cssi/SciSciGPT-SciSciNet huggingface dataset:
798-3 A Comparison of Amiodarone versus Flecainide Using a Quinidine Standard in the Treatment of Resistant Chronic Atrial Fibrillation

Chronic atrial fibrillation (AF) is a ommon arrhythmia with significant morbidity and mortality. The antiarrhythmic effects of amiodarone (AM) and flecainide (FLEC) in patients with resistant chronic AF have been studied separately in several small clinical trials. This study compared AM to FLEC in maintaining normal sinus rhythm (NSR) in patients (pts) with resistant chronic AF. To facilitate the comparison, quinidine (QUIN) was used as the reference standard. Studies using AM or FLEC in the treatment of chronic AF refractory to either Class I AF drugs or sotalol were identified. The results of 6 trials of AM (200–400 mg/day; 315 pts) and 2 trials of FLEC (200–300 mg/day; 163 pts) were aggregated using meta-analysis in NSR at 3 and 12 mos for AM and FLEC were compared relative to corresponding results for QUIN, which were acquired from a meta-analysis of OUIN used as first-line therapy for AF. Duration of chronic AF ranged from 2 wks to 25 yrs. After 3 and 12 mos of treatment with AM, 217 of 299 (72.6%) and 64 of 107 (59.8%) pts, respectively, remained in NSR. These percentages were significantly greater (p l 0.00011 when compared to OUIN at these time points (70% and 50%, respectively). After 3 and 12 mos of treatment with FLEC, the percentage of pts remaining in NSR were significantly lower (p l 0.00011 than OUIN: 79 of 163 (48.5%) and 56 of 163 (34%) pts, respectively. The aggregated percentages of pts requiring withdrawal of AM and FLEC were 9.5% and 8.6%, respectively. Mortality and proarrhythmia could not be assessed. Conclusion This analysis suggests that low-dose AM is more efficacious and equally well-tolerated when compared to FLEC in the management of chronic, drug-resistant AF.
Motivational effects of stimuli paired with buildup of the thirst drive.

S~imma~y.-Albino rats were adapted to a distinctive conditioning environment over a 4-day period and were then divided into experimental and control groups. The experimental group experienced 23 hr. of water privation in the conditioning environment on each of 14 successive days. The control group experienced only the first % hr. of privation in the conditioning environment and spent the rest of each privation period in a control environment. During subsequent tests in the conditioning environment, with Ss satiared, the experimental 5s consumed significantly more water than the control Ss. A replication produced similar results and indicated that the effect could be mediated by general, as well as specific, characteristics of the conditioning environment. The relation of the results to the conditioned drive hypothesis is discussed, and the direction of continuing research is indicated.
The Impact of Lifestyle Behavior on Hypertension Awareness, Treatment, and Control in a Southeastern Population

ABSTRACT Background We were interested in determining the rates of hypertension awareness, treatment, and control in individuals living in the southeastern United States and evaluating the impact of lifestyle behaviors on these rates. Methods This is a cross-sectional survey of a sample of community dwellers in the greater Columbia, South Carolina area. The survey was developed from validated community-based survey questionnaires to evaluate demographic and social history (age, gender, race-ethnicity, income, and education), hypertension history (diagnosis and treatment), and lifestyle behavior (servings of fruits and vegetables [FV] and physical activity [PA] duration and frequency), as well as blood pressure measurement. Results A total of 763 people (mean ± standard error age 52.4 ± 0.7 years; 68% women, 53% African American) agreed to be screened. Of all participants with hypertension (438 [58%]), 82% were aware of their illness and 79% were on treatment. Of all hypertensive participants, 39% had their hypertension controlled below 140/90 mm Hg at the time of the survey. Only 11% reported consuming five or more FV per day and 18% reported PA five or more times per week. African-Americans consumed less FV ( P P Conclusions In a sample of southeastern residents, the control rate was suboptimal despite a relatively high rate of treatment. Low levels of FV consumption and PA were noted especially in African-American patients and may explain this rate.
Adaptive, Region-based, Layered Background Model for Target Tracking

Background subtraction is a method frequently used in target detection and tracking applications. In this paper, we present a new approach to background subtraction that relies on a two-layer background model. This approach uses a single intensity model for all the pixels rather than separate models for individual pixel, by exploiting the spatial dependency of pixels. It models the background without modeling the foreground, and treats background updating and tracking as tightly integrated dynamic processes rather than consecutive static modules. This method can handle illumination changes, permanent changes to the background, and targets that stop moving and later start moving again. Example results are presented
Chromosome Puffs in Drosophila Induced by Ribonuclease

Ribonuclease induces many puffs in salivary gland chromosomes of Drosophila busckii. The left arm of chromosome 2 was analyzed in detail; in this arm seven puffs were induced in a definite sequence.
Metformin hydrochloride in the treatment of type 2 diabetes mellitus: A clinical review with a focus on dual therapy

