cssi/SciSciGPT-SciSciNet huggingface dataset:
Behavior of Mozzarella, Cheddar and processed cheese spread in lubricated and bonded uniaxial compression

The response of a material under uniaxial compression depends both on the bulk material properties and on the frictional effects at the sample-platen interface. Three commercial cheeses (cheddar, mozzarella and processed cheese spread) were studied in uniaxial compression. Frictional effects at the sample surface were examined under three conditions: (1) lubrication of the sample-platen interface; (2) bonding of the sample to the instrument platens; (3) samples neither bonded nor lubricated. The forces required to deform the cylindrical sample to a given strain level were highest for the bonded cases and lowest under lubricated conditions. The stress in lubricated compression, ρL, was calculated from Fh(πRρ2hρ)
Inhibition of Cystine Uptake Disrupts the Growth of Primary Brain Tumors

Glial cells play an important role in sequestering neuronally released glutamate via Na+-dependent transporters. Surprisingly, these transporters are not operational in glial-derived tumors (gliomas). Instead, gliomas release glutamate, causing excitotoxic death of neurons in the vicinity of the tumor. We now show that glutamate release from glioma cells is an obligatory by-product of cellular cystine uptake via system xc-, an electroneutral cystine-glutamate exchanger. Cystine is an essential precursor for the biosynthesis of glutathione, a major redox regulatory molecule that protects cells from endogenously produced reactive oxygen species (ROS). Glioma cells, but not neurons or astrocytes, rely primarily on cystine uptake via system xc- for their glutathione synthesis. Inhibition of system xc- causes a rapid depletion of glutathione, and the resulting loss of ROS defense causes caspase-mediated apoptosis. Glioma cells can be rescued if glutathione status is experimentally restored or if glutathione is substituted by alternate cellular antioxidants, confirming that ROS are indeed mediators of cell death. We describe two potent drugs that permit pharmacological inhibition of system xc-. One of these drugs, sulfasalazine, is clinically used to treat inflammatory bowel disease and rheumatoid arthritis. Sulfasalazine was able to reduce glutathione levels in tumor tissue and slow tumor growth in vivo in a commonly used intracranial xenograft animal model for human gliomas when administered by intraperitoneal injection. These data suggest that inhibition of cystine uptake into glioma cells through the pharmacological inhibition of system xc- may be a viable therapeutic strategy with a Food and Drug Administration-approved drug already in hand.
A GIS-based technique for linking landscape characteristics to non-point source nitrogen export potential: implications for contributing areas management

A Nitrate-N Leaching Index (NLI) is calculated and the results indicate that nitrogen loss in the study area occurs through both leaching and surface runoff. A non-linear regression model of trapping efficiency was combined with a first order decay model to examine the impact of soil characteristics, slope, vegetative cover, land use and distance to streams on the spatial pattern of non-point source nitrogen inputs to streams. The model evaluates the statistical significance of each landscape factor and provides an easy interpretation of the landscape delivery ratio of nitrogen based on a pixel-based characterisation of the watershed. The model was validated by comparing the distributions of the observed and estimated monthly nitrogen concentrations. The exploratory GIS-based method presented here can improve the understanding of the impact of landscape characteristics on nitrate-nitrogen contributing areas and therefore assist watershed management efforts.
A dual-processor solution for the MAC layer of a software defined radio terminal

Considerable work has been devoted to studying flexible computation structures for the physical layer of a software defined radio (SDR) terminal. However there has been almost no research on protocol processors for the upper layer protocols such as the media access control (MAC) and link protocol. A general purpose processor (GPP) is sufficient for the protocol processing of a single mode terminal. However, in the case of a multi-mode system required for SDR, there is a very wide set of possibilities for the MAC layer. In principle these too could be handled by a GPP. However, we show that a better solution is to use a GPP augmented by a small supplemental processor. The GPP is responsible for the relatively complex protocol operations in the active mode, and the supplemental processor handles the idle mode operations. This separation of responsibilities simplifies the implementation of hard real-time responses required by some protocols (for example IEEE 802.11), while maintaining the programmability needed to handle a wide range of protocols. In addition, this organization allows a significant power savings in the idle mode. This is important because the protocol processor must process a large number of tiny idle mode tasks whose aggregate effect over time dominates the power consumption in a wireless termina.As part of our study we develop a hardware model of the supplemental processor in Verilog and its software model in C. Using commercial CAD tools we synthesized out design and evaluated the power consumption and response time of the platform. Our results show that the proposed platform meets the real-time deadlines at low power while maintaining programmability.
Multitone radar design using software radio components

Recent developments in communications and RF technology have enabled system concept formulations and designs for low-cost radar systems using state-of-the-art software radio modules. One of the major benefits of using these RF communications products is the potential for generating frequency-agile waveforms that are re-programmable in real-time and potentially adapt to a scattering environment. In addition, recent simulation results [1] indicate that this type of system enables the development and implementation of multi-function RF systems that yield good performance within embedded shared-spectrum environments. This paper investigates the design and implementation of software radar systems via implementation of commercially available software radio modules. Specifically, the potential for developing alternative multi-tone radar systems that provide significant levels of information with respect to embedded indoor scattering environments is discussed. This approach is developed via the transform domain waveform synthesis/design and implementation of OFDM (Orthogonal Frequency Domain Multiplexing) waveforms and shows good potential for the future development of cooperative multi-function RF systems.
P/E changes: some new results

