cssi/SciSciGPT-SciSciNet huggingface dataset:
Activation of ganglion cells in wild-type and P23H rat retinas with a small subretinal electrode

Abstract Electronic retinal prostheses are being developed for people who become blind due to loss of photoreceptors from the disease retinitis pigmentosa. Previously, we reported on the responses of RGCs in the P23H rat (a model of retinitis pigmentosa) and the Sprague-Dawley (SD) rat to stimulation with a 400-μm diameter electrode ( Jensen and Rizzo, 2011 ). With recent clinical trials now utilizing smaller (50–200 μm) electrodes, I sought to investigate the electrically evoked responses of RGCs in P23H and SD rat retinas with a smaller (125-μm diameter) electrode. Here, I report on the electrically evoked spike activity from RGCs that arose from stimulation of the retinal neural network. With biphasic current pulses of 1 ms per phase, the thresholds for activation of SD rat RGCs ranged from 0.52 to 2.8 μA; thresholds of P23H rat RGCs ranged from 1.2 to 7.8 μA. Median thresholds of RGCs were 1.4 μA in SD rats and 2.5 μA in P23H rats. These thresholds measurements were obtained with the recording electrode placed over the stimulating electrode. I also examined how thresholds of RGCs change as a function of distance (100–500 μm) from the center of the stimulating electrode. The median threshold currents of RGCs were much higher in P23H rats for all distances. What was striking was that the thresholds for activation of RGCs in P23H rat retinas rose much more rapidly. When the recording electrode was only 100–200 μm from the center of the stimulating electrode, the median threshold current of P23H rat RGCs rose by 460%. In contrast, the median threshold current of SD rat RGCs increased only 29%. I also investigated the contribution of photoreceptors to the electrically evoked responses of ON-center RGCs in SD rat retinas by examining the change in RGC thresholds when photoreceptor input to ON bipolar cells was blocked with the mGluR6 antagonist CPPG. At 500–600 μm, CPPG suppressed the light-evoked responses of the RGCs and at the same time increased the amount of current needed to generate an electrically evoked response. Similar to what was observed with SD rat RGCs, CPPG suppressed the light-evoked responses of ON-center P23H rat RGCs. However, the stimulation thresholds were not significantly altered. In conclusion, the data show that the threshold currents for indirect stimulation of both SD and P23H rat RGCs with a 125-μm diameter electrode are much lower than what we found previously with a 400-μm diameter electrode. To achieve high resolution vision with a multielectrode array, the spread of activation of RGCs needs to be limited. Our findings indicate that the spread of activation of RGCs is more confined in the degenerate retina. Lastly, my findings indicate that photoreceptors contribute to the lower stimulation thresholds of RGCs in normal, healthy retinas.
One-loop QCD corrections to the thermal Wilson line model

We calculate the time independent four-point function in high temperature (T) QCD and obtain the leading momentum dependent terms. Furthermore, we relate these derivative interactions to derivative terms in a recently proposed finite T effective action based on the SU(3) Wilson line and its trace, the Polyakov loop. By this procedure we thus obtain a perturbative matching at finite T between QCD and the effective model. In particular, we calculate the leading perturbative QCD correction to the kinetic term for the Polyakov loop.
Molecular cloning of the murine branched chain α-ketoacid dehydrogenase E2 subunit: Presence of 3′ B1 repeat elements

Abstract The cDNA sequence encoding the murine E2 subunit (dihydrolipoyl transacylase) of the branched-chain α-ketoacid dehydrogenase (BCKAD) complex was determined. In the region encoding the mature E2 subunit protein, both the nucleotide composition and predicted amino acid sequence are highly conserved between murine, human, and bovine species. In contrast, the 5′ sequence encoding the amino-terminal preprotein sequence and 3′ untranslated region are less well conserved. The 3′-noncoding region contains sequences highly homologous to the rodent B1 repeat elements, which are related to human Alu repeat sequences. This finding is similar to the presence of three Alu repeat sequences in the 3′-noncoding region of human E2 cDNA.
COULOMB CORRECTIONS TO ONE- AND TWO-CHANNEL STRONG SCATTERING PROCESSES.

We generalize our previous considerations of Coulomb corrections to single-channel processes to the two-channel case. Using a potential model, we derive an extremely simple formula for the corrections which does not necessitate using Coulomb wave functions. This formula is correct to lowest order in $\ensuremath{\alpha}$ but to all orders of the strong scattering. We discuss the application of our results to recent data on pion-nucleon elastic and charge-exchange scattering in the vicinity of the ${N}^{*}(1236)$ resonance. The choice of an appropriate wave equation and the question of mass-difference corrections are also discussed in an appendix.
An algorithm for evaluating the ethics of a placebo-controlled trial.

