cssi/SciSciGPT-SciSciNet huggingface dataset:
Taxonomy and distribution of Orubesa in the Arabian Peninsula and surrounding areas (Coleoptera: Scarabaeoidea)

Occurrence records of the genus Orubesa Reitter, 1895, in the Arabian Penisula and surrounding areas are presented. Morphological study of types and additional specimens, for the first time conside...
Oscillatory calcium release and sustained store-operated oscillatory calcium signaling prevents differentiation of human oligodendrocyte progenitor cells

Endogenous remyelination in demyelinating diseases such as multiple sclerosis is contingent upon the successful differentiation of oligodendrocyte progenitor cells (OPCs). Signaling via the Gαq-coupled muscarinic receptor (M1/3R) inhibits human OPC differentiation and impairs endogenous remyelination in experimental models. We hypothesized that calcium release following Gαq-coupled receptor (GqR) activation directly regulates human OPC (hOPC) cell fate. In this study, we show that specific GqR agonists activating muscarinic and metabotropic glutamate receptors induce characteristic oscillatory calcium release in hOPCs and that these agonists similarly block hOPC maturation in vitro. Both agonists induce calcium release from ER stores and store operated calcium entry (SOCE) likely via STIM/ORAI-based channels. siRNA mediated knockdown (KD) of obligate calcium sensors STIM1 and STIM2 decreased the magnitude of muscarinic agonist induced oscillatory calcium release and attenuated SOCE in hOPCs. In addition, STIM2 expression was necessary to maintain the frequency of calcium oscillations and STIM2 KD reduced spontaneous OPC differentiation. Furthermore, STIM2 siRNA prevented the effects of muscarinic agonist treatment on OPC differentiation suggesting that SOCE is necessary for the anti-differentiative action of muscarinic receptor-dependent signaling. Finally, using a gain-of-function approach with an optogenetic STIM lentivirus, we demonstrate that independent activation of SOCE was sufficient to significantly block hOPC differentiation and this occurred in a frequency dependent manner while increasing hOPC proliferation. These findings suggest that intracellular calcium oscillations directly regulate hOPC fate and that modulation of calcium oscillation frequency may overcome inhibitory Gq-coupled signaling that impairs myelin repair.
Myocardial Dysfunction in Experimental Shock

This chapter deals with the effects of sepsis and endotoxin on the mammalian heart under experimental conditions. Bacterial sepsis, or endotoxin when slowly infused, may produce an early period of hyperdynamic function, which later progresses to a hypodynamic state characterized by low pressure and low cardiac output. Although there may be some differences in clinical and experimental sepsis produced primarily by endotoxin vs bacteria, and certainly there is a difference in treatment of bacterial sepsis, the hemodynamic situation is so similar in the two states that I believe they can be considered together. While some will take issue with this, recent reports indicate that a similar course to Escherichia coli endotoxin shock can be shown by the use of Pseudomonas aeruginosa bacteria (Zellner et al. 1991), both gram-positive and gramnegative bacteria (Natanson et al. 1989 a), Salmonella endotoxin (Murray et al. 1989; Raymond et al. 1988), and tumor necrosis factor (TNF) (Schirmer et al. 1989; Natanson et al. 1989 b) all appear to act via some final common pathway to result in the release of a substance, or substances, which directly depress the myocardium (Lefer 1978, 1982; Carli 1990; Carli et al. 1986; Reilly et al. 1989). Hemodynamic and biochemical alterations all appear to be similar where the data is available. Thus, it appears that models based on the use of purified lipopolysaccharide endotoxin are as valid (Natanson et al. 1989 b), if appropriate consideration of time courses, rate of administration, and dose are taken into account (D’Orio et al. 1987; Jones and Romano 1989), as are the results derived from studies using sublethal injections of bacteria, implanted contaminated sponges, or cecal punctures.
Learning Horn Definitions with Equivalence and Membership Queries

A Horn definition is a set of Horn clauses with the same head literal. In this paper, we consider learning non-recursive, function-free first-order Horn definitions. We show that this class is exactly learnable from equivalence and membership queries. It follows then that this class is PAC learnable using examples and membership queries. Our results have been shown to be applicable to learning efficient goal-decomposition rules in planning domains.
The Gastrointestinal System and the Elderly

Gastrointestinal diseases increase with age, and their clinical presentations are often confused by functional complaints and by pathophysiologic changes affecting the individual organs and the nervous system of the gastrointestinal tract. Hence, the statement that diseases of the aged are characterized by chronicity, duplicity, and multiplicity is most appropriate in regard to the gastrointestinal tract. Functional bowel distress represents the most common gastrointestinal disorder found in the elderly. Indeed, over one-half of all their gastrointestinal complaints are of a functional nature. This, of course, makes the diagnosis of organic complaints all the more difficult in the geriatric patient. In this chapter, we shall deal primarily with organic diseases afflicting the gastrointestinal tract of the elderly. To do otherwise would require the creation of a sizable textbook.
Paraproteins and primary lymphoma in SJL mice. I. Individuality of idiotypes on paraproteins.

