cssi/SciSciGPT-SciSciNet huggingface dataset:
Mechanism of nicotinic action at the adrenal medulla: calcium as a link in stimulus-secretion coupling.

IN experiments to probe the mechanism of transmission of sympathetic activity at the adrenal medulla we have found that acetylcholine, which is believed to be the chemical transmitter, evokes catecholamine secretion through some calcium-dependent process. Our evidence, obtained in experiments in cats' adrenal glands perfused in vivo or in vitro with Locke's solution or variations of it, may be summarized as follows.
Complete Characterization of the Mechanochemical Cycle of a Homomeric Ring ATPase

Understanding how multimeric ring ATPases couple chemical transitions to mechanical motion and coordinate their subunits is essential for elucidating the functions of these important molecular machines. Here we used high-resolution optical tweezers to study one such ATPase - the bacteriophage phi29 DNA packaging motor. This pentameric motor is known to translocate DNA by cycling through a dwell phase, in which subunits load ATPs, and a burst phase, in which 10 base pairs of DNA are packaged in four 2.5-base-pair steps. By monitoring packaging in buffers containing various nucleotides and nucleotide analogs, we determined the exact timing of chemical transitions (nucleotide hydrolysis and product release) with respect to the mechanical phases of the motor's cycle. Our results reveal an intricate coordination mechanism with multiple levels of communication between neighboring subunits. ADP release and ATP binding occur in a concerted alternating fashion, with ATP binding to one subunit facilitating the release of ADP in the following subunit. ATP hydrolysis also appears to occur sequentially around the ring through an intersubunit allosteric effect. Moreover, our data suggest that all five subunits of the ring bind and hydrolyze ATP. Only four out of the five hydrolysis events are coupled to DNA translocation, while the fifth subunit consumes ATP to fulfill a regulatory role, resetting the motor for the next mechanochemical cycle. The phi29 motor is able to tolerate a single inactive subunit and still function, albeit at a much slower pace. These new findings allow us to present the most complete mechanochemical model of a homomeric ring ATPase to date, which should provide insight into the operating principles of other ring-shaped ATPases.
Implicit Attitude Generalization From Black to Black–White Biracial Group Members:

We investigated whether Black–White biracial individuals are perceived as Black in the domain of evaluation. Previous research has documented that White perceivers’ negative evaluation of one Black...
A web accessibility service: update and findings

We report here on our progress on a project first described at the ASSETS 2002 conference. At that time, we had developed a prototype system in which a proxy server intermediary was used to adapt Web pages to meet the needs of older adults. Since that report, we field tested the prototype and learned of problems with the proxy approach. We report on the lessons learned from that work and on our new approach towards meeting the Web needs of older adults and users with disabilities. This new software makes adaptations on the client machine, with greater accuracy and speed than was possible with the proxy server approach. It transforms Web pages "on the fly", without requiring that all Web content be re-written. The new software has been in use for a year and we report here on our findings from the usage. We discuss this approach in the context of Web accessibility standards and Web usability.
Coset representation of closed loop space in string field theory

Abstract By taking analogy with Minkowski space, we construct a closed loop space CM which is an infinite-dimensional coset space and discuss some of its consequences.
Anelasticity of dislocation dipoles

Abstract Flipping of dislocation dipoles between two stable positions is shown to have too high an activation energy to be associated with Bordoni peaks.
The Expression Levels of the Human Papillomavirus Type 16 E7 Correlate with Its Transforming Potential

The transforming potential of the human papillomavirus (HPV) type 16 has been defined largely in the E7, E6, and E5 oncoproteins, with the major transforming capability residing in the E7 gene. In this paper, we found that in cooperation with the activated ras, the HPV16 E7 gene when expressed in a retroviral vector could fully transform baby rat kidney (BRK) cells in transfections, whereas the same construct could only immortalize the BRK cells following retroviral infection. This inability to transform correlated with the low levels of E7 gene RNA expression in the viral infected cells, which harbor a lower number of copies of the E7 gene constructs. Cotransfection of the expression vector FV2E7, which gives high levels of E7 gene expression, and activated ras lead to rapid and efficient morphological transformation of BRK cells which grew easily in soft agar and induced large tumors in athymic nude mice. In contrast, cotransfections of the expression vector FV1E7, which gives lower levels of E7 gene expression, produced much lower numbers of transformed colonies which took longer to form, showed a retarded growth on soft agar, and induced smaller tumors in nude mice. Under these conditions, colonies of immortalized, but morphologically untransformed cells formed in large numbers. These results indicate that the transforming potential is directly correlated to the expression levels of the oncoprotein and that a threshold level of the E7 oncoprotein may be required before the cells can be fully transformed. This supports the hypothesis that the transformation processes include at least two separate and continuous steps which first lead to immortalization and then to metastasis, in agreement with the clinical progression of genital tumors from benign to malignancy. Such a progression may involve enhanced expression of the oncoproteins.
Why scepticism about self‐knowledge is self‐undermining

