cssi/SciSciGPT-SciSciNet huggingface dataset:
First observations of 5fce auroral roars

[1] Auroral radio emissions reveal physics of beam-plasma interactions and provide possibilities to remotely sense ionospheric plasma processes.Sato et al. (2012) recently discovered that auroral roar emissions, long known to occur at two and three times the electron gyrofrequency (fce), also occur at 4fce. Using data from wave receivers in the British Antarctic Survey Automatic Geophysical Observatories, we confirm the existence of 4fce-roars and observe for the first time 5fce-roars. A search at higher frequencies did not find higher harmonics. Both 4fce- and 5fce-roars only occur in sunlit conditions near summer solstice. Harmonic roar emission frequencies scale with the strength of the geomagnetic field, and combining data from four observatories suggests that the 4fce-roar source height lies around 245 km, lower than the 275 km estimated for 2fce-roar. These observations show that the auroral roar generation mechanism acts under a broader set of plasma conditions than previously considered.
Compartmentalized Histoplasma capsulatum Infection of the Central Nervous System

Background. Histoplasmosis is a common fungal infection in the southeastern, mid-Atlantic, and central states; however, its presentation can be atypical. Case Presentation. We report a case of Histoplasma capsulatum infection presenting as slowly progressive weakness in the lower extremities, followed by the development of numbness below the midthoracic area, urinary incontinence, and slurred speech. Brain MRI showed leptomeningeal enhancement, predominantly linear, involving the basal cisterns, the brainstem, and spinal cord. Cerebrospinal fluid analysis showed lymphocytic pleocytosis. Discussion. CNS histoplasmosis is usually seen in patients with disseminated histoplasmosis. Isolated CNS histoplasmosis is rarely seen, especially in immunocompetent patients. Conclusions. Histoplasmosis should be considered in the differential diagnosis of patients experiencing slowly progressive neurological deficit.
L-Buthionine-(S,R)-sulfoximine, an irreversible inhibitor of gamma-glutamylcysteine synthetase, augments LPS-mediated pro-inflammatory cytokine biosynthesis: evidence for the implication of an IkappaB-alpha/NF-kappaB insensitive pathway

The pro-inflammatory cytokines, including tumor necrosis factor (TNF)-alpha and interleukin (IL)-6, contribute to the exacerbation of pathophysiological conditions in the lung. The regulation of cytokines involves the reduction-oxidation (redox)-sensitive nuclear factor-kappaB (NF-kappaB), the activation of which is mediated through an upstream kinase that regulates the phosphorylation and subsequent degradation of inhibitory-kappaB (IkappaB)-alpha, the major cytosolic inhibitor of NF-kappaB. It was hypothesized that lipopolysaccharide (LPS)-induced biosynthesis of TNF-alpha and IL-6 in vitro is tightly regulated by redox equilibrium. Furthermore, the likely involvement of the IkappaB-alpha/NF-kappaB signalling transduction pathway in mediating redox-dependent regulation of LPS-induced cytokine biosynthesis was revealed. Using alveolar epithelial cells, the role of L-buthionine-(S,R)-sulfoximine (BSO), a specific and irreversible inhibitor of gamma-glutamylcysteine synthetase (gamma-GCS), the rate-limiting enzyme in glutathione (GSH - an antioxidant thiol) biosynthesis, in regulating LPS-mediated TNF-alpha and IL-6 production and the IkappaB-alpha/NF-kappaB signalling pathway was investigated. Pre-treatment with BSO, prior to exposure to LPS augmented, in a dose-dependent manner, LPS-induced TNF-alpha and IL-6 biosynthesis, an effect associated with the induction of intracellular accumulation of reactive oxygen species (ROS). Interestingly, BSO blocked the phosphorylation of IkappaB-alpha, reduced its degradation, thereby allowing its cytosolic accumulation, and subsequently inhibited the activation of NF-kappaB. These results indicate that there are ROS and redox-mediated effects regulating pro-inflammatory cytokines, and that the IkappaB-alpha/NF-kappaB pathway is redox-sensitive and differentially involved in mediating redox-dependent regulation of cytokine signaling.
Chromosome organization of the protozoan Trypanosoma brucei.

