cssi/SciSciGPT-SciSciNet huggingface dataset:
Sequential Rearrangement of Interhelical Networks Upon Rhodopsin Activation in Membranes: The Meta IIa Conformational Substate

Photon absorption by rhodopsin is proposed to lead to an activation pathway that is described by the extended reaction scheme Meta I ⇌ Meta IIa ⇌ Meta IIb ⇌ Meta IIbH+, where Meta IIbH+ is thought to be the conformational substate that activates the G protein transducin. Here we test this extended scheme for rhodopsin in a membrane bilayer environment by investigating lipid perturbation of the activation mechanism. We found that symmetric membrane lipids having two unsaturated acyl chains, such as 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), selectively stabilize the Meta IIa substate in the above mechanism. By combining FTIR and UV−visible difference spectroscopy, we characterized the structural and functional changes involved in the transition to the Meta IIa intermediate, which links the inactive Meta I intermediate with the Meta IIb states formed by helix rearrangement. Besides the opening of the Schiff base ionic lock, the Meta IIa substate is characterized by an activation switch in a conserved ...
Motion of test particles in a torsion field

The solution of the Mathisson-Papapetrou equations generalized to the case of the Einstein-Cartan theory, when they describe the motion of a test particle in an external torsion field, is considered. It is shown that a particle of nonzero rest mass moves inertially in a constant “polarized” torsion field, but its spin precesses around the direction of polarization of the spin of the torsion source. It is also found that the motion of a massless particle in a variable torsion field leads to a torsion frequency displacement effect of a photon under the assumption that the photon spin interacts with the torsion.
In situ spectroscopic determination of faradaic efficiencies in systems with forced convection under steady state : Electroreduction of bisulfite to dithionite on gold in an aqueous electrolyte

The reduction of bisulfite on Au electrodes in buffered aqueous solutions (pH = 5.25) was examined by in situ near-normal-incidence UV−visible reflection absorption spectroscopy on a rotating disk electrode (RDE) and in situ transmission UV−visible spectroscopy downstream from a channel-type electrode. The currents associated with dithionite (S2O42-) formation obtained from the spectroscopic measurements were found to be lower than those expected for a one-electron, diffusion-controlled process. Faradaic efficiencies for S2O42- generation derived from RDE data yielded, in the range −0.60 to −0.75 V vs Ag/AgCl, values close to 100%. The advantages of rotating disk over channel-type electrodes for determining faradaic efficiencies by UV−visible spectroscopic techniques are discussed.
Comparison of BASS and VACM current measurements during STRESS

Abstract Current measurements from a vector-averaging current meter (VACM) on a subsurface mooring and a benthic acoustic stress sensor (BASS) on a bottom tripod are compared to assess their relative accuracy. The instruments were deployed off northern California at a midshelf site (water depth approximately 90 m) as part of the STRESS (Sediment Transport Events on Shelves and Slopes) field program. The subsurface mooring and bottom tripod were within a few hundred meters of each other, with the BASS 5.0 m and the VACM 6.7 m above the bottom, during two tripod deployments of 49 and 32 days in the winter of 1988/89. Speed differences between the VACM and BASS current observations have a mean of 0.2 cm s−1 and a standard deviation of 1.2 cm s−1. If the mean speed profile is logarithmic, the expected mean speed difference due to the vertical separation is about 0.4 cm s−1. The average speed difference between the VACM and BASS increases as near-bottom wave orbital velocities get large relative to hourly aver...
A review of acquired thermotolerance, heat‐shock proteins, and molecular chaperones in archaea

Acquired thermotolerance, the associated synthesis of heat-shock proteins (HSPs) under stress conditions, and the role of HSPs as molecular chaperones under normal growth conditions have been studied extensively in eukaryotes and bacteria, whereas research in these areas in archaea is only beginning. All organisms have evolved a variety of strategies for coping with high-temperature stress, and among these strategies is the increased synthesis of HSPs. The facts that both high temperatures and chemical stresses induce the HSPs and that some of the HSPs recognize and bind to unfolded proteins in vitro have led to the theory that the function of HSPs is to prevent protein aggregation in vivo. The facts that some HSPs are abundant under normal growth conditions and that they assist in protein folding in vitro have led to the theory that they assist protein folding in vivo; in this role, they are referred to as molecular chaperones. The limited research on acquired thermotolerance, HSPs, and molecular chaperones in archaea, particularly the hyperthermophilic archaea, suggests that these extremophiles provide a new perspective in these areas of research, both because they are members of a separate phylogenetic domain and because they have evolved to live under extreme conditions.
Transient analysis of dislocation emission from a growing crack

