cssi/SciSciGPT-SciSciNet huggingface dataset:
Possible recognition of the GnRH receptor by an antiserum against a peptide encoded by nucleotide sequence complementary to mRNA of a GnRH precursor peptide

Two peptides, rHRnG and hproHRnG, which were encoded by the nucleotide sequences complementary to mRNA of rat hypothalamic gonadotropin-releasing hormone (GnRH) and human placental proGnRH(−3–13), respectively, were synthesized. A remarkable hydropathic anti-complementarity was observed in the N-terminal region between hproHRnG and human proGnRH(−3–13). Neither hproHRnG nor rHRnG bound GnRH in ELISA unless exremely high concentrations of peptides were used. 125I-GnRH failed to bind with either rHRnG or hproHRnG previously coated polypropylene tubes. Antisera against these peptides were generated in rabbits. All the rabbits produced antibodies with high titer as tested by ELISA. One rabbit immunized with hproHRnG showed markedly reduced serum testosterone levels as compared with those of other rabbits. Intravenous administration of 1 ml serum from this rabbit, antiserum R281, into ovariectomized rats significantly decreased plasma LH. Using antiserum R281, about 10% of female rat pituitary cells were stained by immunohistochemistry. The staining was specific to hproHRnG since it was abolished by preabsorption of the antiserum with hproHRnG, but not with rHRnG, GnRH, LH nor any other peptide tested. This particular antiserum may have recognized the GnRH receptor, and thereby interfered with the action of endogenous GnRH. These results appear to be in agreement with the view that there is a structural similarity between the receptor for a peptide and the so-called complementary peptide.
Frequency of Angina Pectoris and Secondary Events in Patients With Stable Coronary Heart Disease (from the Heart and Soul Study)

The extent to which angina pectoris (AP) predicts secondary cardiovascular events beyond independent of measures of disease severity is unknown. We evaluated the association between AP frequency and secondary events in patients with stable coronary heart disease (CHD). We administered the Seattle Angina Questionnaire to 1,023 participants with stable CHD enrolled from September 2000 to December 2002 and followed for a median of 8.9 years. We used Cox proportional hazards to evaluate the association of AP frequency with death and subsequent hospitalization for AP, revascularization, myocardial infarction (MI), or heart failure. At enrollment, 633 (62%) participants reported no AP, 279 (27%) reported monthly AP, and 111 (11%) reported daily or weekly AP. During follow-up, 396 participants died, 204 were hospitalized for AP, 194 for revascularization, 140 for MI, and 188 for heart failure. Compared with participants without AP, participants with daily or weekly AP were more likely to be hospitalized for AP (hazard ratio [HR] 3.3; 95% confidence interval [CI] 2.3 to 4.7; p
On a coupled random walk process specified by a Hamiltonian

A coupled random walk process specified by an effective Hamiltonian in a potential field is proposed. The Hamiltonian is expressed in terms of a set of jumping probabilities which characterize the random walk processes. The steady state is expressed by the Hamiltonian. Conditions for the Hamiltonian to be reduced to the Ginzburg-Landau type are discussed.
About the cover: Invariants

It carries a natural action of G = SL2(C) via linear substitutions of the variables. In 1868 P. Gordan proved that the algebra C[V ] of G-invariant polynomials on V has a finite basis, that the module of algebraic relations between the generators (called syzygies) is also finitely generated, and provided explicit upper bounds for the degrees of the generators and relations. Previously, Cayley (1821-1895) had solved the problem for forms of degree 3 and 4 in two variables.
Active acromegaly with anterior pituitary failure.

Abstract Although anterior pituitary insufficiency is not unusual in patients with long-standing acromegaly, it is rare in active acromegaly of relatively short duration. Two patients with anterior pituitary insufficiency and active acromegaly are reported on. One patient had had acromegaly 4 years and the other 3 to 5 years before the anterior pituitary insufficiency was diagnosed. In the second patient, anterior pituitary function returned after radiation therapy, although the acromegalic process continued to be active, as judged by elevation in the value for plasma growth hormone.
First-order zig-zag sublaminate plate theory and finite element model for laminated composite and sandwich panels

A refined laminated plate theory and three-dimensional finite element based on first-order zig-zag sublaminate approximations has been developed. The in-plane displacement fields in each sublaminate are assumed to be piecewise linear functions and vary in a zig-zag fashion through-the-thickness of the sublaminate. The zig-zag functions are evaluated by enforcing the continuity of transverse shear stresses at layer interfaces. This in-plane displacement field assumption accounts for discrete layer effects without increasing the number of degrees of freedom as the number of layers is increased. The transverse displacement field is assumed to vary linearly through-the-thickness. The transverse normal strain predictions are improved by assuming a constant variation of transverse normal stress in each sublaminate. In the computational model, each finite element represents one sublaminate. The finite element is developed with the topology of an eight-noded brick, allowing the thickness of the plate to be discretized into several elements, or sublaminates, where each sublaminate can contain more than one physical layer. Each node has five engineering degrees of freedom, three translations and two rotations. Thus, this element can be conveniently implemented into general purpose finite element codes. The element stiffness coefficients are integrated exactly, yet the element exhibits no shear locking due to the use of an interdependent interpolation scheme and consistent shear strain fields. Numerical performance of the current element is investigated for a composite armored vehicle panel and a sandwich panel. These tests demonstrate that the element is very accurate and robust.
A Numerical Investigation of the Cooling Effect of Compressed Natural Gas Throttling on Engine Delivery Ratio