In Ebbs 1996 and 2001 I explained why I believe that a certain sort of argument that seems to support scepticism about self-knowledge is actually incoherent, or self-undermining. Anthony Brueckner has recently tried to show that even if the central premisses of my explanation are true, the sceptical argument in question is not self-undermining. He has also suggested that even if the sceptical argument is self-undermining, it can still serve as a reductio ad absurdum of the assumption that we have selfknowledge. My goal here is to explain why I think neither of these responses is successful.
Current Research of the U. S. Geological Survey: ABSTRACT

The research program of the U. S. Geological Survey comprises a multitude of investigations within two broad categories: research related to the appraisal, development, and utilization of our mineral resources--minerals, mineral fuels, and water--and research whose primary aim is to advance geologic and hydrologic knowledge. Within these two extremely broad fields, the concept of "target areas," including topical "targets" as well as geographic ones, enables us to develop our research program through concerted attacks on broad problems of regional or topical importance. The principal targets in our research on natural resources, End_Page 365------------------------------ accounting for about 60 per cent of our current research effort, are generally in terms of specific commodities. The lines of attack on these targets include district and regional geologic mapping projects and hydrologic studies, as well as related laboratory investigations. In research aimed primarily at increasing our scientific knowledge, the geographic targets range from entire states or drainage basins to groups of a few quadrangles; topical targets are the understanding of a variety of fundamental geologic, oceanographic, and hydrologic principles and processes. These basic research projects, which account for about 40 per cent of the Survey's current research effort, include field studies as well as experimental investigations. Our new long-range program, embarked upon this year, calls for expansion of our mapping and research activities approximately 70 per cent over the next 10 years. Some phases of this long-range program are not measurable in specific units because they are largely concerned with basic research, in which the achievement of one goal may beget several others; in these phases the level of effort is being increased to anticipate and meet the increased requirements that must come with the Nation's continued economic growth. Some finite goals of the more specific phases of the program are: (1) complete once-over topographic map coverage of the entire U. S. with standard 7½- or 15-minute quadrangles by 1976; (2) complete geologic map coverage at 1:250,000 by 1980, and at 1:62,500 by the ye r 2000; and (3) complete aeromagnetic coverage, at 1-mile spacing, by 1973. End_of_Article - Last_Page 366------------
Distinct modulating effects of TipE-homologs 2-4 on Drosophila sodium channel splice variants.

Abstract The Drosophila melanogaster TipE protein is thought to be an insect sodium channel auxiliary subunit functionally analogous to the β subunits of mammalian sodium channels. Besides TipE, four TipE-homologous proteins (TEH1–4) have been identified. It has been reported that TipE and TEH1 have both common and distinct effects on the gating properties of splice variants of the Drosophila sodium channel, DmNav. However, limited information is available on the effects of TEH2, TEH3 and TEH4 on the function of DmNav channel variants. In this study, we found that TEH2 increased the amplitude of peak current, but did not alter the gating properties of three examined DmNav splice variants expressed in Xenopus oocytes. In contrast, TEH4 had no effect on peak current, yet altered the gating properties of all three channel variants. Furthermore, TEH4 enhanced persistent current and slowed sodium current decay. The effects of TEH3 on DmNav variants are similar to those of TEH4, but the data were collected from a small portion of oocytes because co-expression of TEH3 with DmNav variants generated a large leak current in the majority of oocytes examined. In addition, TEH3 and TEH4 enhanced the expression of endogenous currents in oocytes. Taken together, our results reveal distinct roles of TEH proteins in modulating the function of sodium channels and suggest that TEH proteins might provide an important layer of regulation of membrane excitability in vivo. Our results also raise an intriguing possibility of TEH3/TEH4 as auxiliary subunits of other voltage-gated ion channels besides sodium channels.
Tail Buffet Alleviation Through the Use of Wing-Strake Fillet Shapes

Various e llet shapes at the strake ‐wing juncture of a 76/40 deg double-delta wing model were experimentally investigated to gauge the effect of the e llet in alleviating adverse vortex/tail interaction. The vertical tails were instrumented with 28 fast-response pressure transducers. Pressure time histories and frequency power spectral densities were analyzed for four wing ‐strake e llet cone gurations and at three spanwise tail locations. Angle of attack was varied from i 2 to 40 deg, tunnel dynamic pressurewas 26.74 psf (1280 pascals ), and Reynolds number was 1.3 ££ 10 6 . The results show that the e llet geometry can increase or decrease tail buffet in comparison to the baseline, no e llet case. Linear and parabolic e llet shapes were found to increase tail buffet above the baseline case. A diamond e llet shape was found to alleviate tail buffet and shift the tail buffet to a higher frequency. The use of such a shape on e ight vehicles may result in a longer fatigue life of the vertical tails. Nomenclature A = constant,b=V1, 0.0091/s AR = aspect ratio, 2.41 a1 = speed of sound, 1155 ft/s, 352 m/s b = span, 1.36 ft, 0.414 m C = coherence CP = pressure coefe cient, p i p1=q1 c = chord, ft, m cR = root chord, 1.33 ft, 0.405 m cRtail = tail root chord, 0.38 ft, 0.116 m ct = tip chord, 0.21 ft, 0.064 m cttail = tail tip chord, 0.13 ft, 0.040 m f = frequency, Hz G = amplie er gain Iraw = raw integer value (digital) M1 = freestream Mach number, V1=a1, 0.13 P = pressure, psf Pref = reference pressure, psf q1 = tunnel dynamic pressure, 26.74 psf, 1280 pascals Re = Reynolds number, (Ω1V1CR/=π1, 1.3E6 S = wing area, 0.768 ft 2 , 0.071 m 2 Se = transducer sensitivity, V/psf Sr = Strouhal number, (bf /=V1
Numerical Time Integration In Dynamics