The P/E ratio is often used as a metric to compare individual stocks and the market as a whole relative to historical valuations. We examine the factors that affect changes in the inverse of the P/E ratio (E/P) over time in the broad market (S&P 500 Index). Our model includes variables that measure investor beliefs and changes in tax rates and shows that these variables are important factors affecting the P/E ratio. We extend prior work by correcting for the presence of a long-run relation between variables included in the model. As frequently conjectured, changes in the P/E ratio have predictive power. Our model explains a large portion of the variation in E/P and accurately predicts the future direction of E/P, particularly when predicted changes in E/P are large or provide a consistent signal over more than one quarter.
Thermodynamics of ionic surfactant solutions containing added strong electrolytes

Abstract Equations for osmotic and activity coefficients for ionic surfactant solutions have been extended to include the effects of added strong electrolytes. The equations are based on a mass-action model for surfactant aggregation and a rigorous thermodynamic treatment for mixed electrolyte solutions. Measured activity coefficient data for surfactants and for the added strong electrolyte are in good agreement with values calculated from the model. Equations for enthalpies, heat capacities, and volumes of solutions containing surfactant and added electrolyte are obtained directly from temperature and pressure derivatives of the osmotic and activity coefficient equations. Some activity coefficient data and some excess enthalpy data are compared with the model in this paper.
Structures, Energetics and Vibrational Frequencies of Cyclopropyne

The electronic structure of the lowest singlet and triplet states of cyclopropyne have been investigated using ab initio molecular quantum mechanics. Both double zeta (DZ) and double zeta plus carbon d function (DZ + d) basis sets have been used in conjunction with self-consistent-field (SCF), multiconfiguration (MC) SCF, and configuration interaction (CI) methods. Singlet cyclopropyne is predicted to be a transition state for the degenerate rearrangement of propadienylidene (H2C=C=C:). However, triplet cyclopropyne is a minimum on the C3H2 potential energy hypersurface and vibrational frequencies are predicted at two levels of theory. Structures and vibrational frequencies are compared with those of the relatively stable cyclopropene molecule.
Neurochemical recovery in the neocortex after colchicine lesions of the nucleus basalis magnocellularis in rats.

Abstract Neurochemical recovery was investigated in male, Fischer-344 rats up to 3 months after lesions of the nucleus basalis. Bilateral injections of colchicine (1.0 μg/site) into the nucleus basalis magnocellularis (NBM) resulted in a 30% decrease in choline acetyltransferase (ChAT) activity in frontal cortex 4 weeks after surgery, compared to unlesioned controls. ChAT activity in the frontal cortex gradually recovered to control levels by 12 weeks. The loss of ChAT-immunoreactive neurons in the NBM observed 4 weeks after surgery was still evident 12 weeks after surgery. These results suggest that surviving cholinergic neurons in the NBM contribute to recovery of ChAT activity in the neocortex.
Developmentally regulated expression of IGF binding protein-3 (IGFBP-3) in human placental fibroblasts: effect of exogenous IGFBP-3 on IGF-1 action

Abstract Preterm, human, placental fibroblasts exhibit growth rates, in vitro, that vary with gestational age. The observed increase in proliferation rate is associated with enhanced mitogenic responsiveness to IGF-1, IGFBPs can either potentiate or inhibit IGF action at the cellular level. The production of IGFBPs by placental fibroblasts was studied as potential modulators of their responsiveness to IGFs. Human placental fibroblasts were obtained at various gestational ages and maintained in culture. IGFBP-3 protein and mRNA expression were assessed by Northern and ligand blot analyses. First, media conditioned by fibroblasts, in culture, were subjected to ligand blot analysis. Multiple species of IGFBPs were present in each cell line tested. IGFBP-3, migrating as a doublet at approx. 38 42 kDa , was the predominant IGFBP species present. Other IGFBPs of 22–35 kDa were also present. The secretion of IGFBP-3 exhibited a marked decrease at 10–15 weeks gestation relative to 8–9 week fibroblasts but began to increase again by 19 weeks. We next studied the expression of IGFBP-3 mRNA. Total cellular RNA was obtained from rapidly growing cells and subjected to Northern analysis. Placental fibroblasts exhibited decreased steady state levels of IGFBP-3 mRNA at 10–15 weeks gestation consistent with its decreased protein expression. The ability of IGFBP-3 to influence IGF-1 stimulated DNA synthesis was studied in 10 week placental fibroblasts as measured by [ 3 H]thymidine incorporation. IGFBP-3 inhibited IGF-1 (3.3 nM) stimulated DNA synthesis in a dose-dependent manner when added simultaneously with IGF-1 or preincubated with the cells for 48 h prior to the addition of IGF-1. By contrast, maximum effective concentrations of IGFBP-3 (52 nM) potentiated the effect of IGF-1 50–200% when preincubated with bovine fibroblasts for 48 h prior to the addition of IGF-1. These data suggest that IGFBP-3 production is developmentally regulated in human placental fibroblasts and inhibits their mitogenic response to IGF-1. The regulated expression of IGFBP-3 may contribute to the altered growth rate and IGF responsiveness exhibited by placental fibroblasts, in vitro.
Role of Cyclic Nucleotides in Vasopressin-Induced Piglet Pial Artery Dilation and Opioid Release