The purpose of this article is to clarify the decision points that are important to consider when evaluating the ethics of a placebo-controlled trial. The ethical requirements for research involving human subjects are reviewed, and the rationale for and potential problems with concomitant placebo control are explained. A series of case discussions are used to illustrate each decision point. The critical decision points in the evaluation of the ethics of a placebo-controlled trial are as follows: (i) Is placebo being used in place of standard therapy? (ii) Is standard therapy likely to be effective? (iii) Is the toxicity of standard therapy such that patients routinely refuse this treatment? (iv) Could the use of placebo result in severe suffering or irreversible harm? (v) Is the variability in the placebo response such that it is reasonable to consider other options for the control group? (vi) Would a reasonable person with an average degree of altruism and risk aversiveness agree to participate in this study? The algorithm presented in this article gives researchers and research monitors (such as Institutional Review Board members) the tools they need to evaluate the ethics of a study that uses concomitant placebo control.
Rotating disk transition due to isolated roughness with intense acoustic irradiation

The low transition Reynolds numbers associated with boundary-layers which exhibit crossflow instability have made them an important area of study in fluid mechanics. An excellent test bed for the study of this flow is a flat disk rotating in still fluid. An experimental investigation of stability and transition of a rotating disk boundary-layer has been conducted. The effects of isolated roughness elements and acoustic forcing, both alone and in combination, were considered. The flow showed no receptivity to intense monochromatic acoustic forcing except in the presence of sizable roughness. A case was investigated where the growth of the primary instability, seeded by an isolated roughness element, was positively altered in the presence of sound, leading to a downstream movement of transition. In agreement with the work of several investigators, the results of this study suggest that receptivity to long wavelength phenomena, such as traveling sound waves, is contingent upon the presence of strong localized pressure gradients (such as those introduced by roughness) to reduce the length scales of the disturbance to those which are consistent with unstable wavelengths in the flow field.
Scaling laws in steady-state aqueous foams including Ostwald ripening

Abstract This paper presents scaling laws governing the steady-state behavior of pneumatic foams produced by injecting gas in aqueous surfactant solutions under isothermal conditions. Dimensional analysis of the governing equation for the time rate of change of bubble radius in foams due to Ostwald ripening yielded a dimensionless similarity parameter representing the ratio of the average contact time between bubbles to the characteristic time for gas permeation. This dimensionless number was combined with two other dimensionless numbers previously derived for high viscosity fluids and ignoring foam coarsening. Semi-empirical parameters of a power-law relation between these three dimensionless numbers were determined from experimental data collected in the present study as well as from the literature for various gases and aqueous surfactant solutions. They cover a wide range of physical parameters including foam thickness, superficial gas velocity, solubility, surface tension, and average bubble radius.
Atherogenic aspects of desmosterol metabolism caused by prolonged triparanol administration.

Abstract Mongolian gerbils treated with triparanol at the dose levels of 12.5, 25.0, and 50.0 mg/kg body weight for forty weeks resulted in a decrease of blood and liver cholesterol when compared to the controls injected with Wesson Oil. No desmosterol was detected by gas chromatography of control gerbils. However, those treated with 12.5, 25.0 and 50.0 mg of triparanol showed an increase of desmosterol in the blood and liver as the dosage was increased. The total sterols of the liver were lowered by this drug. Microscopic grading of the aorta showed that no lesions were observed in the controls. In the triparanol treated group, the number of gerbils having lesions were increased as the dosage was increased. No lesions were observed in the coronary arteries of any group.
Spectral element modeling of spontaneous earthquake rupture on rate and state faults: Effect of velocity-strengthening friction at shallow depths

We develop a spectral-element methodology (SEM) for simulating dynamic rupture on rate and state faults and use it to study how the rupture is affected by a shallow fault region of steady-state velocity-strengthening friction. Our comparison of the developed SEM and a spectral boundary-integral method (BIM) for an anti-plane (two-dimensional) test problem shows that the two methods produce virtually identical solutions for the finest resolution we use and that the convergence with grid reduction of the developed SEM methodology is comparable to that of BIM. We also use the test problem to compare numerical resolution required for different state evolution laws and for linear slip-weakening friction. Using our three-dimensional implementation of the methodology, we find that a shallow velocity-strengthening fault region can significantly alter dynamic rupture and ground motion. The velocity-strengthening region suppresses supershear propagation at the free surface occurring in the absence of such region, which could explain the lack of universally observed supershear rupture near the free surface. In addition, the velocity-strengthening region promotes faster fall-off of slip velocity behind the rupture front and decreases final slip throughout the entire fault, causing a smaller average stress drop. The slip decrease is largest in the shallow parts of the fault, resulting in the depth profile of slip qualitatively consistent with observations of shallow co-seismic slip deficit. The shallow velocity-strengthening region also reduces the amplification of strong ground motion due to a low-velocity bulk structure.
Questioning community in early childhood education

