cssi/SciSciGPT-SciSciNet huggingface dataset:
Comparison of Simulated and Experimentally Determined Dynamics for a Variant of the LacI DNA-Binding Domain, Nlac-P

Abstract Recent advances in the experimentally determined structures and dynamics of the domains within LacI provide a rare context for evaluating dynamics calculations. A 1500-ps trajectory was simulated for a variant of the LacI DNA-binding domain, which consists of the first three helices in LacI and the hinge helix of the homologous PurR. Order parameters derived from dynamics simulations are compared to those obtained for the LacI DNA-binding domain with 15 N relaxation NMR spectroscopy (Slijper et al., 1997. Biochemistry . 36:249–254). The MD simulations suggest that the unstructured loop between helices II and III does not exist in a discrete state under the conditions of no salt and neutral pH, but occupies a continuum of states between the DNA-bound and free structures. Simulations also indicate that the unstructured region between helix III and the hinge helix is very mobile, rendering motions of the hinge helix essentially independent of the rest of the protein. Finally, the α -helical hydrogen bonds in the hinge helix are broken after 1250ps, perhaps as a prelude to helix unfolding.
Receptor-Associated Protein (RAP) Plays a Central Role in Modulating Aβ Deposition in APP/PS1 Transgenic Mice

Background Receptor associated protein (RAP) functions in the endoplasmic reticulum (ER) to assist in the maturation of several membrane receptor proteins, including low density lipoprotein receptor-related protein (LRP) and lipoprotein receptor 11 (SorLA/LR11). Previous studies in cell and mouse model systems have demonstrated that these proteins play roles in the metabolism of the amyloid precursor protein (APP), including processes involved in the generation, catabolism and deposition of β-amyloid (Aβ) peptides. Methodology/Principal Findings Mice transgenic for mutant APPswe and mutant presenilin 1 (PS1dE9) were mated to mice with homozygous deletion of RAP. Unexpectedly, mice that were homozygous null for RAP and transgenic for APPswe/PS1dE9 showed high post-natal mortality, necessitating a shift in focus to examine the levels of amyloid deposition in APPswe/PS1dE9 that were hemizygous null for RAP. Immunoblot analysis confirmed 50% reductions in the levels of RAP with modest reductions in the levels of proteins dependent upon RAP for maturation [LRP trend towards a 20% reduction ; SorLA/LR11 statistically significant 15% reduction (p<0.05)]. Changes in the levels of these proteins in the brains of [APPswe/PS1dE9](+/−)/RAP(+/−) mice correlated with 30–40% increases in amyloid deposition by 9 months of age. Conclusions/Significance Partial reductions in the ER chaperone RAP enhance amyloid deposition in the APPswe/PS1dE9 model of Alzheimer amyloidosis. Partial reductions in RAP also affect the maturation of LRP and SorLA/LR11, which are each involved in several different aspects of APP processing and Aβ catabolism. Together, these findings suggest a central role for RAP in Alzheimer amyloidogenesis.
Signal transformation and coding in neural systems

The issue of signal transformation and coding by neural units (neurons) is studied using nonparametric nonlinear dynamic models. These models are variants of the general Wiener-Bose model, adapted to this problem in order to represent the nonlinear dynamics of neural signal transformation using a set of parallel filters (neuron modes) followed by a binary operator with multiple real-valued operands (equal in number to the number of modes). The postulated model constitutes a reasonable compromise between mathematical complexity and current neurophysiological evidence. It incorporates nonlinear dynamics and spike generation mechanisms in a fairly general, yet parsimonious manner. Although this study has objectives limited to a single unit, it is hoped that it will facilitate progress in the systematic study of the functional organization of neural systems with multiple units. >
Wide steering angle optical phased array based on silicon nano-membrane

We present a new approach to wide angle optical beam steering based on nano-membrane-based phased array structures with unequally spaced elements. In our approach, the array elements are positioned in such way that grating lobes associated with different sub-arrays do not overlap. Therefore, we reduce the side-lobe-level of the array radiation pattern and at the same time we can avoid the optical coupling between adjacent waveguides by relaxing the half-wavelength spacing requirement for large angle beam steering. By optimizing the optical waveguide structure for the maximum full-width at half-maximum of the single radiator's radiation pattern we discuss the optimum performance achievable using the Unequally-spaced Waveguide Arrays.
Percolation threshold for electronic conduction in β-alumina type compounds: II

Abstract The possibility of making β-alumina compounds mixed conducting by the addition of a certain amount of mixed valent ions has been examined from a theoretical point of view using the cluster variation method (CVM). Electronic conductivity in these substances is assumed to be due to the hopping of small polarons to the nearest neighboring ions on the octahedral sites in the spinel block of β-alumina in a manner similar to that in magnetite. The pair approximation of the cluster variation method indicates the composition of the mixed valent ions necessary to induce the electronic conductivity should be at least 0.24 of the number of octahedral sites. In this paper, we report the results of a higher order approximation of the CVM, namely the triangle+tetrahedron approximation. Our results indicate that a more accurate calculation increases this number to 0.396 thereby indicating that an extremely high level of doping would be necessary to render these compounds mixed conducting.
Vortices and quark confinement in non-abelian gauge theories

Abstract It is shown that finite-length vortices in an SU(n) Nielsen-Olesen model require explicit introduction of monopoles, which are confined in multiples of n by the Meissner effect. The model therefore possesses a natural explanation of quark confinement.
Effects of cation charge-site identity and position on electron-transfer dissociation of polypeptide cations.