Abstract A n exact transient solution for screw dislocation emission in arbitrary directions from a Mode III crack growing due to SH-wave diffraction is performed. An emission criterion based on the dislocation force is then imposed to obtain the instant of emission, the distance traveled by the emitted dislocation prior to its arrest, and the instant of arrest. The formulae for these quantities are examined for dependence on parameters such as emission angle, material yield stress and crack and dislocation speeds. Dynamic effects are clear, and order-of-magnitude evaluations suggest that the quantities are on a micromechanical scale, but not insignificant. In particular, the emission instant behavior indicates that purely brittle fracture is difficult and, moreover, that the instant itself might be incorporated in the emission criterion. Indeed, general suggestions for rendering the criterion more precise are noted. The solution and formulae are then modified to study multiple emission, post-arrest behavior, emission in the crack plane and the response of the dynamic stress intensity factor. These studies indicate that dislocation shielding is enhanced in a transient analysis but decreases after dislocation arrest occurs, and that dislocation arrest can be momentary.
Finite element implementation of non-linear elastoplastic constitutive laws using local and global explicit algorithms with automatic error control†

Implicit stress integration algorithms have been demonstrated to provide a robust formulation for finite element analyses in computational mechanics, but are difficult and impractical to apply to increasingly complex non-linear constitutive laws. This paper discusses the performance of fully explicit local and global algorithms with automatic error control used to integrate general non-linear constitutive laws into a non-linear finite element computer code. The local explicit stress integration procedure falls under the category of return mapping algorithm with standard operator split and does not require the determination of initial yield or the use of any form of stress adjustment to prevent drift from the yield surface. The global equations are solved using an explicit load stepping with automatic error control algorithm in which the convergence criterion is used to compute automatically the coarse load increment size. The proposed numerical procedure is illustrated here through the implementation of a set of elastoplastic constitutive relations including isotropic and kinematic hardening as well as small strain hysteretic non-linearity. A series of numerical simulations confirm the robustness, accuracy and efficiency of the algorithms at the local and global level. Published in 2001 by John Wiley & Sons, Ltd.
Optic nerve responses to light stimulation in the bioluminescent terrestrial snail, Dyakia (Quantula) striata

Abstract 1. 1. Dyakia is the world's only known bioluminescent terrestrial snail. 2. 2. Since Dyakia's bioluminescence may be involved in social communication, a study of the visual system was carried out. 3. 3. Extracellular recordings from the optic nerve revealed an on-response. 4. 4. Effects of varying light intensity, duration and wavelength were viewed. 5. 5. The on-response of Dyakia may be considerably more complex than that of other pulmonate snails.
Structural Insight into Processive Human Mitochondrial DNA Synthesis and Disease-Related Polymerase Mutations

Human mitochondrial DNA polymerase (Pol γ) is the sole replicase in mitochondria. Pol γ is vulnerable to nonselective antiretroviral drugs and is increasingly associated with mutations found in patients with mitochondriopathies. We determined crystal structures of the human heterotrimeric Pol γ holoenzyme and, separately, a variant of its processivity factor, Pol γB. The holoenzyme structure reveals an unexpected assembly of the mitochondrial DNA replicase where the catalytic subunit Pol γA interacts with its processivity factor primarily via a domain that is absent in all other DNA polymerases. This domain provides a structural module for supporting both the intrinsic processivity of the catalytic subunit alone and the enhanced processivity of holoenzyme. The Pol γ structure also provides a context for interpreting the phenotypes of disease-related mutations in the polymerase and establishes a foundation for understanding the molecular basis of toxicity of anti-retroviral drugs targeting HIV reverse transcriptase.
Some personality factors in frigidity

Abstract Perhaps one of the shortest and yet meaningfully comprehensive definitions of frigidity in psychiatry is that of Kleegman [1], a gynecologist. He states, “Frigidity in the female is the inability to have complete sexual response to orgasm in coitus. Absolute frigidity is the lack of any satisfying emotional response. Some frigid women are entirely passive without negative reaction and others react with active rejection or even revulsion. Relative frigidity is the ability to respond to a variable degree with inability to achieve orgasm. Frigidity may be primary or secondary”. Although specific, significant aetiologic studies on frigidity are lacking , psychological factors are generally stated to be preponent. For example, Kroger and Freed [2] and Bergler [3] state that frigidity is “always part of a neuroses”. Anxiety or fear, although in the individual case possibly reflecting widely divers psychopathology, e.g. fear of pain (Malleson [4]; Friedman [5], fear of pregnancy (Lazarus [6], fear of being seen by the male as sexually inadequate (Friedman [5]), etc., is the factor most often quoted as underlying or accompanying frigidity. Other frequently cited psychologic determinants include “conscious” and “unconscious” resentment and hostility towards men, feeling of disgust and revulsion (Brady [7]; Lazarus [6]; and Bergler [3], and ignorance and inhibition (Stokes [8]; Kleegman [1]; Malleson [4]). The present study sets out to provide some basic psychological data on the personality of the frigid female, including some factors which are cited most frequently in the relevant literature (viz., “neuticism”, “anxiety”, and “hostility”).
MO-A-BRD-10: A Fast and Accurate GPU-Based Proton Transport Monte Carlo Simulation for Validating Proton Therapy Treatment Plans

