cssi/SciSciGPT-SciSciNet huggingface dataset:
Cooperative binding of Stat1–2 heterodimers and ISGF3 to tandem DNA elements

Interferon (IFN)-alpha-activated Stat1 homodimers and Stat1-2 heterodimers bind to GAS elements, whereas the transcription factor ISGF3, which contains Stat1, Stat2 and p48, binds to ISREs. We now find that Stat1-2 dimers can form heterotetramers on tandem GAS sites and that the heterotetramers have a much higher binding affinity for a double GAS site than do heterodimers for a single site, suggesting cooperativity mediated through protein-protein interactions. Stat1-2 heterotetramers can also be detected with a single GAS site, again indicating cooperativity mediated through protein-protein interactions. Deleting 40 amino acid residues from the N-terminus of Stat1 abolished Stat1-Stat2 heterotetramer formation, but did not affect heterodimer formation and an N-terminal peptide containing the first 120 residues of Stat2 inhibited heterotetramer formation but did not affect heterodimer formation. Thus, the N-terminal regions of both Stat1 and Stat2 are important for cooperative DNA binding, and heterodimers probably interact with each other through these regions. Cooperative binding of ISGF3 was also observed using the tandem ISREs from the IFN-alpha responsive promoter of the 6-16 gene. A more abundant and larger complex was formed with a probe containing two ISREs than with a probe containing a single ISRE. The N-terminal regions of both Stat1 and Stat2 are important for the cooperative binding of ISGF3 to tandem ISREs but not to a single site. The cooperative DNA-binding activities of ISGF3 and Stat1-2 dimers are likely to contribute to the transcriptional activation of those IFN-alpha-responsive genes that have tandem DNA elements.
Redox Chemistry and [Au(CN)(2)] in the Formation of Gold Metabolites.

The role of hypochlorite ion, which can be generated by the enzyme myleoperoxidase, in the biochemistry of gold(I) anti-arthritic drugs was investigated. Sodium hypochlorite (OCl(-)) directly and rapidly oxidizes AuSTm, Au(CN)(2) (-), AuSTg (gold thioglucose) and auranofin (Et(3)PAuSATg). The resulting gold(III) species were detected by an Ion Chromotography Ion-Pairing technique that was developed to distinguish gold(I) and gold(III). Formation of Au(III) was also demonstrated spectrophotometrically after the conversion to AuCl(4) (-). The reactions of AuSTm, AuSTg, and auranofin are complex and gold(III) appears only after the initial oxidation of the thiolate (and phosphine) ligands.The enzymatic reaction, using MPO with H(2)O(2) and Cl(-) as substrates, leads to slow oxidation of Au(CN)(2) (-), AuSTm or AuSTg. The extent and rate of reaction depend on the concentrations of MPO, H(2)O(2), and Au(I). The continued presence of Au(I) during the initial stages of reaction (oxidation of the thiolates in AuSTm and AuSTg) and the conversion to Au(III) in the latter stages of the reaction were demonstrated. Au(CN)(2) (-), a gold metabolite, binds tightly to serum albumin. Unlike other gold(I) complexes, aurocyanide reacts almost negligibly at Cys-34 via ligand exchange. Instead, there is a strong association (K(1) = 5.5 x 10(4) and K(2) = 7.0 x 10(3); n(1) = 0.8 and n(2) = 3) of intact Au(CN)(2) (-). The full extent of binding is revealed only by equilibrium methods such as NMR or ultrafiltration; the bound gold dissociates extensively on conventional gel-exclusion columns and partially on Penefesky spun columns.The immunological and pharmacological significance of these results are discussed.
An Advective Atmospheric Mixed Layer Model for Ocean Modeling Purposes: Global Simulation of Surface Heat Fluxes

Abstract A simple model of the lowest layer of the atmosphere is developed for coupling to ocean models used to simulate sea surface temperature (SST). The model calculates the turbulent fluxes of sensible and latent heat in terms of variables that an ocean model either calculates (SST) or is forced by (winds). It is designed to avoid the need to specify observed atmospheric data (other than surface winds), or the SST, in the surface flux calculations of ocean models and, hence, to allow a realistic representation of the feedbacks between SST and the fluxes. The modeled layer is considered to be either a dry convective layer or the subcloud layer that underlies marine clouds. The turbulent fluxes are determined through a balance of horizontal advection and diffusion, the surface flux and the flux at the mixed layer top, and, for temperature, radiative cooling. Reasonable simulations of the global distribution of latent and sensible heat flux are obtained. This includes the large fluxes that occur east of ...
Interleukin-2 Receptor Signaling: At the Interface between Tolerance and Immunity

Interleukin-2 receptor (IL-2R) signaling regulates tolerance and immunity. Here, we review recent work concerning the structure, signaling, and function of the IL-2R, emphasizing the contribution of IL-2 for T cell-dependent activity in vivo. IL-2R signaling influences two discrete aspects of immune responses by CD8 + T cells, terminal differentiation of effector cells in primary responses, and aspects of memory recall responses. IL-2 also delivers essential signals for thymic development of regulatory T (Treg) cells and later to promote their homeostasis and function. Each of these outcomes on T effector and Treg cells requires distinct amounts of IL-2R signaling, with low IL-2R signaling sufficient for many key aspects of Treg cells. Thus, tolerance is readily maintained and favored with limited IL-2.
Analytical modeling and mitigation techniques for the energy hole problem in sensor networks