Abstract The isotype distribution and idiotypic determinants of paraproteins (PP) found in sera from aging SJL mice were studied. One or more PP were found in 79% of 9–11 month old mice; the isotypes were γ1 ⩾ α ⩾ γ2a ⪢ γ3 ⪢ γ2b. There was a significant tendency for the PP to occur in pairs or triplets, multiple PP being found in 35% of the mice without an evident association between any two isotypes. Rabbit anti-Id was prepared against four isolated PP, two γ1 and two γ2a. Inhibition of anti-Id-Id interaction was specific for the immunizing PP only and was absent with all other PP studied (8 γ1 and 10 γ2 PP) and with normal SJL Ig. It is concluded that SJL PP fail to exhibit cross-reactive idiotypes and show a wider range of isotype distribution than was previously suspected, although PP of μ, δ, and ϵ isotypes are absent.
Design of optimal frequency sampling filters by the method of Lagrange multipliers

A new method for the design of linear phase frequency sampling filters is introduced. Use of the theory of Lagrange multipliers minimizes the mean squared error between the zero phase frequency responses of the designed and desired filters in the stopband subject to the constraints defined in the passband and transition band. >
Multivalent Conjugates of Sonic Hedgehog Accelerate Diabetic Wound Healing.

Despite their preclinical promise, few recombinant growth factors have been fully developed into effective therapies, in part, due to the short interval of therapeutic activity after administration. To address this problem, we developed nanoscale polymer conjugates for multivalent presentation of therapeutic proteins that enhance the activation of targeted cellular responses. As an example of this technology, we conjugated multiple Sonic hedgehog (Shh) proteins onto individual hyaluronic acid biopolymers to generate multivalent protein clusters at defined ratios (i.e., valencies) that yield enhanced Shh pathway activation at equivalent concentrations relative to unconjugated Shh. In this study, we investigated whether these multivalent conjugates (mvShh) could be used to improve the therapeutic function of Shh. We found that a single treatment with mvShh significantly accelerated the closure of full-thickness wounds in diabetic (db/db) mice compared to either an equivalent dose of unconjugated Shh or the ...
CONSYDERR: a two-level hybrid architecture for structuring knowledge for commonsense reasoning

This paper presents an architecture for structuring knowledge in vague and continuous domains for commonsense reasoning where similarity plays a large role in performing plausible inferences. The architecture consists of two levels: one is an inference network with nodes representing concepts and links representing rules connecting concepts, and the other is a microfeature based replica of the first level. Based on the interaction between the concept nodes and microfeature nodes in the architecture, inferences are facilitated and knowledge not explicitly encoded in a system can be deduced via a mixture of similarity matching and rule application. The architecture is able to take account of many important desiderata of plausible reasoning, and produces sensible conclusions accordingly. >
Metabolism of the Glucosyl Diglycerides and Phosphatidylglucose of Staphylococcus aureus

A glucose containing lipid, phosphatidylglucose (probably 3-sn-phosphatidyl-1'-glucose) and a lipid tentatively identified as phosphatidylethanolamine have been characterized in the lipids of Staphylococcus aureus. These lipids together comprise less than 2% of the total phospholipids of exponentially growing S. aureus and accumulate to 14% of the total phospholipid in stationary-phase cells. These lipids lost no (32)P when cells grown with H(3) (32)PO(4) were transferred to nonradioactive medium during the exponential growth phase. This was in marked contrast to the other phospholipids which lost (32)P rapidly. The loss of (32)P from phosphatidic acid and cardiolipin in exponentially growing cells was biphasic, suggesting heterogeneity of phospholipid phosphate metabolism. The mono- and diglucosyl diglycerides showed a rapid loss of (14)C-glucose during growth in nonradioactive medium but no loss of (14)C from the fatty acids of these lipids. The (14)C in the glucose and fatty acids of the glucosyl diglycerides was derived from glucose.
Practice and Application of Oil Funds: Azerbaijan and Kazakhstan as Case Studies in Addressing the Dutch Disease

This is a study of the issues of economic growth, structural changes, and wealth management in oil-rich transition economies with reference to the cases of Azerbaijan and Kazakhstan. The main research rationale is to analyze the potential consequences of wealth, such as the Dutch Disease and to show the role of oil funds in preventing uneven economic development in a resource-rich country with implications for policymakers of the two countries. The main goal behind establishing such funds is to keep natural resource revenues separate from other state revenues in order to neutralize the effects of high income inflows on real exchange rates, exports and non-resource sectors of the economy, and/or to ensure intergenerational equity. Although both Azerbaijan and Kazakhstan have established oil funds to avoid the potential dangers of the paradox of plenty, there still remains a lot to be done to accomplish this objective.
SLAM: a smart analog module layout generator for mixed analog-digital VLSI design

A tool for the smart layout of analog modules, which aims to provide a flexible analog layout solution for the mixed analog-digital VLSI design environment, is described. New algorithms have been developed for novel primitive cell recognition, intelligent layout and detail routing, and performance-driven optimization. Software implementation and experimental results on several analog VLSI modules such as operational amplifiers and voltage-controlled oscillators are presented. >
Quartz Crystal Microbalance Characterization of Nanostructure Assemblies in Biosensing