Abstract The genome of the protozoan Trypanosoma brucei is known to be diploid. Karyotype analysis has, however, failed to identify homologous chromosomes. Having refined the technique for separating trypanosome chromosomes (L. H. T. Van der Ploeg, C. L. Smith, R. I. Polvere, and K. Gottesdiener, Nucleic Acids Res. 17:3217-3227, 1989), we can now provide evidence for the presence of homologous chromosomes. By determining the chromosomal location of different genetic markers, most of the chromosomes (14, excluding the minichromosomes), could be organized into seven chromosome pairs. In most instances, the putative homologs of a pair differed in size by about 20%. Restriction enzyme analysis of chromosome-sized DNA showed that these chromosome pairs contained large stretches of homologous DNA sequences. From these data, we infer that the chromosome pairs represent homologs. The identification of homologous chromosomes gives valuable insight into the organization of the trypanosome genome, will facilitate the genetic analysis of T. brucei, and suggests the presence of haploid gametes.
Perioperative Nurses' Attitudes Toward Continuing Education

ABSTRACT The primary purpose of this study was to determine perioperative nurses' attitudes toward continuing education (CE) and selected demographic variables. The researcher developed and administered a Likert-type questionnaire to perioperative nurses. The first part of the questionnaire related to demographic variables, length of service at the facility as a registered nurse, and certification status. The second part of the questionnaire was a 30-item attitude scale related to perioperative nurses and CE. The null hypothesis was analyzed using a t -test at a .05 level of significance. Study findings revealed no differences in attitudes toward CE between certified perioperative nurses and noncertified perioperative nurses. AORN J 61 (May 1995) 852–857.
Monoclonal Gammopathy of Undetermined Significance, Waldenström Macroglobulinemia, AL Amyloidosis, and Related Plasma Cell Disorders: Diagnosis and Treatment

The spectrum of plasma cell disorders is broad. Monoclonal gammopathy of undetermined significance and smoldering multiple myeloma are asymptomatic disorders characterized by monoclonal plasma cell proliferation in the bone marrow in the absence of end-organ damage. Waldenstrom macroglobulinemia typically involves an ontogenically less mature lymphoplasmacytic bone marrow cell and is characterized by secretion of a monoclonal IgM protein. Solitary plasmacytoma is the only known potentially curable plasma cell disorder. Finally, AL (immunoglobulin light chain) amyloidosis and POEMS (polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes) syndrome are disorders characterized by low tumor burden but profound multisystemic disease. Updated diagnostic criteria for these disorders, risk stratification models to determine prognosis, and the current management of these diverse entities are discussed in this review.
Synthesis of substituted pyrrolo[2,3-e][1,3,4]thiadiazine 4,4-dioxides

A series of substituted pyrrolo[2,3-e][1,3,4]thiadiazine 4,4-dioxides is synthesized from 1-substituted-2-amino-3-cyanomethylsulfonyl-4,5-dimethylpyrroles.
In vitro analysis of PNIPAAm-PEG, a novel, injectable scaffold for spinal cord repair.

Abstract Nervous tissue engineering in combination with other therapeutic strategies is an emerging trend for the treatment of different CNS disorders and injuries. We propose to use poly(N-isopropylacrylamide)-co-poly(ethylene glycol) (PNIPAAm–PEG) as a minimally invasive, injectable scaffold platform for the repair of spinal cord injury (SCI). The scaffold allows cell attachment, and provides mechanical support and a sustained release of neurotrophins. In order to use PNIPAAm–PEG as an injectable scaffold for treatment of SCI, it must maintain its mass and volume over time in physiological conditions. To provide mechanical support at the injury site, it is also critical that the engineered scaffold matches the compressive modulus of the native neuronal tissue. This study focused on studying the ability of the scaffold to release bioactive neurotrophins and matching the material properties to those of the native neuronal tissue. We found that the release of both BDNF and NT-3 was sustained for up to 4 weeks, with a minimal burst exhibited for both neurotrophins. The bioactivity of the released NT-3 and BDNF was confirmed after 4 weeks. In addition, our results show that the PNIPAAm–PEG scaffold can be designed to match the desired mechanical properties of the native neuronal tissue, with a compressive modulus in the 3–5 kPa range. The scaffold was also compatible with bone marrow stromal cells, allowing their survival and attachment for up to 31 days. These results indicate that PNIPAAm–PEG is a promising multifunctional scaffold for the treatment of SCI.
Evaluation of cyclone performance in different gases