It has previously been observed that the opioids methionine enkephalin and leucine enkephalin contribute to hypoxia-induced pial artery dilation in the piglet. It has also been demonstrated that vasopressin elicits pial artery dilation and contributes to hypoxia-induced pial dilation both directly and indirectly through the release of the above opioids. The present study was designed to investigate the role of cyclic nucleotides in this vasopressin-induced pial artery dilation and opioid release in newborn piglets equipped with a closed cranial window. Pial artery diameter and cortical periarachnoid cerebrospinal fluid (CSF) opioid and cyclic nucleotides were measured after topical application of vasopressin (40, 400, and 4000 pg/mL). Opioid levels and pial diameter were examined in the absence and presence of(Rp)-8-bromo-(Br)-cAMPs and (Rp)-8-Br-cGMPs, purported cAMP and cGMP antagonists, respectively. Periarachnoid cortical CSF cAMP concentration increased in response to topical vasopressin (1048 ± 22, 1199 ± 51, 1334 ± 61 and 1453 ± 59 fmol/mL for control, 40, 400, and 4000 pg/mL vasopressin, respectively, n = 9). Vasopressin elicited pial artery dilation, which was attenuated by(Rp)-8-Br-cAMPs (14 ± 1, 22 ± 1, and 29± 2 versus 8 ± 1, 12 ± 2, and 18 ± 2% dilation for 40, 400, 4000 pg/mL vasopressin, before and after(Rp)-8-Br-cAMPs, respectively, n = 7). Similarly, vasopressin-induced pial artery dilation was accompanied by elevated CSF cGMP and this dilation was attenuated in the presence of(RP)-8-Br-cGMPs (13 ± 1, 21 ± 1, and 29± 2 versus 5 ± 1, 9 ± 1, and 12 ± 1% dilation for 40, 400, and 4000 pg/mL vasopressin before and after(RP)-8-Br-cGMPs, respectively, n = 7). CSF opioid concentrations increased with topical vasopressin and these increases were attenuated by (RP)-8-Br-cAMPs. CSF methionine enkephalin concentrations were 1193 ± 60, 1530 ± 63, 1937 ± 89, and 2422 ± 104 versus 1032 ± 25, 1185 ± 261, 1337± 31, and 1519 ± 44 pg/mL for control, 40, 400, and 4000 pg/mL vasopressin before and after (RP)-8-Br-cAMPs. Similarly, vasopressin-induced CSF methionine enkephalin and leucine enkephalin release was attenuated in the presence of (RP)-8-Br-cGMPs. These data show that both cAMP and cGMP contribute to vasopressin-induced pial artery dilation and the release of the opioids methionine enkephalin and leucine enkephalin.
Do the Math: ESP + Web 2.0 = ESP 2.0!

Abstract As university teacher of English, the author of this paper has been concerned with exploring and exploiting the potential of Web 2.0 tools and applications for English language learners. To this end, I have complemented face-to-face teaching with collaborative Web 2.0 tools, such as blogs and voice threads (online media albums that can hold any type of media, and can be shared with anyone we wish). More specifically, I came in contact with Mr. Larry Ferlazzo, a US teacher who invited my students from International Relations to join a project he had designed and which was called Sister Classes. Our students interacted on an edublog using English, created a few presentations, left audio and written comments on each other's work, exchanged ideas, shared links, podcasts and videos. Other countries from around the world became involved, and we built a community of practice. Thus, in the present paper we assert that creating meaningful content for the students’ specific purposes (in this case, practicing English), is as important as creating connectivity, and that collaborative language learning can prove very efficient. At the same time, we have also identified some methodological limitations to teaching English with the aid of Web 2.0. Consequently, our pedagogical approach may serve for an invitation to further research.
Dynamic light scattering by cultures of heterotrophic marine bacteria

Heterotrophic bacteria may play a significant role in the scattering of light in the ocean. The scattering properties of these microbes are very sensitive to cell size, which is difficult to measure in the submicron size range by common electronic and microscopic techniques. Assessment of bacterial contribution to light scattering is further complicated by the fact that the size of the cells may change under differing conditions of growth. We examined the size of bacterial cells that were either fast-growing or starving by application of the dynamic light scattering (DLS) method. Laboratory cultures of mixed populations of bacteria from oceanic waters off Southern California were measured. In the DLS method, the autocorrelation function of the time-dependent intensity of light scattered by small suspended particles is a measure of Brownian motion which, via the diffusion coefficient, provides information about the particle size distribution. The scattered intensity weighted sizes of formalin-preserved bacteria obtained from DLS were generally consistent with average cell sizes determined by epifluorescence microscopy. This consistency was supported by simulation of the intensity weighted size distribution by means of Mie scattering calculations for microscopically determined size distribution. In addition, the microscopic analysis showed that while the equivalent spherical diameter of fast-growing bacteria was on average 0.85 micrometers , the diameter of starved cells was 40 to 50% less. The starved cells were thus quite similar in size to bacteria found in the nutrient-poor open ocean environments. The cultures of starved bacteria contained small numbers of yeast cells (2 - 4 micrometers in size), and the sensitivity of the DLS analysis to such relatively large scatterers was evident. Our study indicates that the dynamic light scattering, a fast and noninvasive technique, offers new perspectives to study bacteria and other oceanic microparticles.
Robotic grasping of unknown objects: a knowledge-based approach