In this paper we investigate the problem of uneven energy consumption in a large class of many-to-one sensor networks. In a many-to-one sensor network, all sensor nodes generate constant bit rate (CBR) data and send them to a single sink via multihop transmissions. This type of sensor network has many potential applications such as environmental monitoring and data gathering. Based on the observation that sensor nodes sitting around the sink need to relay more traffic compared to other nodes in outer sub-regions, our analysis verifies that nodes in inner rings suffer much faster energy consumption rates (ECR) and thus have much shorter expected lifetimes. We term this phenomenon of uneven energy consumption rates as the ''energy hole'' problem, which may result in severe consequences such as early dysfunction of the entire network. We proposed analytical modeling for this problem, which can help understand the relevance of different factors on energy consumption rates. Using this model, we study the effectiveness of several existing approaches towards mitigating the ''energy hole'' problem, including deployment assistance, traffic compression and aggregation. We have used simulation results to validate our analysis.
Deep Circulation of the North Atlantic over the Last 200,000 Years: Geochemical Evidence

Variations in the cadmium/calcium ratio of North Atlantic Deep Water are recorded in the fossil shells of benthic foraminifera. The oceanic distribution of cadmium is similar to that of the nutrients, hence the cadmium/calcium ratio in shells records temporal variations in nutrient distributions. Data from a North Atlantic sediment core show that over the past 200,000 years there has been a continuous supply of nutrient-depleted waters into the deep North Atlantic. The intensity of this source relative to nutrient-enriched southern waters diminished by about a factor of 2 during severe glaciations. This evidence combined with carbon isotope data indicates that the continental carbon inventory may have been less variable than previously suggested.
Arthroscopic-assisted core decompression of the humeral head

Humeral head osteonecrosis is a progressive disease that requires prompt diagnosis and treatment. Core decompression is a viable treatment option for early-stage cases. Most surgeons perform core decompression by arthroscopically visualizing the necrotic area of bone and using a cannulated drill to take a core. Several attempts are frequently needed to reach the proper location. In the hip multiple passes are associated with complications. We describe the use of an anterior cruciate ligament (ACL) tibial drill guide to precisely localize the area of necrotic bone. Diagnostic arthroscopy is performed to assess the areas of osteonecrosis. Core decompression is performed by use of an ACL tibial guide, brought in through the anterior or posterior portal to precisely localize the necrotic area in preparation for drilling. Under image intensification, Steinmann pins are advanced into the area of osteonecrosis. Once positioned, several 4-mm cores are made. We treated 3 patients with this technique, and all had immediate pain relief. The use of the ACL guide allows precise localization of the area of humeral head involvement and avoids multiple drillings into unaffected areas. Initial indications are that arthroscopic-assisted core decompression with an ACL guide is an effective alternative to previously used methods.
Cr-ZnSe Passively Q-switched fiber-bulk Ho:YAG hybrid laser

The objective of this work was to develop a compact and efficient Tm-fiber-Ho:YAG, hybrid laser passively Q-switched by Cr:ZnSe saturable absorber. We used a folded semi-hemispherical 10 cm long cavity with a plane output coupler and a 0.5 m concave high reflector. In these experiments we studied the performance of two high optical quality Cr:ZnSe crystals as saturable absorbers with initial transmissions of 93.9% and 70% at 2.1 μm. With the 93.9% transmission crystal, passive Q-switching was realized with a maximum output power of 5 W, pulse energy of 0.5 mJ, pulse duration of 150 ns, and Q-switched-to-CW-mode extraction efficiency of 60%. With the 70% transmission crystal, passive Qswitching was achieved with a 75% Q-switched-to-CW-mode extraction efficiency, pulse energy of 3 mJ, and duration of 7ns. The laser demonstrated sustained damage-free, TEM000 operation with 0.5 MW of peak power showing promise for applications requiring high-peak-power, diffraction-limited beams, and single-frequency regimes of operation.
Multidrug-resistant Salmonella and nosocomial infections

Nosocomial infections are a serious threat to optimum patient care. In addition, nosocomial infections can have far-reaching consequences for the hospital personnel and the financial aspects of the hospital. Nosocomial infections with Salmonella spp have been described among hospitalized equine populations more frequently than any other agent. Salmonella spp associated with hospitalized equids often possess more antimicrobial resistance determinants than do Salmonella spp isolated from healthy horses in the general population. There is little evidence to suggest that resistant salmonellae are more virulent than nonresistant forms. MDR forms of Salmonella complicate the selection of appropriate antimicrobials when they are indicated, however. Furthermore, the use of some antimicrobials may apply selection pressure toward enhanced ability of MDR Salmonella to colonize equine patients. Further research should help to elucidate the risky uses of antimicrobials in the hospital setting and define the role of disinfectants and treatments such as NSAIDs in the ecology of MDR forms of nosocomial infections, including Salmonella. In the meantime, thoughtful selection of when and how to use antimicrobials in equine patients, together with deliberate selection of which antimicrobials to use based on monitoring data and other factors, such as safety and spectrum, is advised.
Reporting fish growth: A review of the basics