Abstract A new set of the cyclone efficiency data is reported. The particle collection efficiency data have been obtained as a function of particle size, flow rate, cyclone size, and gas properties. Cyclones of four different dimensions were used covering a flow rate range of 9.1–19.5 l min −1 and a particle size range of 0.5–25 μm. Both liquid and solid particles were used. For varying the gas properties, air and argon were used. The experimental results suggest that in addition to the gas viscosity, the gas density plays an equally important role in cyclone performance. It was found that increasing the gas density enhances particle collection characteristics. Among the several parameters tested, the Reynolds number using the inlet gas velocity and the exit tube diameter was found to show the strongest correlation on the cut size.
Now it's time for rate‐fixing for robots

MTM and other time measurement systems have been applied to human operators for many years. Now it is the time for robots to come under similar scrutiny. RTM uses different analysis methods to give predictions of cycle times within −2% to +3% for optimising selection and operating methods of robots.
Impairment of growth hormone secretion in response to hypoglycemia during early and late pregnancy.

ABSTRACT In order to ascertain whether the diminished pituitary growth hormone (HGH) response observed in late pregnancy may be quantitatively related to the duration of gestation, sequential studies in the HGH responses to insulin-induced hypoglycemia were made during each trimester of pregnancy and at 6–7 weeks post partum in 10 non-obese subjects. The HGH responsiveness to hypoglycemia was progressively diminished during the 3 trimesters and became blunted during the last trimester of pregnancy when compared with their own postpartum controls. Normal brisk HGH response to hypoglycemia was observed at 6–7 weeks post partum. Although the presence of a large quantity of circulating human placental lactogen may account for the inhibitory effect on the hypothalamic-pituitary HGH releasing mechanism in late pregnancy, other hormonal factors such as elevated progesterone and nonprotein-bound cortisol may play a role in the suppressive effect on HGH release during early pregnancy.
Aromatic as well as aliphatic hydrocarbon solvent axonopathy.

Superfund sites that contain mixtures of aromatic and aliphatic solvents represent an undefined health hazard. After prolonged exposure to relatively high levels of certain aliphatic solvents (e.g. n-hexane, 2-hexanone), humans and animals develop a dose-dependent neurodegeneration that occurs clinically as a symmetrical peripheral neuropathy. This is triggered by the action of 2,5-hexanedione (1,2-diacetylethane), a 1,4-diketone (gamma-diketone) metabolite that targets proteins required for the maintenance of neuronal (and testicular Sertoli cell) integrity. Certain aromatic solvents (1,2-diethylbenzene, 1,2,4-triethylbenzene) cause electrophysiological changes consistent with sensorimotor neuropathy in rodents, but the underlying mechanisms and pathogenesis are unclear. Our recent studies show that the o-diacetyl derivative and likely metabolite of 1,2-diethylbenzene, 1,2-diacetylbenzene, behaves as a neurotoxic (aromatic) gamma-diketone of high neurotoxic potency. Rats treated with 1,2-diacetylbenzene develop limb weakness associated with proximal, neurofilament-filled giant axonal swellings comparable to those seen in animals treated with the potent 3,4-dimethyl derivative of 2,5-hexanedione. The blue chromogen induced by treatment with 1,2-diacetylbenzene is under study as a possible urinary biomarker of exposure to aromatic solvents (e.g. 1,2-diethylbenzene, tetralin) with neurotoxic potential. Development and validation of sensitive new biomarkers, especially for non-cancer endpoints, will aid in assessing the health risk associated with exposure to hazardous substances at Superfund sites.
Micrometer scale adhesion on nanometer-scale patchy surfaces: adhesion rates, adhesion thresholds, and curvature-based selectivity.