Abstract Background Type 2 diabetes mellitus typically involves abnormal beta-cell function that results in relative insulin deficiency, insulin resistance accompanied by decreased glucose transport into muscle and fat cells, and increased hepatic glucose output, all of which contribute to hyperglycemia. Objective: This review examines the pharmacology, pharmacokinetics, drug-interaction potential, adverse effects, and dosing guidelines for metformin hydrochloride, a biguanide agent for the treatment of type 2 diabetes. Clinical trial data are reviewed, including efficacy and tolerability information, with a focus on studies of dual metformin therapy (metformin plus another oral agent or insulin) published from 1998 to the present. Pharmacoeconomic considerations are also discussed. Methods: Primary research and review articles were identified through a search of MEDLINE (1966–May 2003) and International Pharmaceutical Abstracts (1970–May 2003) using the terms metformin and/or Glucophage. Web of Science (1995–May 2003) was used to search for additional abstracts. The package inserts for metformin and metformin combination products were consulted. All identified articles and abstracts were assessed for relevance, and all relevant information was included. Priority was given to the primary medical literature and clinical trial reports. Results: Metformin is the only currently available oral antidiabetic/hypoglycemic agent that acts predominantly by inhibiting hepatic glucose release. Because patients with type 2 diabetes often have excess hepatic glucose output, use of metformin is effective in lowering glycosylated hemoglobin (HbA1c) by 1 to 2 percentage points when used as monotherapy or in combination with other blood glucose-lowering agents or insulin. Other metabolic variables (eg, dyslipidemia, fibrinolysis) may be improved with the use of metformin. Body weight is often maintained or slightly reduced from baseline. Metformin is well tolerated and is associated with few clinically deleterious adverse events. The most important and potentially life-threatening adverse event associated with its use is lactic acidosis, which occurs very rarely. Conclusions: Metformin has multiple benefits in patients with type 2 diabetes. It can effectively lower HbA1c values, positively affect lipid profiles, and improve vascular and hemodynamic indices. Adverse effects are generally tolerable and self-limiting. The availability of products combining metformin with a sulfonylurea or rosiglitazone has expanded the array of therapies for the management of type 2 diabetes.
A Davies/Hahn multi-sequence for studies of spin relaxation in pulsed ENDOR

We extend earlier studies of the effects of relaxation on the intensities of pulsed ENDOR signals by introducing a Davies/Hahn (D/H) pulsed ENDOR multi-sequence that corresponds to a series of Davies sequences with the preparation pulse 'turned off'. In this pulse train, the Hahn [pi/2, pi] detection pulse pair of sequence n-1 both generates the echo detected for that sequence and acts as the preparation portion of sequence n, in effect replacing the pi preparation pulse of the Davies sequence. We show both theoretically, through a master-equation approach, and with both (1)H(I=1/2) and (14)N(I=1) ENDOR experiments on the non-heme Fe enzymes, superoxide reductase (SOR) (S=1/2) and AntDO (S=3/2), that under conditions of high electron-spin polarization (high microwave frequency/low temperature) the D/H multi-sequence allows simplification of ENDOR spectra by suppression of nuclear transitions associated with the m(S)=+1/2 (alpha) manifold. As such suppression depends on the sign of A, it allows determination of this sign. The suppression as a function of the time between individual sequences is found to exhibit behaviors that can be classified into three regimes of the ratio of cross-relaxation to spin-lattice relaxation rates: strong cross-relaxation (X-case); comparable rates (XL); negligible cross relaxation (L). Interestingly, the ENDOR behavior of the S=1/2 SOR center indicates it is an L case, while the S=3/2 AntDO is an L case. Overall, the D/H protocol appears to be a robust and general tool for using relaxation effects to manipulate ENDOR spectra.
Excitatory amino acid antagonists (kynurenic acid and MK-801) attenuate the development of morphine tolerance in the rat

Abstract To investigate the possible role of excitatory amino acids (EAAs) in the mechanisms of morphine tolerance, rats were treated either with the wide-spectrum EAA antagonist, kynurenic acid (150 mg/kg), or the specific N -methyl- d -aspartic acid (NMDA) receptor antagonist, MK-801 (0.05 mg/kg), during a four-day induction period of morphine tolerance. Morphine was given once daily at a dose of 15 mg/kg. On the fifth day rats were injected only with morphine (15 mg/kg), and analgesia was assessed using the hot-plate test. Morphine tolerance was significantly reduced by both EAA antagonists. Control experiments showed that at the same doses neither acute nor chronic administration of these antagonists affected morphine analgesia itself in a manner that can explain these findings. The possible involvement of EAAs in the mechanism of morphine tolerance is discussed.
Risk Factors in the Development of Acute Sinusitis in Immunocompromised Patients

Twenty-six patients diagnosed as having hematologic neoplasms were evaluated clinically and radiographically for the presence of sinus disease before receiving immunosuppressive therapy. Evaluation...
A finitely convergent procedure for facial disjunctive programs

Abstract This paper addresses an important class of disjunctive programs called facial disjunctive programs, examples of which include the zero-one linear integer programming problem and the linear complementarity problem. Balas has characterized some fundamental properties of such problems, one of which has been used by Jeroslow to obtain a finitely convergent procedure. This paper exploits another basic property of facial disjunctive programs in order to develop an alternative finitely convergent algorithm.
Differential effects of platelet-derived growth factor isotypes on human smooth muscle cell proliferation and migration are mediated by distinct signaling pathways.