In this article the author describes a general-purpose robotic grasping system for use in unstructured environments. Using computer vision and a compact set of heuristics, the system automatically generates the robot arm and hand motions required for grasping an unmodeled object. The utility of such a system is most evident in environments where the robot will have to grasp and manipulation tasks may be relatively simple. Examples of such domains are planetary exploration and astronaut assistance, undersea salvage and rescue, and nuclear waste site clean-up. This work implements a two-stage model of grasping: stage one is an orientation of the hand and wrist and a ballistic reach toward the object; stage two is hand preshaping and adjustment. Visual features are first extracted from the unmodeled object. These features and their relations are used by an expert system to generate a set of valid reach/grasps for the object. These grasps are then used in driving the robot hand and arm to bring the fingers into contact with the object in the desired configuration. Experimental results are presented to illustrate the functioning of the system.
Variation in use of all types of computed tomography by emergency physicians

Abstract Study Objectives Variation in computed tomography (CT) use between emergency medicine (EM) physicians may delineate appropriate or inappropriate use. We hypothesize that variation in all types of CT use exists between providers and their use in patients with common chief concerns. We determine EM physicians' variability in CT use of all types and whether high use in one area predicts use of other CT types. Methods This was a retrospective study of EM physicians practicing at an 800-bed tertiary level 1 trauma center over a 3.5-year period. Computed tomography rates by type and by patient chief concern were modeled for providers as a function of patient acuity, disposition, age, and time of day using logistic regression. Results Of 195 801 eligible visits, 44 724 visits resulted in at least 1 CT scan. The adjusted rate of CT ordering by providers was 23.8% of patient visits, ranging from 11.5% to 32.7% The upper quartile of providers was responsible for 78% of the CT scans ordered above the mean. There was a large variation in use of all types of CT and by chief concern. There was an 8-fold variation in use of CT abdomen in discharged patients. High head CT use by providers predicts high use in all other CT types. Conclusion We demonstrate a dramatic variation in CT use among EM physicians in all types of CT and common chief concerns. Greater variation was present in patients who were discharged. Large deviation from the mean by a group of providers may suggest inappropriate use.
Laser recording with truncated Gaussian beams

Laser recording with a Gaussian beam and focusing lens of finite aperture is analyzed. It is shown that, for a Laser recording given recorded spot size, optimal values exist for the lens f/number and filling factor, the ratio of Gaussian to lens diameter, which minimize power. Sensitivity curves are presented for power vs f/beam diameter number and vs filling factor. The on-axis focal plane intensity is maximized by deviating from the optimal factor at the expense of a slight power increase. Effects of power variations on recorded spot size are filling considered.
Synthesis, characterization, and X-ray crystal structure of In(DOTA-AA) (AA = p-aminoanilide): a model for 111In-labeled DOTA-biomolecule conjugates.

This report describes the synthesis and structural characterization of the indium complex of 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid mono(p-aminoanilide) (DOTA-AA), a model compound for 111In-labeled DOTA-biomolecule conjugates. In(DOTA-AA) was prepared by reacting DOTA-AA with 1 equiv of InCl3 in 0.5 M ammonium acetate buffer (pH ∼ 6). It was characterized by spectroscopic methods (IR, ES-MS, and 1H NMR), elemental analysis, and X-ray crystallography. For comparison purposes, we also prepared the complex Y(DOTA-AA). ES-MS and 1H NMR data are consistent with the proposed structure. HPLC analysis using a reversed phase method shows that the retention time of In(DOTA-AA) is ∼2.0 min shorter than that of Y(DOTA-AA), demonstrating that In(DOTA-monoamide) is more hydrophilic than Y(DOTA-monoamide). In the solid state, In(DOTA-AA) has a twisted square antiprismatic coordination geometry with all eight donor atoms (N4O4) bonded to the In center. The average In−N and In−O distances are almost ide...
Efficiency of Extension of Mismatched Primer Termini across from Cisplatin and Oxaliplatin Adducts by Human DNA Polymerases β and η in Vitro

DNA polymerases β and η are among the few eukaryotic polymerases known to efficiently bypass cisplatin and oxaliplatin adducts in vitro. Our laboratory has previously established that both polymera...
Neural Correlates of Detecting Pretense: Automatic Engagement of the Intentional Stance under Covert Conditions

Typically developing children begin to produce and understand pretend play between 18 and 24 months of age, and early pretense has been argued to be a candidate ''core'' capacity central to the deployment of representations of other peoples' mental states—''theory of mind.'' In a functional magnetic resonance imaging study, 16 healthy adult volunteers were imaged while watching short (5 sec) clips of actors who either performed simple everyday actions or pretended to perform a similar set of actions, under covert conditions (e. g., participants were not directed to attend to actors' mental states). There was increased activity in the medial prefrontal areas (Brodmann's areas [BA] 9/6/32, 9, and 10), inferior frontal gyrus bilaterally (BA 44, 47), temporo-parietal regions (BA 21 and 22), and parahippocampal areas, including the amygdala, when subjects viewed pretend actions as compared with real actions. This result suggests that at least some areas previously implicated in making explicit mental state judgments are also strongly activated in response to actions that call for mental state interpretation (e. g., pretense) even when there is no explicit instruction for ''mind reading.'' This outcome is discussed in terms of accounts that propose ''theory of mind'' to be underwritten by automatic specialized mechanisms for the interpretation of the behavior of social agents.
Hyponatremia's Impact on Patients and Health Systems

