cssi/SciSciGPT-SciSciNet huggingface dataset:
Molecular Dynamics Studies on the Effects of Water Speciation on Interfacial Structure and Dynamics in Silica-Filled PDMS Composites

Significant changes in materials properties of siloxane based polymers can be obtained by the addition of inorganic fillers. In silica-filled polydimethylsiloxane (PDMS) based composites the mechanism of this reinforcing behavior is presumably hydrogen bonding between surface hydroxyls and backbone siloxane species. We have chosen to investigate in detail the effect of chemisorbed (hydroxyls) and physisorbed water on the interfacial structure and dynamics in silica-filled PDMS based composites. Toward this end, we have combined molecular dynamics simulations and experimental studies employing DMA and NMR analysis. Our results suggest that the polymer-silica contact distance and the mobility of interfacial polymer chains significantly decreased as the hydration (hydroxyl and/or physisorbed water) level at the interface was reduced. The reduced mobility of the PDMS chains in the interfacial domain reduced the overall motional properties of the polymer, thus causing an effective "stiffening" of the polymer matrix. The role of the long-ranged Coulombic interactions on the structural features and chain dynamics of the polymer were also examined. Both are found to be strongly influenced by the electrostatic interactions as identified by the bond orientation time correlation function and local density distribution functions. These results have important implications for the design of nanocomposite silica-siloxane materials.
Attitudes of Baccalaureate Nursing Students toward Persons with Acquired Immunodeficiency Syndrome According to Mode of Human Immunodeficiency Virus Transmission.

The purpose of this descriptive correlational study was to (1) examine differences in baccalaureate nursing students' attitudes toward persons living with acquired immunodeficiency syndrome (AIDS) (PLWAs) according to mode of transmission and (2) identify demographic and academic variables influencing baccalaureate nursing students' attitudes toward PLWAs. Two hundred forty-six students from five geographically dispersed baccalaureate programs returned a completed demographic data sheet, AIDS Knowledge Scale, and AIDS Attitude Scale. The AIDS Attitude Scale, based on Goffman's theory of stigma, assesses stigmatizing attitudes, perceptions of deservedness of care, and attitudes of respect and regard for PLWAs according to five modes of human immunodeficiency virus transmission. The findings of this study demonstrated overall that baccalaureate students were the most stigmatizing toward persons who had developed AIDS through injecting drugs followed by sexual contact (both homosexual and heterosexual) and least stigmatizing toward PLWAs who contracted the virus through maternal transmission or a blood transfusion. Perhaps the PLWA who contracted AIDS through either maternal transmission or a blood transfusion was viewed as an "innocent victim" of the disease, whereas PLWAs who contracted the virus through either shared needles or sexual transmission were viewed as having acquired the infection through the results of their actions. The demographic characteristics of the respondents did not influence AIDS attitudes.
Plasmonics: The dark side of the ring

Small symmetry breaking in the configuration of an ensemble of nanospheres creates huge Fano resonance enhancements in the visible range.
Analysis of transmitted optical spectrum enabling accelerated testing of CPV designs

Concentrated photovoltaics (CPV) has recently gained interest based on its scalability and expected low levelized cost of electricity. The reliability of materials used in CPV systems, however, is not well established. The current qualification test for photodegradation of CPV modules includes only real-time ultraviolet (UV) exposure, i.e. methods for accelerated UV testing have not been developed. Therefore, the UV and infrared (IR) spectra transmitted through representative optical systems is evaluated in this paper. The measurements of concentrating optics are used to assess expected optical performance as well as to understand how to quantify damaging optical exposure. Optical properties (transmittance, refractive index, reflectance, and absorptance) of candidate materials are identified. The dose and flux analysis here identifies the increased significance of IR (as opposed to UV) exposure for CPV systems, particularly for the most concentrating systems. For these, the UV dose may not greatly exceed the unconcentrated global solar condition, but the thermal load scales nearly directly with the geometric concentration.
Quantum effects in weakly coupled superconductors

Abstract The boson method in superconductivity is applied to the study of two superconductors weakly joined. A general theory of the a.c. effects is obtained; in particular the presence of harmonic and subharmonic steps in the 1–5 characteristic of the system is derived.
Tools for dynamic analysis of the general large power system using time-varying phasors

Abstract This paper extends the applicable range of phasors for transient analysis from the traditional slow quasi-stationary range to accommodate fast speeds up to the carrier frequency. Rigorous phasor calculus is developed for time varying low pass phasor signals whose bandwidths are less than the 60 Hz carrier frequency. Symmetrical components technique for analysing quasi-stationary unbalanced power system transients is extended to cover the low pass time-varying phasors. It is also proved that the time varying phasors can be used for computing the fast electromagnetic transients within the linear RLC lumped parameter representation of the transmission network irrespective of the transient speeds. In linear networks, this time-varying phasor concept unifies two classical approaches: (1) transient analysis using instantaneous currents and voltages, and (2) steady state analysis using traditional phasors, into analysing both behaviours precisely using the time-varying phasors.
Bayesian Nonparametric Spatial Modeling With Dirichlet Process Mixing