Background. Platelet-derived growth factor (PDGF) is a potent mitogen and chemoattractant for vascular smooth muscle cells (SMCs). Three isotypes of PDGF (BB, AB, and AA) have been identified; each of these isotypes may have differing effects on the behavior of vascular SMCs. In this study we evaluated the influence of PDGF isotypes on proliferation and migration of human venous SMCs and explored the signaling pathways through which these effects are mediated. Methods. Proliferation was measured by a 72-hour assay of cell number, and migration was evaluated by a 4-hour microchemotaxis assay. The effects of PDGF isotypes on the activities of the signaling proteins mitogen-activated protein kinase (MAP-K), p125 focal adhesion kinase (p125FAK), and tensin were measured by immunoprecipitation of these proteins and subsequent phosphorylation on myelin basic protein (in MAP-K) and Western blotting with antiphosphotyrosine (in tensin and p125FAK). Results. All three isotypes stimulated SMC proliferation (PDGF-BB >AB >AA). PDGF-BB and -AB, but not -AA, stimulated chemotaxis. All three isotypes activated MAP-K with an intensity that corresponded to their proliferative effects. PDGF-BB and -AB tyrosine phosphorylated tensin and p125FAK, whereas PDGF-AA had no effect on either of these proteins. Conclusions. For human vascular SMCs the physiologic effects and the signaling pathways that mediate these effects are specific for each of the three PDGF isotypes. These data also suggest an association between MAP-K and SMC proliferation and between the proteins, p125FAK and tensin, and migration.
Perceptual effects of a flattened fundamental frequency at the sentence level under different listening conditions.

Abstract The purpose of this series of experiments was to examine the effect of a flattened fundamental frequency (F0) contour on the intelligibility of sentence length material in different listening environments. Eight speakers of different genders and ages produced sentences from the Speech Perception in Noise Test (SPIN). Each utterance was subjected to a resynthesis technique that allowed flattening of the fundamental frequency while maintaining the timing and spectral characteristics of the utterances. To avoid learning effects two groups of listeners were chosen to complete word transcription and interval scaling tasks of the unmodified and flattened F0 utterances under different listening conditions (competing white noise or multi-speaker babble) to obtain measures of speech intelligibility. Results were that a flattened fundamental frequency contour negatively influences speech intelligibility regardless of the nature of the competing background noise. Learning outcomes (1) To appreciate the role fundamental frequency variation plays in speech intelligibility. (2) To understand the importance of considering environmental noise in clinical speech intelligibility testing.
Phenethylbiguanide effects on mitochondrial Ca2+ and Mg2+ content

Abstract Phenethylbiguanide (PEBG) in low doses (12 mg/kg) lowered blood sugar in fasted and in glucagon-pretreated fed guinea pigs but not in fed controls. The Ca 2+ content of hepatic mitochondria subsequently isolated from biguanide-treated animals was reduced significantly, the loss occurring predominantly in the loosely bound external fraction. Mitochondrial matrix Mg 2+ content increased significantly after PEBG administration, except in glucagon-treated animals, and the Mg 2+ /Ca 2+ ratio increased after PEBG under all metabolic conditions studied. Except in mitochondria from fasted animals, PEBG added in vitro did not reduce mitochondrial Ca 2+ content, nor did it increase Mg 2+ content. Insulin pretreatment in doses which reduced blood sugar to the same extent as PEBG had no effect on mitochondrial Ca 2+ or Mg 2+ content. We conclude that PEBG administered in vivo produces consistent and significant effects on hepatic mitochondrial divalent metal ion content through a mechanism which is more complex than competitive binding. These metal ion shifts may be involved in the hypoglycemie activity of the drug, probably by limiting the gluconeogenic rate of the liver under a “glucagon-predominant” signal. Insulin appears to inhibit gluconeogenesis by a different mechanism.
Design, implementation, and optimization of MEGAlib's image reconstruction tool Mimrec

MEGAlib, the Medium-EnergyGamma-ray Astronomylibrary, is a toolset to simulate and analyze data from gammaray detectors. An integral part of MEGAlib is its imaging tool Mimrec, which performs list-mode-likelihood image deconvolution. Mimrec has to handle data from coded masks, Compton cameras, and pair conversion telescopes with different response representations, on different imaging grids, with different deconvolution algorithms, etc. This versatility requires a highly modular and object-oriented design to avoid overhead and code redundancy. In addition, since some applications require close to real-time image reconstruction, great care has to be taken to optimize the library.
History of marine biodiversity

During the Phanerozoic, three steps of increasing diversity each had a unique Evolutionary Fauna (EF). During each EF, there were geologically long intervals of community stasis referred to as Ecological Evolutionary Units (EEUs). These intervals were characterized by communities composed of incumbent faunas that dominated particular habitats. Niches that were already occupied by incumbents were seldom invaded by new taxa, and the resilience of the incumbents to new competitors resulted in the long interval stasis. Most EEUs were terminated by extinction events that were caused by severe disruptions of the physical environment such as glaciations and extraterrestrial impacts. During mass extinctions many niches were vacated when incumbents were eliminated. Mass extinctions were followed by recovery intervals lasting on the order of 5 million years during which many surviving clades evolved adaptations which allowed them to move into vacated niches. New incumbents were established during these recovery intervals, and the next EEU began. In many ways, the recovery intervals resemble times when organisms invaded previously unoccupied ecospace, such as the emergence of life on land or the progressive filling of previously unoccupied habitats such as deep-burrowing and high epifaunal tiers that were colonized during the Palaeozoic. The recognition of long intervals of ecological stasis and the importance of physical disruptions in clearing incumbents is forcing revision of the traditional evolutionary viewpoint. The idea that most evolutionary change was accomplished very gradually by competition between organisms and by becoming better adapted to a relatively stable environment is being replaced by a recognition that major morphological and synecological changes tend to occur very rapidly and at times when there are few established competitors. Copyright © 2001 John Wiley & Sons, Ltd.
Towards Ultra-Fast DNA Sequencing using Nanopores and Parallel Optical Readout