Aquaculturists typically report growth using absolute (g/d), relative (Vo increase in body weight), and specific growth rates (Told). Less frequently, von Bertalanffy Growth Functions (VBGF) are used. Each of these rates is a numerical representation of growth which assumes a specific relationship between size and time (linear, exponential, or asymptotic). Aquaculturists typically determine size at time throughout their experiments. Unfortunately, the intermediate data points are usually ignored when computing growth rates (except for VBGF) and the appropriateness of the method for calculating growth for a particular data set is not tested. This paper reviews the basis and computation of each of the growth rates in an effort to encourage aquaculturists to use the appropriate growth rates.
Use of a Sample Translation Technique to Minimize Adverse Effects of Laser Irradiation in Surface-Enhanced Raman Spectrometry

Surface-enhanced Raman spectroscopy (SERS) has proven to be a very powerful tool in the analysis of a wide range of compounds. However, continuous irradiation of the laser beam over the SERS substrate can promote the gross decomposition of the sample analytes and significantly broaden and diminish the intensities of observed spectral bands. In addition, the incident radiation can promote thermal or photolytic fragmentation of analytes, thereby altering the observable bands and possibly leading to a misinterpretation of analytical data. Finally, chemical or morphological changes in the SERS substrate are possible. This work presents the use of a sample translation technique (STT) as a means to minimize these adverse effects. By spinning the sample rapidly, the effective residence time of analytes and substrate within the irradiated zone is dramatically decreased without reduction of spectral acquisition time or the density of analyte in the zone. The technique is studied by acquiring SERS spectra of Naproxen USP, riboflavin, folic acid, Rhodamine 6G, and 4-aminothiophenol using silver islands on glass and silver-poly(dimethylsiloxane) composite substrates under various spinning and stationary conditions. In all cases, spectra show improvements upon spinning at laser powers as low as 4.2 (±0.1) mW. Specific differences in the appearance of the spectra and the potential use of STT for improved SERS qualitative and quantitative determinations are presented.
COMMUNICATOR EFFECTIVENESS IN PRODUCING PUBLIC CONFORMITY AND PRIVATE ATTITUDE CHANGE.

One of the most widely held generalizabons m social psychology IS that the efiEectiveness of a persuasive communication IS mcreased if its source is "credible " The early research by Hovland and Weiss (1951) and by Kelman and Hovland (1953) which gave substance to this conclusion has recently been extended to demonsbate the efficacy of credible communicators even when the amount of change advocated is extreme (Aronson, Tumer, & Carlsmith, 1963) Credibility has been defined traditionally m terms of communicator atbibutes which are perceived by the audience as relevant to the topic bemg communicated Two of its major components which have been experimentally manipulated are the communicator's ability and his motives for personal gam, or what Hovland, Jams, and Kelley (1953) term "expertness" and "trustworthmess," respectively However, positive and negative source baits which bear no objective relevance to the topic of the commumcabon can also be effective m modifying attitudes toward its conclusions The potent effect of such irrelevant communicator characteristics has long been utilized m pracbcal mfluence situabons outside the laboratory by lawyers aware of the miportance of
An efficient annealing algorithm for global optimization in Boltzmann machines

This article proposes a new annealing algorithm for Boltzmann machines. This algorithm uses an exponential formula for temperature scheduling that produces remarkably better solutions for global optimization. The superiority of the new algorithm is shown by computer simulations of several examples on the Boltzmann machine and its variants. The new algorithm is also shown to have better properties compared to the Generalized Simulated Annealing (GSA) and other similar algorithms.
ErratumErratum to “In vitro evolution of H5N1 avian influenza virus toward human-type receptor specificity” [Virology 422 (2011) 105–113]

a Influenza Division, Centers for Disease Control and Prevention, 1600 Clifton Road, Atlanta, GA 30333, USA b Department of Chemical Physiology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA c Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA d Glycan Array Synthesis Core-D, Consortium for Functional Glycomics, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
Assessment of University Foodservice Employee Job Satisfaction and Strategy Formulation for Managerial Practitioners

ABSTRACT The facets of job satisfaction and their perceived importance to college and university foodservice employees (n = 194) were assessed. The survey instrument consisted of three parts: the Job Satisfaction Survey (Spector, 1985) was used to measure facets of job satisfaction and the level of total satisfaction; perceived importance questions for the corresponding job facets; and demographic items. The respondents rated the subscales “nature of work” and “supervision” the highest and the subscales “pay” and “promotion” the lowest. The results of facet satisfaction scores and corresponding perceived importance scores were then paired to be plotted on the Importance-Performance Analysis Grid (Martilla & James, 1977) to provide a strategy for foodservice managers to counteract employee dissatisfaction.
Temperature regulation in laboratory mammals following acute toxic insult