Using a model system based on electrostatics, we probe interactions between spherical particles (negative silica) and planar surfaces that present randomly placed discrete attractive regions, 10 nm in size, in a repulsive background (silica flats carrying cationic surface constructs). Experiments measure the adhesion rates of particles onto the patchy collecting surfaces from flowing dispersions, as a function of the surface loading of the attractive patches, for different particle sizes (0.5 and 1 μm diameter spheres) and different ionic strengths. Surfaces densely populated with patches, such that they present net electrostatic attractions to approaching particles, capture particles at the transport-limited (maximum) rate. Surfaces sparsely loaded with attractive patches (which present a repulsive mean field to approaching particles) are usually still adhesive, but the particle adhesion rate depends on particle size, ionic strength, and patch loading. Most significant is an adhesion threshold, a critica...
Science and the below Average Student: the Effect of Curriculum Materials on Attitudes

Science curriculum materials designed to improve the attitudes of below average students were developed from guidelines based on a survey of the strengths and weaknesses of these students. Materials developed to reflect these guidelines were administered to ninth and tenth grade students in three physical science classes. Students in these classes had I. Q. scores of less than 100, reading achievement below grade placement, and eighth grade science averages of C or below. A control group of three physical science classes was employed. The attitudes of these students toward science class, science laboratory, school, science teacher, and the topic of the materials were measured using five forms of the Semantic Differential, which was administered as a pretest and posttest. The students who received the materials demonstrated significant improvement in attitudes toward science class and science laboratory.
Comments on “selective attention: Perception or response?“ reply

We cannot understand why Treisman and Geffen (1967) think their experiment argues against our theory (Deutsch and Deutsch, 1963). Briefly, Treisman and Geffen ask subjects to repeat and tap to certain words in one message, played to one ear, and only tap to such words when they occur in another message played to the other ear. They find that subjects neglect the words to which they only have to tap. According to our theory, stimuli with a greater weighting of importance inhibit certain outputs (such as storage, motor response) of the structures processing stimuli with a lesser weighting of importance. Now it seems to be clear that Treisman and Geffen have by their instructions (to tap and repeat one set of words and only to tap to another set of words) produced a situation in which one set of stimuli is given a larger weighting of importance than the other. It is therefore not surprising on our theory that the less important set is almost disregarded. It is instructive here to consider Lawson's (1966) ver...
Sources of target stock price run-up prior to acquisitions

Abstract The anticipation of an acquisition attracts informed trading, which can cause a high run-up in the target stock price prior to an announced acquisition bid. Because research has shown that bidders do not reduce their bid price to compensate for a relatively high run-up, a larger run-up increases the cost of the acquisition to bidders. Our analysis determines that the target stock price run-up before an announced bid is higher for bidders that are not private equity firms, do friendly acquisitions, are from outside the U.S., rely on newly borrowed funds to finance the acquisition, rely on more investment bank advisors to facilitate the acquisition, and did not previously establish a toehold position in the target. It is also higher when targets are smaller, have listed options traded on them, and are in the technology field. Lastly, target run-up is lower since Sarbanes-Oxley.
Auxotrophs produced by transposon mutagenesis in Streptomyces tendae ATCC 31160

Six auxotrophs were induced in Streptomyces tendae ATCC 31160 with transposon Tn4560. Insertion of the transposon into chromosomal DNA of these auxotrophs occurred at different sites suggesting that transposition may be random. Transposition frequency was 1 times 10-3. Transposon-tagged antibiotic biosynthetic genes will provide a powerful tool for the isolation of genes involved in nikkomycin biosynthesis.
Mode-locking dynamics of hair cells of the inner ear