Numerical time integration methods for solving sets of simultaneous dynamic equilibrium equations are reviewed. Both mathematical and physical approximations are used in generating numerical solutions to the governing second-order differential equations. The resulting algorithms are classified into two basic categories: explicit (predictor) and implicit (corrector). Explicit methods are computationally efficient, but all explicit second-order accurate methods are only conditionally stable. On the other hand, many implicit methods are unconditionally stable, but may require iteration for convergence at each time step. For linear problems, implicit methods usually can be reduced to explicit form and iteration can be avoided. Methods which are unconditionally stable for linear problems may become unstable for nonlinear problems depending upon the manner in which nonlinearities are evaluated: exactly, or approximately using a pseudo-force or tangent modulus idealization. Methods which introduce numerical (or algorithmic) damping are used to eliminate "spurious" high frequency noise present in nonlinear, and sometimes even linear, structural dynamics problems. The question still remains whether the manner and extent of filtering at high frequencies is realistic. While attempts to develop new time integration algorithms synthesizing the better features of both explicit and implicit methods continue to be made, a basic controversy over the relative advantages and disadvantages of explicit and implicit schemes still exists.© (1984) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Effects of a rotating electric field on the properties of epitaxial (001) Pb(Zr,Ti)O3 ultrathin film: a first-principles-based study.

Pb(Zr,Ti)O3 ultrathin films under open-circuit electrical boundary conditions and subjected to an electric field rotating in the () plane are investigated via the use of an effective Hamiltonian, for different magnitudes of this field. Varying the direction and magnitude of the electric field leads to specific reorganization of dipoles into original configuration states, whose microstructures and macroscopic properties are revealed. In particular, a novel (direction of the electric field?versus?magnitude of the electric field) phase diagram is reported here. The field-induced correlation between the polar distortions and the oxygen octahedral tilting is also discussed.
Investigation of dynamic head load and unload

Several air bearing designs were investigated with respect to dynamic Load and Unload (LUL) induced vibrations. Different ABS designs as well as design changes in the suspension of heads were analyzed using an LDV scanning system as well as a Capacitance Probe unit synchronized together. It was observed that the head and suspension exhibited either stable or unstable flying height behavior during the Load or Unload process over a range of velocities to and from the ramp. The results were used to determine a range of LUL speeds that prevented unstable head resonances as well as disk dings and scratches. Most of these head resonances were due to dynamic instabilities of the suspension and head system. The resonance points were investigated at the center and trailing edges (roll and pitch sensitivity) of the head and suspension. A Polytec LDV and Capacitance Probe were used to follow the stable and unstable flying behavior of the head while stationary and the ramp was allowed to move. Methods are discussed to minimize and dampen out the most severe head/suspension vibration levels. Simulation of the flutter of the integrated lead suspension traces due to air flow and possible ways to damp the flow induced resonance is also discussed
Factor Structure of the Wide Range Assessment of Memory and Learning in a Clinical Population

The Wide Range Assessment of Memory and Learning (WRAML) factor structure is evaluated in a clinical sample of 323 children referred because of problems in school performance (M age 9.83 years, M grade 4.18, M FSIQ 95.03). Of these, 72% had attention deficits, whereas 8 to 35% had learning disabilities. Pairwise principal factor analyses with the Montanelli and Humphreys criterion produced a three-factor solution that accounted for 36% of the variance: Factor 1 is a Visual Content factor (four subtests), factor 2 is a Short-term Verbal factor (2 subtests), and factor 3 is a Verbal Semantic/Strategic factor (2 subtests). “Learning” subtests did not separate out, and Sound-symbol did not load significantly on any factor. Solutions for the two age divisions of the test were highly similar. These findings are not consistent with the WRAML factor structure reported by the test authors and suggest that alternative means of interpretation be considered. Modality-related and functional processing dimensions (stra...
S-MAIDS: A Semantic Model for Automated Tuning, Correlation, and Response Selection in Intrusion Detection Systems

As cyber threats increasingly utilize automated and adaptive attacks to bypass or overwhelm static defenses, the role of intrusion detection and response systems (IDRS) as an active defense layer is becoming more critical. To remain effective against current attacks IDRS must be capable of automating detection of, and response to, threats in their specific environment. Different operating characteristics, detection capabilities, and response actions all contribute to make each environment unique, complicating this automation. In this work we consider IDRS automation in three areas: detector tuning, detector correlation, and response selection. We motivate and present a novel, more finely-grained model of threats, detectors, and responses called S-MAIDS: A Semantic Model of Automated Intrusion Detection Systems. Based on the concept of a "signal" (an observable indicator of an attack), we show the utility of combining such a model with an existing measure of IDRS performance to facilitate automated tuning, cross-system correlation, and response selection. We support our claims through several case-studies demonstrating the application of this model, and provide the model as an OWL ontology.
Cosmic ray production by vibrating neutron stars.