PurposeTo define hyponatremia, discuss its incidence and epidemiology, and summarize the frequency and prognostic implications of hyponatremia in selected clinical conditions.SummaryHyponatremia is...
Individuals Born With Nonsyndromic Oral Clefts Display a Higher Frequency of Dental Anomalies

Article Title and Bibliographic Information Prevalence of dental anomalies in non-syndromic individuals with cleft lip and palate: a systematic review and meta-analysis. Tannure PN, Oliveira CAGR, Maia LC, Vieira AR, Granjeiro JM, de Castro Costa M. Cleft Palate Craniofac J 2011 Jul 8. [Epub ahead of print] Reviewer Deborah A. Redford-Badwal, DDS, PhD Purpose/Question To assess whether individuals born with nonsyndromic oral clefts displayed a higher frequency of dental anomalies Source of Funding Information not available Type of Study/Design Systematic review with meta-analysis of the data Level of Evidence Level 2: Limited-quality, patient-oriented evidence Strength of Recommendation Grade Grade B: Inconsistent or limited-quality patient-oriented evidence
Amino acid sequence and circular dichroism of Indian cobra (Naja naja naja) venom acidic phospholipase A2.

The full amino acid sequence of the acidic phospholipase A2 from Indian cobra (Naja naja naja) venom was determined and its tertiary structure examined by circular dichroism (CD). The sequence was aligned with other sequences of secreted phospholipase A2 from snakes of the genus Naja, using the progressive alignment method of Feng and Doolittle (J. Mol. Evol. (1987) 25, 351–360). The primary sequence of Naja naja naja phospholipases A2 shows up to 85% identity with the other acidic Naja phospholipase A2. CD studies indicate a 40–50% α-helical content in a tertiary structure which resists denaturation at high temperature, with or without chaotropic salts.
Fourier transforms of finite chirps

Chirps arise in many signal processing applications. While chirps have been extensively studied as functions over both the real line and the integers, less attention has been paid to the study of chirps over finite groups. We study the existence and properties of chirps over finite cyclic groups of integers. In particular, we introduce a new definition of a finite chirp which is slightly more general than those that have been previously used. We explicitly compute the discrete Fourier transforms of these chirps, yielding results that are number-theoretic in nature. As a consequence of these results, we determine the degree to which the elements of certain finite tight frames are well distributed.
Quantitative spectral techniques and computer image processing as applied to lithologic mapping

Analysis and interpretation of multi-spectral images from aircraft and space platforms is finally advancing out of the empirical stage and is attaining a solid quantitative foundation. This logical evolution is made possible by wider acceptance and use of digital Image-processing techniques and a better understanding of the in situ spectral-reflectance characteristics of earth materials.
Mechanisms of calcium accumulation and transport in cardiac relaxing system (sarcoplasmic reticulum membranes): effects of Verapamil, D-600, X537A and A23187.

Verapamil and D-600, two potent (I50 = 10−8 to 10−7m) calcium-dependent negative inotropic agents, are thought to act by decreasing calcium conductance (transmembrane calcium influx) across sarcolemmal membranes. These agents, although inhibiting cardiac relaxing system (sarcoplasmic reticulum fragments) calcium binding and uptake, did so at very high concentrations (I50 ∼ 1 mm) suggesting that their negative inotropic effect occurs by an action on a site other than the sarcoplasmic reticulum. The agents did not influence the rate of spontaneous release of calcium from cardiac relaxing system, nor did they affect the rapid release induced by a sudden increase in pH or by the addition of X537A or A23187, potent ionophoric agents that release calcium from sarcoplasmic reticulum fragments. The lack of effect on release suggests that “calcium channels” are not an important component of calcium release from cardiac relaxing system.
Ribosome substructure investigated by scanning force microscopy and image processing

Scanning force microscopy was used to study the ultrastructure of eukaryotic ribosomes from Chironomus pallidivittatus in the polysomal complex. Positively stained polysomes were imaged, and the resulting three-dimensional ribosomal structures were further processed by statistical analyses of virtual cross-sections parallel to the substrate plane. Structural investigations were based on parameters which are minimally influenced by the tip geometry, like section plane centre or axis ratio. In the lower part of the structure a shift of the section centres was observed, suggesting an attached structure. The geometry of the sections revealed an elliptical shape in the upper part (axis ratio 1.52 ± 0.22), with a less elongated shape in the lower region (axis ratio 1.41 ± 0.18). A model for the surface topography of a positively stained ribosome exhibiting a small subunit attached along the long side of an elliptical large structure is proposed.
Some general results in the theory of crystallographic slip