We explore mode locking of spontaneous oscillations of saccular hair cell bundles to periodic mechanical deflections. A simple dynamic systems framework is presented that captures the main features of the experimentally observed behavior in the form of an Arnold tongue. We propose that the phase-locking transition can proceed via different bifurcations. At low stimulus amplitudes F, the transition to mode locking as a function of the stimulus frequency ω has the character of a saddle-node bifurcation on an invariant circle. At higher stimulus amplitudes, the mode-locking transition has the character of a supercritical Andronov-Hopf bifurcation.
Theoretical UV circular dichroism of cyclo(L-proline-L-proline)

MP2, DFT, and molecular mechanics (AMBER, CVFF, and CFF91) geometry optimizations were performed on the cyclic dipeptide cyclo(l-Pro-l-Pro) starting from crystal structure data. Three stable conformations were identified as energy minima by all methods, but assignment of relative energy varied between the methods. The ππ* transition feature of the UV circular dichroic (CD) spectrum was predicted for each minimized structure using the classical physics method of the dipole interaction model. The model was sensitive to the different conformations. The UV-CD predictions were compared individually and as a Boltzmann-weighted composite with published experimental CD spectra [Bowman, R. L.; Kellerman, M.; Johnson, W. C., Jr. Biopolymers 1983, 22, 1045]. For all structures, the original parameters of Applequist [Applequist, J. J. Chem. Phys. 1979, 71, 4324] with a bandwidth of 3000 cm-1 most accurately replicated experiment, except for the CFF91 structures, which matched experiment best with a bandwidth of 4000 ...
Regeneration of colonic mucosa in the rat

As part of a study of ulcer formation and healing, regeneration of colonic mucosa in rats was studied following placement of a surgical lesion. Alterations in mucosubstances and connective tissue were examined and their possible significance discussed. The sequence of events in healing was: (1) The mucosa adjacent to the lesion tipped into the lesioned area. The crypts in this mucosa became lined with cells which contained no mucus and had no striated borders. Later in the experimental period, these undifferentiated cells gave rise to cells containing carboxymucins. Cells containing sulfomucin, neutral mucin, or having striated borders arose from the carboxymucin cells. (2) An epithelial ledge of undifferentiated cells migrated onto a sulfated glycosaminoglycan, fibrous interface between necrotic and living tissue in the lesion. (3) Crypt formation began with the appearance of intraepithelial anlagen. (4) Crypts lengthened by a process of epithelial-connective tissue proliferation from the base of the crypt upwards. Following completion of connective tissue regeneration, crypts formed by invading the reestablished lamina propria. (5) The first mucous cells in the ledge contained carboxymucins. As crypt formation occurred, these cells gave rise to typical columnar absorptive cells, to cells containing sulfomucins, and to cells containing neutral mucins. (6) Lengthening of crypts ceased following the appearance of a sulfated acid glycosaminoglycan—collagenous layer deep in the submucosa.
The diffusion of online shopping: online shoppers and the Computer Competence Index

This paper discusses online shopping in context of diffusion of innovation theory. It proposes that online shopping is a discontinuous innovation whose adoption rate is influenced by several of Rogers' (2004) diffusion deterrents. A new 12-item 'Computer Competence Index' (CCI) is proposed and tested using data from an internet-administered US probability study of 1800 online users. EShoppers are profiled using a tertile split of the CCI. Each tertile's demographics, computer activities, computer-oriented lifestyles, and online purchase activities are reported. Evidence is presented that concepts related to the diffusion of innovation may explain resistance in the growth of online shopping.
Protein synthesis is required for cholera toxin-induced stimulation of arachidonic acid metabolism.