A theoretical study was conducted to investigate the cooling effect of throttling compressed natural gas during the pressure regulation process. The concept of using this effect in cooling down the induction air was investigated. A thermodynamic model was developed for a typical fuel delivery system used on a vehicle fueled with compressed natural gas. The model was based on a set of integral conservation laws applied to each component of the fueling system. Several heat exchanging arrangements between the throttled gas and the inlet air were examined. The effect of the added heat exchanger on engine delivery ratio was examined for different engine sizes as well as for different operating conditions. An increase of 1 to 2.5% in engine delivery ratio was predicted due to the added heat exchanger.
Wheat Response to Nitrogen under Low Phosphorus and Potassium Fertility in a Wheat–Soybean Production System

Abstract Producers control crop fertilization practices. If the amount of grain yield per unit of aboveground biomass produced can be optimized with proper fertilization, nongrain aboveground biomass will be minimized. Achieving this goal would be especially beneficial in a wheat (Triticum aestivum L.) and soybean (Glycine max L.) double‐crop production system where proper fertilization could promote a residue‐management shift from burning and conventional tillage to a conservation or no‐tillage system. The objectives of this study were to i) determine the effect of nitrogen (N) rate on wheat yield, aboveground biomass, and partial harvest index (PHI), and ii) identify an appropriate predictive response model for wheat yield and PHI as a function of total N applied under low phosphorus (P) and potassium (K) fertility. This study was conducted over two cropping seasons at two locations on similar silt‐loam Fragiudalfs in eastern Arkansas where wheat was fertilized at 10 N rates ranging from 0 to 101 kg N h...
Effects of the Insect Growth Regulator, Methoprene, on Onthophagus taurus (Coleoptera: Scarabaeidae)

A bioassay was conducted to determine the impact of methoprene, an insect growth regulator (IGR), on fecundity, larval survival, and size of progeny for Onthophagus taurus Schreber. Adult O. taurus dung beetles were offered methoprene-treated manure in three to five replications each at concentrations of 0.08, 0.45, and 4.5 ppm, respectively. An additional group of adult beetles was immersed in a methoprene-water solution and allowed to reproduce in containers with untreated manure. Data from all treatment groups were compared with untreated control groups. Methoprene did not seem to hinder brood production at 0.45 ppm. Survival of O. taurus was not affected by methoprene-treated manure at 0.08 ppm or when parent beetles were immersed in methoprene-water solution. However, progeny survival was significantly reduced on manure treated with methoprene at 4.5 ppm. Mean pronotal width of O. taurus progeny was significantly smaller in beetles fed methoprene-treated manure (4.5 ppm). The low dose of 0.08 ppm did not affect pronotal widths nor did topical application of methoprene to adults affect pronotal widths in resulting offspring. Although some adverse effects of methoprene were observed at higher concentrations, use of methoprene at concentrations of 0.08 ppm as part of a horn fly control program likely would not greatly affect populations of O. taurus, the most common paracoprid dung beetle in North Carolina.
POSTREPLICATION REPAIR IN uvrA AND uvrB STRAINS OF ESCHERICHIA COLI K‐12 IS INHIBITED BY RICH GROWTH MEDIUM

Escherichia coli K-12 uvrA or uvrB strains grown to logarithmic phase in minimal medium showed higher survival after ultraviolet (UV) irradiation (254 nm) if plated on minimal medium (MM) instead of rich medium. This‘minimal medium recovery’(MMR) was largely blocked by additional recA56 (92% inhibition) or lexA101 (77%) mutations, was partially blocked by additional recB21 (54%), uvrD3 (31%) or recF143 (22%) mutations, but additional polA1 or polA5 mutations had no effect on MMR. When incubated in MM after UV irradiation, the uvrB5 and uvrB5uvrD3 strains showed essentially complete repair of DNA daughter-strand gaps (DSG) produced after UV radiation fluences up to ∼ 6 J/m2 and ∼1 J/m2, respectively, and then they accumulated unrepaired DSG as a linear function of UV radiation fluence. However, when they were incubated in rich growth medium after UV irradiation, they did not show the complete repair of DSG and unrepaired DSG accumulated as a linear function of UV radiation fluence. The fluence-dependent correlation observed for the uvrB and uvrB uvrD cells between UV radiation-induced killing and the accumulation of unrepaired DSG, indicates that the molecular basis of MMR is the partial inhibition of postreplication repair by rich growth medium. Rich growth medium can be just MM plus Casamino Acids or the 13 pure amino acids therein in order to have an adverse effect on survival, regardless of whether the cells were grown in rich medium or not before UV irradiation.
Systolic algorithms as programs

We represent a systolic algorithm by a program consisting of one multiple assignment statement that captures its operation and data flow. We use invariants to develop such programs systematically. We present two examples, matrix multiplication and LU-decomposition of a matrix.
Effects of stress and social support on recurrence in bipolar disorder.