Purpose: To build a GPU-based Monte Carlo (MC) simulation of proton transport with detailed modeling of elastic and non-elastic (NE) protonnucleus interactions, for use in a very fast and cost-effective proton therapy treatment plan verification system. Methods: Using the CUDA framework, we implemented kernels for the following tasks: (1) Simulation of beam spots from our possible scanning nozzle configurations, (2) Proton propagation through CT geometry, taking into account nuclear elastic and multiple scattering, as well as energy straggling, (3) Bertini-style modeling of the intranuclear cascade stage of NE interactions, and (4) Simulation of nuclear evaporation. To validate our MC, we performed: (1) Secondary particle yield calculations in NE collisions with therapeutically-relevant nuclei, (2) Pencil-beam dose calculations in homogeneous phantoms, (3) A large number of treatment plan dose recalculations, and compared with Geant4.9.6p2/TOPAS. A workflow was devised for calculating plans from a commercially available treatment planning system, with scripts for reading DICOM files and generating inputs for our MC. Results: Yields, energy and angular distributions of secondaries from NE collisions on various nuclei are in good agreement with the Geant4.9.6p2 Bertini and Binary cascade models. The 3D-gamma pass rate at 2%–2mm for 70–230 MeV pencil-beam dose distributions in water, soft tissue, bone and Ti phantoms is 100%. The pass rate at 2%–2mm for treatment plan calculations is typically above 98%. The net computational time on a NVIDIA GTX680 card, including all CPU-GPU data transfers, is around 20s for 1×107 proton histories. Conclusion: Our GPU-based proton transport MC is the first of its kind to include a detailed nuclear model to handle NE interactions on any nucleus. Dosimetric calculations demonstrate very good agreement with Geant4.9.6p2/TOPAS. Our MC is being integrated into a framework to perform fast routine clinical QA of pencil-beam treatment plans. Hardware for such a system will cost under $5000. This work was funded in part by a grant from Varian Medical Systems, Inc.
Inhibition of gastric acid secretion by metiamide in Zollinger-Ellison syndrome.

Metiamide, an H2-blocker, promptly and significantly decreased gastric acid secretion in a patient with Zollinger-Ellison syndrome. Acid secretion decreased from mean basal secretion of 16.8 mEq/15 min to less than 0.1 mEq/15 min after metiamide (200 mg orally). The decrease in gastric acid secretion after metiamide was greater than the decrease after propantheline bromide (30 mg orally). H2-Blockers, such as metiamide, may be of value in treatment of patients with Zollinger-Ellison syndrome.
A Model-Integrated, Guideline-Driven, Clinical Decision-Support System

Using evidence-based guidelines to standardize the care of patients with complex medical problems is a difficult challenge. In acute care settings, such as intensive care units, the inherent problems of stabilizing and improving vital patient parameters is complicated by the division of responsibilities among different healthcare team members. Computerized support for implementing such guidelines has tremendous potential. The use of model-integrated techniques for specifying and implementing guidelines as coordinated asynchronous processes is a promising new methodology for providing advanced clinical decision support. Combined with visual dashboards, which show the status of the implemented guidelines, a new approach to computer-supported care is possible. The Vanderbilt Medical Center is applying these techniques to the management of sepsis.
Explicit solutions of partial difference equations and random paths on plane nets

Abstract The problem of a random walk executed on a plane Bravais net with trapping boundaries is discussed. Explicit solutions are found for the six-connected triequiangular net. The analytical solutions are approximate for finite arrays but become exact in certain limiting cases. Numerical solutions have been obtained for finite six-connected nets by means of a high speed digital computer. It is found that the analytical solutions are good approximations to the exact solutions. A rapidly converging overrelaxation procedure for solving the linear algebraic equations was developed. General solutions have been obtained for random paths on lattices more complicated than any heretofore studied. Connections between these solutions and the Green's function solution for the corresponding partial differential equations are discussed.
Limb regeneration following auto- or interspecies transplantation of crab limb tissues

Summary We conducted a series of experiments designed to investigate the regulation of regeneration following implantations of limb tissues in crabs. Autotransplantation (transplantation within the same crab) of the fourth walking leg tissues into claw stumps regenerated either a walking leglike limb, bifurcated limbs, a composite limb with claw and walking leg characteristics, or a normal claw. Interspecies experiments consisted of claw tissues fiom the crab Cancer productus transplanted into the autotomized stump of the fourth walking leg of Cancer gracilis. The resulting regenerates appeared as either a claw-like limb, a walking leg with a toothed dactyl, a walking leg with two dactyls and two pollexes, or a normal walking leg. Reciprocal interspecies transplants of donor walking leg tissues into host claw stumps were able to induce the regeneration of walking leg-like limbs. Most of the regenerates had characteristics of both host and donor limbs. Our results suggest that both donor and host cells par...
Timed multitasking for real-time embedded software

An event-triggered programming model, timed multitasking, is introduced that also takes a time-centric approach to real-time programming but controls timing properties through deadlines and events rather than time triggers.
Comparison of Ab−/−β, H2-DM−, and CIITA−/− in Second-Set Skin Allograft Rejection