The sections in this article are Introduction Principles of QCM QCM Wave Penetration Depth QCM Sensor Specificity Calculation of Equilibrium and Kinetic Constants QCM Application to Life Sciences Interface Between Biology and Nanomaterials Antibodies Nanoparticles QCM Nanoparticle-based Chemical Sensors QCM Nanoparticle-based Biosensors QCM Nanoparticle-based Immunosensors Traditional Immunoassays Immunoassays using Nanotechnology QCM Nanoparticle-based Immunosensors Antigen Mimic Design Glutathione-protected Nanocluster Hemagglutanin Mimic Nanocluster Protective Antigen of B. anthracis Mimic Nanocluster Conclusions and Future Directions Acknowledgments
Density Functional Study of the Aluminum—Graphite Interface

Our group has previously performed a series of ab initio calculations to study the atomic structure, ideal work of adhesion, W ad, and bond character of several aluminum—ceramic interfaces. Periodic interfaces were used where the thicknesses of both the Al and ceramic slabs were previously converged with respect to surface energy. Using a plane-wave density functional code with the local density and generalized gradient approximation, our past calculations find the W ad is proportional to the surface energies of the mating materials, and the degree of polarity in the ceramic surface. Our calculations compare favorably with available experimental work of adhesion values of liquid Al on graphite, and Al on Al2O3. We investigated interfacial geometries after atomic relaxation, and interfacial bonding via plots of charge density, charge density difference, the electron localization function, and the projected density of states. In this paper we focus on our preliminary results for the aluminum—graphite interface.
Scalable Techniques from Nonparametric Statistics for Real Time Robot Learning

Locally weighted learning (LWL) is a class of techniques from nonparametric statistics that provides useful representations and training algorithms for learning about complex phenomena during autonomous adaptive control of robotic systems. This paper introduces several LWL algorithms that have been tested successfully in real-time learning of complex robot tasks. We discuss two major classes of LWL, memory-based LWL and purely incremental LWL that does not need to remember any data explicitly. In contrast to the traditional belief that LWL methods cannot work well in high-dimensional spaces, we provide new algorithms that have been tested on up to 90 dimensional learning problems. The applicability of our LWL algorithms is demonstrated in various robot learning examples, including the learning of devil-sticking, pole-balancing by a humanoid robot arm, and inverse-dynamics learning for a seven and a 30 degree-of-freedom robot. In all these examples, the application of our statistical neural networks techniques allowed either faster or more accurate acquisition of motor control than classical control engineering.
An Exploration of Passive and Active Flexibility in Biolocomotion through Analysis of Canonical Problems

Most aquatic creatures achieve motility through the dynamic interaction of their flexible body with the surrounding medium. This flexibility is used to provide a spectrum of active and passive control, allowing the creature to sometimes prescribe its shape changes and at other times extract energy from the fluid. This mix is particularly important in the moderate Reynolds number regime, in which wake vortices play an important energetic role. A well-devised control strategy for a bio-inspired vehicle should – perhaps must – exploit such flexion and energy exchange; as yet, we lack sufficient understanding to develop such a strategy. In this work, we present two canonical problems that distill fundamental modes of fluid/flexible body mechanics in biological systems, which are analyzed using high-fidelity numerical simulation. The first system consists of an articulated three-link swimmer considered in free-swimming. The second system involves an articulated jellyfish, in which the active/passive flexibility mix is explored by designation of the individual hinges.
Planetary magnetism in the outer solar system.

A brief review of the salient considerations which apply to the existence of magnetic fields in connection with planetary and subplanetary objects in the outer solar system is given. Consideration is given to internal dynamo fields, fields which might originate from interaction with the solar wind or magnetospheres (externally driven dynamos) and lastly fossil magnetic fields such as have been discovered on the Moon. Where possible, connection is made between magnetism, means of detection, and internal body properties.
A non-parametric meta-analysis approach for combining independent microarray datasets: application using two microarray datasets pertaining to chronic allograft nephropathy

With the popularity of DNA microarray technology, multiple groups of researchers have studied the gene expression of similar biological conditions. Different methods have been developed to integrate the results from various microarray studies, though most of them rely on distributional assumptions, such as the t-statistic based, mixed-effects model, or Bayesian model methods. However, often the sample size for each individual microarray experiment is small. Therefore, in this paper we present a non-parametric meta-analysis approach for combining data from independent microarray studies, and illustrate its application on two independent Affymetrix GeneChip studies that compared the gene expression of biopsies from kidney transplant recipients with chronic allograft nephropathy (CAN) to those with normal functioning allograft. The simulation study comparing the non-parametric meta-analysis approach to a commonly used t-statistic based approach shows that the non-parametric approach has better sensitivity and specificity. For the application on the two CAN studies, we identified 309 distinct genes that expressed differently in CAN. By applying Fisher's exact test to identify enriched KEGG pathways among those genes called differentially expressed, we found 6 KEGG pathways to be over-represented among the identified genes. We used the expression measurements of the identified genes as predictors to predict the class labels for 6 additional biopsy samples, and the predicted results all conformed to their pathologist diagnosed class labels. We present a new approach for combining data from multiple independent microarray studies. This approach is non-parametric and does not rely on any distributional assumptions. The rationale behind the approach is logically intuitive and can be easily understood by researchers not having advanced training in statistics. Some of the identified genes and pathways have been reported to be relevant to renal diseases. Further study on the identified genes and pathways may lead to better understanding of CAN at the molecular level.
For a politics we have yet to imagine