Abstract Background: Limited research has examined the impact of social support on the course of bipolar disorder, although results suggest a probable link. This study examines prospectively the effects of stressful events and social support on episode recurrence in bipolar I disorder. Methods: Fifty-two outpatients with bipolar I disorder recruited from an urban community were followed every 3 months for up to 1 year. At the initial interview, individuals reported separately on perceived social support from a best friend, parent, and romantic partner, combined to form a total network support score. Ongoing prospective assessments of stressful life events, symptomatology, and medication compliance were completed over 1 year. Logistic regressions were utilized to predict episode recurrence. Results: As predicted, both higher levels of stress and lower levels of social support from the total network independently predicted depressive recurrence over a 1-year follow-up, after controlling for clinical history and compliance. Social support did not moderate the impact of stress. Limitations: Only a 1-year follow-up was obtained, and sample sizes may have been insufficient to detect prediction of manic episodes. Direction of causality between support and recurrence is hypothesized but cannot be definitively determined. Conclusions: Higher levels of stress and perceptions of less available and poorer quality close relationships are associated with recurrence. Interventions that target these psychosocial vulnerabilities may help alter the course of bipolar I disorder. Research with larger samples should further examine the possible polarity-specific effects of social risk factors.
Cell type specific analysis of human transcriptome data

The central nervous system (CNS) is composed of hundreds of distinct cell types, each expressing different subsets of genes from the genome. High throughput gene expression analysis of complex tissues like the CNS from patients and controls is a common method to screen for potentially pathological molecular mechanisms of psychiatric disease. One mechanism by which gene expression might be seen to vary across samples would be alterations in the cellular composition of the tissue. While there are a few gene ‘markers’ from literature for each cell type, their expression patterns vary significantly resulting in poor sensitivity and specificity. Here, we propose a method utilizing prior information from cell specific transcriptome profiling experiments in mice and co-expression network analysis to select cell type specific gene markers, and further to analytically detect changing cellular composition in human tissues. Our method successfully detects changes in cellularity over time that roughly correspond to known epochs of human brain development.
Ocular effects of GaAs lasers and near infrared radiation

Fiber optic communication systems present a possible or potential hazard to the eyes of engineers and technicians who work with or maintain these systems. To investigate this hypothesis, the retinas of macaque monkeys were exposed to near infrared cw radiation and to GaAs lasers modulated at 22 MHz and 1600 Hz. Trained animals (two) were exposed monocularly under normal physiological conditions to modulated GaAs lasers for several months, on a 5 day/week basis, 1000 sec/day. No loss of visual function or funduscopically visible damage was detected. One of these animals was sacrificed and examined histologically for damage. No differences were detected between the foveae of the exposed and control eyes in this monkey. The radiant exposure in J · cm−2 required to produce minimal lesions was determined on anesthetized animals for cw radiation at three wavelengths (820, 860, 910 nm) and for radiation at 830 nm from a GaAs laser modulated at a digital rate of 44 Mbit/sec. It required from 6 to 8.4 mW of GaAs radiation entering the eye for periods ranging from 400 to 3000 sec to produce a detectable lesion. Since the spot size on the retina was <50 μm in diameter, it is difficult if not impossible to imagine how the human eye could remain focused on such a source for an appreciable time, even if 8 mW were entering the pupil. Extrapolation to man is always dangerous, but these experiments do not suggest that engineers and technicians operating and maintaining fiber optic communication systems are subject to an ocular risk unless they use magnification optics.
2-D discrete time lossless bounded real functions: minimal state space realisation

A circuit realisation for two-dimensional (2-D) nth order discrete-time lossless bounded real functions, with minimum number of delay elements, is presented. Based on this circuit realisation to the corresponding matrix vectors A, b, c' of the Givone-Roesser 2-D state space model, are derived. The dimension of the 2-D state space model is minimal
Computation of Scattering from Penetrable Cylinders with Improved Numerical Efficiency

An integral-equation formulation is used to obtain numerical results for the scattered fields of a penetrable cylinder immersed in either a lossy halfspace or a lossy homogeneous medium. The cylinder is iluminated by a parallel electric line source. A set of plane waves interior to the inhomogeneity (scatterer) is used as basis functions. This results in more than an order of magnitude decrease in the computer time required to obtain numerical results for larger sized targets. Further, the integral-equation solution is extended to include the planar interface between the air and the earth. The validity of the approximate forms proposed earlier to represent the interface is reexamined.
The culture of engineering: Woman, workplace and machine

Synopsis Questions arising from research on automation and women's work have led me to explore patriarchal elements in the culture of engineering/management. In an elite technological institute, the engineering faculty, compared with the humanities faculty, reported more distance in childhood from experiences and qualities generally gender-linked with females—intimacy, sensuality, one's own body, social complexity. Engineers valued social hierarchy on a continuum giving most prestige to scientific abstraction, least to feminine qualities. Such values were transmitted in the engineering classroom, for example, through professors' jokes, to a new generation of engineering/ management. A persistent mind/body dualism was exhibited, subordinating sexuality and the body, and elevating scientific abstraction. The dualism translated into a mechanical view of the person and to continued separation of functions of mind and hand. Further examination of mind/body dualisms may help us to understand how the persistence of this body of ideas in Western technology affects labor processes, and in particular, women, workplace and machine.
Managed Care or Managed Inequality? A Call for Critiques of Market‐Based Medicine