Dramatically reducing the cost of DNA sequencing will revolutionize the healthcare system by enabling patient genomes to be determined in routine procedures. This belief has resulted in large scale investments in alternative sequencing methodologies. One of the most promising techniques to emerge is nanopore sequencing, where individual biomolecules are electrophoreticaly threaded through nanoscale pores. We are developing a novel, nanopore based DNA sequencing platform, which revolves around the unzipping of converted DNA in a solid-state nanopore1. Sequence information is attained with fluorescent probes attached to the DNA using a custom 2-color wide-field mode of detection. The key advantages of this single-molecule method are enzyme free readout processes, and massive parallelization using Total Internal Reflection (TIR) optics. Here we report, for the first time, on our ability to identify all 4 bases in an automated manner, with a high level of certainty and speed. This level of certainty is achieved as a result of the high signal to background in our custom TIR system, and the unzipping mechanism which un-quench the fluorophores at the time of detection. A key element to increasing the speed of sequencing with nanopore-based methods is massively parallelizing the readout. We demonstrate the feasibility of this by the simultaneous detection of optical unzipping events in multiple nanopores. These results strongly support the utility of nanopores in the field of DNA sequencing.1) see: Branton, D. et. al. Nature Biotechnol. 26, 1146 (2008)
Effects of Ni(II), other divalent metal ions, and glucagon upon plasma glucose concentrations in normal, adrenalectomized and hypophysectomized rats

Abstract The effects of Ni(II), administered ip as NiCl2 or NiSO4, upon plasma glucose and serum insulin concentrations have been investigated in Fischer rats. In fasting rats, hyperglycemia occurred at 0.5 hr after injection of Ni(II) in dosages from 12 to 85 μmol/kg. At dosages ≥34 μmol/kg, hyperglycemia persisted for 4 hr after injection of Ni(II). In approximate order of decreasing magnitude and duration, the hyperglycemic responses to equimolar ip injections of divalent ions of selected first transition metals were: Ni ≥ Co ≥ Cu ≥ Zn > Cr > Fe > Mn. Concurrent administration of insulin antagonized the hyperglycemic response to Ni(II). Concentrations of endogenous immunoreactive insulin in serum were increased from 0.5 to 3 hr after injection of Ni(II) in dosage of 68 μmol/kg. Adrenergic blockade with phentolamine and propranolol did not affect the hyperglycemic response to Ni(II). The hyperglycemic responses to Ni(II), Co(II), and glucagon were greatly suppressed but were not completely prevented by adrenalectomy or by hypophysectomy. These findings are attributed to interruption of the permissive actions of glucocorticoids upon hepatic gluconeogenesis and glycogenolysis.
Moderate zinc restriction affects intestinal health and immune function in lipopolysaccharide-challenged mice

Zinc (Zn) is an essential nutrient that affects immune function, especially within the digestive system, although the underlying mechanisms are not well understood. This study examined the effects of short-term moderate Zn restriction on intestinal health and immune function in lipopolysaccharide (LPS)-challenged mice through plasma cytokine profiling and histological evaluation of intestinal tissue sections. Adult male mice were fed with a Zn-adequate (40 ppm) or a Zn-marginal (4 ppm) diet for 4 weeks, and then a bacterial challenge was simulated by intraperitoneal injection of LPS (10 microg/g body weight [BW]) or saline (control). BW was recorded weekly, and feed intake was recorded daily over the last week. Voluntary locomotor activity was assessed 6 and 24 h after the challenge. Plasma and tissues were collected 0, 6 or 24 h after the challenge for analysis. Histological analysis of intestinal samples included evaluation of villi length and width, lamina propria (LP) width, crypt depth and intraepithelial as well as LP leukocyte numbers. Plasma was analyzed for IL-1beta, IL-4, IL-6, IL-10, IL-12p40, IL-12p70, interferon gamma and tumor necrosis factor alpha. Diet did not affect BW and feed intake. The LPS challenge led to decreased voluntary locomotor activity (P<.05). Moderate Zn restriction led to greater leukocyte infiltration in the LP after the LPS challenge (P<.05) and higher plasma IL-6 and IL-10 levels 24 h after the LPS challenge (P<.01). Results indicate that Zn status impacts intestinal responses to LPS through modulation of the cytokine response and leukocyte recruitment, and this impact is evident even with short-term (4 weeks) moderate Zn restriction.
Energy-efficient architecture and enabling technology for advanced SOCs