This special issue assembles a group of articles that explore the political thought of Jacques Ranciere. The idea was not only to understand and critique Ranciere's thought on its own terms, but al...
The effect of hydrophobicity in alkaline electrodes for passive DMFC

The effect of hydrophobicity in alkaline electrodes has been investigated in an effort to improve their performance in passive direct methanol fuel cells. Two approaches have been used to increase the hydrophobicity within the electrodes. One is using a more hydrophobic ionomer, and the other is introducing polytetrafluoroethylene (PTFE) into the catalyst layer. Two types of anion exchange ionomers with different hydrophobicity have been synthesized for this study. The effect of ion exchange capacity, ionic conductivity, and water uptake of the ionomers on the electrode performance has been studied using a half-cell test. The use of a hydrophobic ionomer resulted in enhanced cathode performance even though the ionic conductivity was lower than the more hydrophilic ionomer. Also, the addition of PTFE improved both the cathode and anode performance. The improved alkaline electrode performance was compared to a traditional acid electrode using Nafion as the ionomer. The performance increased threefold as a result of higher hydrophobicity in alkaline electrode.
Synthesis of FePt nanorods and nanowires by a facile method.

FePt nanorods and nanowires have been synthesized by the reduction of Pt(acac)2 and the thermal decomposition of Fe(CO)5 in the presence of solvents/surfactants by simply controlling the sequence of addition of surfactants. The as-synthesized FePt nanorods and nanowires have a face centered cubic structure with average diameter of 3 nm. Length of nanorods and nanowires can be adjusted in the range of 15–150 nm by varying reaction parameters. Nanocrystalline L10 FePt phase with coercivity up to 24 kOe was obtained after heat treatments.
Comprehensive simulation of the middle atmospheric climate : some recent results

This study discusses the results of comprehensive time-dependent, three-dimensional numerical modelling of the circulation in the middle atmosphere obtained with the GFDL “SKYHI” troposphere-stratosphere-mesosphere general circulation model (GCM). The climate in a long control simulation with an intermediate resolution version (≈3° in horizontal) is briefly reviewed. While many aspects of the simulation are quite realistic, the focus in this study is on remaining first-order problems with the modelled middle atmospheric general circulation, notably the very cold high latitude temperatures in the Southern Hemisphere (SH) winter/spring, and the virtual absence of a quasi-biennial oscillation (QBO) in the tropical stratosphere. These problems are shared by other extant GCMs. It was noted that the SH cold pole problem is somewhat ameliorated with increasing horizontal resolution in the model. This suggests that improved resolution increases the vertical momentum fluxes from the explicitly resolved gravity waves in the model, a point confirmed by detailed analysis of the spectrum of vertical eddy momentum flux in the winter SH extratropics. This result inspired a series of experiments with the 3° SKYHI model modified by adding a prescribed zonally-symmetric zonal drag on the SH winter westerlies. The form of the imposed momentum source was based on the simple assumption that the mean flow drag produced by unresolved waves has a spatial distribution similar to that of the Eliassen-Palm flux divergence associated with explicitly resolved gravity waves. It was found that an appropriately-chosen drag confined to the top six model levels (above 0.35 mb) can lead to quite realistic simulations of the SH winter flow (including even the stationary wave fields) through August, but that problems still remain in the late-winter/springtime simulation. While the imposed momentum source was largely confined to the extratropics, it produced considerable improvement in the simulation of the equatorial semiannual oscillation, with both the easterly and westerly phases being somewhat more intense than in the control simulation. A separate experiment was conducted in which the SKYHI model was simplified so that it had no topography and so that the seasonal cycle was frozen in perpetual equinox conditions. These changes result in a model that has much reduced interhemispheric asymmetry. This model spontaneously produces a long period mean flow oscillation of considerable amplitude in the tropical upper stratopause. The implication of this result for the general issue of obtaining a QBO in comprehensive GCMs is discussed.
Cytopathology of spotted cucumber beetle hemocytes containing virus-like particles.

Abstract Spherical, virus-like particles with an average diameter of 70 nm were consistently found in the hemocytes of field-collected, spotted cucumber beetles, Diabrotica undecimpunctata. The particles and associated inclusion bodies occurred both in the cytoplasm and nucleus. Hemocytes containing the particles exhibited structural features which were indicative of virus infection. These were (1) the appearance of fibril-containing membranous vesicles, 70 to 80 nm in diameter, in the perinuclear space and in the cisternae of rough endoplasmic reticulum, (2) accumulation of vesicle-containing cisternae in certain areas of cytoplasm, (3) appearance and condensation of granular material in viroplasm-like structures, and (4) appearance of virus-like particles. The results suggest that the particles are viral in nature and occur widely in leaf-feeding beetles.
Chronic intermittent ethanol exposure enhances NMDA-receptor-mediated synaptic responses and NMDA receptor expression in hippocampal CA1 region.