Customary modeling for continuous point-referenced data assumes a Gaussian process that is often taken to be stationary. When such models are fitted within a Bayesian framework, the unknown parameters of the process are assumed to be random, so a random Gaussian process results. Here we propose a novel spatial Dirichlet process mixture model to produce a random spatial process that is neither Gaussian nor stationary. We first develop a spatial Dirichlet process model for spatial data and discuss its properties. Because of familiar limitations associated with direct use of Dirichlet process models, we introduce mixing by convolving this process with a pure error process. We then examine properties of models created through such Dirichlet process mixing. In the Bayesian framework, we implement posterior inference using Gibbs sampling. Spatial prediction raises interesting questions, but these can be handled. Finally, we illustrate the approach using simulated data, as well as a dataset involving precipitati...
Unidirectional transport of HMM coated particles on fascin crosslinked F-actin arrays

Actin-myosin system plays an important role in biological transport and it can be utilized for various applications: delivery, sorting, and powering microdevices in in vitro. A key of harnessing this powerful and efficient system is directional control. To perform directional control, unipolar F-actin arrays were created on a substrate. Biotinylated gelsolin was used as a tool to anchor F-actin on the streptavidin coated surface. To prevent non-specific binding of F-actin on the surface, blocking agents were employed. In presence of a flow field, anchored F-actin was aligned and fascin helped forming F-actin arrays on the surface. When unipolar F-actin arrays were created, HMM coated particles were successfully moved along F-actin arrays at approx. 1.3 µm/s. This technique will provide constructive information for the future applications of transport and actuation systems using actinmyosin at nanoscale.
Morphological differences between extranidal and intranidal workers in the ant Temnothorax rugatulus, but no effect of body size on foraging distance

Most ant genera are thought to have monomorphic workers, indicating perhaps a high degree of flexibility in task allocation, and the well-studied genus Temnothorax is an example of this. However, considerable size variation may exist between individuals. In addition, though workers can show flexible behavior, it has been shown that individuals may consistently differ in their task profiles. Here we test whether body size variation among workers affects foraging behavior. Two main hypotheses were tested: first, whether larger ants forage at greater distance from the nest, and second, whether larger individuals show a higher propensity to work outside of the nest. Our results showed that ant body size does not significantly affect foraging distance. However, larger ants were more likely to be found outside the nest. Though Temnothorax ants are a common model system, this is the first study demonstrating task allocation based on body size, which is fixed in adults. Our study suggests that particularly small species may have to be examined carefully for body size variation before concluding that body size is uniform and therefore irrelevant for task allocation.
An efficient compression scheme for checkpointing of FPGA-based digital mockups

This paper outlines a transparent and nonintrusive checkpointing mechanism for use with FPGA-based digital mockups. A digital mockup is an executable model of a physical system and used for real-time test and validation of cyber-physical devices that interact with the physical system. These digital mockups are typically defined in terms of a large set of ordinary differential equations. We consider digital mockups impelemented on field-programmable gate arrays (FPGAs). A checkpoint is a snapshot of the internal state of the model at a specific point in time as captured by some controller that resides on the same FPGA. We require that the model continues uninterrupted execution during a checkpointing operation. Once a checkpoint is created, the corresponding state information is transferred from the FPGA to a host computer for visualization and other off-chip processing. We outline the architecture of a checkpointing controller that captures and transfers the state information at a desired clock cycle using an aggressive compression technique. Our compression technique achieves 90% reduction in data transferred from the FPGA to the host computer under periodic checkpointing scenarios. The checkpointing with compression yields 15-36% FPGA size overhead, versus 6–11% for checkpointing without compression.
Physico-chemical changes in ‘Saba’ bananas during normal and acetylene-induced ripening

Abstract Physico-chemical changes in ‘Saba’ bananas, a variety widely used as a raw material for several products in the Philippine food industry, were analysed under conditions of normal and acetylene-induced ripening. Starch degradation, the formation of reducing and non-reducing sugars and an increase in the moisture content, pectins and acidity of the pulp, occurred during ripening. Acetylene accelerated the rate of chemical change, without significantly affecting the final levels at which chemical constituents were present in the ripe pulp. Peel colour and pulp texture were both found to be useful indices of the stage of ripeness of the pulp after harvest. Changes in these physical parameters correlated well with the starch and sugar content of the pulp, irrespective of the rate of ripening.
The neuroprotective effect of ladostigil against hydrogen peroxide-mediated cytotoxicity

The multifunctional, anti-Alzheimer drug, ladostigil (TV3326) [(N-propargyl-(3R) aminoindan-5yl)-ethyl methyl carbamate] combines the neuroprotective effects of the anti-Parkinson drug, rasagiline, a selective monoamine oxidase (MAO)-B inhibitor, with the cholinesterase (ChE) inhibitory activity of rivastigmine in a single molecule. Ladostigil has been shown to possess potent antiapoptotic and neuroprotective activities in various oxidative insults in vitro and in vivo, such as prevention of the fall in mitochondrial membrane potential and regulation of Bcl-2 family proteins. In the present study, we demonstrate that ladostigil (1 microM) increased cell viability, associated with the increase of catalase activity and decrease of intracellular reactive oxygen species (ROS) production in human SH-SY5Y neuroblastoma cells exposed to (hydrogen peroxide) H(2)O(2). Furthermore, ladostigil significantly elevated mRNA levels of the antioxidants enzymes, catalase, NAD(P)H quinone oxidoreductase 1 (NQO1) and peroxiredoxin 1 (Prx 1) in H(2)O(2)-treated SH-SY5Y cells. Chronic treatment with ladostigil (1 mg/kg gavage per day for 30 days) markedly up-regulated mRNA expression levels of various antioxidant enzymes in aged rat hippocampus (e.g. glutathione peroxidase precursor (GSHPX-P), glutathione S-transferase (GST) and glucose-6-phosphate dehydrogenase (G6PD)). These findings indicate that in addition to its multiple neuroprotective characteristics, ladostigil also possesses antioxidant properties, which might be beneficial for the treatment of oxidative stress (OS) in aging and age-associated neurodegenerative diseases.
Vibrational spectrum of hydrogenated amorphous SiC films