I HAVE recently pointed out1 that a vibrating neutron star, which is expected to be formed as a remnant of the explosion of a Type I supernova, may store up to 1051 or 1052 ergs as mechanical energy of vibration. This energy may be dissipated by various non-thermal mechanisms. If a magnetic field is embedded in the neutron star, then the vibrations will produce hydromagnetic waves which travel along the field lines, and these will be capable of accelerating charged particles to high energies by transit2 and stochastic3 acceleration processes. There is a possibility that the synchrotron radiation of X-rays from the Crab Nebula results from acceleration processes of this type, where the accelerated electrons have been able to diffuse into the outer expanding envelope. Such a diffusion is rendered easier if there should be a corona produced around the neutron star, which expands to form a stellar wind, thus drawing radially outward the magnetic lines of force. Such coronal heating may arise from shocks produced by the vibrations in the atmosphere1 or by electromagnetic interaction, between the magnetic field and the surrounding plasma (Manley, O., private communication).
Atomic layer deposition of dielectrics for carbon-based electronics

Abstract Carbon based nanomaterials like nanotubes and graphene have emerged as future generation electronic materials for device applications because of their interesting properties such as high-mobility and ability to carry high-current densities compared to conventional semiconductor materials like silicon. Therefore, there is a need to develop techniques to integrate robust gate dielectrics with high-quality interfaces for these materials in order to attain maximum performance. To date, a variety of methods including physical vapor deposition, atomic layer deposition (ALD), physical assembly among others have been employed in order to integrate dielectrics for carbon nanotube and graphene based field-effect transistors. Owing to the difficulty in wetting pristine surfaces of nanotubes and graphene, most of the ALD methods require a seeding technique involving non-covalent functionalization of their surfaces in order to nucleate dielectric growth while maintaining their intrinsic properties. A comprehensive review regarding the various dielectric integration schemes for emerging devices and their limitations with respect to ALD based methods along with a future outlook is provided.
Making heads or tails: planarian stem cells in the classroom.

Stem cells hold great promise in the treatment of diseases ranging from cancer to dementia. However, as rapidly as the field of stem cell biology has emerged, heated political debate has followed, scrutinizing the ethical implications of stem cell use. It is therefore imperative to promote scientific literacy by educating students about stem cell biology. Yet, there is a definite lack of material to engage students in this subject at the basic science level. Therefore, we have developed and implemented a hands-on introductory laboratory module that introduces students to stem cell biology and can be easily incorporated into existing curricula. Students learn about stem cell biology using an in vivo planarian model system in which they down-regulate two genes important in stem cell differentiation using RNA interference and then observe the regenerative phenotype. The module was piloted at the high school, community college, and university levels. Here, we report that introductory biology students enrolled at a community college were able to demonstrate gains in learning after completion of a one-hour lecture and four 45-minute laboratory sessions over the course of three weeks. These gains in learning outcomes were objectively evaluated both before and after its execution using a student quiz and experimental results. Furthermore, students’ self-assessments revealed increases in perceived knowledge as well as a general interest in stem cells. Therefore, these data suggest that this module is a simple, useful way to engage and to teach students about stem cell biology.
Electrodiagnosis at median occlusal position for human subjects with mandibular joint syndrome

Abstract Neuromuscular inhibitory effects were monitored in the temporalis and masseter muscles for ten patients with mandibular joint (MJ) syndrome, and ten control subjects with normal occlusions. Analysis of the electromyographic (EMG) silent period in the controls showed no significant difference between durations at median occlusal position, following placement of a maxillary acrylic occlusal splint, and during gum chewing. However, for the patients with MJ syndrome, there was an immediate decrease in their mean EMG silent-period duration upon placement of the splint from 19.23 msec to 15.52 msec. This shortened duration was the same with or without a splint after the pain symptoms had subsided. Precise occlusal adjustment of the dentition at the pain-free appointment resulted in a further reduction (10.83 msec) to within the range of the normal control subjects at median occlusal position. Inhibitory pauses during gum chewing showed similar treatment interactions but, during some chewing cycles, no silent periods were evident.
Phosphorus and proton nuclear magnetic resonance studies in sarcoplasmic reticulum membranes and lipids. A comparison of phosphate and proton group mobilities in membranes and lipid bilayers