Abstract In previous studies, we found that chronic intermittent ethanol (CIE) treatment–a model of ethanol consumption in which animals are exposed to and withdrawn from intoxicating levels of ethanol on a daily basis–produces neuroadaptive changes in hippocampal area CA1 excitatory synaptic transmission and plasticity. Synaptic responses mediated by N-methyl- d -aspartate (NMDA) receptors are known to be sensitive to ethanol and could play an important role in the neuroadaptive changes induced by CIE treatment. To address this issue, we compared electrophysiological recordings of pharmacologically isolated NMDA-receptor-mediated field excitatory postsynaptic potentials (fEPSPs) in the CA1 region of hippocampal slices prepared from control rats and rats exposed to 2 weeks of CIE treatment administered by vapor inhalation. We found that fEPSPs induced by NMDA receptor activation were unaltered in slices prepared shortly after cessation of CIE treatment (i.e., ≤1 day of withdrawal from CIE). However, following 7 days of withdrawal from CIE treatment, NMDA-receptor-mediated fEPSPs were augmented relative to age-matched controls. Western blot analysis of NMDA receptor subunit expression showed that, at 7 days of withdrawal, the level of protein for NR2A and NR2B subunits was elevated in the CA1 region of hippocampal slices from CIE-treated animals compared with slices from age-matched controls. These results are consistent with an involvement of NMDA-receptor-mediated synaptic responses in the neuroadaptive effects of CIE on hippocampal physiology and suggest that such changes may contribute to ethanol-induced changes in processes dependent on NMDA-receptor-mediated synaptic responses such as learning and memory, neural development, hyperexcitability and seizures, and neurotoxicity.
Synthesis of a structural analog of ptilomycalin A

Abstract Ptilomycalin A analog 2 was prepared by coupling amido alcohol 9 with guanidinium carboxylate 31. The synthesis of 2 requires 13 steps via a longest linear sequence from acrylate 22.
Gel mineralization as a Model for Bone Formation

Extrusion freeform fabrication is a 3-D layerwise writing technique for forming objects directly under the control of a CAD program. This method is one of a family of rapid prototyping methods which include stereolithography, selective laser sintering and fused deposition modeling. This system can be used to build shapes, layer by layer, from hydrogels of agarose, polyacrylamide or other cross-linked water-soluble acrylic polymers. Mineralization can be induced in these gels by first building a part from an aqueous gel slurry containing calcium sulfate powder. This part is then immersed in a carbonate or phosphate solution which diffuses into the gel and precipitates calcite or calcium phosphates as the sulfate slowly dissolves. The resulting material contains 5-10 vol% mineral, 5 vol% agarose and 85-90 vol% water. On drying a bone-like composite is formed. If the original part is not a solid but a mesh of connected struts, the drying step results in a stronger part.
Phobic anxiety in late-life in relationship to cognition and 5HTTLPR polymorphism

Anxiety in late-life may functionally impair the older adult. In this study the polymorphic region 5HTTLPR of the SLC6A4 gene was examined in relation to phobic anxiety and cognitive function. Sixty-four community-dwelling older adults were genotyped for the 5HTTLPR polymorphism to examine whether late-life phobias are associated with the short (s) allele and whether cognitive impairment may precipitate phobic behaviors in association with the s allele. Our findings suggested that phobic anxiety symptoms are significantly related to lower cognitive function. However, in this sample we did not detect a significant association between phobic anxiety and the 5HTTLPR genotype. The interaction between age-related changes in cognition and anxiety remain an important area for future studies.
Task-analytic approach to the automated design of graphic presentations

BOZ is an automated graphic design and presentation tool that designs graphics based on an analysis of the task for which a graphic is intended to support. When designing a graphic, BOZ aims to optimize two ways in which graphics help expedite human performance of information-processing tasks: (1) allowing users to substitute simple perceptual inferences in place of more demanding logical inferences, and (2) streamlining users' search for needed information. BOZ analyzes a logical description of a task to be performed by a human user and designs a provably equivalent perceptual task by substituting perceptual inferences in place of logical inferences in the task description. BOZ then designs and renders an accompanying graphic that encodes and structures data such that performance of each perceptual inference is supported and visual search is minimized. BOZ produces a graphic along with a perceptual procedure describing how to use the graphic to complete the task. A key feature of BOZ's approach is that it is able to design different presentations of the same information customized to the requirements of different tasks. BOZ is used to design graphic presentations of airline schedule information to support five different airline reservation tasks. Reaction time studies done with real users for one task and graphic show that the BOZ-designed graphic significantly reduces users' performance time to the task. Regression analyses link the observed efficiency savings to BOZ's two key design principles: perceptual inference substitutions and pruning of visual search.
Perceived self-motion elicited by postrotary head tilts in a varying gravitoinertial force background