The molecular events in the mechanism of action of cholera toxin were analyzed using Chinese hamster ovary (CHO) cells. Cholera toxin stimulated both 3',5'-cyclic adenosine monophosphate (cAMP) synthesis and arachidonic acid metabolism in these cells. The turnover of phospholipid by cholera toxin-induced stimulation of phospholipase activity evoked the synthesis of PGE2 and other prostaglandins. Cholera toxin-induced release of both [3H]arachidonic acid and PGE2 was blocked by addition of either cycloheximide or actinomycin D. In contrast, accumulation of cAMP in cholera toxin-treated CHO cells was unaffected by adding these drugs. Further, dibutyryl cAMP or forskolin caused [3H]arachidonic acid release, which also was blocked by cycloheximide and actinomycin D. We concluded that the sequence of molecular events in cholera toxin-treated CHO cells first involved activation of adenylate cyclase, which caused an increase in cAMP. In turn, cAMP promoted transcription of mRNA that encoded either a specific phospholipase or a phospholipase-activating protein. The emerging arachidonic acid metabolites (e.g., PGE2 and PGF2 alpha) might be important mediators of cholera toxin's stimulatory effects on vascular permeability and smooth muscle contraction in the intestine during cholera.
A new method for extracting trees and buildings from sparse LiDAR data in urban areas

In this letter, we propose a new method for extracting trees and buildings from sparse Light Detection and Ranging (LiDAR) point clouds. We use two features, height and normal variation, to classify LiDAR points into buildings and trees. The accuracy obtained from an urban area in New Orleans, Louisiana, is 92% for both buildings and trees. The results indicate that three-dimensional objects such as buildings and trees can be effectively classified using the new method. The results also show that the new method is very effective and suitable for sparse LiDAR data in urban areas.
Sedimentologic Data on Ordovician-Silurian Boundary in Central Appalachians: ABSTRACT

The Ordovician-Silurian boundary in the western Valley and Ridge province is in an unfossiliferous, continental sequence, and has been traditionally placed to separate red Juniata Formation from the overlying white Tuscarora Formation. The systemic boundary, thus based on color differences, has been assumed to represent a time-parallel surface of considerable paleogeographic significance. Detailed field and mineralogic data now indicate that this assumption leads to ambiguities in correlations, and that a new means of defining the boundary is necessary. Sedimentologic aspects of rocks adjoining the color boundary provide primary control on diachroneity. Westward-prograding and eastward-transgressing fluvial regimes generated a sequence of distinct conglomerate, sandstone, and shale lithofacies recognizable over wide areas and occupying the 3,500-ft interval between datable Upper Ordovician and Middle Silurian fossiliferous marine units. Boundaries based on lithofacies approach more closely than other kinds of boundaries to time-parallel surfaces. The color boundary, for example, fluctuates as much as 400 ft vertically, both parallel with and across depositional strike, irregularly and unpredictably crossing lithofacies boundaries. Zones of constant clay, heavy, and opaque mineralogy within lithofacies are likewise randomly truncated y the color boundary. These data strongly suggest that redefinition of the Ordovician-Silurian systemic boundary in terms of the newly recognized lithofacies sequence is in order. Such revision depends fundamentally on precise time correlations of specific lithofacies with age-established marine units outside the Valley and Ridge area. In the absence of such rock units and of meaningful ichno-fossil data, exact location of the boundary may not be possible. End_of_Article - Last_Page 658------------
Task based synthesis of serial manipulators

Computing the optimal geometric structure of manipulators is one of the most intricate problems in contemporary robot kinematics. Robotic manipulators are designed and built to perform certain predetermined tasks. There is a very close relationship between the structure of the manipulator and its kinematic performance. It is therefore important to incorporate such task requirements during the design and synthesis of the robotic manipulators. Such task requirements and performance constraints can be specified in terms of the required end-effector positions, orientations and velocities along the task trajectory. In this work, we present a comprehensive method to develop the optimal geometric structure (DH parameters) of a non-redundant six degree of freedom serial manipulator from task descriptions. In this work we define, develop and test a methodology to design optimal manipulator configurations based on task descriptions. This methodology is devised to investigate all possible manipulator configurations that can satisfy the task performance requirements under imposed joint constraints. Out of all the possible structures, the structures that can reach all the task points with the required orientations are selected. Next, these candidate structures are tested to see whether they can attain end-effector velocities in arbitrary directions within the user defined joint constraints, so that they can deliver the best kinematic performance. Additionally least power consuming configurations are also identified.
Vorticity and its rate of change just downstream of a curved shock