This session highlights energy-efficient architectures, implementations of application-specific SoC in advanced process technologies, and silicon photonics building blocks for chip-scale optical interconnects.
Non-adiabatic effects in the broadening and shift of the K 7s - 4p transition by Ar

This paper reports the use of a quantum theory of spectral line broadening and a realistic model potential to investigate non-adiabatic and inelastic excited state atomic collisions. The fully quantum mechanical lineshifts and widths are computed for the transition perturbed by Ar, using non-adiabatic theory. The effects of the j degeneracy and inelastic collisions for the transition are included and many validity tests are performed. Two-parameter pseudopotentials are used, for which , the radius about the Ar atom, and , the electron density (which is assumed constant within ) are adjustable. These parameters are varied to fit the computed shifts and widths to the experimental values over a range from 443 to 760 K. The contributions to the width and shift from the 7s state are larger than from the 4p state because of a shallow well in the 7s potential around 12.5 A. The contribution of the non-adiabatic and inelastic terms to the width are small, although they increase with temperature and there are no inelastic contributions to the lineshift.
Substance use trends among active duty military personnel: findings from the United States Department of Defense Health Related Behavior Surveys, 1980-2005.

Aims This study was designed to assess trends in cigarette, illicit drug, and heavy alcohol use among active-duty military personnel from 1980 to 2005 and to examine the influence of socio-demographic changes within the military on patterns of substance use. Design Substance use prevalence rates were estimated from cross-sectional data obtained from nine self-report surveys administered to more than 150 000 active-duty service members world-wide over a 25-year period. Direct standardization was used to adjust for socio-demographic changes. Measurements Measures included self-reported cigarette use, illicit drug use and heavy alcohol use in the 30 days prior to the survey. Heavy alcohol use was defined as drinking five or more drinks per typical drinking occasion at least once a week in the past 30 days. Findings Cigarette and illicit drug use among military personnel declined sharply and significantly from 1980 to 1998. Heavy alcohol use decreased in the mid-1980s but was stable from 1988 to 1998. Both cigarette smoking and heavy alcohol use increased significantly between 1998 and 2002 and remained at those levels in 2005. Illicit drug use remained low. Logistic regression analyses indicated that trends were influenced by other factors besides socio-demographic changes across survey years. Conclusions The military has made notable progress in decreasing cigarette smoking and illicit drug use, but has made less progress in reducing heavy alcohol use. Additional emphasis should be placed on understanding recent increases in substance use and on planning effective interventions and prevention programs to reduce use in this high-risk population.
Hypersensitivity to antibiotics in patients with cystic fibrosis

Abstract Background Hypersensitivity reactions to parenterally administered antibiotics (HRPA) are a substantial problem in managing CF. We conducted this observational study to assess their nature and frequency as well as risk factors. Methods By reviewing medical records and conducting interviews, age, sex, FEV1, ∆F508-genotype, pseudomonal colonisation, allergy history, antibiotic exposure and HRPA were recorded. Results Of 100 patients included in the study, 60 had ≥1 HRPA. Overall, 3205 antibiotic courses with 185 HRPA were ascertained. Changes in therapy followed 65% of HRPA. Eighty-four percent of severe HRPA occurred during days 1–4. Approximately 10% of treatment courses with cefepime and piperacillin/tazobactam caused HRPA. Years of pseudomonal colonisation and cumulative annual exposure were significant risk factors. Conclusions During days 1–4 of antibiotic treatment patients are at elevated risk for HRPA. HRPA are drug-specific and dependent on cumulative annual exposure. Elucidation of HRPA's immunological mechanisms and development of diagnostic algorithms for clinical use are required.
A Variational Approach to Multiple Layers¶of the Bistable Equation in Long Tubes

Multiple-layer solutions of the balanced bistable equation in infinite tubes are constructed via a variational method. I start with a characterization of Palais-Smale sequences which easily gives some global minima in the desired function classes as single layers. Assuming these minima are isolated as critical points, I paste them together to serve as an approximate multiple-layer solution. If there were no exact solutions near the approximate one, the negative gradient flow of the energy functional would significantly lower the energy. On the other hand, if the minima are kept far from each other, the energy of a function near the approximate solution is not much less than that of the approximate solution. This contradiction proves the existence of a solution.
Shock Mitigation using Compressible Two-Phase Jets for Z-Pinch IFE Reactor Applications

Compressible liquid/gas jets offer the opportunity to limit and mitigate the mechanical consequences of rapid heating/evaporation of the protective jets in a high-yield, low repetition rate Inertial Fusion Energy (IFE) system such as the Z-Pinch IFE reactor. In this investigation, experiments have been conducted to quantify the extent by which a two-phase jet can attenuate a shock wave. The experiments have been conducted using annular two-phase (water/air) jets with different velocities, void fractions, and initial shock strength. The shock is produced using an exploding wire located along the jet axis. Three different confinement geometries (i.e. boundary conditions) have been used in the experiments, namely, "unconfined" shocks, "radially-confined" shocks, and "radially-and-axially-confined" shocks. A total of 738 experiments corresponding to 39 different test conditions have been conducted. Quantitative data for the transient pressure history at the confinement wall with and without an intervening jet have been obtained; both single-phase (liquid) and two-phase (liquid-gas) jets at different velocities and void fractions have been tested. The data shows that the experiments are highly repeatable, and that two-phase jets at moderate void fractions (~1%) can attenuate a shock wave significantly more than a single-phase (liquid) jet
Development of poly(ortho esters): a historical overview