In current early childhood literature, it appears that anything called ‘a caring community of learners’ is considered excellent practice. In this article, however, we look critically at the idea of community. We examine the shifts in the field that led to community's transformation from an implicit assumption to a recognized and explicit requirement in high‐quality early childhood educational environments, identify some of the more troubling and problematic aspects of community that are currently missing from the scholarly literature, and make suggestions about ways to continue this important conversation. Our goal is not to discount the value of community in early childhood educational practices, but to enrich and complicate our understandings of this important aspect of our work with young children.
Airborne plume tracking with sensor networks

This paper presents a framework and demonstrates results from a process detection based approach to tracking an airborne plume in sensor networks. Data integration and pattern detection in large sensor networks measuring gas and radiation plumes suffer from low resolution observations, missed detections, and numerous false positive reports. Large numbers of nodes and the hypothesis management concept of a Process Query System (PQS) can compensate for lower data quality. A result of the process detection based approach to this problem is models that can be implemented in many different scenarios. Plume predictor models are illustrated which allow data association between sensor nodes in typical outdoor wind conditions. We demonstrate a simulation of a mobile plume source in a sensor network designed for use in the same PQS. A kinematic model is developed for a vehicle carrying a plume source. Inverse models for this mobile plume source will work in conjunction with the existing software systems, thus allowing PQS to rapidly be adapted to a new problem domain with minimal modifications. This scenario of a mobile airborne plume source approximates a moving container emitting a detectable substance in a transportation network, where the container movement is restricted by existing vehicle corridors.
PARENTING AND CO‐PARENTING OF GRANDCHILDREN: EFFECTS ON GRANDPARENTS' WELL‐BEING AND FAMILY SOLIDARITY

Increasing numbers of grandparents are raising their grandchildren because of problems within the parental generation such as drug and alcohol addiction, AIDS, divorce, and unemployment. Yet little is known about how grandparents who “parent” or “co‐parent” then‐grandchildren differ from other grandparents, or the extent to which parenting or co‐parenting grandchildren affects grandparent's psychological, physical, or financial well‐being, or feelings of family solidarity. The purpose of this research is to: (1) compare the characteristics of grandparents who go on to parent or co‐parent their grandchildren to grandparents who do not, and (2) assess the effects of entering the two caregiving arrangements — parenting and co‐parenting — on changes in grandparent's psychological, physical, and financial well‐being, as well as their feelings of family solidarity. The data for this study came from 659 grandparents from the USC Longitudinal Study of Generations (LSG) who participated in at least two consecutive waves of data collection measured at three year intervals between 1985 to 1994: parenting grandparents (N = 12), co‐parenting grandparents (N = 27), and non‐parenting grandparents (N = 620). Analysis of the quantitative data reveals that grandparents who parent or co‐parent their grandchildren tend to be younger and less healthy than non‐parenting grandparents. Contrary to expectation, the data also indicate that there is no statistically significant decline in psychological, physical, or financial well‐being, nor in normative or marital solidarity after grandparents begin to caregive. Although the majority of grandparents show stability or improvement in overall psychological well‐being, some show decline. The qualitative data suggests that the extent to which grandparents can choose their level of involvement in caregiving influences and the age of the grandchild, whether they experience caregiving as positive or negative.
Thermal adaptation in biological membranes: Functional significance of changes in phospholipid molecular species composition

Quantities of 1-palmitoyl 2-docosahexaenoyl phosphatidylcholine (16∶0/22∶6-PC or PDPC) increase from 24 to 40 weight percent as a consequence of cold acclimation in mitochondrial membranes of rainbow trout liver (J. Comp. Physiol. 156, 665–674, 1986). The present study was undertaken to assess the impact of such a large change in the proportions of a single molecular species on the fluidity, lateral packing (as sensed by phospholipase A2), and permeability of biological membranes. These properties were examined in multilamellar liposomes prepared from binary mixtures of dipalmitoyl phosphatidylcholine (DPPC) and PDPC in proportions increasing from 10 to 40 mole% PDPC. Glucose permeability was positively correlated with both assay temperature and PDPC content. The temperature dependence of Na+ permeability declined steadily as the mole fraction of PDPC increased; consequently, sodium permeability was positively correlated with PDPC content at 5°C, but inversely correlated at 20°C. Phospholipase A2 activity was independent of both assay temperature and vesicle composition. Vesicles of all compositions displayed a single transition in the temperature dependence of 1,6 diphenyl-1,3,5-hexatriene (DPH) fluorescence polarization, which shifted to lower temperature and broadened as proportions of PDPC increased. At temperatures belowthe transition, fluidity was positively correlated with the mole fraction of PDPC, but interfacial and deeper regions of the bilayer were affected differently by variations in PDPC content. Nonelectrolyte permeability was the only index of membrane structure or function to be significantly correlated with the fluidity of the bilayer interior. The tendencies of PDPC to both fluidize the membrane and to reduce the temperature sensitivity of electrolyte permeation may promote the adaptation of membrane function to low temperature.
Socially-appropriate approach paths using human data