We measured the effects of postrotary head tilts on the perceived duration and the apparent axis of illusory self-rotation experienced following counterclockwise body rotation in high (1.8 G), normal (1 G), and low (0 G) gravitoinertial force environments. In the absence of head movements, the duration of illusory afterrotation was shorter in 0 G and 1.8 G than in 1 G, and it was further shortened by 40° pitch-back head movements in 1 G and 1.8 G. Clockwise illusory afterrotation about the torso’s verticalz-axis was always experienced in trials without postrotary head tilts. In trials with head movements, half the subjects experienced no change in this pattern; however, half experienced transient rightward roll of the torso’sz-axis, which remained the rotation axis. The duration and extent of apparent roll were greater in 0 G and smaller in 1.8 G than in 1 G. We provide a functional explanation for the tendency for perceived self-rotation to be determined relative to the torso and to the gravitoinertial vertical rather than solely in relation to head position and head-fixed angular velocity sensors.
Contacting participants for follow-up: how much effort is required to retain participants in longitudinal studies?

Abstract Participant retention is essential to the success of longitudinal research projects. Locating participants for follow-up is often time consuming and expensive, which may result in researchers limiting their contact efforts for budgetary reasons. Yet if such a protocol is instituted a fair number of participants will likely be lost. This paper examines the impact of restricted persistence on participant retention and selective attrition in longitudinal research. The data was collected from the developmental trends study (DTS), a longitudinal study of the development of disruptive behavior disorders, consisting of 177 clinic-referred boys who were followed from childhood through young adulthood. The results indicated that limiting contact efforts would have resulted in significant participant loss and selective attrition for participants with disruptive behavior disorders. Cost-estimates showed that the extra effort required to retain ‘difficult’ participants was minimal compared to the initial investment in study costs. Implementing systematic and comprehensive approaches to retention will result in favorable retention rates and can be done in a cost-effective manner.
Development of FT-IR Attenuated Total Internal Reflection Dichroism Techniques for Structural Characterization of Polymer Surfaces.

We describe our continuing effort to develop FT-IR attenuated total reflection (ATR) dichroism techniques for the characterization of polymer surface structure and molecular orientation. Following theoretical background, we review the two-dimensional and three-dimensional analyses work based on a specially designed internal reflection crystal and a specially built ATR-sample attachment. In the current development section, we describe briefly the intensity correction procedures used in variable angle studies and an attempt to design a hemispheric crystal attachment to eliminate problems encountered with face-cut reflection crystals.
Caregiver-patient dyads: Documenting the verbal instructions caregivers provide in joint cognitive tasks

Thirty spousal caregivers and their partners (who had been diagnosed as having primary degenerative dementia) jointly performed four cognitive tasks: Block Design (from the WAIS-R), the Token Test, and two memory tasks. Two of the tasks were unstructured, and two were structured. Caregivers served as the instructor on all tasks. Interactions were videotaped. Results showed that caregivers provided appropriate verbal instructions to a greater extent on the unstructured nonverbal task (Block Design) than on the unstructured memory task. Results are discussed in terms of implications for dyadic cognition research and intervention in dementia.
Repolarization abnormalities in mitral valve prolapse.

Abstract Inferolateral ST depression, T wave inversion, and QT prolongation have been frequently described in reporta of largely symptomatic mitral valve prolapse (MVP) patients, but not in a recent population-based survey of mainly asymptomatic subjects with MVP. To learn if there is a relationship between these ECG changes and symptoms, physical findings or hemodynamic sequelae, we reviewed ECGs from 119 patients, ages 18 to 60 years who had MVP diagnosed by echocardiography. Seventy-four percent had symptoms characteristic of MVP. ST-T changes were found as frequently in asymptomatic patients (29%) as in those symptomatic (27%), and did not identify those with homodynamic sequelae of MVP (apical systolic murmurs, Doppler-defined mitral regurgitation, or left atrial enlargement). QT prolongation was found more frequently in the symptomatic group (25% vs 10%) but did not predict syncope. When compared to the expected 0.9% prevalence of ST abnormalities in a normal population, ST-T changes and QT prolongation are indeed frequent in MVP, but are not useful in identifying clinically important subsets.
Local treatment of abdominal wound reduces tumor implantation.