Abstract Background. Responses against donor MHC antigens are the major contributor to allograft rejection. Currently, it is unclear whether both direct and indirect recognition pathways are necessary and/or sufficient for allograft rejection. Previously, we found donor MHC class II and H2-DM to have dramatic effects on cardiac allograft survival. Methods. Here, we used H2-DM− mice, which express CLIP–MHC class II complexes, and CIITA−/− mice, which lack all class II proteins, to examine the role of direct and indirect recognition on skin allograft rejection. Recipients were primed with donor cultured keratinocytes and later tested for accelerated memory response by challenge with full-thickness tail skin grafts. Results. As previously reported, Ab−/−β grafts survived longer than wild-type grafts, while H2-DM− grafts were rejected as rapidly as wild-type grafts. Skin grafts deficient for both β2m and H2-DM survived longer than grafts lacking only H2-DM, but not as long as Ab−/−β grafts. Additionally, CIITA−/− grafts survived as long as Ab−/−β grafts. Conclusions. The delayed rejection of Ab−/−β compared to H2-DM− suggests that indirect recognition of surface-expressed donor MHC class II is sufficient to mediate rapid skin allograft rejection. The equivalent survival of CIITA−/− and Ab−/−β grafts suggests that indirect presentation of donor class II molecules (Aα or Eβ) present in Ab−/−β but not CIITA−/− mice does not contribute to graft rejection. These results reveal a modest role for surface-expressed donor class II in primed keratinocyte rejection, but also reveal a dramatic contrast to the cardiac allograft system and indicate tissue/organ-specific mechanisms of rejection.
A generalized q-multinomial Vandermonde convolution

Bender's generalization of the q-binomial Vandermonde convolution is reformulated with weaker constraints. This and a similar convolution for q-multinomial coefficients are proved by interpreting the coefficients as generating functions that enumerate multidimensional lattice paths.
Broadly neutralizing anti-HIV-1 antibodies disrupt a hinge-related function of gp41 at the membrane interface

A vaccine capable of stimulating protective antiviral antibody responses is needed to curtail the global AIDS epidemic caused by HIV-1. Although rarely elicited during the course of natural infection or upon conventional vaccination, the membrane-proximal ectodomain region (MPER) of the HIV-1 glycoprotein of Mr 41,000 (gp41) envelope protein subunit is the target of 3 such human broadly neutralizing antibodies (BNAbs): 4E10, 2F5, and Z13e1. How these BNAbs bind to their lipid-embedded epitopes and mediate antiviral activity is unclear, but such information might offer important insight into a worldwide health imperative. Here, EPR and NMR techniques were used to define the manner in which these BNAbs differentially recognize viral membrane-encrypted residues configured within the L-shaped helix–hinge–helix MPER segment. Two distinct modes of antibody-mediated interference of viral infection were identified. 2F5, like 4E10, induces large conformational changes in the MPER relative to the membrane. However, although 4E10 straddles the hinge and extracts residues W672 and F673, 2F5 lifts up residues N-terminal to the hinge region, exposing L669 and W670. In contrast, Z13e1 effects little change in membrane orientation or conformation, but rather immobilizes the MPER hinge through extensive rigidifying surface contacts. Thus, BNAbs disrupt HIV-1 MPER fusogenic functions critical for virus entry into human CD4 T cells and macrophages either by preventing hinge motion or by perturbing MPER orientation. HIV-1 MPER features important for targeted vaccine design have been revealed, the implications of which extend to BNAb targets on other viral fusion proteins.
Communicating hydrocephalus induced by mechanically increased amplitude of the intraventricular cerebrospinal fluid pulse pressure: rationale and method.

Abstract The effect of increasing the amplitude of the intraventricular cerebrospinal fluid (CSF) pulse pressure in lambs was studied in acute experiments. The intraventricular CSF pulse pressure was mechanically increased by a device which rhythmically inflated and deflated an intraventricular balloon synchronously with the cardiac rate. No variation in mean intraventricular CSF pressure was recorded following the increase in CSF pulse pressure. The neuropathological findings indicated a direct pathogenic effect on periventricular structures exerted by the intraventricular CSF pulsations, which were increased to three to six times the normal values.
On the relative and absolute strength of a memory trace.