For service robots operating in indoor environments, the crucial task of navigation is often complicated by the presence of people. Simply treating humans in the environment as additional (often moving) obstacles can violate the complex set of social rules by which people navigate around each other. In contrast, emulating human behavior and navigating in a socially appropriate manner could positively affect people's comfort with a robot's presence and motion. We present a method of generating social paths for a robot to approach a person based on a small amount of human data. We also conducted a study in which a robot approached participants using both these social paths and straight-line, nonsocial paths. We found that both approaches were rated comparably when the robot approached from the participant's front or side, but the social approach was significantly preferred when the robot came from behind the participant.
Shadow wage assessments of the value of home production: Patterns from the 1970's

When measuring economic well-being, household income figures are routinely adjusted for nonwage income, taxes, and government transfers. Rarely are the figures adjusted to reflect the value of household work. An opportunity cost methodology is used in this article to expand the operationalization of household income so that it includes not only money income but the economic value of home production activities as well. The analysis indicates that the average married couple in the United States increases its access to goods and services dramatically by engaging in home production. While the average economic contribution stemming from spouses' home production is sizable, its distribution is somewhat uneven. Gini ratios calculated using income figures that include home production reveal greater distributional differences than do the Gini ratios calculated using only money income.
Dietary treatment of chronic sinusitis

T HE dietary treatment of chronic sinusitis is dependent for its success or vaIue upon a definite and carefuIIy determined diagnosis of the condition itseIf. Many faIse ideas prevai1, so that it sometimes happens that a patient accepts a diagnosis of sinus disease when he has been given onIy a superficia1 examination, whereas he shouId have the benefit of carefu1 observation and cIassif?cation by one who is quaIified to know chronic sinusitis from some of the various pathoIogic manifestations in the nose. However, the genera1 practitioner is Iearning more about sinus pathoIogy as he studies, reads, and takes postgraduate courses. It is fashionabIe among many peopIe today to refer to a coId as sinus disease, and to a persistent coId as a “chronic sinus.” They may be right, or they may reaIIy have aIIergic or inffammatory conditions of the nasa1 mucous membrane, or perhaps the disease may be mereIy an affectation. FormerIy we Iaid great stress on intumescent or hypertrophic rhinitis, and that of the atrophic variety, as a usua1 and more common condition of the nose. Going farther back, a11 nasa1 conditions were cIassifled under the genera1 name of “catarrh,” and aImost a11 peopIe, particuIarIy in our northern climates, beIieved they had catarrh-a name which covered practicaIIy a11 nasa1 pathoIogy during the oIder regime. It is, therefore advisabIe to understand the newer pathoIogy, and to recognize that the chronic manifestations in the noseother than specia1 entities, such as syphilis, tubercuIosis, rhinoscIeroma, tumors maIignant or benign, poIypi, ozena, Ieprosy, and other unusua1 conditions-may be for the most part cIassif?ed as aIIergic, hypertrophic, intumescent, atrophic, with defMICHIGAN
Asymptotic stabilization of the hanging equilibrium manifold of the 3D pendulum

SUMMARY The 3D pendulum consists of a rigid body, supported at a fixed pivot, with three rotational degrees of freedom; it is acted on by gravity and it is fully actuated by control forces. The 3D pendulum has two disjoint equilibrium manifolds, namely a hanging equilibrium manifold and an inverted equilibrium manifold. This paper shows that a controller based on angular velocity feedback can be used to asymptotically stabilize the hanging equilibrium manifold of the 3D pendulum. Lyapunov analysis and nonlinear geometric methods are used to assess the global closed-loop properties. We explicitly construct compact sets that lie in the domain of attraction of the hanging equilibrium of the closed-loop. Finally, this controller is shown to achieve almost global asymptotic stability of the hanging equilibrium manifold. An invariant manifold of the closed-loop that converges to the inverted equilibrium manifold is identified. Copyright # 2007 John Wiley & Sons, Ltd.
New Performance Criteria for Quadruplex Recorder Servo Systems

The tendency of TV broadcasters to rely increasingly upon videotape record/ playback equipment to solve the complex problems of daily program operations as well as generation of specially assembled program material creates new performance requirements for the equipment, particularly in the area of servo systems. The new performance requirements are described, such as improved stability of the record servo system for high-quality recordings, increased dynamic range and correction bandwidth of the pixlock servo, and ability to cope with nonsynchronously switched recording intervals with minimum visible playback disturbance. The advent of new circuit techniques and system design philosophies such as the utilization of digital process control, digital servo error detection and a high-efficiency “hybrid” power amplifier has enabled the design of a new capstan and headwheel servo system which meets the above-mentioned requirements.
Statistical-mechanical derivation of generalised langmuir equation and its application for the interpretation of chromatographic data for the adsorption of water and methanol on non-porous carbon materials