The effect of cation charge site on gas-phase ion/ion reactions between multiply protonated model peptides and singly charged anions has been examined. Insights are drawn from the quantitative examination of the product partitioning into competing channels, such as proton transfer (PT) versus electron transfer (ET), electron transfer followed by dissociation (ETD) versus electron transfer without dissociation (ET, no D), and fragmentation of backbone bonds versus fragmentation of side chains. Peptide cations containing protonated lysine, arginine, and histidine showed similar degrees of electron transfer, which were much higher than the peptide having fixed-charge sites, that is, trimethyl ammonium groups. Among the four types of cation charge sites, protonated histidine showed the highest degree of ET, no D, while no apparent intact electron-transfer products were observed for peptides with protonated lysine or arginine. All cation types showed side chain losses with arginine yielding the greatest fracti...
A constitutive model for plastically anisotropic solids with non-spherical voids

Abstract Plastic constitutive relations are derived for a class of anisotropic porous materials consisting of coaxial spheroidal voids, arbitrarily oriented relative to the embedding orthotropic matrix. The derivations are based on nonlinear homogenization, limit analysis and micromechanics. A variational principle is formulated for the yield criterion of the effective medium and specialized to a spheroidal representative volume element containing a confocal spheroidal void and subjected to uniform boundary deformation. To obtain closed form equations for the effective yield locus, approximations are introduced in the limit-analysis based on a restricted set of admissible microscopic velocity fields. Evolution laws are also derived for the microstructure, defined in terms of void volume fraction, aspect ratio and orientation, using material incompressibility and Eshelby-like concentration tensors. The new yield criterion is an extension of the well known isotropic Gurson model. It also extends previous analyses of uncoupled effects of void shape and material anisotropy on the effective plastic behavior of solids containing voids. Preliminary comparisons with finite element calculations of voided cells show that the model captures non-trivial effects of anisotropy heretofore not picked up by void growth models.
Vitamin E supplement use and the incidence of cardiovascular disease and all-cause mortality in the Framingham Heart Study: Does the underlying health status play a role?

Background Observational studies generally showed beneficial associations between supplemental vitamin E intake and cardiovascular disease (CVD) risk whereas intervention trials reported adverse effects of vitamin E supplements. We hypothesize that these discordant findings result from differing underlying health status of study participants in observational and intervention studies.
WORD: Hip-Hop, Language, and Indigeneity in the Americas

Indigenous hip-hop artists throughout the Americas are currently challenging cultural genocide and contemporary post-racial discourse by utilizing ancestral languages in hip-hop cultural production. While the effects of settler colonialism and white supremacy have been far-reaching genocidal projects throughout the Americas, one primary site of resistance has been language. Artists such as Tall Paul (Leech Lake Band of Ojibwe), Tolteka (Mexica), and Los Nin (Quecha), who rap in Ojibwe, Nahuatl, and Kichwa respectively, trouble the pervasive structure of U.S. cultural imperialism that persists throughout the Americas. As a result, Indigenous hip-hop is a medium to engage the process of decolonization by 1) disseminating a conscious pan-indigeneity through lyricism and alliance building, 2) retaining and teaching Indigenous languages in their songs, and 3) implementing a radical orality in their verses that revitalizes both Indigenous oral traditions/storytelling and the early message rap of the 1970s and 1...
The Myocardial Depressant Effect of Beta-Receptor Blocking Agents

dl -Propranolol, d -propranolol, and practolol were administered in increasing doses to conscious dogs before and after acute coronary artery occlusion. dl -Propranolol and practolol caused dose-dependent decreases in cardiac output, stroke volume, stroke work, and maximum rate of left ventricular pressure rise before and after coronary artery occlusion. These parameters were reduced 25-40% after the largest cumulative doses--1.43 mg/kg for dl -propranolol and 52 mg/kg for practolol--were administered. The degree of beta-receptor blockade increased in proportion to the logarithm of plasma drug concentration. After occlusion, both drugs produced identical decreases in cardiac output at equivalent degrees of beta-receptor blockade. Neither drug affected resting heart rate before infarction, and neither drug reduced the tachycardia induced by coronary artery occlusion; this tachycrotic response probably resulted from cardiac vagal withdrawal. Mean systemic arterial blood pressure and total peripheral vascular resistance increased following beta-receptor blockade before infarction, most likely because of increased peripheral vascular alpha-adrenergic activity. These two effects did not occur after coronary artery occlusion, probably because vascular alpha-adrenergic activity had already been stimulated. d -Propranolol produced none of these effects. We concluded that the cardiodepressant effect of beta-receptor blocking agents in the doses administered was caused by their inhibition of endogenous sympathetic tone to the heart rather than by their quinidinelike action.
Effect of microstructural heterogeneity on the mechanical behavior of nanocrystalline metal films