Crystallographic slip of a Bravais lattice is analyzed utilizing the main results of a recently constructed theory of structured solids, where explicit account is taken of the influence of dislocation density identified in terms of Curl of plastic deformationGp. In the present paper, the scope of the subject is enlarged to also include defects (other than dislocations) such as substitutional impurities and vacancies and it is shown that these point defects may also be characterized in terms of the plastic deformation fieldGp. Several general results pertaining to the kinematics and kinetics of Crystallographic slip are proved within the scope of an appropriate constraint theory suitable for Crystallographic slip; the latter is motivated by the well-known basic mechanism of Crystallographic slip that constrains the admissible modes of plastic deformation. The constraint responses (or forces) that are necessary to maintain the active slip systems, as well as the conditions for the transitions between the slip systems, are determined. In spite of the nature of the assumption pertaining to the mechanism of Crystallographic slip on distinct slip systems, it is shown that the yield surface does not necessarily exhibit sharp corners. Instead, the shape of the yield surface is in the form of hyperplanes joined by round corners. In fact, the presence of sharp corners is mainly a result of the use of a special set of constitutive assumptions. The predictive capability of the theoretical results is further illustrated by using a two-dimensional crystal subjected to simple shear. The effect of the initial dislocation density on the response of the sheared-crystal is studied by carrying out detailed calculations for two substantially different initial dislocation densities. The calculations show that while the response of the crystal is sensitive to the initial dislocation density in the early stages of deformation, its influence diminishes with progressively larger deformations. Furthermore, the crystal exhibits a well-defined shear band which evolves naturally due to the presence of initial dislocation distribution and is easily visible at large deformations.
Re-thinking data center power delivery: Regulating series-connected voltage domains in software

In this paper, the fundamental advantages of series-connected voltage domains are briefly discussed in light of existing power distribution architectures for data centers. The key technical challenges of this architecture are addressed; and results from a working prototype system are presented as a proof of concept. In particular, a straightforward software-only solution is presented which eliminates the need for power conversion hardware between the distribution bus and server. Based on power-aware load balancing of web traffic and server frequency, this design is shown to provide adequate voltage regulation for a cluster of four web servers sharing the same line current. Compared with measurements of maximum server performance, the series-connected configuration shows only a minor reduction in net throughput. As a step toward improving system reliability and performance, a hardware supplement for over-voltage protection is presented along with measurements verifying its operation at full server load.
Variation in American Sign Language: The case of DEAF

Variation in sign languages has been a neglected area of research in sociolinguistics. This article, part of a large-scale study of variation in American Sign Language (ASL) designed to redress that situation, examines variation in the form of the sign DEAF, which can be produced by moving the forefinger from ear to chin, from chin to ear, or by contacting the lower cheek. Multivariate analysis of more than 1600 tokens of DEAF extracted from sociolinguistic interviews with 207 signers residing in seven regions of the United States shows that both linguistic and social factors significantly constrain choice among the three variants. The analysis also illustrates patterns that parallel variation in spoken languages. However, despite the similarities to variation in spoken languages, we suggest that results for the regional patterning of variation are best explained by reference to Deaf history, particularly to changes in the status and use of ASL in deaf education.
Dating violence among emancipating foster youth

Youth emancipating from foster care have been found to be at higher risk for many adverse outcomes. Only one prior published study exists, however, about the dating violence experiences of foster youth. Asking similar questions about dating violence, this study attempted to replicate the prior findings regarding prevalence and to explore associations between foster care placement history, maltreatment history and mental health/substance abuse and self-reported dating violence. The youth reported a higher prevalence of dating violence than found in studies of the general youth population. Self-reported PTSD symptoms and drug use were associated with higher likelihood of dating violence victimization. The majority of youth self-reporting as dating violence perpetrators also self-reported as victims. Implications for research and practice are discussed.
Portal vein thrombosis and survival in patients with cirrhosis

The effects of occlusive portal vein thrombosis (PVT) on the survival of patients with cirrhosis are unknown. This was a retrospective cohort study at a single center. The main exposure variable was the presence of occlusive PVT. The primary outcome measure was time-dependent mortality. A total of 3295 patients were analyzed, and 148 (4.5%) had PVT. Variables independently predictive of mortality from the time of liver transplant evaluation included age [hazard ratio (HR), 1.02; 95% confidence interval (CI), 1.01-1.03], Model for End-Stage Liver Disease (MELD) score (HR, 1.10; 95% CI, 1.08-1.11), hepatitis C (HR, 1.44; 95% CI, 1.24-1.68), and PVT (HR, 2.61; 95% CI, 1.97-3.51). Variables independently associated with the risk of mortality from the time of liver transplant listing included age (HR, 1.02; 95% CI, 1.01-1.03), transplantation (HR, 0.65; 95% CI, 0.50-0.81), MELD (HR, 1.08; 95% CI, 1.06-1.10), hepatitis C (HR, 1.50; 95% CI, 1.18-1.90), and PVT (1.99; 95% CI, 1.25-3.16). The presence of occlusive PVT at the time of liver transplantation was associated with an increased risk of death at 30 days (odds ratio, 7.39; 95% CI, 2.39-22.83). In conclusion, patients with cirrhosis complicated by PVT have an increased risk of death.
Using daily interactive voice response technology to measure drinking and related behaviors in a pharmacotherapy study.