The chromatographic method is applied to the study of water and methanol adsorption on non-porous carbon materials—graphitised carbon black and thermally expanded graphite. It is shown that the processing of the experimental isotherms in coordinates of the classic Langmuir equation results in their linearization in two ranges of relative pressure, indicating the presence of two types of adsorption centres on the surface, which can be identified as the carboxyl and phenolic hydroxyl groups, respectively. A generalised Langmuir equation based on a statistical-mechanical approach is proposed, capable for the description of both monomolecular and polymolecular adsorption on the surface. It is shown that this equation provides for a better description of the adsorption of polar molecules on non-porous carbon materials.
Anomalies of Meridional Overturning: Mechanisms in the North Atlantic

Abstract Optimal observations are used to investigate the overturning streamfunction in the North Atlantic at 30°N and 900-m depth. Those observations are designed to impact the meridional overturning circulation (MOC) in numerical models maximally when assimilated and therefore establish the most efficient observation network for studying changes in the MOC. They are also ideally suited for studying the related physical mechanisms in a general circulation model. Optimal observations are evaluated here in the framework of a global 1° model over a 10-yr period. Hydrographic observations useful to monitor the MOC are primarily located along the western boundary north of 30°N and along the eastern boundary south of 30°N. Additional locations are in the Labrador, Irminger, and Iberian Seas. On time scales of less than a year, variations in MOC are mainly wind driven and are made up through changes in Ekman transport and coastal up- and downwelling. Only a small fraction is buoyancy driven and constitutes a sl...
Neutron spectral unfolding using the Monte Carlo method

Abstract A solution to the neutron unfolding problem, without approximation or a priori assumptions as to spectral shape, has been devised, based on the Monte Carlo method, and its rate of convergence derived. By application to synthesized measurements with controlled and varying levels of error, the effect of measurement error has been investigated. This Monte Carlo method has also been applied to experimental stray neutron data from measurements inside a reactor containment vessel.
Extraordinary Efficiency Growth in Response to New Technology Entry: The Carburetor's 'Last Gasp'

Technologies often experience a period of extraordinary improvement or a “last gasp” before being superseded. Although last gasps are important both to technological transitions and firm strategies, their origin has been little studied. The most common explanation is that the materialization of a threat from a new technology causes adherents of the threatened technology to work harder to improve its performance. Anecdotal evidence has been cited in support of this “trying harder” explanation, but it has not yet been subjected to a test against alternative explanations. In this article, I develop two new explanations for last gasps. The first, a selection effect, is that new technologies force old technologies out of inefficient applications, making them appear to be more efficient. The second, a spillover effect, is that technologies introduced contemporaneously with a superseding technology may provide spillover improvements to incumbent technologies. I use data from the EPA and from carburetor repair manuals to test these and the existing “trying harder” explanation, I find that the carburetor’s last gasp was caused by both selection and spillover effects. However, only those firms that also produced the new technology were able to capture the benefits of these spillovers.
A new method for measuring technological change

Abstract This paper presents a new method for testing for technological change. The innovation here is the introduction of a production function which is sufficiently flexible to detect the change. The production function is assumed to be a function not only of the relevant inputs but also of technology-changing parameters.
A clickable inhibitor reveals context-dependent autoactivation of p90 RSK

p90 ribosomal protein S6 kinases (RSKs) integrate upstream signals through two catalytic domains. Autophosphorylation of Ser386 by the regulatory C-terminal kinase domain (CTD) is thought to be essential for activation of the N-terminal kinase domain (NTD), which phosphorylates multiple downstream targets. We recently reported fmk, an irreversible inhibitor of the CTD of RSK1 and RSK2. Here we describe fmk-pa, a propargylamine variant that has improved cellular potency and a 'clickable' tag for assessing the extent and selectivity of covalent RSK modification. Copper-catalyzed conjugation of an azidoalkyl reporter (the click reaction) revealed that fmk-pa achieves selective and saturable modification of endogenous RSK1 and RSK2 in mammalian cells. Saturating concentrations of fmk-pa inhibited Ser386 phosphorylation and downstream signaling in response to phorbol ester stimulation, but had no effect on RSK activation by lipopolysaccharide. RSK autoactivation by the CTD is therefore context dependent, which suggests that NTD and CTD inhibitors should have distinct physiological effects.
Modeling Growth and Quorum Sensing in Biofilms Grown in Microfluidic Chambers

Biofilms are highly organized structures coordinately formed by multiple species of bacteria. Quorum sensing (QS) is one cell-cell communication mechanism that is used by bacteria during biofilm formation. Biofilm formation is widely acknowledged to occur through a sequence of spatially and temporally regulated colonization events. While several mathematical models exist for describing biofilm development, these have been developed for open systems and are not applicable to closed systems where biofilm development and hydrodynamics are interlinked. Here, we report the development of a mathematical model describing QS and biofilm formation in a closed system such as a microfluidic channel. The model takes into account the effect of the external environment viz the mass and momentum transport in the microfluidic channel on QS and biofilm development. Model predictions of biofilm thickness were verified experimentally by developing Pseudomonas aeruginosa PA14 biofilms in microfluidic chambers and reflect the interplay between the dynamics of biofilm community development, mass transport, and hydrodynamics. Our QS model is expected to guide the design of experiments in closed systems to address spatio-temporal aspects of QS in biofilm development and can lead to novel approaches for controlling biofilm formation through disruption of QS spatio-temporal dynamics.
A new boundary integral equation for molecular electrostatics with charges over whole space