Conventionally, mean grain size is considered the most critical microstructural parameter in determining the mechanical behavior of pure metals. By systematically controlling the distribution of grain orientations in aluminum films, we show that microstructural heterogeneity alone induces large variation in the mechanical behavior of nanocrystalline metal films. Aluminum films with relatively homogeneous microstructure (all grains with identical out-of-plane orientation) show substantially less early Bauschinger effect compared to films with heterogeneous microstructure, irrespective of film thickness or grain size. On the other hand, the films with homogeneous microstructure show relatively higher yield stresses. A direct correspondence is found between the nonuniformity of plastic deformation and early Bauschinger effect, which confirms the critical role of microstructural heterogeneity.
The effect of surface heterogeneity on pseudo-line tension and the flotation limit of fine particles

Abstract The contact angles θ for water at methylated quartz surfaces were measured using the sessile-drop technique to determine the advancing contact angle, and using a captive-bubble technique to examine the effect of bubble size on contact angle. No linearity between cos θ and 1 r where r is the drop base radius, was observed for these systems as would be expected for an ideal system. In fact the pseudo-line tension decreased with decreasing bubble size. Also, the degree of quartz methylation effected a change in the pseudo-line tension. The pseudo-line tension increased from 0.4·10−6 N to 3.3·10−6 N with an increase in the fractional coverage of trimethylsilyl groups from 0.14 to 0.51 for large bubbles (bubble base diameter d > 0.34 mm), whereas the pseudo-line tension decreased from 2.2·10−7 N to 0.8·10−7 N with an increase in fractional coverage for small bubbles (bubble base diameter d = 0.06–0.2 mm). The flotation limit of fine particles has been re-examined based on the effect of bubble size on contact angle, and a new surface chemistry-limited relationship describing the minimum particle size which can be floated is proposed: where rc is the critical bubble (drop) radius for which there is no effective attachment between solid surface and dispersed phase, 7LV is the interfacial tension at the liquid-vapor interface, Δp is the density difference between the particle and the liquid and V is the bubble ascent velocity.
A simplified SO(6,2) model of SU(3)

A new realization is obtained of the representation of so(6,2) which has been shown recently by Flath and Biedenharn, and also by Bracken and MacGibbon, to define a model of SU(3). In contrast to the realization in terms of six pairs of boson operators used previously, which involved cubic expressions, the new realization involves only quadratic expressions in eight pairs of boson operators, and is manifestly hermitian. Properties of this new “oscillator realization”, and in particular its advantages over the old realization, are discussed briefly. It is deduced that the representation of so(6,2) is integrable to a unitary group representation.
Tourist shoppers' satisfaction with regional shopping mall experiences

Purpose – The purpose of this paper is to assess whether tourist shopper segments are an attractive market for shopping centers. This research aims to explore whether or not tourist shoppers are more satisfied than resident shoppers with their shopping experience and whether tourist shoppers have the intention to spend more than their resident shopper counterparts.Design/methodology/approach – Data for this report come from personal face‐to‐face mall intercepts of shoppers (n=578) in two new generation malls (West Edmonton Mall and Mall of America in Bloomington) and two heritage‐destination (Pier 39 in San Francisco and Forum Shops in Las Vegas) centers.Findings – Analysis concludes that although the shopping center and retail industry place increasing emphasis on leisure shopping and tourism, the results of this study suggest that the tourist shopper market may not be the most valuable customer group. Resident shoppers of tourist‐focused shopping centers are more satisfied than tourist shoppers of those...
Electrical characterization of thin Al2O3 films grown by atomic layer deposition on silicon and various metal substrates

Abstract Al2O3 films with thicknesses ranging from 30 to 3540 A were grown in a viscous flow reactor using atomic layer deposition (ALD) with trimethylaluminum and water as the reactants. Growth temperatures ranged from 125 to 425 °C. The Al2O3 ALD films were deposited successfully on a variety of substrates including Au, Co, Cr, Cu, Mo, Ni, NiFe, NiMn, Pt, PtMn, Si, stainless steel, W, and ZnO. Electrical properties were characterized by current–voltage and capacitance–voltage measurements using a mercury probe. These measurements focused mainly on Al2O3 ALD films deposited on n-type Si(1 0 0) and on Mo-coated Si(1 0 0) substrates. Excellent insulating properties were observed for nearly all of the Al2O3 films. For a typical Al2O3 ALD film with a 120 A thickness, leakage currents of
The effects of modifying color-meaning concepts on racial concept attitudes in five- and eight-year-old children☆

Abstract Williams and Edwards (1969) found that changing the positive and negative evaluations given to color concepts by preschool children through reinforcement procedures over two sessions reduced their racial concept attitude scores measured during a third session. The present study replicated their negative reinforcement and control procedures with 5-year-old children, and extended their research to include 8-year-old children. The present results replicated the original findings and in fact showed a larger change in racial attitude scores. While the color-meaning concepts were modified to a greater extent in the older children, the effect of the negative reinforcement procedure on racial attitude scores was similar for the two age groups.
Damper Seal Comparison in a High-Pressure Re-Injection Centrifugal Compressor During Full-Load, Full-Pressure Factory Testing Using Direct Rotordynamic Stability Measurement