Phosphorus nuclear magnetic resonance spectra, recorded at 101 MHz, of rabbit sarcoplasmic reticulum membrane fragments and lipid extracts of these membranes are characterized by single broad lines (approx. 1 kHz half width). The line width may be, in part, field dependent. The estimated residual (zero field) width is interpreted in terms of local proton dipolar fields, randomly modulated in time. The correlation time for such motion is estimated to be on the order of 10−5 s. This motional time constant for the phosphate head group in membranes and lipid disperions is approx. 102–103 slower than that characteristic of portions of they hydrocarbon chains and cholind methyl groups. The phosphorus spectra, in contrast to the proton NMR spectra, is insensitive to chemical alteration of the membrane protein. Likewise, in lipid extracts, the accompanying increased fluidity in some proton regions of the lipid molecules is not manifest in the phosphate group. While increasing the temperature to 40°C narrows the 31P line width there is no evidence of a highly mobile state for the phosphate group like that found for the choline group.
Simulation of spatial learning in the Morris water maze by a neural network model of the hippocampal formation and nucleus accumbens

Cells in the hippocampal formation show spatial firing correlates thought to be critical to the role played by this structure in spatial learning. Place cells in the hippocampus proper show location-specific activity, whereas cells in the postsubiculum fire as a function of momentary directional heading. One question which has received little attention is how these spatial signals are used by motor structures to actually guide spatial behavior. Here we present a model of how one kind of spatial behavior, instrumental learning in the Morris water maze, could be guided by the spatial information in the hippocampal formation. For this, we concentrate on the hippocampal projection to the nucleus accumbens, which is strongly implicated in instrumental learning. In the model, simulated firing patterns of place cells and head direction cells activate "motor" cells in the "accumbens." Each motor cell causes a particular locomotor movement in a simulated rat. In this way, the "rat" locomotes through the simulated environment. Each step places the animal in a slightly different location and directional orientation, which, in turn, activates a different set of place and head direction cells, thus causing the next locomotor response, and so on. Connection strengths between cells are initially set randomly. When the animal encounters the reward location, however, connections are altered, so that recently active synapses are strengthened. Thus, successful moves in a particular locational and directional context are "stamped in." Simulated rats show rapid learning, similar in many ways to that of actual rats. In particular, they generate efficient routes to the goal after minimal experience, and can do so from somewhat novel starting positions. Consideration of the model architecture shows that 1) combined use of directional and place information is an example of a linearly inseparable problem and that 2) some types of novel route generation, often thought to require a "cognitive mapping" strategy, can be generated from the S-R type model used here.
Theoretical Studies of Reactions of Silanes

Abstract Computational investigations of abstraction reactions of the form X + SiR 3 H → XH + SiR 3 are reviewed, where X = H, O, F and Cl and SiR 3 H represents SiH 4 , Si 2 H 6 and (CH 3 ) n SiH 4− n (n = 1–3). SiH bond dissociation enthalpies and energy barriers for the formation of transition states can be calculated to within 5 kJ mol −1 using e.g. Gaussian 2 theory. Analysis of isodemic reactions provides a route to reliable thermochemistry for systems too large for Gaussian 2 theory. Expressions for rate constants calculated ab initio using transition state theory are given; they are in generally good agreement with experimental measurements.
Inflammatory T cells rapidly induce differentiation of human bone marrow stromal cells into mature osteoblasts.

Activated T cells secrete multiple osteoclastogenic cytokines which play a major role in the bone destruction associated with rheumatoid arthritis. While the role of T cells in osteoclastogenesis has received much attention recently, the effect of T cells on osteoblast formation and activity is poorly defined. In this study, we investigated the hypothesis that in chronic inflammation activated T cells contribute to enhanced bone turnover by promoting osteoblastic differentiation. We show that T cells produce soluble factors that induce alkaline phosphatase activity in bone marrow stromal cells and elevated expression of mRNA for Runx2 and osteocalcin. This data indicate that T cell derived factors have the capacity to stimulate the differentiation of bone marrow stromal cells into the osteoblast phenotype. RANKL mRNA was undetectable under any conditions in highly purified bone marrow stromal cells. In contrast, RANKL was constitutively expressed in primary osteoblasts and only moderately up-regulated by activated T cell conditioned medium. Interestingly, both bone marrow stromal cells and osteoblasts expressed mRNA for RANK, which was strongly up-regulated in both cell types by activated T cell conditioned medium. Although, mRNA for the RANKL decoy receptor, osteoprotegerin, was also up-regulated by activated T cell conditioned medium, it's inhibitory effects may be mitigated by a simultaneous rise in the osteoprotegerin competitor TNF-related apoptosis-inducing ligand. Based on our data we propose that during chronic inflammation, T cells regulate bone loss by a dual mechanism involving both direct stimulation of osteoclastogenesis, by production of osteoclastogenic cytokines, and indirectly by induction of osteoblast differentiation and up-regulation of bone turnover via coupling.
Femtosecond pulse propagation in cryogenic GaAs waveguides

High-speed optoelectronic devices must be interconnected with optical waveguides. Furthermore, it is quite likely that optical waveguides will be required to interface with superconducting devices that operate at cryogenic temperatures. Thus, it is important to examine femtosecond pulse propagation in cryogenic waveguides. Our approach uses the time domain susceptibility by Fourier transforming frequency domain models of semiconductors developed by Adachi. The resulting time domain susceptibility functions are closed form and cover the temperature range from 0 to 800 K. With this new model, time domain solutions to Maxwell's equations are now obtained for a femtosecond pulse propagating in a GaAs waveguide. The effects of linear dispersion and attenuation are examined for waveguides at different temperatures. However, the solution is limited to one spatial dimension in the direction of propagation to simplify the numerical algorithm.
Normative data in women aged 85 and older: verbal fluency, digit span, and the CVLT-II short form.