Infrared absorption spectra are presented of amorphous Si1−xCx films made by the glow discharge process. Four bands, representing the stretching modes of SiH, CH, and SiC, and the wagging mode of SiCH3, were followed over the entire alloy composition range. It is shown that the compositional dependence of these bands varies in a manner predicted by a model in which Si and C atoms are randomly distributed throughout the film without chemical ordering. The bonded hydrogen content in the films is estimated to be of the order of 20 to 30 at%, depending on composition, with the silicon atoms bonding to a single hydrogen and the carbons bonding predominantly as CH2 and CH3 groups. Infrarotabsorptionsspektren von amorphen Si1−xCx-Schichten werden mitgeteilt, die durch einen Glimmentladungsprozes hergestellt wurden. Vier Banden, die die Streckungsmoden von SiH, CH, SiC und die „wagging”-Mode von SiCH3 darstellen, lassen sich uber den gesamten Zusammensetzungsbereich der Legierung verfolgen. Es wird gezeigt, das die Zusammensetzungsabhan gigkeit dieser Banden durch ein Modell vorhergesagt wird, in dem die Si- und C-Atome statistisch in der gesamten Schicht ohne chemische Ordnung verteilt sind. Es wird gefunden, das der Anteil an gebundenem Wasserstoff in den Schichten die Grosenordnugn von 20 bis 30 At% hat, je nach Zusammensetzung, wobei die Siliziumatome an isoliertem Wasserstoff gebunden und die Kohlenstoffatome vorwiegend als CH2− und CH3−Gruppen gebunden sind.
The metathesis-facilitated synthesis of terminal ruthenium carbide complexes: a unique carbon atom transfer reaction.

Ruthenium benzylidene metathesis catalysts react with 2,3-dicarbomethoxymethylene−cyclopropane, eliminating styrene and dimethyl fumarate, and producing the first terminal ruthenium carbide complexes. The products are diamagnetic, air-stable, and moderately soluble in hydrocarbon solvents. An X-ray study of Ru(⋮C:)Cl2(P(C6H11)3) (1,3-dimesityl-4,5-dihydroimidazol-2-ylidene) shows a Ru−C distance of 1.650(2) A, consistent with the presence of a very short Ru−C triple bond.
A general stiffness method for the solution of nonlinear cable networks with arbitrary loading

Abstract A general matrix stiffness method for the solution of nonlinear elastic cable networks with distributed loading is presented. The procedure is applicable to interconnected networks with irregular boundaries with member, joint, and temperature loading. Accurate numerical evaluation of the stiffness coefficients was found to be critical to the convergence and stability of the solution. An algorithm is presented which meets these requirements. The governing equations are the equations of equilibrium for the joints and the equations of equilibrium for the members. The equations of equilibrium for each member are satisfied at each iteration by solving for the required member end forces assuming that all joints are fixed. The linearized equations describing the joint force-displacement relationships are then formulated. Each joint may have up to three degrees of freedom. These equations are solved for corrections to the joint coordinates. The member forces are then recomputed using the loading corresponding to the new network configuration. Each joint is checked for equilibrium and the process is repeated until equilibrium is achieved. Relative errors of 10 −3 have been shown to be readily achievable for all joints. The method may be used to compute the prestressed configuration of the network if either the length or desired tension of the members is given. The linearization occurs in the numerical evaluation of the stiffness coefficients. The numerical procedure for evaluating the stiffness coefficients is critical to the convergence of the entire process. The stiffness coefficients must possess uniform accuracy to prevent divergence in nonlinear networks. A stiffness coefficient accuracy parameter was identified. The procedure must be applicable to a wide range of cable force-displacement relationships which are not known a priori . An algorithm has been devised and implemented that yields very good convergence. Each member is characterized by nine stiffness coefficients which are functions of the member loading as well as the location of the end points. The stiffness coefficients Kxx, Kxy, Kxz, Kyz, Kyy, Kyz, Kzx, Kzy and Kzz are evaluated numerically by considering small displacements of the joint in each of the x , y and z directions for each cable. The stiffness coefficients are defined in the usual manner, i.e. Kxy is the force component in the x direction which results from a displacement in the y direction. Each cable is treated as a catenary with uniform loading over its length for both the preload and loaded conditions. For the preload ease only the cable weight and any concentrated joint loads are considered. For the case where wind and ice are considered, the cable shape between joints is still considered to be a catenary whose plane and curvature have been changed. Comparisons of special cases with results of previous investigations are given.
Rapid enzymatic urine screening test to detect bacteriuria in pregnancy