Rotordynamic stability in high-pressure centrifugal compressors is of great concern to both the original equipment manufacturer (OEM) and the end-user, because of the potential for costly downtime should problems occur. To minimize these problems, damper seals have been developed to provide substantial damping to the rotor system. These seals are placed in the process gas at locations where large pressure differentials occur and contain relatively large lengths and diameters. Previous studies demonstrated the improvement provided by damper seals both analytically and with measurement during full-load, full-pressure testing (Moore, et al. [1]). The present study compares the damping and leakage control performance of two seal geometry, a hole pattern seal and a smooth seal. The smooth seal is intended to simulate a hole pattern seal that has “plugged up” because of contaminants in the process gas. The dimensions of the seals are identical in all other aspects. Two tests were performed using an eight-stage, back-to-back re-injection compressor as the test vehicle. The logarithmic decrement and seal leakage rates results are compared for the two seal designs. Analytical predictions are then compared with the measurements. The smooth seal demonstrates damping similar to the hole pattern design, but has a large leakage penalty.Copyright © 2003 by ASME
Synthesis, structure, and spectroscopy of phenylacetylenylene rods incorporating meso-substituted dipyrrin ligands.

The synthesis, structure, and spectroscopic characterization of a series of phenylacetylenylene rodlike molecules containing dipyrromethene (dipyrrin) ligands are described. The combination of the phenylacetylenylene groups with the porphyrinogenic dipyrrin moieties results in a rich absorption spectroscopy for these compounds, although the fluorescence of the phenylacetylenylene moiety is quenched by presence of the dipyrrin chelator. The Cu 2 + and Fe 3 + complexes of these ligands have been prepared and three of these compounds have been structurally characterized by using single-crystal X-ray diffraction. Unlike other octahedral metal-dipyrrin complexes described to date, one of the iron complexes demonstrates ideal threefold symmetry in the solid-state. The elongated structure and high symmetry of these complexes suggests the use of these mesosubstituted phenylacetylenylene ligands as an interesting class of extended, branched molecules for the construction of supramolecular architectures.
FGFR2 intronic SNPs and breast cancer risk: Associations with tumor characteristics and interactions with exogenous exposures and other known breast cancer risk factors

Recent genome-wide association studies have revealed several new candidate genes for breast cancer, including fibroblast growth factor receptor 2 (FGFR2) gene. The associations were also replicated in several other independent studies. The next important step is to study whether these common variants interact with known breast cancer risk factors, exogenous exposures and tumor characteristics. In a population-based case-control study of 1,170 breast cancer cases and 2,115 controls, we examined genetic associations of four intronic FGFR2 single-nucleotide polymorphisms (SNPs) and breast tumor characteristics and assessed the potential interactions with smoking, alcohol consumption, adiposity and known breast cancer risk factors. FGFR2 variants were significantly associated with breast cancer risk regardless of estrogen and progesterone receptor status, metastasis, lymph node involvement and histologic and nuclear grade. The FGFR2-breast cancer association was modified by smoking status, with increased risk for former and current smokers compared to never smokers; former/current smokers carrying two copies of the rs1219648 minor allele were at highest risk with a crude OR (95% confidence interval) of 2.11 (1.52-2.92) compared to never smokers with no rs1219648 variant alleles. Our study found no evidence for either modification of FGFR2 and breast cancer by alcohol intake or adiposity, even when analyses were stratified by menopausal status. Although these results require further replication, they may provide new insight into the possible new exposures that may interact with FGFR2 susceptibility alleles.
The influence of Oort clouds on the mass and chemical balance of the interstellar medium

The contribution of stellar encounters and interstellar erosion to comet cloud mass injection to the ISM is calculated. It is shown that evaporative mass loss from passing stars and SNe results in an average Galactic mass injection rate of up to 10 to the -5th solar mass/yr if such clouds are frequent around solar-type stars. Cometary erosion by interstellar grains produces an injection rate of 10 to the -5th to 10 to the -4th solar mass/yr. An injection rate of 2 x 10 to the -5th solar mass/yr is calculated. Each of these rates could be increased by a factor of about 15 if the comet clouds contain a significant amount of smaller debris. It is concluded that the total mass injection rate of material to the ISM by comet clouds is small compared to other ISM mass injection sources. Comet cloud mass loss to the ISM could be responsible for a sizeable fraction of the metal and dust abundances of the ISM if Oort clouds are common.
MRI of peroneal nerve entrapment due to a ganglion cyst

Ganglion cysts are relatively common entities, but impingement upon the peripheral nerves is rare. We describe a case in which peroneal nerve palsy was caused by a ganglion cyst demonstrated by MRI.
Defective PAPS-synthesis in epiphyseal cartilage from brachymorphic mice.