Subjects studied either an 8- or 16-word list and later recalled the items while a voice key recorded each response latency. The trials were partitioned by recall total in order to examine the means and distributions of both latencies and interresponse times as a function of recall total. Each analysis was consistent with the view that an item’s absolute strength determineswhether it is recalled whereas an item’s relative strength determineswhen it is recalled. In addition, mean latency was effectively proportional to study list length yet independent of recall total. All of the analyses were consistent with the view that the set of study items is sampled according to a relative-strength rule until all items are found and that a sampled item is recovered into consciousness only when its absolute strength exceeds a fixed threshold.
Communicating In and Through “Murderball”: Masculinity and Disability in Wheelchair Rugby

This article investigates communicative practices surrounding wheelchair rugby, a growing sport played worldwide by people with quadriplegia. Researchers have studied extensively the practice of using sport for rehabilitation, but the role of communication in this process has been overlooked. We argue that participating in this sport is itself a communicative act challenging ableist views of disability, and that the behavior of wheelchair rugby players transforms the stigma associated with their condition via enactments of hypermasculinity. Additionally, we suggest that the sport's organizational culture operates as a space for newly quadriplegic persons to learn strategies for coping with their disability and the life changes that surround it. While we recognize the rehabilitative potential of these enactments, we note the ways the activity reifies patriarchal notions of gender and sport as well as validates traditional, often ableist norms of masculinity that complicate the social meanings of disability...
The State of Gender Studies in Political Science

What effect has the study of gender had on political science? Compared to other branches of the social sciences, political science has been among the most resistant to feminist analysis. Political science scholarship generally is divided into four main subfields: political theory, American politics, comparative politics, and international relations. There are great disparities between these areas in the types and amount of gender scholarship that has been done. While feminist theory has become an accepted part of political theory, it has had a more limited impact in the other areas. Furthermore, where gender scholarship has appeared, it is often guided by intellectually conservative epistemological and methodological assumptions. Focusing on current major themes and significant works in the discipline, this article explores the differences in gender scholarship between subfields.
An Approach To A Versatile Focal Plane Array Test Facility

ABSTRACT The CECOM Center for Night Vision and Electro-Optics (C NVEO) infrared Focal Plane Array test facility is being upgraded to improve speed and test capability. Prior to the upgrade,the test station was capable of testing FPA's, but it did not meet present and future testing needs. Deficiencies such as; high system noise, inflexible dewar configuration, limited levels of automation, in addition to the inability to perform focussed spot and FPA spectral responsivity measurements were reasons to improve the test station. It was important during this development that the ability to characterize a diverse variety of Infrared (IR) Focal Plane Array designs, sizes, formats, materials, and applications be maintained or increased. Considerations relating to this will be discussed. In the future, the test station will be able to test HgCdTe and PtSi arrays on a much larger scale than at present and test other new technologies as well. The goal is to be able to fully characterize one Focal Plane Array per day.
N-terminal sequence of alpha2-gliadin.

Abstract Automatic sequencing has been used to determine a 25-residue N-terminal amino acid sequence of α 2 -gliadin, a wheat protein with a molecular weight near 31 000. The sequence corresponding to the major residue at each position was: NH 2 -Val-Arg-Val-Pro-Val-Pro-Gln-Leu-Gln-Pro-Gln-Asn-Pro-Ser-Gln- -Gln-Gln-Pro-Gln-Glu-Gln-Val-Pro-Leu-Val- Heterogeneity was noted for Positions 1 (about 1 3 alanine) and 5 (about 1 3 methionine). The heterogeneity may indicate a mixture of wheat varieties in the flour used to prepare the α 2 -gliadin. A 10-residue sequence of whole α-gliadin from a single wheat variety (Scout 66) had the same main sequence found for α 2 -gliadin, but without this heterogeneity.
ALIZARIN RED DYE AS A MARKER FOR MEASURING GROWTH IN CORALLINA OFFICINALIS L. (CORALLINACEAÈ, RHODOPHYTA)1

The vital stain alizarin red was incorporated into the calcified walls of incipient medullary cells of Corallina officinalis L. while they were being produced in a terminal meristem. After about 5 h the stained tier of medullary cells formed a red-purple band from which additional growth could be measured in the field and in non-agitated cultures. Alizarin red was also taken up by epithallial cells and one month after staining, plants in the field lacked stained epithallia, whereas those in culture retained some of the stain. Possibly the lack of water motion in culture reduced the epithallial sloughing that occurs in nature. Growth rates measured by this technique were approximately 1.4 mm per month in the field and 1.2 mm per month in culture and were not affected by alizarin red.
Errors inherent in reconstruction of obscured targets from multilook imagery: I. Background and theory

Automated target recognition has benefited from cross- fertilization of development in related subdisciplines of image processing such as medical imaging. For example, the application of computerized tomography to synthetic aperture radar (SAR) imaging has produced 3-D reconstructions of ground targets on an experimental basis. In practice, by acquiring multiple views of a target (also called multi-look imaging -- MLI) that are subsequently merged mathematically, one can obtain reasonable approximations to higher-dimensional reconstructions of a target of interest. For example, multiple two-dimensional airborne images of ground objects can be merged via the Fourier transform (FT) to obtain one or more approximate three-dimensional object reconstructions. Additional methods of 3D model construction (e.g., from affine structure) present advantages of computational efficiency, but are sensitive to positioning errors. In this series of papers, analysis of MLI is presented that applies to various scenarios of nadir, near-nadir, or off-nadir viewing with a small or large number of narrow-or wide-angle views. A model of imaging through cover describes the visibility of a given target under various viewing conditions. The model can be perturbed to obtain theoretical and simulated predictions of target reconstruction error due to (1) geometric projection error, (2) focal-plane quantization error and camera noise, (3) possible sensor platform errors, and (4) coverage of looks. In this paper, an imaging model is presented that can facilitate prediction of limiting sensor geometry and view redundancy under various imaging constraints (e.g., target and cover geometry, available range of look angles, etc.). Study notation is a subset of image algebra, a rigorous, concise, computationally complete notation that unifies linear and nonlinear mathematics in the image domain. Image algebra was developed at University of Florida over the past decade under the sponsorship of DARPA and the U.S. Air Force, and has been implemented on numerous sequential workstations and parallel processors. Hence, our algorithms are rigorous and widely portable.
Ochratoxin A in cocoa and chocolate products from the Italian market: Occurrence and exposure assessment