Background and Objectives: Pneumoperitoneum increases the trocar-site tumor implantation rate using a human colon cancer cell line in a hamster model. The purpose of this study was to determine whether local treatment of trocar sites with potential tumoricidal agents can inhibit tumor implantation after pneumoperitoneum. Methods GW-39 human colon cancer cells (0.5 ml of 2.5% v/v; 8.0 × 105 cells) were injected throughout the abdomen of 133 Golden Syrian hamsters through a midline incision. The animals were randomized to receive either untreated 5-mm trocars in each abdominal quadrant (group I control, n = 49), trocars dipped in 10% povidone-iodine (group II, n = 53), or trocars coated with 1% silver sulfadiazine (group III, n = 51). The midline wounds were also coated with the respective agents before closing. Pneumoperitoneum was then maintained at 10 mmHg for 10 min, after which the trocar wounds were closed. In group II, the trocar sites were treated with a coat of povidone-iodine after the trocars were withdrawn and before closing. Gross and microscopic tumor implants were analyzed at 7 weeks postoperatively. Results The rate of tumor cell implantation at trocar sites was reduced from 93% (172/184) in the control group to 75% (126/168) and 78% (141/180) in groups II and III, respectively (P < 0.0001). Fewer palpable tumors were detected in groups II and III (40% and 23%, respectively) than in the control group (72%, P < 0.0001). Mean tumor mass in group III (0.4 ± 0.1 g), but not in group II (1.0 ± 0.2 g), was significantly less than that in the control group (1.3 ± 0.1 g, P < 0.01). Overall tumor involvement of the larger midline wound was similar for all groups (I = 80%, II = 79%, III = 71%). However, palpable tumors were identified more frequently in group I (67%) than in groups II and III (43%, P < 0.05; 22%, P < 0.01, respectively). Conclusion Pretreatment of abdominal wounds with povidone-iodine or silver sulfadiazine can reduce tumor implantation after pneumoperitoneum in a hamster model. J. Surg. Oncol. 1998;69:9–14. © 1998 Wiley-Liss, Inc.
Nonlinear system identification of frictional effects in a beam with a bolted joint connection

Abstract We perform nonlinear system identification (NSI) of the effects of frictional connections in the dynamics of a bolted beam assembly. The methodology utilized in this work combines experimental measurements with slow-flow dynamic analysis and empirical mode decomposition, and reconstructs the dynamics through reduced-order models. These are in the form of single-degree-of-freedom linear oscillators (termed intrinsic modal oscillators—IMOs) with forcing terms derived directly from the experimental measurements through slow-flow analysis. The derived reduced order models are capable of reproducing the measured dynamics, whereas the forcing terms provide important information about nonlinear damping effects. The NSI methodology is applied to model nonlinear friction effects in a bolted beam assembly. A ‘monolithic’ beam with identical geometric and material properties is also tested for comparison. Three different forcing (energy) levels were considered in the tests in order to study the energy-dependencies of the damping nonlinearities induced in the beam from the bolted joint. In all cases, the NSI methodology employed was successful in identifying the damping nonlinearities, their spatial distributions and their effects of the vibration modes of the structural component.
Evaluation of Imaging Systems Using the Posterior Variance of Emission Counts

We investigate an approach to evaluation of emission-tomography (ET) imaging systems used for region-of-interest (ROI) estimation tasks. In the evaluation we employ the concept of “emission counts” (EC), which are the number of events per voxel emitted during a scan. We use the reduction in posterior variance of ROI EC, compared to the prior ROI EC variance, as the metric of primary interest, which we call the “posterior variance reduction index” (PVRI). Systems that achieve a higher PVRI are considered superior to systems with lower PVRI. The approach is independent of the reconstruction method and is applicable to all photon-limited data types including list-mode data. We analyzed this approach using a model of 2-D tomography, and compared our results to the classical theory of tomographic sampling. We found that performance evaluations using the PVRI index were consistent with the classical theory. System evaluation based on EC posterior variance is an intuitively appealing and physically meaningful method that is useful for evaluation of system performance in ROI quantitation tasks.
Invasive Species and Biodiversity Crises: Testing the Link in the Late Devonian

During the Late Devonian Biodiversity Crisis, the primary driver of biodiversity decline was the dramatic reduction in speciation rates, not elevated extinction rates; however, the causes of speciation decline have been previously unstudied. Speciation, the formation of new species from ancestral populations, occurs by two primary allopatric mechanisms: vicariance, where the ancestral population is passively divided into two large subpopulations that later diverge and form two daughter species, and dispersal, in which a small subset of the ancestral population actively migrates then diverges to form a new species. Studies of modern and fossil clades typically document speciation by vicariance in much higher frequencies than speciation by dispersal. To assess the mechanism behind Late Devonian speciation reduction, speciation rates were calculated within stratigraphically constrained species-level phylogenetic hypotheses for three representative clades and mode of speciation at cladogenetic events was assessed across four clades in three phyla: Arthropoda, Brachiopoda, and Mollusca. In all cases, Devonian taxa exhibited a congruent reduction in speciation rate between the Middle Devonian pre-crisis interval and the Late Devonian crisis interval. Furthermore, speciation via vicariance is almost entirely absent during the crisis interval; most episodes of speciation during this time were due to dispersal. The shutdown of speciation by vicariance during this interval was related to widespread interbasinal species invasions. The lack of Late Devonian vicariance is diametrically opposed to the pattern observed in other geologic intervals, which suggests the loss of vicariant speciation attributable to species invasions during the Late Devonian was a causal factor in the biodiversity crisis. Similarly, modern ecosystems, in which invasive species are rampant, may be expected to exhibit similar shutdown of speciation by vicariance as an outcome of the modern biodiversity crisis.
Family Dynamics and Substance Abuse: A Preliminary Study.