Abstract Activity levels of sulfotransferases, requisite for the sulfation of chondroitin sulfate proteoglycan, were measured in cell-free homogenates prepared from neonatal epiphyseal cartilage of normal C57B1/6J or homozygous brachymorphic mice. In the presence of [35S]-PAPS only or [35S]-PAPS plus an exogenous sulfate acceptor, comparable amounts of 35 SO 4 2− were incorporated into chondroitin sulfate by the normal and mutant types of cartilage. In contrast, the mutant cartilage catalyzed the conversion of only 30% of the 35 SO 4 2− into chondroitin sulfate as compared to normal mouse cartilage when synthesis was initiated from ATP and H235SO4. These results suggest that the production of an undersulfated proteoglycan which has previously been reported in brachymorphic mice (Orkin, R.W. et al . (1976) Devel. Biol. 50 , 82–94) may result from a defect in the synthesis of the sulfate donor PAPS.
A model kinetic equation for an electron plasma

A kinetic model equation for an electron plasma is proposed. The principal new feature of the equation is an attempt to incorporate collision terms which model both short-range two-body scattering and many-body small-angle scattering. The equation is then used to study the time relaxation of a spatially uniform plasma. A simplified form of the model is finally used to analyse sound propagation in the plasma. Dispersion equations are derived and studied in several limiting cases. Landau damping in the small wave-number limit is shown to be less important than collisional damping for most plasmas.
Genomic analysis of primary tumors does not address the prevalence of metastatic cells in the population.

Genomic analysis of primary tumors does not address the prevalence of metastatic cells in the population
Discovering interesting sub-paths in spatiotemporal datasets: a summary of results

Given a spatiotemporal (ST) dataset and a path in its embedding spatiotemporal framework, the goal is to to identify all interesting sub-paths defined by an interest measure. Sub-path discovery is of fundamental importance for understanding climate changes, agriculture, and many other application. However, this problem is computationally challenging due to the massive volume of data, the varying length of sub-paths and non-monotonicity of interestingness throughout a sub-path. Previous approaches find interesting unit sub-paths (e.g., unit time interval) or interesting points. By contrast, we propose a Sub-path Enumeration and Pruning (SEP) approach that finds collections of long interesting sub-paths. Two case studies using climate change datasets show that SEP can find long interesting sub-paths which represent abrupt climate change. We provide theoretical analyses of correctness, completeness and computational complexity of the proposed approach. We also provide experimental evaluation of two traversal strategies for enumerating and pruning candidate sub-paths.
Insights from comparative analyses of aging in birds and mammals

Many laboratory models used in aging research are inappropriate for understanding senescence in mammals, including humans, because of fundamental differences in life history, maintenance in artificial environments, and selection for early aging and high reproductive rate. Comparative studies of senescence in birds and mammals reveal a broad range in rates of aging among a variety of taxa with similar physiology and patterns of development. These comparisons suggest that senescence is a shared property of all vertebrates with determinate growth, that the rate of senescence has been modified by evolution in response to the potential life span allowed by extrinsic mortality factors, and that most variation among species in the rate of senescence is independent of commonly ascribed causes of aging, such as oxidative damage. Individuals of potentially long-lived species, particularly birds, appear to maintain high condition to near the end of life. Because most individuals in natural populations of such species die of aging-related causes, these populations likely harbor little genetic variation for mechanisms that could extend life further, or these mechanisms are very costly. This, and the apparent evolutionary conservatism in the rate of increase in mortality with age, suggests that variation in the rate of senescence reflects fundamental changes in organism structure, likely associated with the rate of development, rather than physiological or biochemical processes influenced by a few genes. Understanding these evolved differences between long-lived and short-lived organisms would seem to be an essential foundation for designing therapeutic interventions with respect to human aging and longevity.
Ion-pair association of substituted phenolates with K+ in octanol

The speciation, environmental distribution, and ultimate fate of phenolic compounds, a class of hydrophobic ionizable organic compounds, is influenced by both their hydrophobic and electrostatic characteristics. In this study, electrical conductance measurements were employed to characterize the ion-pair association properties of a monovalent inorganic cation (K+) with substituted phenolate anions in the model hydrophobic solvent, 1-octanol. Quantification of such processes is important for characterizing the overall partitioning to and speciation in octanol of phenolic compounds. Data were analyzed and association constants were calculated using a modified form of the Fuoss–Onsager equation for electrical conductivity. Results indicate that the magnitude of ion-pair association correlates with the electron-donating and -withdrawing characteristics of phenolic ring substituents. A quantitative structure–activity relationship was developed correlating ion-pair association constants to the sum of Hammett substituent constants for each species. The data suggest that for some phenolate salts, charged triple ion or higher aggregate formation may occur at elevated concentrations. A qualitative interpretation of this phenomenon and the selectivity of its occurrence are discussed.
The effect of male mating history on paternal investment, fecundity and female remating in the seed beetle Callosobruchus maculatus