Individuals aged 85 years and above (i.e., the oldest old) represent the fastest growing segment of the US population and are at increased risk of developing dementia. This represents an important challenge for the clinical neuropsychologist, as the extant normative data on neuropsychological measures remain relatively limited for this age group. Therefore the aim of the present study was to characterize the performance effects of age and education in a large, well-characterized sample of women between the ages of 85 and 95 years on the California Verbal Learning Test-II (CVLT-II) Short Form (Delis, Kramer, Kaplan, & Ober, 2000), verbal fluency tasks, and the WAIS-III Digit Span Test (Wechsler, 1997). In order to minimize the likelihood that women with an incipient neurodegenerative process were included in the final normative sample, we applied regression-based change scores to identify and exclude women who evidenced a statistically significant decline on a global cognitive screening measure over a 20-y...
The effects of structural disorders and microstructural mechanisms on semi-crystalline P3HT behavior

Abstract Semiconducting conjugated polymers, such as P3HT, have applications for photovoltaic and flexible electronics. However, charge transport is sensitive to the mechanical behavior of the donor P3HT. A computational framework has, therefore, been used to identify the microstructural mechanisms, at different physical scales, that affect behavior. The approach accounts for the microstructure as an interrelated three-phase model that is physically representative of crystalline domains, an amorphous interphase, and tie-chain bridging regions. Based on our predictions, the face-on packing crystalline orientations had higher toughness in comparison with the edge-on packing orientations that had higher strengths due to local dislocation-density interaction mechanisms. The higher inelastic deformation, associated with face-on orientations, disrupted the conjugation structure in the crystalline phase, and this could affect charge. These predictions indicate that the behavior of P3HT polymers can be optimized by controlling the packing orientations, the crystallinity, the entangled chain density, and the tie chain interconnectivity.
Abstract 1957: Targeted polymer-based nanoparticles containing camptothecin: Development and function

Proceedings: AACR 103rd Annual Meeting 2012‐‐ Mar 31‐Apr 4, 2012; Chicago, IL Camptothecin (CPT) is a naturally occurring broad range anti-cancer alkaloid that acts by inhibiting DNA enzyme topoisomerase I and HIF-1α activities. However, its systemic delivery has been problematic due to its low solubility and toxicity. To this end, we have designed a CPT delivery system that increases the solubility of CPT by more than three orders of magnitude and is capable of directing CPT specifically to cancerous cells. This delivery system is composed of CPT conjugated to a copolymer of mucic acid and poly(ethylene glycol) (MAP). When this conjugate is placed in water it self-assembles into MAP-CPT nanoparticles. The polyol containing backbone of MAP is able to form reversible covalent bonds with boronic acids (BA). Targeting can therefore be achieved through using BA as the linker between the targeting agent and MAP-CPT nanoparticles. MAP-CPT nanoparticles with varying MAP lengths of 20kDa, 65kDa and 100kDa and BA linkers with different binding constants to MAP-CPT nanoparticles are synthesized and characterized. Particle sizes of 40nm in diameter are observed by dynamic light scattering and visualized by particle tracking methods (Nanosight) and cryo-transmission electron microscopy. This particle size takes advantage of the accumulation of nanoscaled entities in tumor tissue via enhanced permeability and retention (EPR) effect. In addition, the slightly negative particle surface charge of −1mV reduces clearance by the reticuloendothelial system (RES) and minimizes undesirable interaction with blood components. A prolonged pharmacokinetic (PK) profile of MAP-CPT system is observed in Balb/C mice with greater than 10% of injected dose remaining in circulation 24 hours post injection for MAP-CPT nanoparticles containing 65kDa or 100kDa MAP. Maximum tolerable dose (MTD) for MAP-CPT nanoparticles containing MAP at 20kDa, 65kDa and 100kDa are found to be 20, 10 and 8mg of CPT/kg respectively in nude mice. Initial anti-tumor data using MAP-CPT nanoparticles in A/J mice bearing Neuro2A (mice neuroblastoma) tumors show tumor regression after two weekly doses of MAP-CPT nanoparticles. We are currently investigating a targeted version of the MAP-CPT nanoparticles through anti-tumor studies comparing targeted (using Herceptin antibodies) versus non-targeted efficacy in nude mice bearing BT-474 (HER2 over-expressing human breast carcinoma) tumors. MAP-CPT, a delivery system for the small hydrophobic drug CPT, is developed and has favorable particle size and surface charge properties, prolonged PK profile and targeting potential. Efforts to define the relationships between targeted and non-targeted versions of the MAP-CPT nanoparticles are in progress. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1957. doi:1538-7445.AM2012-1957
The failure mechanism of low-voltage electrical relays