Abstract Objective: To determine the sensitivity, specificity, and positive and negative predictive values of an enzymatic urine screening test for diagnosing bacteriuria in pregnancy. Methods: Clean-catch midstream urine samples were collected from 383 women who had routine prenatal screening for bacteriuria. Sensitivity, specificity, and positive and negative predictive values for each screening test (enzyme activity, nitrites or leukocytes on dipstick, and bacteria or pyuria on microscopic examination) were estimated using urine culture as the criterion standard. Urine cultures were considered positive if they grew 104 colony-forming units of a single uropathogen. Standard deviations used to calculate 95% confidence intervals were based on binomial distribution. A sample of 30 urine specimens was selected to evaluate interrater agreement using Cohen’s kappa statistic. Results: Five of 383 samples were contaminated, leaving 378 samples for evaluation. Thirty of 43 specimens with positive urine culture had positive enzyme activity. Of 335 samples with no growth, 150 had negative enzyme activity. Sensitivity, specificity, and positive and negative predictive values for the Uriscreen enzymatic screening test (Bard Patient Care Division, Murray Hill, NJ) were 70%, 45%, 14%, and 92%, respectively. Sensitivity of the Uriscreen was lower than that of bacteria alone. Interrater agreement for Uriscreen testing was high among the three testers (κ = .86). Conclusion: The Uriscreen enzymatic screening test had inadequate sensitivity for rapid screening for bacteriuria in pregnancy.
Ventricular pump function in heart failure with normal ejection fraction : Insights from pressure-volume measurements

The syndrome of heart failure in the setting of normal ejection fraction (HFNEF) is manifest in a clinically heterogeneous group of patients with multiple and varied comorbid conditions. In this report, we review available data derived from pressure-volume (PV) analyses in patients with and in animal models of HFNEF. Pressure-volume analysis of ventricular function is challenging in the clinical setting but provides unique insights into the systolic, diastolic, and overall pumping characteristics of the heart. Results of such analyses have thus far been limited to small cohorts of patients but suggest that different cohorts of patients with HFNEF having PV relations that imply different pathophysiologic mechanisms exist. This emphasizes the need to take a view of this syndrome, which extends beyond diastolic dysfunction, particularly when it comes to proposing and investigating therapeutic targets. We therefore propose that progress can be made in advancing therapeutics for HFNEF if it is appreciated that different underlying pathophysiologic mechanisms may be important in different cohorts and if attention expands beyond diastolic dysfunction as the sole target. Similar to the success that was achieved in advancing therapeutics for systolic heart failure when attention shifted away from the heart to the neurohormonal and renal axes, our interpretation of data in human beings and in animal models suggests that addressing similar targets (perhaps not in exactly the same manner) may prove to be fruitful, at least for some patients with HFNEF as well.
Uncertainty Quantification in Fission Cross Section Measurements at LANSCE

Neutron-induced fission cross sections have been measured for several isotopes of uranium and plutonium at the Los Alamos Neutron Science Center (LANSCE) over a wide range of incident neutron energies. The total uncertainties in these measurements are in the range 3–5% above 100 keV of incident neutron energy, which results from uncertainties in the target, neutron source, and detector system. The individual sources of uncertainties are assumed to be uncorrelated, however correlation in the cross section across neutron energy bins are considered. The quantification of the uncertainty contributions will be described here.
ERK and AKT signaling cooperate to translationally regulate survivin expression for metastatic progression of colorectal cancer

The mitogen-activated extracellular signal-regulated kinase/extracellular signal-regulated kinase (MEK/ERK) and phosphatidylinositol 3-kinase (PI3K)/AKT pathways are often concurrently activated by separate genetic alterations in colorectal cancer (CRC), which is associated with CRC progression and poor survival. However, how activating both pathways is required for CRC metastatic progression remains unclear. Our recent study showed that both ERK and AKT signaling are required to activate eukaryotic translation initiation factor 4E (eIF4E)-initiated cap-dependent translation via convergent regulation of the translational repressor 4E-binding protein 1 (4E-BP1) for maintaining CRC transformation. Here, we identified that the activation of cap-dependent translation by cooperative ERK and AKT signaling is critical for promotion of CRC motility and metastasis. In CRC cells with coexistent mutational activation of ERK and AKT pathways, inhibition of either MEK or AKT alone showed limited activity in inhibiting cell migration and invasion, but combined inhibition resulted in profound effects. Genetic blockade of the translation initiation complex by eIF4E knockdown or expression of a dominant active 4E-BP1 mutant effectively inhibited migration, invasion and metastasis of CRC cells, whereas overexpression of eIF4E or knockdown of 4E-BP1 had the opposite effect and markedly reduced their dependence on ERK and AKT signaling for cell motility. Mechanistically, we found that these effects were largely dependent on the increase in mammalian target of rapamycin complex 1 (mTORC1)-mediated survivin translation by ERK and AKT signaling. Despite the modest effect of survivin knockdown on tumor growth, reduction of the translationally regulated survivin profoundly inhibited motility and metastasis of CRC. These findings reveal a critical mechanism underlying the translational regulation of CRC metastatic progression, and suggest that targeting cap-dependent translation may provide a promising treatment strategy for advanced CRC.
Mass spectrometric studies of solid surfaces