The purpose of this paper is to provide a concise review of the effects of acute chemical toxicity on thermoregulation in mammals, with particular emphasis on the effects of xenobiotic compounds in laboratory rodents. It has been shown that acute administration of compounds such as nickel, cadmium, lead, and some pesticides causes a reduction in the body temperature of mice when tested at normal room temperatures. When provided with the option of selecting their preferred ambient temperature, the toxic-treated animals generally select cool temperatures which augment the hypothermic effect of the toxic compounds. It would appear that many of the xenobiotic compounds have central as well as peripheral effects on the control of body temperature. That is, the hypothermic animals select cool temperatures, a condition indicative of a centrally mediated decrease in the set-point. This decrease in set-point, or regulated hypothermia, may be beneficial to survival since the lethality of most xenobiotic compounds increases with rising body temperature. The observation that acute doses of various compounds leads to behaviorally and autonomically mediated changes in body temperature may have significant implications for the measurement of other biological effects of these chemical agents (e.g., CNS dysfunction, bradycardia, immunosuppression).
Advanced Design Composite Material Aircraft Study

The objective of this study was to apply advanced composites to a completely new fighter/attack aircraft in an unconstrained manner, in order to obtain an aircraft which is smaller, lighter, and cheaper than an equivalent advanced metal counterpart. Design criteria and requirements were defined and trade studies performed to identify the preferred air vehicle. A structural arrangement of the selected configuration was established to verify the anticipated weight and cost savings and selected critical structural sections were designed in detail.
The CO molecule: the role of basis set and correlation treatment in the calculation of molecular properties

Abstract Although Hartree-Fock wave functions can provide a semi-quantitative description of the electronic structure of molecules, accurate predictions cannot be made without explicit inclusion of the effects of electron correlation. In correlated calculations, the accuracy of the wave function is determined by two expansions: the many-electron expansion in terms of molecular orbitals that defines the form of the wave function and the basis set used to expand the one-electron molecular orbitals. Thus, to assess the accuracy of a given wave function (correlation method), it is necessary to examine the dependence of a given property on the basis set. In this work, systematic sequences of correlation consistent basis sets ranging in size from double- to sextuple-zeta (cc- pVnZ ) have been employed together with several commonly used electron correlation methods, e.g., MPn ( n = 2 − 4), CCSD, CCSD(T), and MRCI, to calculate the spectroscopic constants and selected molecular properties of the carbon monoxide molecule. The computed spectroscopic constants show excellent convergence toward the complete basis set (CBS) limit, and the intrinsic errors of each correlation method have been assessed and compared. The effects of correlating the ls-like core electrons have also been determined using a sequence of core-valence cc- pCVnZ basis sets with the CCSD(T) and ACPF methods. A number of other properties have also been calculated for each correlation method as a function of the correlation consistent basis set: the dipole moment, quadrupole moment, dipole polarizability, and the first and second hyperpolarizabilities. For these calculations, results using the aug-cc- pVnZ basis sets are compared with those obtained using basis sets incorporating another complete shell of diffuse functions, d-aug-cc- pVnZ . In each case well-behaved convergence toward the CBS limit is observed for each theoretical method. For both the calculated spectroscopic constants and molecular properties, comparisons are made to previous calculations and the available experimental data.
Interview with John C. Cushman.

John C. Cushman was born in eastern Pennsylvania near Philadelphia and attended public schools. He studied biology as an undergraduate at Ursinus College (BS 1982), a small, private liberal arts college. After receiving his MS and PhD degrees (1984 and 1987, respectively) in microbiology at the Waksman Institute of Microbiology at Rutgers University, New Brunswick, NJ, he conducted postdoctoral research as a National Science Foundation Fellow in Plant Biology on crassulacean acid metabolism (CAM) induction by salinity and water-deficit stress at the University of Arizona, Tucson.
Look left, look right, look left again: an application of fractal symbolic analysis to linear algebra code restructuring

Fractal symbolic analysis is a symbolic analysis technique for verifying the legality of program transformations. It is strictly more powerful than dependence analysis; for example, it can be used to verify the legality of blocking LU factorization with pivoting, a task for which dependence analysis is inadequate. In this paper, we show how fractal symbolic analysis can be used to convert between left- and right-looking versions of three kernels of central importance in computational science: triangular solve, Cholesky factorization, and LU factorization with pivoting.
The nosologic relationship between generalized anxiety disorder and major depression

Generalized anxiety disorder (GAD) has undergone a series of revisions in its diagnostic criteria that has moved it, nosologically, away from its original affiliation with panic disorder (PD) and closer to major depressive disorder (MDD). This, together with its high comorbidity and putative shared genetic risk with MDD, has brought into question its place in future psychiatric nosology, prompting the planners of Diagnostic and Statistical Manual-V (DSM-V) and International Classification of Diseases-11 (ICD-11) to set up a workgroup tasked to better understand the relationship between GAD and MDD. This review attempts to summarize the extant data to compare GAD and MDD on a series of research validators to explore this relationship. Although insufficient data currently exist for GAD in several key validator classes, tentative conclusions can be drawn on the diagnostic status of GAD in relation to MDD. Although GAD possesses substantial overlap with MDD in the areas of genetics, childhood environment, demographics, and personality traits, this tends to hold true for other anxiety disorders (ADs) as well, with the strongest evidence for PD. Data from life events, personality disorders, biology, comorbidity, and pharmacology are mixed, showing some areas of similarity between GAD and MDD but some clear differences, again with a moderate degree of nonspecificity. Thus, although the bulk of evidence supports a close underlying relationship between them, the relatively nonspecific nature of these findings provides little more reason to question the nosologic validity of GAD in relation to MDD than that of some other anxiety disorders.
Pilot Study of Safety Belt Usability for Vehicle Occupants Seated in Wheelchairs