This review article critiques the growing dominance of market-based medicine in the United States against the background of existing problems with quality of care, rising costs, devaluation of doctor-patient relationships, and, especially, persistent inequalities of access and outcomes. It summarizes the present state of health care delivery by focusing on the concurrent trends of growth in managed care, expanding profits, increasing proportion of those uninsured, and widening racial, ethnic, and class disparities in access to care. Allowing market forces to dictate the shape of health care delivery in this country ensures that inequalities will continue to grow and modern medicine will become increasingly adept at managing inequality rather than managing (providing) care. The article challenges anthropology to become more involved in critiquing these developments and suggests how anthropologists can expand on and contextualize debates surrounding the market's role in medicine, here and abroad.
Ultrafast shock-induced chemistry in carbon disulfide probed with dynamic ellipsometry and transient absorption spectroscopy

We used transient visible/near-infrared absorption spectroscopy and ultrafast dynamic ellipsometry to characterize carbon disulfide (CS2) shocked with an ultrafast laser pulse. We found a volume-decreasing reaction, characterized by the deviation of the shock and particle velocity (us and up) points from the unreacted Hugoniot, above up = 1.5 km/s. This result contrasts with literature plate-impact data, which found the reaction-induced deviation from the unreacted Hugoniot to occur at up = 1.2 km/s. We attribute this disparity to the difference in timescale between plate-impact experiments (ns to μs) and our ultrafast experiments (sub-ns), as our ultrafast experiments require higher shock pressures and temperatures for an observable reaction. The volume-decreasing reaction was accompanied by a large increase in absorption of the reaction products, necessitating the use of impedance matching techniques to characterize the us-up points above the reaction cusp. Using transient absorption spectroscopy, we di...
Imaging Pancreatic Cancer Using Surface-Functionalized Quantum Dots

In this study, CdSe/CdS/ZnS quantum dots (QDs) were used as optical contrast agent for imaging pancreatic cancer cells in vitro using transferrin and anti-Claudin-4 as targeting ligands. CdSe/CdS/ZnS was chosen because the CdSe/CdS/ZnS QDs have better photoluminescence (PL) efficiency and stability than those of CdSe/ZnS. The transferrin-mediated targeting is demonstrated in both a cell-free coprecipitation assay as well as using in vitro confocal microscopy. Pancreatic cancer specific uptake is also demonstrated using the monoclonal antibody anti-Claudin-4. This targeted QD platform will be further modified for the purpose of developing as an early detection imaging tool for pancreatic cancer.
Barriers to employment among out-of-school youth

Abstract This paper examines employment patterns for out-of-school youth who were part of the recent Center for Employment Training replication evaluation, with a specific focus on their association with education level, childbearing, and arrest status. We find that high school dropouts work less than graduates, owing largely to greater employment instability for men and to both instability and longer spells of joblessness for women. Female dropouts fare particularly poorly, especially those with children. For women, we find no negative association between employment or wages and having children at study entry. Finally, men with prior arrests experience longer spells of joblessness than other men, and they earn substantially lower wages. Describing the nature of employment problems for disadvantaged youth and their association with several potentially important factors can inform program design in the ongoing challenge to find what works.
Selective Deflection and Localization of Flowing Aerosols onto a Substrate

Pulsed airflow cued by the fluorescence spectrum of a particular aerosol can be used to distinguish and deflect particles of biological origin out of an aerosol stream, permitting concentration of these particles for subsequent analysis (Pan et al. 2004). However, these high velocity pulses of air have an inherent tendency to scatter particles, confounding efforts to concentrate these deflected particles for analysis. The ability to concentrate large numbers of biological particles into a small area on a collection substrate is particularly important for more species-specific techniques such as Raman and FTIR (Fourier Transform Infra-Red) spectroscopy, which require long integration times due to their weak signal strength. In the present work, a simple method is developed for deflecting and localizing particles after classification by a pulsed airflow. The concept is both modeled and experimentally tested. A specially designed funnel is used to localize the scattered particles onto an area of substrate as small as 1 mm in diameter. Computational fluid dynamics simulations were performed to investigate the interaction of the pulsed airflow with the deflected particles and the localizing funnel, in order to gain insight into design parameters and operating conditions that affect the efficiency of this technique. The results show that the combination of pulsed airflow with a localizing funnel effectively deflects and localizes the concentrated bioaerosol onto a small area of substrate or an opening of a microfluidic cell.
Internal Friction Peaks Caused by Deformation in Ta and Nb.