Abstract At the present time, three poly(ortho ester) systems have been described. The first one was developed at the Alza Corporation and is prepared by the transesterification reaction between a diol and diethoxytetrahydrofuran. It is currently marketed under the trade name of Alzamer®. A second poly(ortho ester) system, developed at SRI International, is prepared by the addition of polyols to the diketene acetal 3,9 bis (ethylidene 2,4,8,10 tetraoxaspiro [5,5] undecane). A third poly (ortho ester) system, also developed at SRI International, is prepared by a transesterification reaction between a triol and an ortho ester, followed by self-condensation of the reaction product. Major utility of poly(ortho esters) as bioerodible drug delivery devices resides in their acid sensitivity which allows preparation of devices with lifetimes ranging from hours to many months by using acidic or basic excipients physically incorporated into the matrix.
Experience is a good, but not perfect, teacher

The paper ‘‘Determination of optimal viewing regions for X-ray coronary angiography based on a quantitative analysis of 3D reconstructed’’ models by Garcia et al. in this issue of the International Journal of Cardiovascular Imaging provides an instructive comparison between quantitative determination of beam angles and those routinely used in current clinical practice. Optimum viewing angles were determined using segment by segment estimate of foreshortening and vessel overlap for each coronary artery segment in 137 patients. The data was then pooled to produce an optimum range of viewing angles for each segment. The analysis largely confirmed conventional wisdom but did identify new and potentially useful projections for a few vessel segments. The estimates of individual segment foreshortening provided in the present work could be of clinical use in situations where only 2D imaging is available. This data might improve the selection of device lengths. The authors point out that optimum imaging angles for individual patients could be pre-computed when 3D data sets are available (e.g., CT angio). The use of individualized data should further improve angiographic and interventional practice.
Modified cranking model for the Nilsson potential

Abstract A modified cranking term is deduced for the Nilsson hamiltonian by requiring Galilei invariance for the momentum-dependent potential terms. Modified moments of inertia are calculated. A simple approximation for the new cranking term is suggested.
Liver stem cells: prospects for treatment of inherited and acquired liver diseases

It is now understood that there are three cell compartments which physiologically contribute to vertebrate liver parenchymal maintenance and regeneration after injury: mature liver cells (hepatocytes, cholangiocytes), intraorgan stem/progenitor cells (cells of the proximal biliary tree, periductal cells) and extraorgan stem cells (from the circulation and the bone marrow). All of these cell populations, as well as other, non-physiologic stem cells (e.g., mesenchymal stromal cells from the bone marrow, fetal hepatoblasts, embryonic stem [ES] cells), may be used therapeutically for treatment of inherited and acquired liver diseases. This article will summarise our current understanding of these various cell populations, and review possible approaches to their therapeutic use, including cell transplantation, bioartificial liver devices (BLDs), gene therapy and administration of exogenous factors to stimulate normal physiological responses to repair.
Manipulation and reversal of the probability of a correct stimulus prediction in a choice reaction task

In a two-stimulus, two-response choice reaction time (RT) experiment, the probability of a correct stimulus prediction was controlled: the probability (P) was.70 or.30 for 400 trials or P was.70 or.30 for 200 trials and 1 — P for the remaining 200 trials. The difference between RT to correctly predicted stimuli and RT to incorrectly predicted stimuli was greater when P was.70 than when it was.30. When P shifted from.30 to.70, the effect of prediction outcome increased; the effect of prediction outcome decreased when P shifted from.70 to.30. Implications for learning in the development of expectancies for predicting correctly are discussed.
Spare capacity and phenotypic flexibility in the digestive system of a migratory bird: defining the limits of animal design

Flexible phenotypes enable animals to live in environments that change over space and time, and knowing the limits to and the required time scale for this flexibility provides insights into constraints on energy and nutrient intake, diet diversity and niche width. We quantified the level of immediate and ultimate spare capacity, and thus the extent of phenotypic flexibility, in the digestive system of a migratory bird in response to increased energy demand, and identified the digestive constraints responsible for the limits on sustained energy intake. Immediate spare capacity decreased from approximately 50% for birds acclimated to relatively benign temperatures to less than 20% as birds approached their maximum sustainable energy intake. Ultimate spare capacity enabled an increase in feeding rate of approximately 126% as measured in birds acclimated for weeks at −29°C compared with +21°C. Increased gut size and not tissue-specific differences in nutrient uptake or changes in digestive efficiency or retention time were primarily responsible for this increase in capacity with energy demand, and this change required more than 1–2 days. Thus, the pace of change in digestive organ size may often constrain energy intake and, for birds, retard the pace of their migration.
Perinatal circulatory physiology.