In this paper, a new integral equation of electrostatics is proposed as an integral form of a basic dielectric continuum model, which is traditionally represented in a form of Poisson differential equation. As an application in protein simulations, the new integral equation is reduced to a second kind Fredholm boundary integral equation on the interface between the solute and solvent regions for a piecewise constant permittivity function, together with two new integral expressions for the electrostatics within the solute and solvent regions. The new integral equation and expressions work for any charge problem over the whole space (including the one with charges on the interface). This valuable feature is verified numerically for a dielectric sphere model with a point charge inside, outside, or on the sphere in this paper.
Finite element analysis of a concrete slab under various non-uniform support conditions

A two-dimensional finite element program was utilised to study the effects of a non-uniform subgrade support on the tensile stresses in a concrete slab. A total of 12 subgrade support conditions were created including uniform and non-uniform support. The modulus of subgrade reaction (k-value) for different support areas was arbitrarily assigned either a soft (50 psi/in., 13.5 MPa/m) or stiff (500 psi/in., 135 MPa/m) value. Three axle types (single, tandem and steer-drive), three linear temperature differentials (none, negative and positive), two loading paths (edge and wheel path) and multiple longitudinal wheel positions were considered in the analysis. The theoretical analyses showed that several non-uniform subgrade support cases had a profound impact on the peak tensile stresses in a slab. In particular, a stiff subgrade with soft edges and a subgrade with randomly assigned soft and stiff locations significantly increased the peak tensile stresses relative to a uniformly soft support condition by at l...
Structually distinct genes for the surface protease of Leishmania mexicana are developmentally regulated

Abstract gp63 is a highly abundant glycosylphosphatidylinositol (GPI)-anchored membrane protein expressed in both the promastigote and the amastigote forms of Leishmania species. In Leishmania mexicana , gp63 exists as a heterogeneous family of proteins that are differentially processed and localized during the 2 developmental stages. In this study we determined the molecular organization of the L. mexicana gp63 gene family, demonstrating that the gp63 genes fall into 3 linked families of tandemly repeated, but structurally distinct, entities designated as C1, C2 and C3. The C1 and C2 gene clusters contain 4–5 copies each, while the C3 gene may be single copy. Whilst promastigotes contain transcripts from all 3 gene classes, the intracellular amastigote only expressed detectable transcript from the C1 gene class. Moreover, the sequence of the C1 genes predicts a unique carboxy terminus substantially different from the GPI anchor addition signal sequence found in other Leishmania spp. and which has characteristics incompatible with substitution with a GPI anchor. These findings have significance for both the diversity of gp63 and for the regulation of tightly clustered, tandem gene arrays.
4-Maleimidohippuric acid — a tailor-made, direct, site-specific nephrotoxin: effects on renal function and ultrastructure in pentobarbital-anesthetized dogs

Abstract A model has been proposed to explain at least one of the possible pathways through which a xenobiotic might produce proximal tubule necrosis. The model is formulated on the idea that a compound must possess two structural fea tures: (i) a carboxyl or amino acid moiety that would allow for selective uptake into proximal tubule cells via the strategically located antilurninal membrane-bound organic anion transport system or the luminal membrane-bound amino acid transport system(s), respectively, and (ii) a highly reactive moiety that can directly alkylate proximal tubular components, or a moiety that can be biotransformed within proximal tubular cells to such a substance. In an attempt to validate the proposed structural features as prerequisites for xenobiotic induction of proximal tubular necrosis, a novel compound, 4-maleimidohippuric acid (4-MHA), was synthesized which possesses an anionic group and a reactive moiety. Following the administration of 4-MHA directly into the renal artery of pentobarbital-anesthetized dogs, specific unilateral ultrastructural damage was noted only in the S 1 and S 2 cell types of the proximal tubule; the most notable renal function changes included proteinuria and glucosuria. Anionic, but non-alkylating, relatives of 4-MHA failed to alter renal function or ultrastructure. The specific proximal tubular toxicity of 4-MHA validates the proposed structural requirements for induction of proximal tubular necrosis.
Imaging of Cervical Lymph Nodes in Head and Neck Cancer: The Basics