Summary A mass spectrometer has been used to identify the secondary particles emitted from solid surfaces during bombardment with rare gas ions of moderate energy. The targets studied include semi-conductors and insulators, such as ethyl-covered germanium, coal, silicon carbide, graphite and diamond. Elements with low ionization potentials produce mainly positively charged atoms and molecules, elements with high electron affinities yield mostly negative ions. Adsorbed gases and radicals are mainly desorbed as neutral particles, while neutrals characteristic of the matrix are hard to detect. The complex negative ion patterns obtained from carbon-containing surfaces will be discussed in detail.
The Native Oxide Effects on the Optical Properties of TbFe2

The native oxide effects on the optical properties of a polycrystalline TbFe 2 were studied using spectroscopic ellipsometry and the grazing-incident X-ray reflectivity technique. The spectra of the dielectric functions for the TbFe 2 sample exposed to air at room temperature were measured, as the sample was oxidized. The spectra of the reflectance, optical conductivity, and skin depth were obtained in a 12 h interval. As the thickness of the oxide layer gets larger, the magnitude of the optical conductivity decreases. The thickness of the native oxide layer for the fully oxidized surface was estimated using an X-ray reflectivity measurement.
Effect of changing data collection parameters on statistical motor unit number estimates

The effect of number of samples and selection of data for analysis on the calculation of surface motor unit potential (SMUP) size in the statistical method of motor unit number estimates (MUNE) was determined in 10 normal subjects and 10 with amyotrophic lateral sclerosis (ALS). We recorded 500 sequential compound muscle action potentials (CMAPs) at three different stable stimulus intensities (10–50% of maximal CMAP). Estimated mean SMUP sizes were calculated using Poisson statistical assumptions from the variance of 500 sequential CMAP obtained at each stimulus intensity. The results with the 500 data points were compared with smaller subsets from the same data set. The results using a range of 50–80% of the 500 data points were compared with the full 500. The effect of restricting analysis to data between 5–20% of the CMAP and to standard deviation limits was also assessed. No differences in mean SMUP size were found with stimulus intensity or use of different ranges of data. Consistency was improved with a greater sample number. Data within 5% of CMAP size gave both increased consistency and reduced mean SMUP size in many subjects, but excluded valid responses present at that stimulus intensity. These changes were more prominent in ALS patients in whom the presence of isolated SMUP responses was a striking difference from normal subjects. Noise, spurious data, and large SMUP limited the Poisson assumptions. When these factors are considered, consistent statistical MUNE can be calculated from a continuous sequence of data points. A 2 to 2.5 SD or 10% window are reasonable methods of limiting data for analysis. Muscle Nerve 27: 320–331, 2003
Validation of target volume and position in respiratory gated CT planning and treatment

The capability of a commercial respiratory gating system based on video tracking of reflective markers to reduce motion-induced CT planning and treatment errors was evaluated. Spherical plastic shells (2.8–82 cm3), simulating the gross target volume (GTV), were placed in a water-filled body phantom that was moved sinusoidally along the longitudinal axis of the CTscanner and the accelerator for ±1 cm at 15–30 cycle/min. During gated CTimaging, the x-ray exposure was initiated by the gating system shortly before the end of expiration (so that the imaging time would be centered at the end of expiration); it was terminated by the scanner after completion of each slice. In nongated CTimages, the target appeared distorted and often broken up. GTVs volume errors ranged 16%–110% in axial scans, and 7%–36% in spiral scans. In gated CTimages, the spheres appeared 3 and 5 mm longer than their actual diameters (volume errors 2%–16%), at the respective respiration rates of 15 and 20 cycles/min. At 30 cycles/min the target appeared 1 cm longer, and volume error ranged 25%–53%. During treatment, gating kept the beam on for a duration equal to the CT acquisition time of 1 s/slice. The difference in positional errors between gated CT and portal films was 1 mm, regardless the size of residual motion errors. Because of the potential of suboptimal placement of the gating window between CTimaging and treatment, an extra 1.5–2.5 mm safety margin can be added regardless of the size of residual motion error. For respiratory rates ⩾30 cycles/min, the effectiveness of gating is limited by large residual motion in the 1 s CT acquisition time.
Ribozyme gene therapy for HIV infection Intracellular immunization of lymphocytes and CD34+ cells with an anti-HIV-1 ribozyme gene

Abstract The ultimate goal of gene therapy for HIV infection is to repopulate the immune system with genetically altered cells that would resist infection. We previously reported that a hairpin ribozyme that cleaves HIV-1 RNA in U5 suppressed the replication of diverse strains of HIV-1, including clinical isolates, in human at-cell lines and primary T-cells. Transduction of CD34+ cells enriched from cord blood of normal or HIV-infected donors also yielded stable ribozyme expression and no apparent effect on phenotype or proliferation of the transduced cells. Furthermore, the macrophages progeny cells were resistant to HIV infection. Currently, to minimize the chance of viral resistance as well as to increase anti-viral potency, we developed vectors expressing two ribozymes or a fusion RRE-ribozyme gene. The fusion molecule displayed both a decoy and enhanced ribozyme activity. A phase I clinical protocol to test the safety and function of a double ribozyme vector in ex vivo transduced human PBL has been approved by the NIH RAC, and a second trial for autologous reinfusion of gene altered CD34+ cells derived from cord blood for HIV infected newborns is planned.
Resistance to cadmium-induced hepatotoxicity in immature rats.