This study investigates the usability of wheelchair occupant restraint systems (WORS) that are used for crash protection of individuals seated in wheelchairs during motor vehicle transit. Ten independent adults with significant functional limitations who use wheelchairs for primary mobility were observed and interviewed while performing reach and manipulation tasks associated with WORS usage. Participants' opinions on ease of use and comfort-related factors were obtained for four occupant restraint scenarios. The study results show evidence of user problems with common WORS designs for use by wheelchair-seated individuals with significant functional limitations. Results from this pilot study suggest redesign of latch plates and buckles used in WORS to enable wheelchair-seated individuals with functional limitations to don and buckle belt restraints more easily and independently. Additionally, this study provides guidance to occupant-restraint manufacturers and wheelchair designers regarding belt-restraint...
Biopolymer mechanics: stability, dynamics, and statistics

Motivated by the dynamics of twisted biopolymers such as DNA and filaments of Bacillus subtilis, we formulate the over-damped dynamics of a twisted elastic rod. The development exploits the 'natural' frame, in which curve dynamics are described by a pair of non-linear partial differential equations, partitioning bending from twisting motions and highlighting their geometric interplay. A number of open problems are highlighted, along with connections with questions about cellular structure and statistical dynamics.
Wind estimation and prediction for adaptive optics control systems

Performance of adaptive optics (AO) systems is limited by the tradeoff between photon noise at the wavefront sensor and temporal error from the duty cycle of the controller. Optimal control studies have shown that this temporal error can be reduced by predicting the turbulence evolution during the control cycle. We formulate a wind model that divides the wind into two components: a quasi-static layer and a wind-driven frozen-flow layer. Using this internal wind model, we design a computationally efficient controller that is able to estimate and predict the dynamics of a single windblown layer and simulate this controller using on-sky data from the Palomar Adaptive Optics system. We also present results from a laboratory implementation of multi-conjugate AO (MCAO) with multi-layer wind estimation in conjunction with tomographic reconstruction. The tomography engine breaks the atmosphere into discrete layers, each with its own wind estimator. The resulting MCAO control algorithm is able to track and predict the motion of multiple wind layers with wind estimates that update at every controller cycle. Once the wind velocities of each layer are known, the deformable mirror update speed is no longer limited by the wavefront sensor exposure time so it is possible to send multiple correction updates to the deformable mirror each control cycle in order to dynamically track wind layers across the telescope aperture. The result is better dynamics in the feedback control system that enables higher closed-loop bandwidth for a given wavefront sensor frame rate.
Constructing the “Good Mother”: The Experience of Mothering Ideologies by Work Status

The purpose of this study was to explore how mothers construct their worker–parent identity within a cultural context of competing mothering ideologies. We used narrative data from interviews with 95 married mothers with at least 1 child under the age of 5 to compare the construction of intensive mothering expectations by middle-class full-time employed mothers, part-time employed mothers, and at-home mothers. Although previous research has shown that mothers alter work status to live up to intensive mothering expectations, our results show that mothers also alter their construction of intensive mothering expectations to reconcile these demands with their work status choices. The results also suggest that mothers with different employment decisions differ in their construction of Y. Elvin-Nowak and H. Thomsson's (2001) 3 discursive positions—accessibility, happy mother/happy child, and separation of work and home.
Single kinesin molecules crossbridge microtubules in vitro.

Abstract Kinesin is a cytoplasmic motor protein that moves along microtubules and can induce microtubule bundling and sliding in vitro. To determine how kinesin mediates microtubule interactions, we determined the shapes and mass distributions of squid brain kinesin, taxol-stabilized microtubules (squid and bovine), and adenosine 5'-[beta, gamma-imido]triphosphate-stabilized kinesin-microtubule complexes by high-resolution metal replication and by low-temperature, low-dose dark-field scanning transmission electron microscopy of unfixed, directly frozen preparations. Mass mapping by electron microscopy revealed kinesins loosely attached to the carbon support as asymmetrical dumbbell-shaped molecules, 40-52 nm long, with a mass of 379 +/- 15 kDa. The mass distribution and shape of these molecules suggest that these images represent kinesin in a shortened conformation. Kinesin-microtubule complexes were organized as bundles of linearly arrayed microtubules, stitched together at irregular intervals by cross-bridges typically < or = 25 nm long. The crossbridges had a mass of 360 +/- 15 kDa, consistent with one kinesin per crossbridge. These results suggest that kinesin has a second microtubule binding site in addition to the known site on the motor domain of the heavy chain; this second site may be located near the C terminus of the heavy chains or on the associated light chains. Thus, kinesin could play a role in either crosslinking or sliding microtubules.
Finite-size Monte Carlo results for anisotropic quantum Hall liquids