Fetal circulation is designed to utilize placenta for gas exchange whereas postnatal circulation uses lungs for gas exchange. Fetal circulatory pathways, namely, umbilical vessels, ductus venosus, foramen ovale and ductus arteriosus facilitate placental gas exchange and promote distribution of oxygenated blood to the vital organs of the fetus. Mechanical factors, prostaglandins and low PO2 in the lung keep the fetal circulatory pathways open. Postnatal circulatory changes include elimination of the placenta, development of pulmonary circulation, and closure of fetal circulatory pathways. Postnatal circulatory changes markedly influence the clinical presentation and clinical course of the neonate with congenital heart defects.
Guided-ion beam and theoretical study of the potential energy surface for activation of methane by W+.

A guided-ion beam tandem mass spectrometer is used to study the reactions, W+ + CH4 (CD4) and [W,C,2H]+ + H2 (D2), to probe the [W,C,4H]+ potential energy surface. The reaction W+ + CH4 produces [W...
Information‐theoretic analysis of the reference state in contact potentials used for protein structure prediction

Using information-theoretic concepts, we examine the role of the reference state, a crucial component of empirical potential functions, in protein fold recognition. We derive an information-based connection between the probability distribution functions of the reference state and those that characterize the decoy set used in threading. In examining commonly used contact reference states, we find that the quasi-chemical approximation is informatically superior to other variant models designed to include characteristics of real protein chains, such as finite length and variable amino acid composition from protein to protein. We observe that in these variant models, the total divergence, the operative function that quantifies discrimination, decreases along with threading performance. We find that any amount of nativeness encoded in the reference state model does not significantly improve threading performance. A promising avenue for the development of better potentials is suggested by our information-theoretic analysis of the action of contact potentials on individual protein sequences. Our results show that contact potentials perform better when the compositional properties of the data set used to derive the score function probabilities are similar to the properties of the sequence of interest. Results also suggest to use only sequences of similar composition in deriving contact potentials, to tailor the contact potential specifically for a test sequence.
"Chinese-Mexicans" and "Blackest Asians": Filipino American Youth Resisting the Racial Binary.

This study provides a deeper understanding of the interracial connections not just between non-whites and whites, but among non-whites. Filipino American youth attending high school in New York City contended with a dominant bipolar racial discourse that marginalizes the racialized experiences of Asians and Pacific Islanders. However, instead of feeling invisible or marginalized, data point to how they negotiated a black–white racial discourse to decide when and how they enter dialogues about race. Filipino youth reconceptualized this racial binary to position themselves on a continuum to form the racial ‘middle ground’ between blacks and whites. Importantly, rather than a racial hierarchy that places whites at the top, youth used discursive strategies to place themselves on a racial continuum that emphasizes the interconnectedness among racial minorities.
Estimating the Power to Detect Dichotomous Moderators with Moderated Multiple Regression

A QuickBASIC program for estimating the statistical power to detect the effects of dichotomous moderator variables using moderated multiple regression (MMR) is available. The program runs on IBM and IBM-compatible personal computers and estimates power based on specific values for (a) total sample size, (b) sample sizes across the two categories of the hypothesized moderator, and (c) correlation coefficients between predictor and criterion scores for each of the two moderator-based subgroups. The compiled run time and source code versions of the program can be obtained from the first author.
MOCVD growth of cubic GaN on 3C-SiC deposited on Si (100) substrates

The growth of cubic GaN on 3C-SiC/Si(100) by metal-organic chemical vapor deposition (MOCVD) under various growth temperatures, thicknesses of 3C-SiC, and V/III ratios was studied. The fractions of cubic and hexagonal phases in the films were estimated from the integrated x-ray diffraction intensities of the cubic (002) and hexagonal (1011) planes. A smooth SiC layer, a high growth temperature, and a moderate V/III ratio are three key factors for the nucleation of the cubic phase and its subsequent growth. Hexagonal GaN with its c-axis perpendicular to the substrate preferentially grows at the low temperature of 750°C. The inclusion of the cubic phase increases with increasing growth temperature. The optimum growth conditions for dominant cubic GaN formation were a growth temperature of 950°C, a 1.5 µm thick SiC layer, and a V/III ratio of 1500. With these growth conditions, a cubic GaN layer with the cubic component of 91% was obtained.
A muscle column preparation from the rat's left ventricle.

A muscle preparation from the left ventricle of the rat heart suitable for in vitro studies is described. It consists of one of the trabeculae carneae of the posterior ventricular wall extending from the apex of the ventricle to the auriculoventricular junction. Studies on the excitability, extensibility, tension development, and oxygen consumption of the preparation are reported. The preparation offers economic and technical advantages over other types of isolated heart muscle preparations currently in use.
Risk of preterm birth that is associated with vaginal douching.