A theory is developed for the vorticity and its substantial derivative just downstream of a curved shock wave, the resulting formulas are exact, algebraic, and explicit. Analysis is for a cylinder-wedge or sphere-cone body, at zero incidence, whose downstream half-angle is θb. Derived formulas directly depend only on the ratio of specific heats, γ, the freestream Mach number, M1, the local slope and curvature of the shock, and the dimensionality parameter, σ, which is zero for a two-dimensional shock and unity for an axisymmetric shock. In turn, the slope and curvature depend on γ, M1, and θb. Numerical results are provided for a bow shock in which θb is 5°, 10°, or 15°, M1 is 2, 4, or 6, and γ = 1.4. There is little dependence on the half angle but a strong dependence on the freestream Mach number and on dimensionality. For vorticity and its substantial derivative, the dimensionality dependence gradually decreases with increasing Mach number. In comparison to the two-dimensional case, an axisymmetric shock generates considerable vorticity in a region relatively close to the symmetry axis. Moreover, the magnitude of the vorticity, in this region, is further enhanced in the flow downstream of the shock. This dimensionality difference in vorticity and its substantial derivative is attributed to the three-dimensional relief effect in an axisymmetric flow.
Locally Bayesian Learning With Applications to Retrospective Revaluation and Highlighting

A scheme is described for locally Bayesian parameter updating in models structured as successions of component functions. The essential idea is to back-propagate the target data to interior modules, such that an interior component's target is the input to the next component that maximizes the probability of the next component's target. Each layer then does locally Bayesian learning. The approach assumes online trial-by-trial learning. The resulting parameter updating is not globally Bayesian but can better capture human behavior. The approach is implemented for an associative learning model that first maps inputs to attentionally filtered inputs and then maps attentionally filtered inputs to outputs. The Bayesian updating allows the associative model to exhibit retrospective revaluation effects such as backward blocking and unovershadowing, which have been challenging for associative learning models. The back-propagation of target values to attention allows the model to show trial-order effects, including highlighting and differences in magnitude of forward and backward blocking, which have been challenging for Bayesian learning models.
Variation in tibial torsion

A skeletal collection from the African country of Sudan was examined to determine if torsion of the tibia in an African population varies from established norms for European, Asian, and American populations. A large variation in tibial torsion was observed. There was a distinct limb asymmetry with more torsion on the right than left. No association of tibial torsion with gender was identified. A small but appreciable increase in average torsion (7°) was identified when this population was compared with previously reported populations. This study documents a variation in tibial torsion not appreciated in earlier studies. © 1994 Wiley-Liss, Inc.
Clutter leakage approximations for staring mosaic sensors with simultaneous line of sight (LOS) drift and jitter

Two approximations are developed for estimation of background clutter-induced noise in the Nth-differenced output of a single pixel of a drifting, jittering optical sensor. The viewing geometry and coordinate transformations are reviewed and an exact integral solution in the frequency domain is given. Its basis, an analysis done by Williams and Fried, is summarized in an appendix. Then the approximate forms are derived and their limitations discussed. The approximations are readily scalable and lend themselves to iterative, optimization-loop type performance calculations. Their applicability is limited to sensor LOS motion of a fraction of a pixel per frame time. Within that domain agreement with exact solutions is good.© (1980) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Platelets and endothelium: Effect of collagen-induced platelet aggregates on pulmonary vessels