The authors discuss family patterns of interaction that are thought to contribute to the maintenance of substance abuse. Preliminary research findings pertaining to the interaction patterns are also presented. The data suggest that these families are often highly interdependent, that in about 50% of the cases they ideally desire some sort of triangulation between parents and offspring, and that in about 50% of the cases they have or are working toward a hierarchical reversal. Therefore, in addition to evaluating characteristics of the substance abuser, the authors recommend that counselors consider the nature of relationships within the client's family of origin.
Cramer-Rao bounds for estimation of turbulence-induced wavefront aberrations

In this paper we examine the accuracy with which Zernike coefficients for turbulence-induced wavefront aberrations can be estimated from conventional and Hartmann-sensor images. The performance limit for the estimation of the first 30 Zernike coefficients with a conventional image is shown to be significantly better than the performance limit of an 8 x 8 Hartmann sensor array.
White female respiratory cancer mortality. A geographical anomaly.

The objectives of this research were to determine if white female respiratory cancer mortality rates in central cities and suburbs of the United States were increasing more rapidly than rural rates and to identify metropolitan regions which exemplify this trend. White female respiratory cancer mortality rates were found to have increased at about the same rate or more rapidly in the vast majority of central cities than in their suburbs and adjacent rural areas. This observation stands in sharp contrast to the trend for white male respiratory cancer and for almost every other type of white population cancer, which were characterized by much smaller city/suburb and city/rural ratios of cancer mortality rates in 1970–1975 than in 1950–1954. In addition, metropolitan areas in the South (e.g., Houston) and West (e.g., Los Angeles, San Francisco-Oakland) were found in 1970–1975 to have higher rates of these diseases than their counterparts in the Northeast (e.g., New York City and Philadelphia) and Northcentral regions (e.g., Chicago, Cleveland, Detroit). Higher rates in Southern and Western regions than in Northeastern and North-central metropolises is a reversal of the geographical pattern of the 1950s.
Purtscher's retinopathy: a case report and review.

Abstract A case of posttraumatic loss of vision was seen in the emergency department that was diagnosed as Purtscher's retinopathy or traumatic retinal angiopathy. Purtscher's retinopathy presents as an acute loss of vision after a traumatic event or as a sequelae of another disease process. The case is presented with a discussion of the pathophysiology, diagnosis, prognosis, and treatment options for this entity.
The hydrogenase of Proteus vulgaris.

Abstract The hydrogenase of Proteus vulgaris was shown by centrifugal behavior and electron microscopic examination to be particulate. All attempts to disrupt the particles by enzymic, chemical or physical means failed. Some chemical analyses of the particles are given.
Science education: a neuroscientist's view of translational medicine.

Editor's Note: In 2003, the Society for Neuroscience initiated the Science Educator Award to recognize an outstanding neuroscientist who has made significant contributions to the education of the public ( ). The first recipient was Eric
Ion transport in a model gramicidin channel. Structure and thermodynamics.

The potential of mean force for Na+ and K+ ions as a function of position in the interior of a periodic poly(L,D)-alanine model for the gramicidin beta-helix is calculated with a detailed atomic model and realistic interactions. The calculated free energy barriers are 4.5 kcal/mol for Na+ and 1.0 kcal/mol for K+. A decomposition of the free energy demonstrates that the water molecules make a significant contribution to the free energy of activation. There is an increase in entropy at the transition state associated with greater fluctuations. Analysis reveals that the free energy profile of ions in the periodic channel is controlled not by the large interaction energy involving the ion but rather by the weaker water-water, water-peptide and peptide-peptide hydrogen bond interactions. The interior of the channel retains much of the solvation properties of a liquid in its interactions with the cations. Of particular importance is the flexibility of the helix, which permits it to respond to the presence of an ion in a fluidlike manner. The distortion of the helix is local (limited to a few carbonyls) because the structure is too flexible to transmit a perturbation to large distances. The plasticity of the structure (i.e., the property to deform without generating a large energy stress) appears to be an essential factor in the transport of ions, suggesting that a rigid helix model would be inappropriate.
Why Is the Concerted (2+2) Mechanism of the Reactions of SO3 with Alkenes Favored over the (3+2) Mechanism? Density Functional and Correlated ab Initio Calculations and a Frontier MO Analysis

The (2+2) cycloadditions of SO3 to ethene, propene, and 2-methylpropene were investigated with Hartree−Fock, MP2, QCISD(T), and hybrid Hartree−Fock/density functional theory (HF-DFT) methods. Exper...
On Lewis' exact invariant for the linear harmonic oscillator with time-dependent frequency

Abstract In this paper we purport to show that Lewis' exact invariant for a linear harmonic oscillator with a time-dependent frequency arises as a consequence of the invariance of the problem under local Lie groups of transformations. We will also show that Lewis' invariant can be deduced via a systematic perturbation theory for the case with slowly-varying frequency as a power series in the small parameter ϵ characterizing the slow variations in the frequency.