1. In many organisms, males provide nutrients to females via ejaculates that can influence female fecundity, longevity and mating behaviour. The effect of male mating history on male ejaculate size, female fecundity, female longevity and female remating behaviour in the seed beetle Callosobruchus maculatus was determined. 2. The quantity of ejaculate passed to females declined dramatically with successive matings. Despite the decline, a male’s ability to fertilize a female fully did not appear to decline substantially until his fourth mating. 3. When females multiply mated with males of a particular mated status, the pattern of egg production was cyclic, with egg production increasing after mating. Females multiply mated to virgins had higher fecundity than females mated to non-virgins, and females mated to twice-mated males had disproportionately increased egg production late in their life. 4. Females that mated to multiple virgins, and consequently laid more eggs, experienced greater mortality than females mated only once or mated to non-virgins, suggesting that egg production is costly, and rather than ameliorating these costs, male ejaculates may increase them by allowing or stimulating females to lay more eggs. 5. Females mating with non-virgin males remated more readily than did females mated to virgins. Females given food supplements were less likely to remate than females that were nutritionally stressed, suggesting that females remate in part to obtain additional nutrients.
An adenine nucleotide-phosphoenolpyruvate counter-transport system in C3 and C4 plant chloroplasts

A rapid counter-exchange between ATP and phosphoenolpyruvate (PEP) has been demonstrated in pea and maize mesophyll chloroplasts. Chloroplasts preloaded with either [14C] ATP or [14C] PEP readily exchange the radioactive compound with the externally added anions, ATP or PEP, whereas, cold external Pj counter-transports only with internal [14C] PEP. Flooding the system with cold Pj, however, will significantly reduce the counter-transport of external cold PEP with internal [14C] ATP. This ATP-PEP exchange is also markedly decreased by lowering the incubation temperature. The results indicate that the ATP-PEP counter-exchange could represent a key transport system in plant chloroplasts and may be particularly important in the photosynthesis of C4 plants. Furthermore, they provide information required to elucidate the mechanism of the ATP-PEP counter-transport system.
Mapping Neural Activation onto Behavior in an Entire Animal

For almost a century, neuroscientists have tried to understand how patterns of neuronal activity generate behavior. Many of the early studies turned to the “simple” systems of invertebrates in the hope of discovering the components of circuits and their connections. A striking finding was the existence of “command neurons” in arthropods and molluscs that produce complex and coordinated movements when stimulated ( 1 , 2 ). The challenge was then to identify the connections between these neurons and other neurons important for those behaviors. This approach was always limited to examining only a few neurons from the tens or hundreds of thousands in the animal ( 3 ). On page 386 of this issue, Vogelstein et al. ( 4 ) usher in a new era of integrated methods for deciphering how an entire nervous system generates behavior.
Dynamic Integration of a Grid Connected DFIG Wind Turbine with a Fuel Cell

This paper proposes a novel integration of a doubly- fed induction generator (DFIG) and a fuel cell. With the proposed scheme, it is possible to inject power from a DC power source like a fuel cell into the AC grid without using an additional inverter. The fuel cell is connected across the DC link of the back-to-back converters of a DFIG injecting power either into the grid or the rotor circuit. This is achieved by a low voltage DC link. Dynamic models of DFIG and PEM fuel cell are derived which are used to simulate the integrated system. Through vector control, active and reactive power generated by the DFIG is controlled. In addition, power factor correction can also be achieved. The complete system was simulated in Matlab/Simulink and an experimental setup was built to validate the proposed scheme. Simulation and experimental results are presented to support the integrated system.
Antecedents of Consumer Attitudes toward Cause-Related Marketing

ABSTRACT Using a nationally representative sample, this study demonstrated the importance of psychographics in profiling cause-related marketing advocates. For specific social causes relating to minorities, public self-consciousness and a sense of personal and social responsibility appeared to be important predictors. For charitable causes, along with the two factors just mentioned, several other psychographic factors including interpersonal trust, religious belief, social networks, external locus of control, and advertising skepticism had positive relationships with consumer attitudes toward cause-related marketing. Previous prosocial activities such as charitable contributions and civic engagement also affected consumer support for corporate cause-marketing efforts. Practical and theoretical implications were discussed.
Assessing the Regional Economic Development Impacts of Universities: A Review of Current Approaches:

Research universities in the United States have increasingly become involved in economic development since the mid-1980s. There has been a corresponding growth of interest in measuring the impacts of higher education on regional economies. This article reviews the approaches used to examine the influence of research universities on regional economic development outcomes. Considerable attention is paid to the methodological advantages and shortcomings of four major research designs evidenced in the literature: single-university impact studies, surveys, knowledge production functions, and cross-sectional and quasiexperimental designs. University activities, particularly knowledge-based activities such as teaching and basic research, have been found to have substantial positive effects on a variety of measures of regional economic progress.
Clinical pharmacology of mephenytoin and ethotoin.