The mechanism of increase in the resistance of low-voltage electrical contacts with the number of on-off switch cycles is investigated. Experiments are conducted at room temperature on Au and a number of base metals (Ni, Fe, Ti and Sb) in mixtures of air and organic vapors (benzene, toluene and xylene). The increase in contact resistance is found to be primarily due to carbon formation on the contact surfaces. It is proposed that molecules of the organic vapor first adsorb on the contact surfaces, possibly forming a monolayer. Then, as a spark strikes, carbon is produced by pyrolysis of that layer. Subsequently, more vapor adsorbs on carbon and the process repeats. When a sufficient amount of carbon builds up on the electrodes the contact resistance will be very high. >
Differential impact of university student living groups

The impact of university student living groups on freshmen students' personal and social development was assessed. The social environments of 42 student living groups were measured by the University Residence Environment Scale, which assesses 10 salient dimensions of the social environment. Indices of student personal and social growth were assessed by a biographical and experience questionnaire at the beginning and the end of the freshman year. The social environments of the living groups had differential impacts on student interactions and activities and student self-descriptions and feelings. For example, living groups that emphasized academic achievement facilitated negative affect and exhaustion and inhibited artistic appreciation and impulsive-deviancy. Student living groups constitute important subenvironments which should be assessed in future college impact studies.
Experimental Issues in the Measurement of Multi-component Relaxation Times in Articular Cartilage by Microscopic MRI

Abstract A number of experimental issues in the measurement of multi-component T2 and T1ρ relaxations in native and enzymatically digested articular cartilage were investigated by microscopic MRI (μMRI). The issues included the bath solutions (physiological saline and phosphate buffered saline (PBS)), the imaging resolution (35–140 μm), the specimen orientations (0° and 55°), and the strength of spin-lock frequencies (0.5–2 kHz) in the T1ρ experiments. In addition to cartilage, the samples of agar gel and doped water solution were also used in the investigation. Two imaging sequences were used: CPMG-SE and MSME. All raw data were analyzed by the non-negative least square (NNLS) method. The MSME sequence was shown to result in the observation of multi-component T2, even in the gel and liquid samples, demonstrating the artificial uncleanness of this sequence in the multi-component measurements. The soaking of cartilage in PBS reduced the observable T2 components to one at both 0° and 55°, suggesting the effect of phosphate ions on proton exchange between different pools of water molecules. The cartilage orientation with respect to the external magnetic field and the spin-lock strengths in the T1ρ experiment both affected the quantification of the multi-component relaxation. The transitions between a mono-component and multi-components in cartilage under various experimental conditions call for the extra caution in interpreting the relaxation results.
Instructional Uses of Podcasting in Online Learning Environments: A Cooperative Inquiry Study.

A report on the results of a year-long cooperative inquiry study in which 11 faculty members at a southeastern university examined their various uses of podcasting for instruction. Through participation in the study, members developed insights into what technologies are most commonly applied to the task of podcast production and dissemination as well as instructional purposes and tasks commonly addressed when using podcasting as a teaching strategy. The benefits of using podcasting instead of traditional text-based media were explored. The group discovered the faculty members involved were making use of 4 distinct podcasting technologies to apply 8 discrete instructional strategies.
Transport of GABA from the perfused ventricular system of the cat.

— The transport of GABA was studied in anaesthetized cats undergoing ventriculo-cisternal perfusion with radioactive GABA. Steady-state clearance of GABA from the CSF was greater than that of other amino acids previously studied, and was saturated at lower substrate concentrations, with an apparent Kt of 5·4 × 10-5 M, after correcting for non-saturable transport. GABA clearance was inhibited by the inclusion of taurine or β-alanine in the perfusion fluid, but not by a number of the common neutral and acidic amino acids. Study of punch biopsies of brain tissue taken adjacent to the venticular system, at the completion of perfusions, showed accumulation of radioactive GABA in the tissue to values four times higher than those found in the perfusion fluid. Of the radioactivity which had been removed from the ventricular system, only 11 per cent remained in the brain at the completion of the perfusion. Excised cat choroid plexus showed a saturable uptake of GABA which was inhibited by inclusion of taurine, β-alanine, or β-guanidino propionic acid in the incubation medium.
Lessons from Examining Same-Sex Intimate Partner Violence