Background: Interactive voice response technology (IVR) allows investigators to collect daily measures of drinking, medication adherence, mood, and other treatment-relevant variables that may change day to day during a clinical trial. Despite these advantages, no published studies have used IVR in alcohol pharmacotherapy trials. Methods: Subjects provided daily data via IVR during the 12-week treatment period. Seven subjects completed the trial. Results: We found a high level of participant adherence to the IVR protocol, higher levels of drinking reported by IVR than by a commonly used recall method, and distinct within-day associations between daily mood and alcohol consumption: these could not be obtained through traditional assessment methods. Conclusions: IVR seems to be feasible for the collection of daily indicators of treatment outcomes and processes in pharmacotherapy studies among problem drinkers.
The mechanism of photophosphorylation I. Inhibition of the light-induced proton translocation by inorganic phosphate

Abstract Inorganic phosphate, in the absence of added ADP, inhibits the steady state level of the light-induced proton uptake by isolated chloroplasts. Fifty percent inhibition is obtained at a phosphate concentration of 2.0 mM, but precise determinations at higher phosphate concentrations are complicated by considerable buffering. The inhibition is dependent upon the presence of Mg++, indicating that energy transfer may be involved. The results are consistent with the formation of a high energy, labile, phosphorylated intermediate prior to ATP in the energy transfer chain.
THE USE OF ARCS AND NODES FOR THE DETERMINATION OF CRITICAL PATHS IN PERT/CPM NETWORKS

The critical path in a PERT/CPM network is determined in various textbooks by finding the path with associated minimal slack for the network arcs or by finding the path with associated minimal slack for the network nodes. This paper points out that the use of nodes can result in a network path being incorrectly identified as a path of maximum length.
Alzheimer brain-derived tau oligomers propagate pathology from endogenous tau.

Intracerebral injection of brain extracts containing amyloid or tau aggregates in transgenic animals can induce cerebral amyloidosis and tau pathology. We extracted pure populations of tau oligomers directly from the cerebral cortex of Alzheimer disease (AD) brain. These oligomers are potent inhibitors of long term potentiation (LTP) in hippocampal brain slices and disrupt memory in wild type mice. We observed for the first time that these authentic brain-derived tau oligomers propagate abnormal tau conformation of endogenous murine tau after prolonged incubation. The conformation and hydrophobicity of tau oligomers play a critical role in the initiation and spread of tau pathology in the naive host in a manner reminiscent of sporadic AD.
Peroxisomes Are Required for Lipid Metabolism and Muscle Function in Drosophila melanogaster

Peroxisomes are ubiquitous organelles that perform lipid and reactive oxygen species metabolism. Defects in peroxisome biogenesis cause peroxisome biogenesis disorders (PBDs). The most severe PBD, Zellweger syndrome, is characterized in part by neuronal dysfunction, craniofacial malformations, and low muscle tone (hypotonia). These devastating diseases lack effective therapies and the development of animal models may reveal new drug targets. We have generated Drosophila mutants with impaired peroxisome biogenesis by disrupting the early peroxin gene pex3, which participates in budding of pre-peroxisomes from the ER and peroxisomal membrane protein localization. pex3 deletion mutants lack detectible peroxisomes and die before or during pupariation. At earlier stages of development, larvae lacking Pex3 display reduced size and impaired lipid metabolism. Selective loss of peroxisomes in muscles impairs muscle function and results in flightless animals. Although, hypotonia in PBD patients is thought to be a secondary effect of neuronal dysfunction, our results suggest that peroxisome loss directly affects muscle physiology, possibly by disrupting energy metabolism. Understanding the role of peroxisomes in Drosophila physiology, specifically in muscle cells may reveal novel aspects of PBD etiology.
Ultrastructural studies of vitreomacular traction syndrome

We performed electron microscopic studies on seven specimens removed from the posterior retina at the time of vitrectomy for vitreomacular traction syndrome. Fibrous astrocytes were the predominant cell type in all cases. Fibrocytes were present in two cases and myofibrocytes were seen in three cases. Additional cellular and extracellular features included fragments of internal limiting membrane in six cases, old collagen in all cases, new collagen in one case, occasional macrophages in four cases, and fibrous astrocytes with myofibroblastic differentiation in one case.
The clinical importance of atypical glandular cells of undetermined significance on the cytologic smear.

The objective of the study was to assess the prevalence of underlying cervical and endometrial lesions among patients with atypical glandular cells of undetermined significance (AGCUS) on the cytologic smear. Eighty-six patients with AGCUS, without evidence of squamous intraepithelial lesions, underwent coloposcopy and endocervical curettage (ECC) within 6 months of the initial finding. Endometrial samplings were performed in 25 patients. Coloposcopy, endocervical curettage, and endometrial biopsy results were reviewed. A significant lesion was defined as cervical intraepithelial neoplasia and/or any structural or histologic abnormality of the cervix or uterus (i.e., polyp). Statistical analyses were performed using the t test, chi-square, and Fisher's Exact tests comparing patients with underlying lesions to those without. A significant lesion(s) was identified in 21 (24.4%) patients, with 8 (9.3%) of the lesions being high-grade cervical neoplasias. An additional 14 (16.3%) patients, with negative initial work-ups, had underlying lesions or major cytologic abnormalities diagnosed on subsequent follow-up. All of the endometrial findings were benign. None of the following were statistically significant predictors of underlying pathology: age, gravidy, parity, medications, medical history, tobacco use, history of sexually transmitted diseases including human immunodeficiency virus, previous abnormal cytologic smear, concurrent diagnosis of atypical squamous cells of undetermined significance, or evidence of human papillomavirus. AGCUS is often associated with clinically important underlying lesions. Patients should therefore undergo colposcopy and ECC. Endometrial sampling and possible cervical conization should be performed when coloposcopic evaluation is nondiagnostic.
Degradation of polychlorinated dibenzo-p-dioxin and dibenzofuran contaminants in 2,4,5-T by photoassisted iron-catalyzed hydrogen peroxide

