadienyll shared important catalytic and spectroscopic features with a commercial catalyst and unsupported MO&. These strong similarities implied that the active sites in the sulfide cluster-derived catalysts could be used as models of the sites in conventionally prepared hydrodesulfurixation catalysts. The active sites in the bimetallic sulfide cluster-derived catalysts appeared to be highly dispersed ensembles containing MO’+ (6 < 4), cobalt or iron, and sulfur. The structure of these ensembles remains to be determined but our results provide evidence that the promotional effect in hydrodesulfurization catalysis is at least partly due to strong, direct interactions between molybdenum and the promoter. There were differences between the thiophene hydrodesulfurization product distributions. The sulfide cluster-derived catalysts produced significant amounts of Cz and C, hydrocarbons while the commercial catalyst produced mostly C, hydrocarbons. These results suggested that C-C bond hydrogenolysis preceded C-S bond cleavage over the sulfide cluster-derived catalysts, More subtle differences between the product distributions of the cluster-derived catalysts have been attributed to differences in the nature of sulfide ligands in their precursors.
The Mössbauer and magnetic properties of ferritin cores

Abstract Background: Mossbauer and magnetization measurements, singly or in combination, extract detailed information on the microscopic or internal magnetism of iron-based materials and their macroscopic or bulk magnetization. The combination of the two techniques affords a powerful investigatory probe into spin relaxation processes of nanosize magnetic systems. The ferritin core constitutes a paradigm of such nano-magnetic system where Mossbauer and magnetization studies have been broadly combined in order to elucidate its composition, the initial steps of iron nucleation and biomineralization, particle growth and core-size distribution. In vivo produced and in vitro reconstituted wild-type and variant ferritins have been extensively studied in order to elucidate structure/function correlations and ferritin’s role in iron overloading or neurodegenerative disorders.Scope of Review: Studies on the initial stages of iron biomineralization, biomimetic synthetic analogues and ferrous ion retention within the ferritin core are presented. The dynamical magnetic properties of ferritin by Mossbauer and magnetization measurements are critically reviewed. The focus is on experiments that reveal the internal magnetic structure of the ferritin core. Novel magnetic measurements on individual ferritin molecules via AFM and nanoSQUID investigations are also mentioned. Major Conclusions: A complex two-phase spin system is revealed due to finite-size effects and non-compensated spins at the surface of the anti-ferromagnetic ferritin core. Below the blocking temperature surface spins participate in relaxation processes much faster than those associated with collective magnetic excitations of interior spins. General Significance: The studies reviewed contribute uniquely to the elucidation of the spin-structure and spin-dynamics of anti-ferromagnetic nanolattices and their possible applications to nano/bio-technology.
Predictive Analysis by Incorporating Uncertainty through a Family of Models Calibrated with Structural Health-Monitoring Data

AbstractComplex analysis and design of structures, especially landmark structures such as long-span bridges, have been conducted by many engineers and researchers. Currently, it is possible to collect more and precise monitoring data as well as to develop complex three-dimensional (3D) FEM models. These models, which can be calibrated using structural health-monitoring (SHM) data, can be used for the estimation of component and system reliability of bridges. However, the uncertainties related to the data, analysis, and nonstationary nature of the structural behavior need to be better incorporated by using a set of models that are continuously updated with monitoring data. This set of models constitutes a family as a result of the approach by which the models are obtained and the relationships among them. The objective of this paper is to explore the impact of uncertainty in predicting the system reliability obtained by a one-time, initially calibrated FEM model as well as by a family of FEM models continu...