Internal friction peaks in Ta and Nb which arise after these metals have undergone cold-work are observed at temperatures between 200°C and 300°C for a frequency of 1 cps. Numerous similarities of the peak in Ta to one reported by Schoeck and Mondino are observed, but some differences are also observed. The peaks in both metals anneal away rapidly at their maxima, making quantitative measurement of their properties difficult. These peaks may be caused by an oxygen-dislocation interaction, as was suggested by Schoeck and Mondino, but several differences between these peaks and other cold-work peaks make this assignment not certain.
Pollen and associated microfossils in the marine surface sediments of the Great Bahama Bank

Abstract This study clearly indicates that pollen grains and certain other maceration-resistant microfossils found in surface sediment of the Great Bahama Bank are sedimented primarily in response to water turbulence and other hydrological factors. Low levels of pine-pollen concentration are found in the same areas as sandy sediment—areas of relatively turbulent water. Muddy sediment and high levels of pine-pollen concentration are similarly associated in the areas of sluggish water movement. This is very significantly true of the area of quiet water west of Eleuthera Island, where pine pollen occurs abundantly in the mud, despite the absence of pine trees on the island. This shows that pine pollen is moved about widely on the Bank and sediments out in the areas of relatively nonturbulent water. The discovery that large amounts of pine pollen—as much as 2,000 per 100 l. of water—are present in the water on the Bank months after the trees ceased flowering further substantiates this fact. “Microforaminifera” are more generally distributed; they occur both in muddy sediment and in sandy sediment at various locations. Apparently they are found more or less where they lived, having been moved about relatively little on the Bank. Hystrichosphaerids show a distribution intermediate between that of pine pollen and that of “microforaminifera”; they are relatively concentrated in the muddy sediment, as a response to nonturbulence of the water, but they also sediment out to some extent at other locations on the Bank. This is interpreted as showing that hystrichosphaerids are denser than pine pollen. The study shows the possible use of palynological analysis in the investigation of paleosediment types and paleohydrologic features of sedimentary basins.
Relative stabilities of nitrenium ions derived from polycyclic aromatic amines. Relationship to mutagenicity.

Abstract The relative energetics of arylamine N -hydroxylation and N-O heterolysis (ArNH 2 → ArNHOH → ArNH + ) for condensed systems of two, three and four rings were calculated using semiempirical AM1 molecular orbital theory. The overall thermodynamics of N -hydroxylation were almost insensitive to the structure of the amine while differences in the energetics of nitrenium ion formation varied from 0 to 35 kcal mol −1 . Limited correlations between the latter and the experimental TA98 and TA100 mutagenicities of the amines are presented.
On Impact of Dynamic Virtual Machine Reallocation on Data Center Efficiency

Modern OS virtualization technology allows for "live migration" of virtual servers between physical hosts after the initial consolidation thus providing new avenues for performance optimization. This paper focuses on quantifying by how much data center efficiency can be improved using dynamic (i.e., in response to demand changes) real-location of virtual machines between physical servers. An analytical performance model of dynamic virtual machine reallocation is presented. It allows to estimate the reduction (as compared to the static consolidation) in the number of physical servers required to host the workload (under the same requirements of the maximum number of capacity overloads). Model is validated using simulations and several insights based on the analysis are provided.
Design and performance of reflective ultra-broadband terahertz time-domain spectroscopy with air-biased-coherent-detection

In general, a reflective spectrometer is more suitable for the spectroscopic measurement for highly absorptive samples. We report the design and evaluation of a reflective terahertz time-domain spectroscopy (R-THz-TDS), using air as THz wave emitter and sensor, together with air-biased-coherent-detection (ABCD) method. With an 85 fs pulse amplified laser, we demonstrate a usable bandwidth from 0.5 THz to 12 THz, together with a peak dynamic range (DR) better than 2000:1 and a peak THz electrical field greater than 30 kV/cm. With a 32 fs pulse amplified laser, the usable bandwidth is further expanded to a continuous 35 THz. Several far-infrared optical properties such as phonon resonance and plasma resonance in various samples are reported. We also compared both transmission and reflection measurements. Furthermore, the time-resolved optical pump-THz probe experiment is performed. The evolution of carrier dynamics of GaAs and InSb samples are demonstrated in this study. Finally, the uniqueness and advantage of this R-THz-TDS spectrometer are comprehensively compared with traditional THz-TDS and Fourier transform infrared (FTIR) spectroscopy, including radiation source, detector, DR, bandwidth, resolution, peak power, and other features. In terms of signal-to-noise ratio (SNR), this study provides the SNR variation with frequency in both broadband R-THz-TDS and FTIR spectroscopy.
Understanding Acceptance of High Technology Products: 50 Years of Research

This survey of research on acceptance of technology over the past fifty years was conducted to identify and clarify those variables that influence technology acceptance, particularly those that are related to aspects of the technology itself. We surveyed the literature across many domains, selected articles related to this research area, and coded these articles based on the studied variables and products. The results of this survey are an organizational schema for all of the variables as well as specific guidance on the generalized effects of relevant variables such as perceived usefulness, perceived compatibility, and perceived privacy. For each critical variable, we discuss the implications to guide designers of high-technology products.
Silent atrial fibrillation: A clinical conundrum