At low temperatures, two-dimensional electron systems in a perpendicular magnetic field exhibit remarkable quantum phenomena. In these extreme conditions, strongly correlated electron systems stabilize in different quantum phases as the filling factor of Landau levels is varied. In this Brief Report we present finite-size Monte Carlo simulation results for anisotropic quantum Hall liquid states observed at certain even-denominator filling factors. The anisotropic electronic liquid phases are described by a broken rotational symmetry wave function. Our investigations of systems of few electrons in disk geometry indicate that an anisotropic liquid-crystalline quantum Hall phase with broken rotational symmetry is energetically favored relative to an isotropic liquid one.
Line intensities in HBr vibration-rotation spectra

Abstract Accurate analytic expressions for electric dipole transition moments for 0–1, 0–2, and 1–2 band vibration-rotation absorption spectra are obtained following an approach developed by the authors in a previous paper. The expressions, which include anharmonic effects to the quintic potential constant, are essentially identical to those independently derived by Toth, Hunt, and Plyler. Specific calculations are made for HBr vibration-rotation intensities, comparisons being made with the observations of Babrov et al. and Rao and his colleagues. It is concluded that the data of Babrov et al. are reasonably selfconsistent, as gauged through the present theory, leading to the dipole moment function M(x) = (0.824 ± 0.02) + (0.6438 ± 0.006)x + (0.167 ± 0.06)x2 Debye, x being the relative internuclear separation, (R − R e ) R e . The more recent higher resolution measurements of Rao and his collaborators, which lead to the dipole moment function M(x) = 0.826 + 0.482x + 0.037x2 Debye, are far less self-consistent. It is argued that the ultimate resolution of present discrepancies cannot lie in further theoretical refinements.
Craft production in Detroit: Spatial, temporal, and social relations of work in the home

Abstract People who produce craft work in their home provide a case for the study of the integration of productive and reproductive occupations in the home. This study of crafters in the Metropolitan Detroit area indicates that the boundaries between domains of work and home are fluid, changing according to the time of the year, the needs of family members, and economic pressures. The autonomy to move between domains without having to ask “permission” is a highly valued attribute of this type of work.
Identification of Serine Esterases in Tissue Homogenates

Abstract Serine esterases react with [3H]diisopropylphosphofluoridate ([3H]DFP) to produce radioactive adducts that can be resolved by denaturing slab gel electrophoresis. To identify an esterase or its catalytic subunit, a potential substrate was included in the reaction mixture with the expectation that it would suppress the enzyme's reaction with [3H]DFP. The nature of the enzyme could be inferred from the character of the substrates that suppress labeling. The validity of this analytical method was tested with two serine proteases, trypsin and α-chymotrypsin, and two serine esterases, acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE), and several of their natural or model substrates or inhibitors. Application of the method to complex biological systems was tested with chicken embryo brain microsomes. Trypsin labeling with [3H]DFP was suppressed by α-N-benzoyl- l -arginine ethyl ester (BAEE) and poly- l -lysine but not by benzoyl- l -tyrosine ethyl ester (BTEE). [3H]DFP labeling of chymotrypsin was suppressed by both BAEE and BTEE. Labeling of AChE and BuChE was suppressed by their natural and some related substrates and inhibitors. [3H]DFP reacted with brain microsomes to produce nine distinct radioactive bands. When the relevant substrates and inhibitors of AChE were included in the reaction mixtures, labeling of only the 95-kDa band was suppressed, implicating it as AChE. Labeling of the 85- and 79-kDa bands was inhibited by butyrylcholine, suggesting that these proteins have BuChE activity.
Respiratory and circulatory analysis of CO2 output during exercise in chronic heart failure.

BACKGROUNDThe output of carbon dioxide (VCO2) is controlled by both hemodynamics and ventilation. To understand VCO2 in patients who have chronic heart failure (CHF), we studied 14 patients who had New York Heart Association functional class III failure by measurements of hemodynamics, ventilation, and arterial and venous blood gases at rest and at 50 W of cycle ergometry exercise.METHODS AND RESULTSFick principle analysis of VCO2 showed that because of a limited increase in cardiac output, CHF patients widened their venoarterial CO2 content difference from 4.9 +/- 3.5 ml/dl at rest to 11.1 +/- 4.0 ml/dl with exercise (p less than 0.05). This increase in CO2 content difference was achieved with no change in venous CO2 content (from 54.3 +/- 3.3 ml/dl at rest to 54.5 +/- 4.8 ml/dl at exercise, p = NS); however, there was a decrease of arterial CO2 content (from 49.4 +/- 3.7 ml/dl at rest to 43.4 +/- 2.3 ml/dl with exercise, p less than 0.05). Modeling of the CO2 tension-content relation showed that there w...
Characterization of pediatric wheelchair kinematics and wheelchair tiedown and occupant restraint system loading during rear impact