The objective of this study was to determine the fate of polychlorinated dibenzo-p-dioxin (PCDD) and dibenzofuran (PCDF) contaminants in the herbicide 2,4,5-trichlorophenoxyacetic acid after treatment by photoassisted Fe3+-catalyzed hydrogen peroxide oxidation, which is being investigated for waste treatment. Toluene-extraction of aqueous reagent grade 2,4,5-T gave 30 quantifiable PCDD/F isomer peaks, some of which represented more than one congener. They included 13 tetra- through heptachloro PCDDs totalling 18.4 ng/g, and 17 tetra- through octachloro PCDFs totalling 12.9 ng/g. Treatment with Fe3+/H2O2/hv (mole ratio 2,4,5-T:Fe3+:H2O2 = 1:10:200; visible fluorescent light, 300 nm cutoff) in aerated solution at pH 2.8 resulted in 89–100% removal of all PCDD/F peaks except that for OCDF, which was 66% removed. The 2,4,5-T was shown previously to be completely mineralised to HCl and CO2. Direct photolysis of the PCDD/Fs was negligible. The 2,3,7,8-tetra-CDD referenced “toxic equivalent” used in risk assessment was reduced by 99.9% (U.S. Environmental Protection Agency method) or 99.6% (international method). Reaction mixtures supplemented with 2,3,7,8-(UL-14C)-tetra-CDD and 2,3,4,7,8-(dichlorophenyl-14C)-penta-CDF evolved up to 45 and 64%, respectively, theoretical yield of 14CO2. Most of the remaining 14C was converted to hydrophilic forms not extractable by toluene. Dark (Fe3+/H2O2) treatment was somewhat less effective overall.
Monkey Sound Localization: Head-Restrained versus Head-Unrestrained Orienting

The sound localization abilities of three rhesus monkeys were tested under head-restrained and head-unrestrained conditions. Operant conditioning and the magnetic search coil technique were used to measure eye and head movements to sound sources. Whereas the results support previous findings that monkeys localize sounds very poorly with their heads restrained, the data also reveal for the first time that monkeys localize sounds much more accurately and with less variability when their heads are allowed to move. Control experiments using acoustic stimuli known to produce spatial auditory illusions such as summing localization confirmed that the monkeys based their orienting on localizing the sound sources and not on remembering spatial locations that resulted in rewards. Overall, the importance of using ecologically valid behaviors for studies of sensory processes is confirmed, and the potential of the rhesus monkey, the model closest to human, for studies of spatial auditory function, is established.
Skeletal Maturation in Children with Cushing Syndrome Is Not Consistently Delayed: The Role of Corticotropin, Obesity, and Steroid Hormones, and the Effect of Surgical Cure

Objective To assess skeletal maturity by measuring bone age (BA) in children with Cushing syndrome (CS) before and 1-year after transsphenoidal surgery or adrenalectomy, and to correlate BA with hormone levels and other measurements. Study design This case series conducted at the National Institutes of Health Clinical Center included 93 children with Cushing disease (CD) (43 females; mean age, 12.3 ± 2.9 years) and 31 children with adrenocorticotropic hormone–independent CS (AICS) (22 females, mean age 10.3 ± 4.5 years). BA was obtained before surgery and at follow-up. Outcome measures were comparison of BA in CD vs AICS and analysis of the effects of hypercortisolism, insulin excess, body mass index, and androgen excess on BA. Results Twenty-six of the 124 children (21.0%) had advanced BA, compared with the expected general population prevalence of 2.5% (P Conclusion Contrary to common belief, endogenous CS in children appears to be associated with normal or even advanced skeletal maturation. When present, BA advancement in CS is related to obesity, insulin resistance, and elevated adrenal androgen levels and aromatization. This finding may have significant implications for treatment decisions and final height predictions in these children.
Vaporization associated with surface electrical switching in semiconducting AsTeI and AsTeGe glasses

Abstract Vapor species resulting from electrically-induced threshold switching and memory filament formation on the surfaces of bulk AsTeI and AsTeGe glasses are identified. The common parent species are As 4 (most intense) and Te 2 . The results emphasize the importance of thermal mechanisms, and yield information concerning the kinetics of filament formation.
INTRODUCTION: PHILOSOPHY AND FEMINISM

Rejetant l'objection sceptique concernant l'opposition entre le feminisme et la philosophie, l'A. montre que les frontieres entre les deux disciplines ne sont pas immuables et que la pensee feministe regenere le debat contemporain en soulevant des questions metaphilosophiques essentielles. Les articles qui suivent s'attachent a souligner la pluralite des philosophies feministes