Effective prescribing of anticonvulsants requires foreknowledge of baseline pharmacokinetic data. Little such information is available about the hydantoins other than phenytoin, although one of them, mephenytoin, is widely used. Useful pharmacokinetic data should be derived from patients already exposed to anticonvulsants to reflect the induction of hepatic oxidative enzymes. Single-dose studies of mephenytoin (Mesantoin) and ethotoin (Peganone) were performed in adult inpatients on stable regimens of other anticonvulsants. Five patients received mephenytion, 7 mg per kilogram of body weight. Serial blood sampling was performed rigorously. The time to peak concentration (Tmax) for mephenytoin was 1 hour, with a half-life (T1/2) of 7 hours; the T1/2 of its metabolite, 5-ethyl-5-phenylhydantion, was 96 hours. Ethotoin administration was 25 mg per kilogram in 5 patients. Ethotoin Tmax was 2 hours, with a T1/2 of 5 hours. Saliva accurately represented the unbound fraction for all three agents. Mean salivary levels (as percentage of total levels) were 61% for mephenytoin, 73% for its metabolite, and 54% for ethotoin. The implication for therapy are that following mephenytoin administration, the metabolite 5-ethyl-5-phenylhydantoin will provide anticonvulsant effectiveness, with its long half-life producing stable blood levels on simple dose schedules. Ethotoin, in contrast, has a short half-life and would require divided daily doses to achieve a steady state. This, rather than pharmacological ineffectiveness, limits its usefulness.
A priori L 2 error estimates for finite-element methods for nonlinear diffusion equations with memory

This paper studies finite-element approximations to the solutions of the nonlinear diffusion equations with memory. An elliptic projection with memory associated with our equations is defined and then used in the derivations of optimal error estimates for semidiscrete and Crank–Nicolson finite-element approximations.
Aberrantly Over-Expressed TRPM8 Channels in Pancreatic Adenocarcinoma: Correlation with Tumor Size/Stage and Requirement for Cancer Cells Invasion

The transient receptor potential melastatin-subfamily member 8 (TRPM8) channels control Ca2+ homeostasis. Recent studies indicate that TRPM8 channels are aberrantly expressed and required for cellular proliferation in pancreatic adenocarcinoma. However, the functional significance of TRPM8 in pancreatic tissues is mostly unknown. The objectives of this study are to examine the expression of TRPM8 in various histopathological types of pancreatic tissues, determine its clinical significance in pancreatic adenocarcinoma, and investigate its functional role in cancer cells invasion. We present evidence that, in normal pancreatic tissues, anti-TRPM8 immunoreactivity is detected in the centroacinar cells and the islet endocrine cells. In pre-malignant pancreatic tissues and malignant neoplasms, TRPM8 is aberrantly expressed to variable extents. In the majority of pancreatic adenocarcinoma, TRPM8 is expressed at moderate or high levels, and anti-TRPM8 immunoreactivity positively correlates with the primary tumor size and stage. In the pancreatic adenocarcinoma cell lines that express relatively high levels of TRPM8, short hairpin RNA-mediated interference of TRPM8 expression impaired their ability of invasion. These data suggest that aberrantly expressed TRPM8 channels play contributory roles in pancreatic tumor growth and metastasis, and support exploration of TRPM8 as a biomarker and target of pancreatic adenocarcinoma.
Variability in Arctic sea ice drift

[1] Analysis of Arctic sea ice drift from 1979–1997 using a Lagrangian perspective shows the complexities of ice drift response to variations in atmospheric conditions. Changes in ice dynamics influence the redistribution of ice, and any transported material, from different source areas. Sources of ice exported to Fram Strait shifted in about 1986/87 from dominance of the Kara Sea and Severnaya Zemlya to the New Siberian Islands, East Siberian Sea, and Chukchi Sea. Average travel time of multiyear ice within the perennial pack of the central Arctic Basin, reached a maximum in 1987/88, and decreased by at least 1 year between 1984–1989 and 1990–1997. Consistent with the observations of other investigators, this decrease in ice travel time occurred following a major export or “surge” of old ice to Fram Strait from the Beaufort Gyre in 1988 through 1990, which decreased the fraction of thick, ridged ice within the central basin.
Estimating Uncertainty in the Stock-Recruitment Relationship for St. Marys River Sea Lampreys

For successful control of the St. Marys River sea lamprey (Petromyzon marinus) population, one critical uncertainty that needs to be characterized is uncertainty in the stock-recruitment relationship. A statistically-based, age-structured population model was developed to estimate the parameters of a Ricker stock-recruitment relationship for St. Marys River sea lampreys and the associated uncertainty in these parameters. This analysis indicated considerable stock-independent variability in recruitment across a range of stock sizes, potentially limiting the effectiveness of control options that reduce the spawning population in comparison to those that reduce the larval population. Point estimates of the stock-recruitment parameters suggest moderate compensation, but the uncertainty in these point estimates is large, spanning a range from negligible to high compensation. By characterizing these uncertainties and incorporating the results into a decision analytic framework, it is then possible to evaluate the effects of compensation and stock-recruitment uncertainty on management options available for St. Marys River sea lamprey control.
Adjuvant therapy for pancreatic cancer: back to the future.