This study characterizes pediatric wheelchair kinematic responses and wheelchair tiedown and occupant restraint system (WTORS) loading during rear impact. It also examines the kinematic and loading effects of wheelchair headrest inclusion in rear impact. In two separate rear-impact test scenarios, identical WC19-compliant manual pediatric wheelchairs were tested using a seated Hybrid III 6-year-old anthropomorphic test device (ATD) to evaluate wheelchair kinematics and WTORS loading. Three wheelchairs included no headrests, and three were equipped with slightly modified wheelchair-mounted headrests. Surrogate WTORS properly secured the wheelchairs; three-point occupant restraints properly restrained the ATD. All tests used a 26km/h, 11g rear-impact test pulse. Headrest presence affected wheelchair kinematics and WTORS loading; headrest-equipped wheelchairs had greater mean seatback deflections, mean peak front and rear tiedown loads and decreased mean lap belt loads. Rear-impact tiedown loads differed from previously measured loads in frontal impact, with comparable tiedown load levels reversed in frontal and rear impacts. The front tiedowns in rear impact had the highest mean peak loads despite lower rear-impact severity. These outcomes have implications for wheelchair and tiedown design, highlighting the need for all four tiedowns to have an equally robust design, and have implications in the development of rear-impact wheelchair transportation safety standards.
Beltrami's model and the independence of the parallel postulate

E. Beltrami in 1868 did not intend to prove the consistency of non-euclidean plane geometry nor the independence of the euclidean parallel postulate. His approach would have been unsuccessful if so intended. J. Houel in 1870 described the relevance of Beltrami's work to the issue of the independence of the euclidean parallel postulate. Houel's method is different from the independence proofs using reinterpretation of terms deployed by Peano about 1890, chiefly in using a fixed interpretation for non-logical terms. Comparing the work of Beltrami and Houel with the treatment of non-euclidean geometry after the development of the axiomatic method in the 1890s indicates an important shift in mathematicians’ attitudes towards mathematical theories.
Structural Dynamics of the S4 Voltage-Sensor Helix in Lipid Bilayers Lacking Phosphate Groups

Voltage-dependent K + (Kv) channels require lipid phosphates for functioning. The S4 helix, which carries the gating charges in the voltage-sensing domain (VSD), inserts into membranes while being stabilized by a protein-lipid interface in which lipid phosphates play an essential role. To examine the physical basis of the protein-lipid interface in the absence of lipid phosphates, we performed molecular dynamics (MD) simulations of a KvAP S4 variant (S4mut) in bilayers with and without lipid phosphates. We find that, in dioleoyltrimethylammoniumpropane (DOTAP) bilayers lacking lipid phosphates, the gating charges are solvated by anionic counterions and, hence, lack the bilayer support provided by phosphate-containing palmitoyloleoylglycerophosphocholine (POPC) bilayers. The result is a water-permeable bilayer with significantly smaller deformations around the peptide. Together, these results provide an explanation for the nonfunctionality of VSDs in terms of a destabilizing protein-lipid interface.
A 5Gb/s 2×2 MIMO crosstalk cancellation scheme for high-speed I/Os

We describe a multiple-input multiple-output crosstalk cancellation (MIMO-XTC) architecture, particularly applicable to single-ended I/O. The MIMO architecture efficiently cancels crosstalk and improves jitter and eye-opening at the same time. A continuous-time prototype design was fabricated using a 130nm CMOS process and occupies 0.03mm2of die area. The XTC equalizer performance has been verified for a variety of FR4 channel spacings and data rates. Measured eye diagrams show that the jitter pp reduces by 67%UI and the vertical eye opening increases by 58.2% at 5Gb/s. The prototype MIMO-XTC circuit consumes 2.8 mW/Gbps/lane which is roughly 2 times lower than other XTC schemes.
Hippocampal aging in rats: a morphometric study of multiple variables in semithin sections.

Abstract Quantitative analyses of pyramidal cells, astrocytes, dark glia (microglia and dark oligodendrocytes), lipofuscin accumulation and astrocyte reactivity were carried out in semithin sections from field CA3 of the hippocampus of rats in 3 age groups (4–7 mo., 13–15 mo., 25–28 mo.). A decrease in neuronal density (∼25%) and an increase in dark glia were found in the oldest group. The astrocyte population was stable with age. Lipofuscin increased by 13–15 mo. and increased further by 25–28 mo. Qualitative examples of several kinds of glial reactivity are also described. Our observations indicate that hippocampal changes in aging rats exhibit some similarities to brain changes reported in other mammalian species, and also illustrate the value of semithin sections for examining multiple neuromorphologic correlates of brain aging.
Age-Associated Sperm DNA Methylation Alterations: Possible Implications in Offspring Disease Susceptibility