Imaging can identify pathologic cervical adenopathy in a significant number of patients with head and neck cancer who have no palpable adenopathy on physical examination. This article reviews nodal classification, drainage patterns of different head and neck cancers, various cross-sectional imaging features of metastatic lymph nodes from head and neck cancer, nodal staging, and certain features like extracapsular spread and carotid and vertebral invasion that the clinician should know because they have therapeutic and prognostic implications. New imaging techniques and the role of fluorodeoxyglucose positron emission tomography imaging in recurrent disease are discussed.
Liquid crystal-on-silicon implementation of the partial pixel three-dimensional display architecture

We report the implementation of a liquid crystal-on-silicon, three-dimensional (3-D) diffractive display based on the partial pixel architecture. The display generates multiple stereoscopic images that are perceived as a static 3-D scene with one-dimensional motion parallax in a manner that is functionally equivalent to a holographic stereogram. The images are created with diffraction gratings formed in a thin liquid crystal layer by fringing electric fields from transparent indium tin oxide interdigitated electrodes. The electrodes are controlled by an external drive signal that permits the 3-D scene to be turned on and off. The display has a contrast ratio of 5.8, which is limited principally by optical scatter caused by extraneous fringing fields. These scatter sources can be readily eliminated. The display reported herein is the first step toward a real-time partial pixel architecture display in which large numbers of dynamic gratings are independently controlled by underlying silicon drive circuitry.
Experimental measurements of the effective thermal conductivity of a lithium titanate (Li2TiO3) pebbles-packed bed

Abstract Tritium breeding materials, which have the ability to react with neutrons and produce tritium, are required to fuel fusion reactions. Tritium is produced inside the fusion blanket by neutron irradiation of lithium ceramics (tritium breeders). Using the lithium ceramics in form of pebbles-packed bed is a promising concept for fusion blankets, and worldwide efforts have been dedicated to its R&D. Thermal properties of lithium ceramic pebble beds have a significant impact upon the thermal performance of the fusion blanket. Specifically, the effective thermal conductivity of lithium ceramic pebble beds is important for the design and analysis of fusion blankets. The experimental apparatus of this study was designed and built based on the principles of the steady state and axial heat flow methods in order to conduct the required measurements. The objective of this study is to measure the effective thermal conductivity of a Li2TiO3 pebble bed as a function of the average bed temperature. The pebble bed has pebbles of 1.7–2.0 mm diameter and a packing fraction of 61%. Helium at atmospheric pressure was used as a filling gas. The experimental results showed that the effective thermal conductivity decreased from 1.40 to 0.94 W/m K with the increase of the average bed temperature from 50 to 500 °C. The results presented in this work will help to create a database of the effective thermal conductivity of Li2TiO3 pebble beds which can be used for the design and analysis of fusion blankets.
DNS of the collision of co-axial vortex rings

Abstract The collision of two identical, coaxial vortex rings with opposite sign of circulation at Re Γ = 1000–3000 and slenderness ratios ϵ in the range [0.1477 ⩽ ϵ ⩽ 0.2957] is investigated using an accurate numerical method. First, the linear stability of the axi-symmetric collision flow is analyzed numerically by solving the nonlinear, axi-symmetric basic flow and the linearized, 3-d disturbance equations simultaneously. The basic flow is linearly stable for the Reynolds number Re Γ = 1955, but exhibits algebraic growth phases. Then the fully nonlinear equations are solved for the Reynolds numbers Re Γ = 1806.91, Re Γ = 2701.82 and the same but enhanced initial disturbances. It is shown that the two vortex rings mutually expand in diameter with the subsequent formation of instabilities along the circumference of the resultant, compound vortex ring.
Quantitative, video-based histochemistry to measure regional effects of anticholinesterase pesticides in rat brain.

Abstract Acetylcholinesterase histochemistry was coupled to inexpensive and widely available apparatus for video microscopy and densitometry to study enzyme activity and inhibition in different parts of the rat brain. Quantitative histochemistry, under properly defined conditions, yielded an output that increased linearly with incubation time and section thickness and was a smooth hyperbolic function of substrate concentration. The time-course of staining after in vivo exposure to eserine revealed no sign that carbamate-induced cholinesterase inhibition was readily reversed in vitro. Brains from rats treated either with a carbamate or an organophosphate anticholinesterase pesticide showed significant regional variation in cholinesterase inhibition. The histochemical data corresponded well with data from biochemical assays of acetylcholinesterase activity (overall correlation coefficient of absolute values, r = 0.95). Also, a comparison of assay types by two-way analysis of variance showed no significant main effect. These results support the conclusion that video-based histochemistry is suitable for detailed studies of developmental and toxicological influences on cholinesterases in multiple microscopic regions of the rat brain.
Optimization model for generic rank determination of structural matrices

Abstract A simple and rigorous approach that determines the generic rank of a structural matrix is presented. This approach is based upon an integer linear programming (ILP) formulation which features the property of total unimodularity in the set of constraints. The integer linear programming formulation of the proposed approach with the addition of integer cuts can be used to identify all the structurally redundant equations and/or excess columns of a system. This approach can also be used as a systematic tool to search for all the possible (not necessarily feasible) sets of controlled and manipulated variables of large-scale control systems. The features of the proposed algorithm are illustrated through a representative set of example problems.
Leveraging the Financial Crisis to Fulfill the Promise of Progressive Management