Abstract Because the concentration of metallothionein (MT) in perinatal rat liver is 10 to 20 times higher than levels present in liver of untreated adult rats, it was of interest to determine if immature rats are less susceptible to the hepatotoxic effects of cadmium (Cd) seen in adults. Male Sprague-Dawley adult rats received a hepatotoxic dose of 4.0 mg Cd/kg, iv, and 10-day-old rats received 4.0, 5.0,or 6.0 mg Cd/kg, iv. Ten hours following Cd injection, plasma enzyme activities in adults were elevated (aspartate aminotransferase, 50-fold; sorbitol dehydrogenase, 87-fold) and histologic examination showed extensive hepatic injury; however, no damage was evident in 10-day-old rats, even at the 6 mg Cd/kg dose. Two hours after injection of 3.5 mg Cd/kg, iv (7 μCi 109 Cd/mg Cd), the concentration of Cd was higher in liver, heart, and brain and lower in kidneys of 10-day-old rats compared to adults. An age comparison of the hepatic subcellular distribution of Cd revealed a higher amount of Cd in cytosol and less in the particulate fraction of 10-day-old rats. Furthermore, cytosolic Cd was predominantly bound to MT. These data support the hypothesis that presynthesized levels of MT are important in producing tolerance to acute Cd toxicity and that tolerance results from an altered hepatic subcellular distribution of Cd.
Multi-task classification with infinite local experts

We propose a multi-task learning (MTL) framework for non-linear classification, based on an infinite set of local experts in feature space. The usage of local experts enables sharing at the expert-level, encouraging the borrowing of information even if tasks are similar only in subregions of feature space. A kernel stick-breaking process (KSBP) prior is imposed on the underlying distribution of class labels, so that the number of experts is inferred in the posterior and thus model selection issues are avoided. The MTL is implemented by imposing a Dirichlet process (DP) prior on a layer above the task-dependent KSBPs.
Mutagenesis Is Elevated in Male Germ Cells Obtained from DNA Polymerase-beta Heterozygous Mice

Gametes carry the DNA that will direct the development of the next generation. By compromising genetic integrity, DNA damage and mutagenesis threaten the ability of gametes to fulfill their biological function. DNA repair pathways function in germ cells and serve to ameliorate much DNA damage and prevent mutagenesis. High base excision repair (BER) activity is documented for spermatogenic cells. DNA polymerase-beta (POLB) is required for the short-patch BER pathway. Because mice homozygous null for the Polb gene die soon after birth, mice heterozygous for Polb were used to examine the extent to which POLB contributes to maintaining spermatogenic genomic integrity in vivo. POLB protein levels were reduced only in mixed spermatogenic cells. In vitro short-patch BER activity assays revealed that spermatogenic cell nuclear extracts obtained from Polb heterozygous mice had one third the BER activity of age-matched control mice. Polb heterozygosity had no effect on the BER activities of somatic tissues tested. The Polb heterozygous mouse line was crossed with the lacI transgenic Big Blue mouse line to assess mutant frequency. The spontaneous mutant frequency for mixed spermatogenic cells prepared from Polb heterozygous mice was 2-fold greater than that of wild-type controls, but no significant effect was found among the somatic tissues tested. These results demonstrate that normal POLB abundance is necessary for normal BER activity, which is critical in maintaining a low germline mutant frequency. Notably, spermatogenic cells respond differently than somatic cells to Polb haploinsufficiency..
Distortion-product emissions in rabbit. I: Altered susceptibility to repeated pure-tone exposures

An important issue in understanding the development of noise-induced hearing loss is whether prior acoustic overstimulation alters the susceptibility of the cochlea to further damage. The present work was designed to establish a model of activity-dependent changes in the susceptibility of the cochlea to acoustic overstimulation by regularly exposing the ear to a low-frequency pure tone. As a quantitative index of cochlear function, 2f1-f2 distortion-product otoacoustic emissions (DPOAEs) were monitored systematically over time in three groups of rabbits, with each group experiencing a unique paradigm that incorporated repeated exposure to the low-frequency tone. Common to each rabbit's exposure protocol was that a given experimental session consisted of two exposure episodes, separated by a 40-min period. Experimental sessions were repeated three times, with 2- to 3-day recovery periods interposed between sessions. The rate of decrement in DPOAE amplitude over a prescribed time period was utilized as a measure of susceptibility to the acoustic trauma. The overall results indicated that ears were more susceptible to exposure 40 mins after the first exposure of a session than they were initially. A series of control experiments indicated that the robustness of the acoustic middle-ear reflex (AMR) did not change between the exposure episodes. Consequently, changes in the AMR could not account for the increased susceptibility seen following the first exposure. However, in awake rabbits with stronger AMRs, higher pure-tone exposure levels were needed to produce increased susceptibility to the second exposure. After 2-3 days of intersession recovery, susceptibility to the effects of excessive sound returned close to its original baseline level. The outcome of these studies demonstrated a reduced capacity for the ear to resist the harmful effects of exposure to a moderately intense tone, which was repeated twice over a brief 40-min period, but little change in susceptibility when identical exposures were repeated over longer intersession intervals of several days.
On the equivalence of single machine earliness/tardiness problems with job rejection