Recent evidence demonstrates a role for paternal aging on offspring disease susceptibility. It is well established that various neuropsychiatric disorders (schizophrenia, autism, etc.), trinucleotide expansion associated diseases (myotonic dystrophy, Huntington's, etc.) and even some forms of cancer have increased incidence in the offspring of older fathers. Despite strong epidemiological evidence that these alterations are more common in offspring sired by older fathers, in most cases the mechanisms that drive these processes are unclear. However, it is commonly believed that epigenetics, and specifically DNA methylation alterations, likely play a role. In this study we have investigated the impact of aging on DNA methylation in mature human sperm. Using a methylation array approach we evaluated changes to sperm DNA methylation patterns in 17 fertile donors by comparing the sperm methylome of 2 samples collected from each individual 9–19 years apart. With this design we have identified 139 regions that are significantly and consistently hypomethylated with age and 8 regions that are significantly hypermethylated with age. A representative subset of these alterations have been confirmed in an independent cohort. A total of 117 genes are associated with these regions of methylation alterations (promoter or gene body). Intriguingly, a portion of the age-related changes in sperm DNA methylation are located at genes previously associated with schizophrenia and bipolar disorder. While our data does not establish a causative relationship, it does raise the possibility that the age-associated methylation of the candidate genes that we observe in sperm might contribute to the increased incidence of neuropsychiatric and other disorders in the offspring of older males. However, further study is required to determine whether, and to what extent, a causative relationship exists.
The fine structural morphology of adrenal cortices of normal and stressed squirrel monkeys.

The fine structural morphology of the male squirrel monkey adrenal cortex has been examined. When compared to other laboratory animals, the squirrel monkey adrenal cortex secretes large amounts of cortisol and maintains extraordinarily high plasma cortisol levels for prolonged periods of time. The normal cortical cells have numerous mitochondria with either a tubulo-vesicular or lamellar internal membrane arrangement, a well-developed agranular endoplasmic reticulum which is arranged in juxtaposition to mitochondria and lipid droplets, several lysosomes, and numerous thin-walled blood vessels of large caliber, suggestive of a rich blood flow through the gland. These characteristics have heretofore been associated with hypersecretion. Their presence in the squirrel monkey cortex, known to have high secretory activity, lends credence to the correlation of hyperdevelopment of the agranular reticulum with increased rates of secretion of corticoids. During chair restraint, the plasma cortisol levels rise two to three fold. Adrenocortical cells thus stressed exhibit a depletion and disorientation of membranes both of the agranular endoplasmic reticulum and mitochondria and a loss of ribosomes, lysosomes and, to some degree, intracellular lipid. The animal appears to be responding maximally to the stress of chair restraint. These fine structural characteristics are interpreted as an example of an adrenal cortex in the process of becoming functionally exhausted, since these animals sometimes do not survive the stress of chair restraint.
CT Enterography: Noninvasive Evaluation of Crohn's Disease and Obscure Gastrointestinal Bleed

CT enterography (CTE) is a noninvasive imaging test using neutral intraluminal contrast and intravenous contrast to evaluate the small bowel. Multiphasic imaging is used in evaluating obscure gastrointestinal bleeding (OGIB), and single-phase enteric imaging is used for all other indications, including Crohn's disease (CD). CTE findings of CD include bowel wall thickening, mucosal hyperenhancement, and mural stratification. CTE findings of angiodyplasias include a vascular tuft visible during arterial phase and an early draining mesenteric vein. Early studies indicate that CTE is superior to barium examination in the evaluation of CD and is complementary to capsule endoscopy in the evaluation of OGIB.
The effect of 9-β-D-arabinofuranosyl-2-fluoroadenine and 1-β-D-arabinofuranosylcytosine on the cell cycle phase distribution, topoisomerase II level, mitoxantrone cytotoxicity, and DNA strand break production in K562 human leukemia cells

Antimetabolites and topoisomerase (topo) II-reactive drugs are frequently combined in the therapy of acute leukemia. The two types of agents are thought to be synergistic in their actions against malignant blasts but the mechanism for this synergism is incompletely described. This study sought to determine whether the combination of two rather than one antimetabolite with the topo II-reactive intercalator mitoxantrone would be greater than the effect of the single antimetabolite ara-C on mitoxantrone’s cytotoxic actions. We also aimed to determine a mechanism for synergism should it occur. The model system used was K562 human leukemia cells. The second antimetabolite selected was F-ara-A, the active form of fludarabine. The resultant combination (F-ara-A, ara-C, and a topo II-reactive drug) is one currently being tested against acute myelogenous leukemia in clinical trials. F-ara-A itself had little effect on the cytotoxicity or the topo II-mediated DNA cleaving actions of mitoxantrone, while ara-C potentiated these actions as it does those of other topo II-reactive drugs. Surprisingly F-ara-A enhanced the actions of ara-C on mitoxantrone-associated cytotoxicity by at least an order of magnitude. The effect of the addition of F-ara-A to ara-C on mitoxantrone-induced DNA cleavage was considerably smaller, but present. Antimetabolite treatment did not increase the amount of topo II within cells measured directly by immunoblotting or indirectly by quantifying the maximum number of topo II – DNA complexes stabilized by mitoxantrone. Rather, the antimetabolites altered the distribution of the cells in the cell cycle. Antimetabolite treatment caused a large increase in S-phase cells, a phase in which cells are more sensitive to topo II-reactive drugs than the associated topo II-mediated DNA cleavage would predict. Therefore, it is likely that this shift in the distribution of the cells within the cell cycle accounts for both the enhanced cytotoxicity of mitoxantrone in antimetabolite pretreated cells and the discrepancy between the magnitude of antimetabolite action on topo II-mediated DNA cleavage.