The financial crisis has the potential to unite two long-simmering threats to the legitimacy of business school research and pedagogy into a single conflagration. Business schools have come under i...
Inhibition of the mitochondrial F1F0-ATPase by ligands of the peripheral benzodiazepine receptor

Although PK11195 binds to the peripheral benzodiazepine receptor with nanomolar affinity, significant data exist which suggest that it has another cellular target distinct from the PBR. Here we demonstrate that PK11195 inhibits F1F0-ATPase activity in an OSCP-dependent manner, similar to the pro-apoptotic benzodiazepine Bz-423. Importantly, our data indicate that cellular responses observed with micromolar concentrations of PK11195, which are commonly attributed to modulation of the PBR, are likely a direct result of mitochondrial F1F0-ATPase inhibition.
Social relationships of fledgling budgerigars, Melopsitticus undulatus

Abstract The social relationships of newly independent domesticated budgerigars were studied from 1 day to 3 weeks after fledging. Birds were kept in large, outdoor flight cages, so that juveniles fledged into flocks containing many unfamiliar juveniles and adults. When measured on a per available bird basis, fledglings initiated more social interactions than expected with their siblings and their fathers, and many fledglings formed a mutual affiliative relationship with one of their siblings (a partner). Rates at which juveniles initiated social interactions with various categories of flock-mates were studied using principal components analyses; social initiations to fathers and unfamiliar adults and juveniles loaded on one factor, while social initiations to mothers and siblings loaded with opposite signs on a second factor. Conversely, fledglings attracted more social initiations from their siblings, fathers and other fledglings than expected on a per available bird basis. Principal components analyses of social initiations directed by other birds to new fledglings gave no indication that some individuals were generally more attractive to flock-mates than were other individuals. Patterns of social activity for the first 3 weeks were comparable for male and female fledglings, and were unrelated to fledging order. However, family size did affect early social behaviour. Fledglings from broods of one (singletons) tended to initiate and receive more social interactions from parents and strangers than did fledglings with siblings, and individuals from larger families interacted more per unit time with siblings than did birds from smaller families. These results suggest that early social relationships in some birds may be at least as complex as those previously described for mammalian species.
The velocity of second sound in dilute 3 He- 4 He solutions below 0.6°K

The velocity of second soundu 2 in dilute solutions of3He in4He has been measured by a pulse, time-of-flight technique using a new type of mechanical transducer. Tables of measured values ofu 2 as a function of temperature between 0.03 and 0.6° K are presented for3He concentrations in the range 0.14–6.3% at the saturated vapor pressure and under hydrostatic pressures of 10 and 20 atm. Estimates of the upper limit of the intrinsic attenuation of second sound have also been made and these are consistent with theory provided that the experimental values of the phonon thermal conductivity lifetime are used in place of the values calculated by Baym and Ebner.
Basics of private and public management

This article presents a review of the book “Basics of Private and Public Management,” by Stahrl W. Edmunds.
The Simplified Method to Calculate Two-Dimensional Heat Conduction Equations of Heating Slab

The most eﬀective way of determining the whole billet temperature ﬁeld is to use a simulation model. Large amount of calculation as well as computational time is consumed to employ two-dimensional finite difference method since the heating process is extremely complex, then it’s necessary to simplify the calculation process. In this paper, a simplified method in one-dimension format was presented to calculate two-dimensional heat conduction equations of heating slab. The billet simulated was placed in a changeable thermal flux boundary environment, in which the thermal flux was proportional to fourth power of temperature. During the heating process, the changeable parameters were taken into account: i. e different billet dimensions, different billet thermal conduction, different specific heat, etc. The comparision between results of two-dimensional finite difference method and the simplified method verified that the simplified method can satisfy accuracy requirement as well as calculation time saving, which enable the simplified method online using.
Suprathermal electron 90° pitch angle depletions at reverse shocks in the solar wind

[1] ACE/SWEPAM suprathermal electron pitch angle distributions often show depletions centered on and symmetric about 90 degree pitch angle. It has been suggested that these distributions can arise from a combination of focusing and mirroring of electrons associated with connection to magnetic field enhancements beyond the spacecraft. Assuming adiabatic particle motions, the width of the depletion in pitch angle is predicted to be a function of the strength of the magnetic field enhancement relative to the field at the measurement location. In this work, we test this model of depletion formation by examining depletions upstream from reverse shocks observed by ACE. Roughly symmetric depletions centered on 90 degree pitch angle were observed upstream from each of the 20 reverse shocks encountered by ACE from February 1998 to February 2003. In addition, the widths of the shock-associated depletions are consistent with formation by adiabatic focusing and mirroring of electrons, providing strong support for the validity of this model.