Abstract Objective: The purpose of this study was to examine the association between vaginal douching and preterm birth. Study Design: We enrolled hospitalized women after delivery in a case-control study. Women who were delivered of a live preterm singleton infant were assigned as cases. Women who were delivered at term were randomly selected as control subjects. We surveyed women about their douching habits and risk factors for preterm birth and abstracted data from the records. Results: After adjustment, vaginal douching within 6 months of pregnancy was not significantly associated with preterm birth (odds ratio, 1.1; 95% CI, 0.8-1.6). However, in secondary analyses, douching more than once per week (odds ratio, 4.0; 95% CI, 1.0-15.5) or longer than 10 years (odds ratio, 1.9; 95% CI, 1.1-3.2) was associated with preterm birth. Conclusion: Vaginal douching does not appear to be a strong risk factor for preterm birth. Further study is needed to confirm the risk that is associated with frequent or long-term douching. (Am J Obstet Gynecol 2002;186:1345-50.)
The Outlook for United States Foreign Direct Investment in the Andean Pact Countries in the Seventies

THE GENERAL LATIN AMERICAN VIEW OF PRIVATE FOREIGN INVESTMENT:The climate for private foreign direct investment is deteriorating rapidly in many countries of Latin America as the socialization of development is becoming not only more widespread, but also more leftist-oriented. Paradoxically, the gap between the lip-service paid to, and actual policies adopted regarding private foreign investment in this region, is increasing as rapidly as is the need for such external investment inflows. The contemporary Latin American attitude towards private foreign direct investment, especially with respect to investments by international corporations, is summarized below.© 1972 JIBS. Journal of International Business Studies (1972) 3, 69–94
Reimagining Yentl While Revisiting Feminism in the Light of Relational Approaches to Gender and Sex

This article is an imaginative endeavor based upon the short story “Yentl the Yeshiva Boy” written by Isaac Bashevis Singer (1982). In taking creative license and entering Yentl's world, a new voice and narrative emerges for her and the major characters in the story. Using psychoanalytic relational theories on multiple self-states and postmodern gender and sexuality perspectives, this article undertakes fleshing out the characters and the motives of Bashevis Singer in writing the story. From each character's point of view we learn more of Yentl's subjectivity, her multiply oriented desires from multiple self-states, and expand Singer's story from its original linear course. In Singer's work, Yentl is a two dimensional girl possessing the “soul of a man,” which would mean in the 19th-century Poland Jewish shtetl world that she longs to study Torah/Talmud in a yeshiva. From this paradoxical premise the story eventually ends with Yentl surrendering all claim to the male world of study and then vanishing from...
Substrate inhibition in human hydroxysteroid sulfotransferase SULT2A1: Studies on the formation of catalytically non-productive enzyme complexes

The cytosolic sulfotransferase hSULT2A1 is the major hydroxysteroid (alcohol) sulfotransferase in human liver, and it catalyzes the 3′-phosphoadenosine-5′-phosphosulfate (PAPS)-dependent sulfation of various endogenous hydroxysteroids as well as many xenobiotics that contain alcohol and phenol functional groups. The hSULT2A1 often displays substrate inhibition, and we have hypothesized that a key element in this response to increasing substrate concentration is the formation of non-productive ternary dead-end enzyme complexes involving the nucleotide product, adenosine 3′,5′-diphosphate (PAP). One of these substrates for hSULT2A1 is dehydroepiandrosterone (DHEA), a major circulating steroid hormone in humans that serves as precursor to both androgens and estrogens. We have utilized DHEA in both initial velocity studies and equilibrium binding experiments in order to evaluate the potential role of ternary complexes in substrate inhibition of the enzyme. Our results indicate that hSULT2A1 forms non-productive ternary complexes that involve either DHEA or dehydroepiandrosterone sulfate, and the formation of these ternary complexes displays negative cooperativity in the binding of DHEA.
High resolution NMR spectroscopy and some examples of its use

High resolution nuclear magnetic resonance (NMR) spectroscopy has gained wide acceptance in the study of fatty acids and other lipids. Some of the techniques are described and examples of identification and structure determination of fatty compounds are given. Nuclear magnetic resonance spectroscopy is of particular value in the examination of acids with various types of unsaturation, such as mono- and polyenoic, acetylenic, allenic and conjugated. Acids with a cyclopropene or cyclopropane ring have been detected and studied by NMR. Positional isomers of certain substituted acids can be identified by the NMR spectrum alone. Other lipids such as glyceryl ethers, phosphatidylcholines, sphingomyelin and plasmalogens have been investigated with the aid of NMR. Reference is made to studies of other compounds, including steroids, rotenones, gossypol, glycosides, sugars, amines, amino acids and polymers.
Structure of catechol 1,2-dioxygenase from Pseudomonas arvilla

Abstract Catechol 1,2-dioxygenase was first studied by Hayaishi and colleagues in 1950. In 1967, catechol 1,2-dioxygenase from Pseudomonas arvilla C-1 (PaCTD) was chosen as a model system for the catecholic intradiol dioxygenases due to its activity, stability and expression level. Here we report the 2.65 A structure of the ββ isozyme of PaCTD. The structure supports the hypothesis first made by Vetting and Ohlendorf [The 1.8 A crystal structure of catechol 1,2-dioxygenase reveals a novel hydrophobic helical zipper as a subunit linker, Struct. Fold. Des. 8 (2000) 429–440.] that the catechol 1,2-dioxygenases are lipid binding proteins. The 5 amino-terminal helices involved in dimerization and forming the lipid binding site are shown to be plastic in their positions and orientations. The sequence differences between the α and β polypeptides are located at the part of the monomers distant from dimerization surface and thus permit the formation of the 3 isozymes (αα, αβ, and ββ) of PaCTD. The reported inactivation by sulfhydryl-modifying reagents is explained by the structure. The 10-residue Helix F (residues 203–212) is proposed to be central in communicating between the lipid binding site and the active site.