Abstract Three hundred samples of cocoa and chocolate-based products were randomly collected in South, Center and North Italy. One hundred and seventy nine, out of the 300 samples analyzed, were positive for ochratoxin A (OTA) contamination, representing 60% of the purchased products. All 40 cocoa samples showed OTA contamination, while grouping all the chocolate products the positive samples accounted for 53%. The mean OTA concentration levels for cocoa and chocolate products were well below the corresponding Italian legal limits. Teenagers’ male age group resulted as the highest consumers for cocoa powder (2.9 g per day), while the OTA highest weekly intake was reported for the younger age groups (0.10 and 0.38 ng/kg bw/week, for infant and children respectively). With respect to chocolate products, the highest daily consumption and the highest intake are reported for children (7.3 g and 0.57 ng/kg bw/week, respectively). As far as single chocolate products are concerned, the highest weekly intake is referred to the consumption of Easter chocolate eggs by the infant/children age group (0.10 ng/kg bw/week). The overall analysis of the exposure assessment suggests that the very low value of body weight for infant and children categories drives the exposure calculations. On the basis of the risk assessment carried out in this study, the exposure to OTA, due to the consumption of cocoa and chocolate products, is to be considered not a major concern. Therefore, the Italian Superior Council of Health considered the data arising from this study, adequate to repeal the existing Italian legal limits and to align national legislation with the EU provisions.
Finite element analysis of heat transfer in anisotropic solids: application to manufacturing problems

A general formulation for the finite element analysis of heat transfer problems in anisotropic laminated composite materials is presented. Two-dimensional analyses using quadrilateral isoparametric elements are performed for two classes of problems: laser cutting of laminates and non-destructive testing using thermography. Results show complex temperature distributions near the laser beam. The size of the heat affected zone is estimated and the power required to cut is shown to depend on the orientation of the fibers relative to the cutting direction. Temperature distributions in laminates with delaminations subjected to heat flow through the thickness, are shown to be strongly affected by the location of the delamination. 8 refs.
Combinatorial aspects of the Lascoux–Schützenberger tree

Abstract In 1982, Richard Stanley introduced the formal series Fσ(X) in order to enumerate reduced decompositions of a given permutation σ. Stanley (European J. Combin. 5(4) (1984) 359) not only showed Fσ(X) to be symmetric, but in certain cases, Fσ(X) was a Schur function. Stanley conjectured that for arbitrary σ, F σ (X) was always Schur positive. Edelman and Greene subsequently proved this fact (Combinatories and Algebra (Boulder, CO, 1983), Amer. Math. Soc., Providence RI, 1984, pp. 155–162; Adv. in Math. 63(1) (1987) 42). Using the techniques of Lascoux and Schutzenberger (Lett. Math. Phys. 10(2–3) (1985) 111) for computing Littlewood–Richardson coefficients, we will exhibit a new bijective proof of the Schur positivity of Fσ(X).
Mood disorders in patients with COPD: overview of current research and future needs.

Depression is major problem for the medically ill population but few recommendations have been made regarding treatment with specific compounds in many of these illnesses. This review attempts to consider the inter-relationship between smoking, pulmonary disease and mood disorders. It has been reported that nearly 50% of patients with chronic pulmonary illnesses report depressive symptoms at some time during the course of their illness, but with the complex issues regarding respiratory drive and substance dependence, little in the way of specific clinical information have been made for this group. In this review, the theorectical relationship that exists between dopamine, serotonin and nicotine and how the biochemical nicotine dependence issues (with regard to mood) may actually be a key element in the understanding and treatment of depression later in the life of the development of chronic lung disease and depressio, are discussed.
Kinetics of reaction of nitrite with deoxy hemoglobin after rapid deoxygenation or predeoxygenation by dithionite measured in solution and bound to the cytoplasmic domain of band 3 (SLC4A1).