The Asymptomatic Atrial Fibrillation and Stroke Evaluation in Pacemaker Patients and the Atrial Fibrillation Reduction Atrial Pacing Trial (ASSERT) reported that about 10% of the patients in a pool of 2850 selected subjects (older than 65 years of age) with pacemakers had subclinical atrialfibrillation (AF). The studyalso reported that the risk of developing an ischemic stroke or systemic embolism was 2.5 fold higher for patients with subclinical AF, comparedwith patients without after a follow-up period of 2.5 years [1]. These findings remain relevant and important with about a million cardiac pacemakers being implanted every year all over the world (N200,000 in United States) [2]. The term “silent AF” is complicated as most patients with paroxysmal AF never report clinical symptoms, especially during the earlier stages [3]. Also, about 25% of ischemic strokes reported have no underlying etiology identified [4]. Silent AF could have well been the presumed phenomena behind this mystery; as there is no data on how common this phenomenon is in non-cardiac pacemaker patients. It is also unclear if silent AF is a precursor for paroxysmal AF or if it is a separate entity by itself. Studies especially in stroke patients have shown that the yield of AF detection increases with the duration of cardiac monitoring [5]. The important clinical conundrum that remains is first; how aggressive should the clinician be in detecting silent AF? And second; what shouldwe dowith a documented episode of silent AF in pacemaker patients? Unfortunately, little is known on the antiarrhythmic management and strategies for stroke prevention in this group. Data from the CRYSTAL-AF (Cryptogenic Stroke And underlying Atrial Fibrillation) a study designed to monitor subclinical tachyarrhythmia's with implantable loop recorders in patients with history of stroke without a clear etiology; is eagerly awaited to help provide additional insight on the benefit of longer duration of monitoring [6]. Until then, in patients with the highest risk of stroke (high CHADS2 score); physicians should be vigilant about this phenomena andmake a clinical judgment about the need for anticoagulation. Future research is warranted to help guide clinicians with optimal treatment strategies for this unique phenomenon.
Elastic Properties of Silica Xerogels

Abstract : Longitudinal and transverse acoustic wave velocities have been measured for silica xerogels as a function of relative humidity in order to calculate elastic constants. The silica zerogels studied are microporous with open porosity of 53 vol %. The longitudinal wave velocity exhibits a minimum at about 35% RH (relative humidity). The transverse wave velocity decreases to a constant value for 35% and greater relative humidity. Consequently, Young's modulus is a minimum at 35% RH while the shear modulus decreases to a constant value at 35% RH. The bulk modulus and Poissons' ratio exhibit minimum values at about 15% RH. Young's modulus decreases from 4.91 GPa to 3.42 GPa at 35% RH and then increases to 3.60 GPa at 55% RH. Poisson's ratio decreases from 0.184 to 0. 164 at 15% RH and then increases to 0.272 at 55% RH. Below 35% RH, silica xerogels adsorb a monolayer of hydroxyls while above 35% RH silica xerogels show pore filling. (aw)
Age of the Mesozoic Oceanic Crust in the California Coast Ranges

K-Ar ages of approximately 155 m.y. were measured on minerals from ophiolites at two localities in the California Coast Ranges. Upper Jurassic rocks of the Great Valley sequence are n i depositional contact with underlying ophiolites, which are interpreted as Mesozoic oceanic crust that formed during differentiation of mantle material at a spreading ridge some 15 m.y. before deposition of the Great Valley sequence began.
Hardness results for coloring 3-colorable 3-uniform hypergraphs

We consider the problem of coloring a 3-colorable 3-uniform hypergraph. In the minimization version of this problem, given a 3-colorable 3-uniform hypergraph, one seeks an algorithm to color the hypergraph with as few colors as possible. We show that it is NP-hard to color a 3-colorable 3-uniform hypergraph with constantly many colors. In fact, we show a stronger result that it is NP-hard to distinguish whether a 3-uniform hypergraph with n vertices is 3-colorable or it contains no independent set of size /spl delta/n for an arbitrarily small constant /spl delta/ > 0. In the maximization version of the problem, given a 3-uniform hypergraph, the goal is to color the vertices with 3 colors so as to maximize the number of non-monochromatic edges. We show that it is NP-hard to distinguish whether a 3-uniform hypergraph is 3-colorable or any coloring of the vertices with 3 colors has at most 8/9 + /spl epsi/ fraction of the edges nonmonochromatic where /spl epsi/ > 0 is an arbitrarily small constant. This result is tight since assigning a random color independently to every vertex makes 8/9 fraction of the edges non-monochromatic. These results are obtained via a new construction of a probabilistically checkable proof system (PCP) for NP. We develop a new construction of the PCP Outer Verifier. An important feature of this construction is smoothening of the projection maps. Dinur, Regev and Smyth (2002) independently showed that it is NP-hard to color a 2-colorable 3-uniform hypergraph with constantly many colors. In the "good case", the hypergraph they construct is 2-colorable and hence their result is stronger. In the "bad case" however, the hypergraph we construct has a stronger property, namely, it does not even contain an independent set of size /spl delta/n.
Basal and metal-induced expression of metallothionein isoform 1 and 2 genes in the RWPE-1 human prostate epithelial cell line