We consider the single-machine maximum earliness problem with rejection.We present an O(nlogn) algorithm for the problem.We consider the single-machine total earliness problem with rejection.We present a pseudo-polynomial time algorithm for the problem. We present optimal algorithms for single-machine scheduling problems with earliness criteria and job rejection and compare them with the algorithms for the corresponding problems with tardiness objectives. We present an optimal O(nlogn) algorithm for minimizing the maximum earliness on a single machine with job rejection. Our algorithm also solves the bi-criteria scheduling problem is which the objective is to simultaneously minimize the maximum earliness of the scheduled jobs and the total rejection cost of the rejected jobs. We also show that the optimal pseudo-polynomial time algorithm for the total tardiness problem with job rejection can be used to solve the corresponding total earliness problem with job rejection.
The 2002 Midterm Election: A Typical or an Atypical Midterm?

I t had been an inevitability rivaling death and taxes. The president’s party would lose seats in the U.S. House of Representatives in almost every midterm election. The president’s party had lost House seats in 32 of the 33 midterms from 1866 to 1994. The sole exception was a gain of nine seats for Democrats in the 1934 midterm election during FDR’s first term and in the throes of the New Deal realignment. Then came the 1998 and the 2002 midterms. With a strong economy and the pending impeachment vote against President Clinton, Democrats gained four seats in 1998. This past November, in the aftermath of the 9/11 terrorism and with a president with strong approval ratings, Republicans also broke from the traditional pattern of in-party midterm losses and gained five seats in the House and two in the Senate, regaining their control of the Senate that they had lost when Vermont Senator Jim Jeffords renounced his Republican affiliation in 2001. The results of the 2002 midterm raise a number of questions. To what extent was the midterm (and the 1998 midterm) an aberration? Why were Republicans as the in-party able to gain seats? What explains 2002 and what might the 2002 (and the 1998) results indicate about various theories of inter-election seat change?
High power GaN oscillators using field-plated HEMT structure

5 GHz MMIC GaN oscillators based on AlGaN/GaN HEMTs are presented. The use of field-plated HEMT structures in these oscillators resulted in increased output power and dc-to-RF efficiency. An oscillator using an AlGaN/GaN HEMT with 0.5 mm gate width and 1.1 /spl mu/m field-plate extension, biased at V/sub ds/ = 40 V and V/sub gs/ = -4.5 V, delivers 1.9 W of output power with a dc-to-RF efficiency of 21.5%. Phase noise was measured to be -132 dBc/Hz at a 1 MHz offset frequency. The oscillator output power density was found to be 3.8 W/mm and is the highest yet reported. Studies of the output power, dc-to-RF efficiency, and phase noise with different field-plate extensions are also presented.
Joint Hypermobility and Headache: Understanding the Glue That Binds the Two Together – Part 1

Background Heritable connective tissue disorders (HCTD) present with a wide array of findings, including headache. Because of their unusual substrate, headaches in HCTD can derive from both common and uncommon circumstances. Methods Literature review. Results Ehlers–Danlos hypermobile type can be recognized by multiple joint findings and its tendency to progress to a multisystem chronic pain syndrome. Ehlers–Danlos classic type also manifests joint laxity and similar pain complaints, but is differentiated by its skin laxity and fragility. Ehlers–Danlos vascular type presents the most severe risk due to blood vessel and hollow organ rupture. Marfan syndrome demonstrates skeletal abnormalities, lens dislocations, and aortic root dilation that can result in dissection. Conclusions In a headache patient, recognizing the presence of an HCTD improves the strategy for diagnosis and management. A brief review of findings related to joints, skin, and arteries may prompt further investigation into the HCTDs.
Brief report: difficulty in understanding social acting (but not false beliefs) mediates the link between autistic traits and ingroup relationships.

Why do individuals with more autistic traits experience social difficulties? Here we examined the hypothesis that these difficulties stem in part from a challenge in understanding social acting, the prosocial pretense that adults routinely produce to maintain positive relationships with their ingroup. In Study 1, we developed a self-administered test of social-acting understanding: participants read stories in which a character engaged in social acting and rated the appropriateness of the character’s response. Adults who scored 26 or higher on the Autism Spectrum Quotient (AQ) questionnaire gave significantly lower ratings than comparison participants (AQ < 26). Study 2 found that difficulty in understanding social acting, but not false beliefs, mediated the link between autistic traits and perceived ingroup relationships.
5-Thio-d-Glucose Elevates Renal Transforming Growth Factor β-1 at a Dose that Does Not Prevent Streptozocin Diabetes in Rats1