Abstract Purpose: The role of adjuvant therapy in the management of pancreatic cancer, resected with curative intent, remains controversial. This editorial review updates the status of adjuvant therapy in this context and introduces the first North American co-operative group study in this arena in roughly 20 years. Results: To the extent that there has been a “standard” of care in this context, it has been defined in large part by the early work of the Gastrointestinal Study Group (GITSG). Their trial was activated in the mid 1970’s using split course radiation therapy and bolus 5-FU. In the intervening 20+ years the morbidity/mortality of pancreaticoduodenectomy (PDD) has been dramatically reduced; concurrently, understanding of prognostic factors impacting on outcomes for resected patients has been significantly enhanced. In major centers the mortality of PDD is roughly 1% and survival has been shown to correlate with a number of factors including tumor size, nodal involvement, and margin status. With currently available techniques doses of continuous course radiation therapy in the range of 50–55 Gy to sites of pancreatic tumor resection and adjacent lymph node regions have been given in a number of trials with acceptable morbidity. 5-FU sequencing and administration have been advanced and gemcitabine, an agent with clear radiosensitizing properties, has been approved for use against pancreatic cancer. Conclusions: Following PDD increasing numbers of physiologically intact patients are confronting the survival statistics associated with resected pancreatic cancer. Their interest in improved therapeutic outcomes, combined with the noted improvements in radiation and chemotherapeutic management, has set the stage for renewed and intensified study. Accordingly, the intergroup mechanism of the Cancer Therapy and Evaluation Program (CTEP) of the NCI has designed, approved, and activated a modern Phase III, adjuvant protocol incorporating recently gained knowledge in this management context. Prospective randomization will be utilized to compare gemcitabine and 5-FU as single agents before and after chemoradiotherapy with 5-FU. Successful and timely completion of this newly activated intergroup study, RTOG 97-04, will establish a current, cooperative group experience, data base, and standard in the context of adjuvant therapy for pancreatic cancer and serve to provide momentum for further studies.
Spectrophotometric determination of salicylamide in complex mixtures

Abstract This paper describes a photometric assay procedure for the determination of small amounts of salicylamide in the presence of a variety of foreign substances. This method is based on the formation of a blue colored indophenol derivative from the reaction of salicylamide with N,2,6 -trichloro- p -benzoquinoneimine.
Improved Function After Combined Physical and Mental Practice After Stroke: A Case of Hemiparesis and Apraxia

This study describes change in functional performance and self-perception after participation in combined training with physical practice followed by mental practice. The patient was a 44-yr-old white man who experienced a single left ischemic stroke 7 mo before enrollment in the study. He engaged in physical and mental practice of two functional tasks: (1) reaching for and grasping a cup and (2) turning pages in a book with the more-affected arm. Practice took place 3 times per week during 60-min sessions for 6 consecutive wk. Primary outcome measures were the Arm Motor Ability Test (AMAT) and the Canadian Occupational Performance Measure (COPM). An abbreviated version of the Florida Apraxia Battery gesture-to-verbal command test approximated severity of ideomotor apraxia. After intervention, the patient demonstrated increased functional performance (AMAT) and self-perception of performance (COPM) despite persistent ideomotor apraxia. The results of this single-case report indicate functional benefit from traditional rehabilitation techniques despite comorbid, persisting ideomotor apraxia.
EPR characterization of ascorbyl and sulfur dioxide anion radicals trapped during the reaction of bovine Cytochrome c Oxidase with molecular oxygen

The reaction intermediates of reduced bovine Cytochrome c Oxidase (CcO) were trapped following its reaction with oxygen at 50 micros-6 ms by innovative freeze-quenching methods and studied by EPR. When the enzyme was reduced with either ascorbate or dithionite, distinct radicals were generated; X-band (9 GHz) and D-band (130 GHz) CW-EPR measurements support the assignments of these radicals to ascorbyl and sulfur dioxide anion radical (SO2(-.)), respectively. The X-band spectra show a linewidth of 12 G for the ascorbyl radical and 11 G for the SO2(-.) radical and an isotropic g-value of 2.005 for both species. The D-band spectra reveal clear distinctions in the g-tensors and powder patterns of the two species. The ascorbyl radical spectrum displays approximate axial symmetry with g-values of g(x)=2.0068, g(y)=2.0066, and g(z)=2.0023. The SO2(-.) radical has rhombic symmetry with g-values of g(x)=2.0089, g(y)=2.0052, and g(z)=2.0017. When the contributions from the ascorbyl and SO2(-.) radicals were removed, no protein-based radical on CcO could be identified in the EPR spectra.
Inhibition and substrate activity of conformationally rigid vigabatrin analogues with γ-aminobutyric acid aminotransferase

Several cyclopentene GABA analogues were synthesized as conformationally rigid analogues of the epilepsy drug vigabatrin and tested as inhibitors and substrates of γ-aminobutyric acid aminotransferase (GABA-AT). None of these compounds produced time-dependent inhibition. (1R,4S)-(+)-4-Amino-2-cyclopentene-1-carboxylic acid ((+)-3), (4R)-(−)-4-amino-1-cyclopentene-1-carboxylic acid ((−)-4), and d,l-3-amino-1-cyclopentene-1-carboxylic acid (6) are good substrates. The Km and kcat values for the latter two compounds are very similar to those of GABA, suggesting that they bind in an orientation similar to that of GABA. The Km value for (+)-3 is 24 times lower than that for GABA, although its kcat value is only one-fourth that for GABA; nonetheless, it is a better substrate for GABA-AT than is GABA. All of these compounds, as well as the enantiomers of 3 and 4 and d,l-trans-4-amino-2-cyclopentene-1-carboxylic acid (5), are competitive inhibitors of GABA-AT. These results demonstrate the effects of the carboxyl...