The reaction of deoxyhemoglobin with nitrite was characterized in the presence of dithionite using hemoglobin in solution or bound to the cytoplasmic domain of band 3 (CDB3). Deoxyhemoglobin was generated by predeoxygenation (nitrogen flushing followed by addition of dithionite), or transiently, by rapidly mixing oxyhemoglobin with nitrite and dithionite simultaneously. Wavelength-dependent kinetic studies confirmed the formation of nitrosyl hemoglobin. Furthermore, the rate of reaction was independent of dithionite concentration, indicating that dithionite does not reduce nitrite to nitric oxide directly. Model simulation studies showed that superoxide anion generated by dithionite reduction of molecular oxygen was not a factor in the reaction kinetics. CDB3-bound hemoglobin reacted faster with nitrite than did hemoglobin in solution. This difference was most pronounced for predeoxygenated hemoglobin and least pronounced for rapidly deoxygenated hemoglobin. The smaller difference observed in the rapid de...
Co3O4 Nanoparticle Water-Oxidation Catalysts Made by Pulsed-Laser Ablation in Liquids

Surfactant-free, size- and composition-controlled, unsupported, <5-nm, quantum-confined cobalt oxide nanoparticles with high electrocatalytic oxygen-evolution activity were synthesized by pulsed laser ablation in liquids. These crystalline Co3O4 nanoparticles have a turnover frequency per cobalt surface site among the highest ever reported for Co3O4 nanoparticle oxygen evolution catalysts in base and overpotentials competitive with the best electrodeposited cobalt oxides, with the advantage that they are suitable for mechanical deposition on photoanode materials and incorporation in integrated solar water-splitting devices.
A Mössbauer study of the surface martensite in 1095 steel

The extent of the martensitic transformation on the surface was measured with reference to the bulk value in a quenched 1095 steel using the Mossbauer effect scattering technique. The difference between surface and bulk austenite concentration was most evident in oil-quenched specimens which have 27 to 29 pct austenite in the bulk while retaining only 15 to 17 pct on the surface. This effect persisted even when 0.1 cm of material was removed by electropolishing of the as-quenched surface, confirming that the martensitic transformation could proceed spontaneously at the new surface exposed by electropolishing. Analysis of the Mossbauer and X-ray diffraction data indicated that the surface martensite extended to a depth greater than 0.3 Μm and less than 20 to 30 μm. Implications of these observations to the determination of retained austenite are discussed.
145 Interval Analysis of a Randomized, Open Label, Multi‐Center Study Comparing Apligraf Vs. Standard Multilayer Compression in the Reduction of Pain Associated WItH Venous Leg Ulcerations

Background: According to The American Pain Society, pain should be considered a fifth vital sign. Pain is a prominent feature of venous leg ulcerations (VLUs). Sixty-five percent of VLU patients complain of severe pain. In several multicenter clinical trials, Apligraf, a bioengineered living skin construct, has been shown to accelerate healing in venous leg ulcerations. Anecdotal clinical observations suggest that Apligraf treatment is associated with pain relief. A treatment modality which promotes healing and reduces pain would significantly improve the quality of life in patients with VLU. Methods: VLU patients with pain scores greater than 5/10 on a numerical scale or requiring narcotic analgesia were randomized to receive either Apligraf and compression or compression alone. There was a 3-week “wash-out” period to ensure that pain was not due to other factors such as inadequate compression or infection. Patients were enrolled only after a negative quantitative biopsy. The intensity of pain was self-scored and a quality-of-life questionnaire was completed at each visit. Weekly wound area measurements were obtained with digital planimetry. Results: Thus far in the enrollment period we have already seen a trend toward a significant reduction in pain in the Apligraf group. This pain relief occurs shortly after application indicating that a mechanism distinct from clinical healing. The Apligraf group also demonstrated acceleration in wound healing as well as a decreased time-to-complete closure. Conclusion: Interval analysis of this multicenter trial suggests that Apligraf accelerates wound healing and reduces the pain associated with venous leg ulcerations. Acknowledgment: Unrestricted Educational grant, Organogenesis Inc.
Creativity, inquiry, or accountability? Scientists' and teachers' perceptions of science education

Although there have been numerous studies that indicate the benefits of teachers and students working with scientists, there is little research that documents scientists' views of science education, science teacher preparation, and the goals of science education. Furthermore, little is known about how scientists' views of science education may differ from those held by science teachers. Through the use of semistructured interviews, the perceptions of 37 scientists from diverse science domains and 21 middle and high school science teachers were explored. Participating scientists expressed concerns about the variability in quality of teaching, programs, and resources available for science instruction. Scientists expressed a desire for teachers to have more experience conducting science research and developing their own critical thinking skills. When asked what goals are most important for science education, 40% of the scientists emphasized that teachers should make science fun and exciting for their students. Science teachers' perceptions of science education were compared with the scientists' perceptions. Thirty percent of the teachers agreed with the scientists that too much variability in program or instructional quality exists in science education. Seventy-six percent of the science teachers also thought there is a need to teach critical thinking skills, but more importantly there is a need to inspire creativity and a desire to learn science in students. Both teachers and scientists expressed concerns about how high-stakes accountability inhibits efforts to improve science education. © 2008 Wiley Periodicals, Inc. Sci Ed92:1058–1075, 2008
Quasi-stationary distributions for absorbing continuous-time denumerable Markov chains