Studies of early nephropathy in streptozocin (STZ)-treated rats are complicated by the nephrotoxicity of this agent. Inhibitors of the diabetogenic actions of STZ have been described, but their effects on the kidney have not been assessed. This study examined the effects of one agent, 5-thio-d-glucose (5TG) on renal hypertrophy and transforming growth factor β 1 (TGF-β1). Forty male Sprague Dawley rats were divided into four groups: saline controls (SC), 5TG alone, 5TG + STZ, and STZ. After 2 weeks of observation, urine, plasma, and kidneys were studied. Nine of 10 STZ rats were diabetic at the time of euthanasia, as were 5 of 10 5TG + STZ animals. Both tissue levels of messenger RNA and protein for active and total TGF-β1 were elevated in STZ and 5TG-STZ animals compared with SC. 5TG also elevated mRNA and produced protein levels intermediate to the other groups. 5TG plus STZ is an unacceptable control for nephropathy studies in STZ diabetes, both because of lack of efficacy at the dose studied and the i...
Nationalism and Pluralism and the Process of Political Development in Eastern Europe

This paper examines the interaction of nationalism, pluralism and political development in six countries of Eastern Europe from the end of World War II up to the 1980s. To make the analysis more manageable, nationalism is conceptualized as national political culture and pluralism is identified by the presence of interest groups. Both these concepts, of course, play a major role in the process of all political development. The paper's main question concerns the ability of the countries under discussion to weather the developmental crises that have descended upon the region in the current decade.Of the six East European countries examined, only Hungary has succeeded reasonably well in its task of crisis management. Furthermore, it is both the national political cultures and the groups in the respective countries examined that have been largely responsible for the varying degrees of political development. Finally, on the strength of the experience in the 1980s, it is assumed that both these factors will play...
Activin-attenuated expression of transcripts encoding granulosa cell-derived insulin-like growth factor binding proteins 4 and 5 in the rat: a putative antiatretic effect.

Given the suggestion that intraovarian insulin-like growth factor (IGF)-binding proteins (IGFBPs) may constitute markers of follicular atresia, we investigated the possibility that activin, a putative antiatretic principle, may modulate granulosa cell-derived IGFBPs. Untreated granulosa cells cultured for 72 h exhibited a progressive increase in the steady-state levels of transcripts corresponding to IGFBP-4 and IGFBP-5 (1.5-fold and 12-fold, respectively). Transcript levels corresponding to IGFBP-5 were consistently higher than their IGFBP-4 counterparts. Treatment with activin-A (50 ng/ml) for 72 h produced significant (p IGFBP-4). Activin-B was as effective as activin-A in reducing IGFBP-4 transcripts (31% decrement, p 0.1). No apparent effect was observed for the corresponding proteins. Activin-A action was specific in that treatment with transforming growth factor (TGF)-β 1 , inhibin-A, or Mullerian-inhibiting substance (MIS)-all related peptides-failed to produce statistically significant alterations in the steady-state levels of IGFBP-4 and IGFBP-5 transcripts. Taken together, these observations reveal that activin-A exerts a substantial, relatively rapid, follistatin-neutralizable, dose- and time-dependent inhibitory effect on granulosa cell-derived IGFBP transcripts (IGFBP-5 > IGFBP-4). Other members of the TGFβ superfamily (e.g., inhibin-A, TGFβ 1 , and MIS) were without significant effect on the expression of IGFBP-4 and IGFBP-5. To the extent that the inhibition of IGFBP-4 and IGFBP-5 expression is associated with, and possibly causally related to, the promotion of follicular health, the present observations are in keeping with the proposition that activin may play an antiatretic role in the dynamic process of follicular selection.
A High Performance Totally Ordered Multicast Protocol

This paper presents the Reliable Multicast Protocol (RMP). RMP provides a totally ordered, reliable, atomic multicast service on top of an unreliable multicast datagram service such as IP Multicasting. RMP is fully and symmetrically distributed so that no site bears an undue portion of the communication load. RMP provides a wide range of guarantees, from unreliable delivery to totally ordered delivery, to K-resilient, majority resilient, and totally resilient atomic delivery. These QoS guarantees may be selected on a per packet basis. RMP provides many communication options, including virtual synchrony, a publisher/subscriber model of message delivery, a client/server model of delivery, an implicit naming service, mutually exclusive handlers for messages, and mutually exclusive locks.
Dynamic Interactions between Pit-1 and C/EBPα in the Pituitary Cell Nucleus

The homeodomain (HD) transcription factors are a structurally conserved family of proteins that, through networks of interactions with other nuclear proteins, control patterns of gene expression during development. For example, the network interactions of the pituitary-specific HD protein Pit-1 control the development of anterior pituitary cells and regulate the expression of the hormone products in the adult cells. Inactivating mutations in Pit-1 disrupt these processes, giving rise to the syndrome of combined pituitary hormone deficiency. Pit-1 interacts with CCAAT/enhancer-binding protein alpha (C/EBPalpha) to regulate prolactin transcription. Here, we used the combination of biochemical analysis and live-cell microscopy to show that two different point mutations in Pit-1, which disrupted distinct activities, affected the dynamic interactions between Pit-1 and C/EBPalpha in different ways. The results showed that the first alpha-helix of the POU-S domain is critical for the assembly of Pit-1 with C/EBPalpha, and they showed that DNA-binding activity conferred by the HD is critical for the final intranuclear positioning of the metastable complex. This likely reflects more general mechanisms that govern cell-type-specific transcriptional control, and the results from the analysis of the point mutations could indicate an important link between the mislocalization of transcriptional complexes and disease processes.