Even though scientific and legal recognition of same-sex relationships has increased, same-sex intimate partner violence (IPV) has not been included in the core conceptualization of the research and theorizing about IPV. Because of its inherent disjuncture from the patriarchal and hetero-normative marriage model, battering in the lesbian, gay, bisexual, and transgendered community needs a much closer examination. Examining the violence that occurs in same-sex relationships allows us to reframe how we look at IPV and scrutinize the ideological frameworks, cultural narratives, and stereotypes that have been set forth as well investigate further the predictors of violence and the use of scales created. This article reviews the research on same-sex IPV primarily within the United States. In placing the lessons of same-sex IPV in the foreground, we are able to uncover some common truths about IPV in general. Viewing IPV through a same-sex lens removes gender-based assumptions about the manifestations of IPV, enabling us to see how other cultural and systemic factors may contribute to IPV. At the same time, incorporating the experience of same-sex couples facilitates viewing gender as a marker for variables requiring further study rather than as an explanation. When we change our focus of IPV in such a way, we discover it is a function of a complex interaction of culture, social structures, social status, and interpersonal dynamics.
The influence of processing variables on injection molded in situ composites based on polyphenylene sulfide and a melt processable glass

Abstract This work was concerned with addressing how processing variables such as resin viscosity, melt temperature and mold filling rate influenced the mechanical properties of injection molded composites consisting of polyphenylene sulfide (PPS) reinforced with a melt processable phosphate glass. During injection molding, both the PPS and melt processable glass were deformable allowing the reinforcing phase morphology to be developed during the filling of the mold. Processing variables such as resin viscosity, mixing history, melt temperature, and mold filling rate were investigated to help maximize the reinforcing contribution of the melt processable glass. It was determined that the composites with the highest mechanical properties could be achieved by utilizing a higher viscosity resin, enhancing the mixing history, and molding at melt temperatures greater than 330°C. For a composite blend containing 40 wt% (26 vol%) glass, the utilization of the optimum processing conditions led to the formation of composites that offered machine direction moduli 2–3 times greater than that of the neat PPS.
Effects of age, experience, and malnourishment on object retention in learning set.

Repeated presentation of 100 6-trial problems produced significant retention of individual object discriminations in both 25-mo.-old and 6-mo.-old infant monkeys. The amount retained was a function of amount learned in any one sequence and was independent of age and experience. Deprivation in the form of malnutrition of 6-mo.-old monkeys produced superior performance in intraproblem learning and subsequent retention, but the retention loss remained constant. A 3-mo. retention interval produced a reduction in retention of individual items in the 25-mo.-old Ss but not in the younger animals. Return to a normal diet resulted in a decrease in performance, a return to performance normal for 6-mo.-olds after a 3-mo. interval. It appears that retention loss and the superior performance of the deprived group can be traced to changes in stimulus-preference error. The results are consistent with experiments using short memory intervals.
Resonant width and energy determined by photoionization from excited divalent atoms.

Explicit examples are presented to illustrate the presence of a more symmetric resonant structure in spectra from bound excited states of a divalent atom. Comparison between the theoretical ground-state and bound excited-state photoelectron spectra shows that both the resonant energy ${\mathit{E}}_{\mathit{r}}$ and the resonant width \ensuremath{\Gamma} of a doubly excited autoionization state of a divalent atom (e.g., alkaline-earth-metal atom) can be determined experimentally from photoionization originated from a bound excited state more effectively.
Bacterial Infection and Wasting in Neonatally Thymectomized Rats.

SummaryThe incidence of intercurrent bacterial infections and wasting was considerably higher among neonatally thymectomized rats than in splenectomized or sham-operated controls. Administration of oxytetracycline or implantation of thymus auto-grafts immediately after thymectomy markedly reduced the incidence of bacterial infection and wasting in thymectomized rats. Oxytetracycline-treated thymectomized and control animals showed a considerably more effective antibody response to horse serum than untreated controls. Bacterial infection, usually in the form of abscesses in the region of the ablated thymus or bronchopulmonary inflammation, was noted in all wasted animals. A predominantly plasmacytic inflammatory reaction and elevation of serum gamma globulin level were observed in most wasted neonatally thymectomized rats in spite of their lymphopenia and splenic atrophy. The findings suggest that bacterial infections, presumably acquired early in life, contribute to the subsequent development of immunolog...
Perinatal choline deficiency produces abnormal sensory inhibition in Sprague-Dawley rats.

Abstract Adequate choline levels in rodents during gestation have been shown to be critical to several functions, including certain learning and memory functions, when tested at adulthood. Choline is a selective agonist for the α7 nicotinic receptor which appears in development before acetylcholine is present. Normal sensory inhibition is dependent, in part, upon sufficient numbers of this receptor in the hippocampus. The present study assessed sensory inhibition in Sprague–Dawley rats gestated on normal (1.1 g/kg), deficient (0 g/kg) or supplemented (5 g/kg) choline in the maternal diet during the critical period for cholinergic cell development (E12–18). Rats gestated on deficient choline showed abnormal sensory inhibition when tested at adulthood, while rats gestated on normal or supplemented choline showed normal sensory inhibition. Assessment of hippocampal α-bungarotoxin to visualize nicotinic α7 receptors revealed no difference between the gestational choline levels. These data suggest that attention to maternal choline levels for human pregnancy may be important to the normal functioning of the offspring.