The stationary conditional, doubly limiting conditional and limiting conditional mean ratio quasi-stationary distributions are given for continuous-time Markov chains with denumerable state space both in terms of the transition matrixP(t) and the infinitesimal, generatorQ.
Reducing the Costs of Participation Are States Getting a Return on Early Voting

The authors address the puzzle of why governments have implemented methods of early voting when those methods appear not to have an effect on turnout. Using an aggregate analysis, the authors find that early voting seems to produce a short-lived increase in turnout that disappears by the second presidential election in which it is available. They also address whether the additional costs to government are worth the negligible increase in participation. They conclude that these reforms merely offer additional convenience for those already likely to vote.
Depression of the cat cortical visual evoked potential by soman.

Abstract The effects of intravenous administration of the anticholinesterase agent soman (pinacolyl methylphosphonofluoridate, 3–15 μg/kg) on the visual evoked potential (VEP) were examined in cats using phase-reversed sine wave grating stimuli of different spatial frequencies and contrasts. Doses of 5–7 μg/kg caused a depression of the VEP across all spatial frequencies in an abrupt, non-graded fashion. Studies in which contrast was varied showed that VEP depression resulted primarily from a decrease in the system gain rather than a change in the contrast sensitivity, and that response depression increased with increasing contrast. The dominant changes in gain revealed by these studies are consistent with a modulation of potassium conductance in the cell membrane which previous studies have shown to be dependent on a cholinergic mechanism.
Ultrahigh-resolution optical coherent tomography using continuum generation from a photonic crystal fiber

We developed an ultrahigh resolution optical coherence tomographic system utilizing broadband continuum generation from a photonic crystal fiber for high axial resolution. Longitudinal resolution of 1.3 μm has been achieved in a biological tissue by use of continuum light from 800 - 1400 nm as the light source. The system employed a dynamic focusing tracking method to maintain high lateral resolution over a large imaging depth. Subcellular imging is demonstrated.
Electron-phonon interaction using Wannier functions

We introduce a technique based on the spatial localization of electron and phonon Wannier functions to perform first-principles calculations of the electron-phonon interaction with an ultradense sampling of the Brillouin zone. After developing the basic theory, we describe the practical implementation within a density-functional framework. The proposed method is illustrated by considering a virtual crystal model of boron-doped diamond. For this test case, we first discuss the spatial localization of the electron-phonon matrix element in the Wannier representation. Then, we assess the accuracy of the Wannier-Fourier interpolation in momentum space. Finally, we study the convergence of the electron-phonon self-energies with the sampling of the Brillouin zone by calculating the electron and phonon linewidths, the Eliashberg spectral function, and the mass enhancement parameter of B-doped diamond. We show that more than ${10}^{5}$ points in the irreducible wedge of the Brillouin zone are needed to achieve convergence.
Tobacco Budworm: Observations on the Laboratory Adaptation of a Wild Strain

The mating and oviposition patterns of field-collected tobacco budworms, Heliothis virescens (F.), reared in the laboratory for 7 consecutive generations were compared with those of a laboratory strain. In the laboratory, females of the laboratory-adapted strain had a higher percentage of matings, and they mated more frequently than those of the wild strain. However, with each successive generation, the response of the fieldcollected strain came closer to the response of the laboratory strain. The laboratory strain oviposited significantly earlier than the field strain through generation 3; thereafter, no differences were noted. Responses of F1 progeny from crosses between the laboratory and field strain suggest that the oviposition pattern is genetically controlled.
PET imaging in pediatric neuroradiology: current and future applications

Molecular imaging with positron emitting tomography (PET) is widely accepted as an essential part of the diagnosis and evaluation of neoplastic and non-neoplastic disease processes. PET has expanded its role from the research domain into clinical application for oncology, cardiology and neuropsychiatry. More recently, PET is being used as a clinical molecular imaging tool in pediatric neuroimaging. PET is considered an accurate and noninvasive method to study brain activity and to understand pediatric neurological disease processes. In this review, specific examples of the clinical use of PET are given with respect to pediatric neuroimaging. The current use of co-registration of PET with MR imaging is exemplified in regard to pediatric epilepsy. The current use of PET/CT in the evaluation of head and neck lymphoma and pediatric brain tumors is also reviewed. Emerging technologies including PET/MRI and neuroreceptor imaging are discussed.
Effects of SKF525A, Phenobarbital, Fasting, and Carnitine on the Anticonvulsant Activity and Neurotoxicity of Valproate in Mice

The anticonvulsant potency of valproate (VPA), as measured by the maximal electroshock seizure model in mice, was improved by pretreatment with the microsomal inhibitor SKF525A and by fasting, but was reduced by chronic phenobarbital pretreatment. Carnitine did not significantly alter the anticonvulsant properties of VPA. These findings suggest that the efficacy of VPA can be improved by factors that alter its metabolic pattern.