The human prostate gland has low basal expression of the metallothionein-1 and -2 proteins. In prostate cancer, MT-1/2 protein expression is variable and correlates directly with the increasing Gleason score of the tumor. The goal of the present study was to determine if the RWPE-1 cell line is a good model to elucidate the mechanisms underlying the alterations in MT-1/2 expression that occur during the development of prostate cancer. It was shown that the RWPE-1 cell line and in situ prostate tissue have identical expression profiles of MT-1 and MT-2 isoform-specific mRNAs (MT-1E, MT-1X and MT-2A) and similar levels of MT-1/2 protein. It was also shown that the RWPE-1 cells respond to Zn(+2) and Cd(+2) exposure by induction of the basally expressed MT mRNAs and the accumulation of high levels MT-1/2 protein (in excess of 10% of total protein). It was also shown that additional MT-1 mRNAs were expressed when the cells were exposed to either metal; MT-1A, MT-1F, MT-G and MT-1H for Cd(+2)-exposed cells; and, MT-1F, MT-G and MT-1H for Zn(+2)-exposed cells. The results suggest that RWPE-1 cells may be a valuable system to define the interplay between Zn(+2) concentration, Cd(+2) exposure and MT in normal and malignant prostate epithelial cells.
HandAlign: Bayesian multiple sequence alignment, phylogeny and ancestral reconstruction.

Summary: We describe handalign, a software package for Bayesian reconstruction of phylogenetic history. The underlying model of sequence evolution describes indels and substitutions. Alignments, trees and model parameters are all treated as jointly dependent random variables and sampled via Metropolis–Hastings Markov chain Monte Carlo (MCMC), enabling systematic statistical parameter inference and hypothesis testing. handalign implements several different MCMC proposal kernels, allows sampling from arbitrary target distributions via Hastings ratios, and uses standard file formats for trees, alignments and models. Availability and Implementation: Installation and usage instructions are at http://biowiki.org/HandAlign Contact: ude.yelekreb@hhi Supplementary information: Supplementary material is available at Bioinformatics online.
SdeK Is Required for Early Fruiting Body Development in Myxococcus xanthus

Myxococcus xanthus cells carrying the V4408 Tn5lac insertion at the sde locus show defects in fruiting body development and sporulation. Our analysis of sde expression patterns showed that this locus is induced early in the developmental program (0 to 2 h) and that expression increases approximately fivefold after 12 h of development. Further studies showed that expression of sde is induced as growing cells enter stationary phase, suggesting that activation of the sde locus is not limited to the developmental process. Because the peak levels of sde expression in both an sde 1 and an sde mutant background were similar, we conclude that the sde locus is not autoregulated. Characterization of the sde locus by DNA sequence analysis indicated that the V4408 insertion occurred within the sdeK gene. Primer extension analyses localized the 5* end of sde transcript to a guanine nucleotide 307 bp upstream of the proposed start for the SdeK coding sequence. The DNA sequence in the 212 and 224 regions upstream of the sde transcriptional start site shows similarity to the s 54 family of promoters. The results of complementation studies suggest that the defects in development and sporulation caused by the V4408 insertion are due to an inactivation of sdeK. The predicted amino acid sequence of SdeK was found to have similarity to the sequences of the histidine protein kinases of two-component regulatory systems. Based on our results, we propose that SdeK may be part of a signal transduction pathway required for the activation and propagation of the early developmental program. In response to starvation, cells of the gram-negative soil bacterium Myxococcus xanthus initiate a developmental program that culminates in the formation of a dome-shaped structure called a “fruiting body.” Construction of the multicellular fruiting body requires nutrient deprivation, the coordinated effort of approximately 10 5 cells, and a solid surface. Within the fruiting body, individual cells differentiate into environmentally resistant and metabolically quiescent spores (for reviews, see references 17, 18, and 47). Fruiting body development proceeds through a series of steps that require cell-cell signaling. At least five extracellular signals (designated A-signal through E-signal) are needed for
Mg2+-Induced Compaction of Single RNA Molecules Monitored by Tethered Particle Microscopy

We have applied tethered particle microscopy (TPM) as a single molecule analysis tool to studies of the conformational dynamics of poly-uridine(U) messenger (m)RNA and 16S ribosomal (r)RNA molecules. Using stroboscopic total internal reflection illumination and rigorous selection criteria to distinguish from nonspecific tethering, we have tracked the nanometer-scale Brownian motion of RNA-tethered fluorescent microspheres in all three dimensions at pH 7.5, 22°C, in 10 mM or 100 mM NaCl in the absence or presence of 10 mM MgCl2. The addition of Mg2+ to low-ionic strength buffer results in significant compaction and stiffening of poly(U) mRNA, but not of 16S rRNA. Furthermore, the motion of poly(U)-tethered microspheres is more heterogeneous than that of 16S rRNA-tethered microspheres. Analysis of in-plane bead motion suggests that poly(U) RNA, but less so 16S rRNA, can be modeled both in the presence and absence of Mg2+ by a statistical Gaussian polymer model. We attribute these differences to the Mg2+-induced compaction of the relatively weakly structured and structurally disperse poly(U) mRNA, in contrast to Mg2+-induced reinforcement of existing secondary and tertiary structure contacts in the highly structured 16S rRNA. Both effects are nonspecific, however, as they are dampened in the presence of higher concentrations of monovalent cations.
Review of the Neotropical Leaf Beetle SubgenusDorynota s. str. Chevrolat (Coleoptera: Chrysomelidae: Cassidinae: Dorynotini)

Abstract A review of Dorynota Chevrolat s. str. is presented in which 18 species are included in the subgenus. Three new species are described: Dorynota (s. str.) monneorum Simoes and Sekerka, new species and Dorynota (s. str.) borowieci Simoes and Sekerka, new species from Brazil, and Dorynota (s. str.) wappesi Sekerka and Simoes, new species from Bolivia. Two new synonyms are proposed: Dorynota (s. str.) aculeata (Boheman, 1854) = Dorynota (s. str.) pubescens (Blake, 1939), new synonymy, and Dorynota (s. str.) cornigera Boheman, 1854 = Dorynota (s. str.) bellicosa Boheman, 1854, new synonymy. Dorynota (s. str.) pugnax Boheman, 1854, restored status, is resurrected from synonymy with Dorynota (s. str.) nodosa (Boheman, 1854). Thirty-five new country and region records are reported for 10 species. A key to species and color photographs of all species are provided.
Designing Systems for the 90s

For almost 30 years, training designers have tried to develop effective training for automated systems. Even with their best efforts, though, training has been seen as something other than the system itself. Specifically, training has been designed to help minimize the disruption caused by the implementation of the system. In the 1990s, a different effort will be called for. The system itself will have to take on much of the training responsibility—including minimizing disruption. This will require training designers, metamorphosed into full-scale performance technologists, to become part of thesystem design team itself, since their expertise will be crucial to effective system design.
Scale and rotation invariant texture classification

The problem of classifying scaled and rotated texture images is addressed using a number of different approaches. The first approach extracts invariant features from texture images; moment invariant features and log-polar filter features are employed. The second approach follows a mental transformation procedure similar to the process of scaled and rotated shape recognition carried out by human beings. Texture images are rotated and scaled to a specific size and orientation which allows the application of a more general rotation-scale sensitive classification scheme. A two-stage estimation procedure is introduced to determine the required scaling and rotation factors. Simulations show that the mental transformation approaches outperformed the other approaches, giving a good averaged error rate of 10%. >
Does the turing test demonstrate intelligence or not

The Turing Test has served as a defining inspiration throughout the early history of artificial intelligence research. Its centrality arises in part because verbal behavior indistinguishable from that of humans seems like an incontrovertible criterion for intelligence, a “philosophical conversation stopper” as Dennett (1985) says. On the other hand, from the moment Turing’s seminal article (Turing, 1950) was published, the conversation hasn’t stopped; the appropriateness of the Test has been continually questioned, and current philosophical wisdom holds that the Turing Test is hopelessly flawed as a sufficient condition for attributing intelligence. In this short article, I summarize for an artificial intelligence audience an argument that I have presented at length for a philosophical audience (Shieber, to appear) that attempts to reconcile these two mutually contradictory but well-founded attitudes towards the Turing Test that have been under constant debate since 1950 (Shieber, 2004). The arguments against the sufficiency of the Turing Test for determining intelligence rely on showing that some extra conditions are logically necessary for intelligence beyond the behavioral properties exhibited by a subject under a Turing Test. Therefore, it cannot follow logically from passing a Turing Test that the agent is intelligent. I will argue that these extra conditions can be revealed by the Turing Test, so long as we allow a very slight weakening of the criterion from one of logical proof to one of statistical proof under weak realizability assumptions. Crucially, this weakening is so slight as to make no conceivable difference from a practical standpoint. Thus, the Gordian knot between the two opposing views of the sufficiency of the Turing Test can be cut.
Crystalline Texture of CoCrPt Films on CrMn/NiAl and Cr/NiAl Underlayer Structures

In this study, we examine the effects of CrMn/NiAl and Cr/NiA1 underlayer structures on the crystalline texture and microstructure of CoCrPt magnetic films using x-ray and electron diffraction. The former underlayer structure was found to induce better CoCrPt (image1) texture. The stress in the CoCrPt layer was measured. The effective in-plane anisotropy energy densities of the CoCrPt films on the above two underlayers were also measured by using out-of-plane torque and Miyajima methods and the result was consistent with the texture analysis.
Acceleration feedback for control of a flexible manipulator arm

Many studies to date have dealt with control and modeling strategies for endpoint positioning of flexible manipulator arm systems, and some actual experiments have been documented in verification of developed methods. This article describes laboratory results for a single-link flexible manipulator arm in which three separate control strategies are compared and contrasted. Namely, the control schemes compared are: compensation using classical root locus techniques with endpoint position feedback, a full state feedback, observer-based design, and compensation using endpoint acceleration feedback. The last technique, designs using accelerometer feedback, has received very little attention to date, and results here indicate great promise for use in flexible manipulator control.
Lightning study inside out

Whoever said lightning doesn't strike twice in the same place wasn't at the National Severe Storms Laboratory in Oklahoma this summer with researchers from NASA's Langley Research Center at Hampton, Virginia. A Langley team of 19 people can testify that lightning not only struck twice but three times, while they intentionally guided a modified F-106B jet fighter through severe southwest thunderstorms.