Abstract Since endothelial injury may be the intiating event of atherosclerosis, much effort is concentrated on identifying possible causative agents of endothelial injury. Platelets are currently high on this list, but definitive proof of their harmful potential is lacking. The hypothesis that degranulating platelets may induce endothelial injury and/or endothelial leakage in the small arteries, arterioles, and capillaries of the rat's lung was tested. Intravascular platelet clumping was induced by the iv injection of calfskin collagen, followed (in one group of rats) by iv carbon black. After 15 min to 6 hr the lungs were processed for light and electron microscopy. Many small arteries, arterioles, and occasional capillaries contained emboli of platelets and collagen. No endothelial changes indicative of injury were found (i.e., necrosis, blebs, vacuoles, swelling) nor was there any evidence of vascular leakage. It is concluded that massive degranulation of platelets, in this model, occurs without causing endothelial damage.
He2Cl2 and He3Cl2 van der Waals clusters: A quantum Monte Carlo study

The results of the first variational and Green’s function Monte Carlo calculations of the vibrational ground states of He2Cl2 and He3Cl2 van der Waals (vdW) clusters are presented in this paper. The quantum dynamics of all internal degrees of freedom are treated exactly. The ground state wave function of He2Cl2 is characterized by means of the probability distribution functions of the intermolecular degrees of freedom, which reveal an exceptionally fluxional vdW complex. A simple model for the ground state of HenCl2 vdW clusters was developed. The zero‐point energies of He2Cl2 and He3Cl2 predicted by this model are in remarkable agreement (to within 0.6%) with the accurate results.
Rare-earth distribution patterns in eight terrestrial materials

Abstract The rare-earth element contents and relative abundances in a phosphorite, two coals, a composite mixture of sea shells, two corals, and two carbonatites have been determined by neutron activation analysis. The abundance distribution patterns in the phosphorites and calcareous marine materials are close to that of well-differentiated sediments. The coals are extra-abundant in Eu and depleted in the heavier and lighter lanthanides, relative to sediments. The distributions in the carbonatites resemble each other, but vary quite markedly from the sediment pattern, as is characteristic of most other materials with igneous origins. Considerable latitude was found in the rare-earth element concentrations. The La content of the phosphorite was 160 ppm; of the coals 4·9 and 3·3 ppm; of the shells and corals 0·13, 0·08 and 0·052 ppm; and of the carbonatites 181 and 76 ppm.
Determining molecular weight distributions from viscosity versus shear rate flow curves

Using the theoretical approach of Bersted and Slee, we developed a technique of determining the molecular weight distribution (MWD) from the viscosity vs. shear rate flow curve. Each molecular weight fraction was assumed to have a characteristic deformation rate. Below this rate, the viscosity was equal to the zero shear value. Above this rate, the viscosity was reduced to the zero shear viscosity of the molecular weight characteristic of the higher rate. The relationship between the weight fraction of each component and the viscosity/rate curve was derived from these assumptions. The flow curves of very well-characterized polystyrenes were determined. MWDs were then calculated using the BerstedSlee approach and compared with results from size exclusion chromatography. Comparisons were also made with the results of Malkin and Teishev. They used the same assumptions as Bersted and Slee but chose a different methodology for determining the MWD.
Trans-arctic-ocean tests of fine-silt luminescence sediment dating provide a basis for an additional geochronometer for this region

Abstract New geochronometers are needed for sediments of the Arctic Ocean spanning at least the last half million years, largely because oxygen-isotope stratigraphy is relatively ineffective in this ocean, and because other dating techniques require significant assumptions about sedimentation rates. Multi-aliquot luminescence sediment-dating procedures were applied to polymineral, fine-silt samples from 9 core-top and 37 deeper samples from 20 cores representing 19 sites across the Arctic Ocean. Most samples have independent age assignments and other known properties (e.g., % coarse fraction, % carbonate, U-Th isotopes). Thick-source alpha-particle counting indicates that for most regions the contribution of measured unsupported 230Th and 231Pa to calculated dose rates is
Choice of implicit and explicit operators for the upwind differencing method

The flux-vector and flux-difference splittings of Steger-Warming, Van Leer and Roe are tested in all possible combinations in the implicit and explicit operators that can be distinguished in implicit relaxation methods for the steady Euler and Navier-Stokes equations. The tests include one-dimensional inviscid nozzle flow, and two-dimensional inviscid and viscous shock reflection. Roe's splitting, as anticipated, is found to uniformly yield the most accurate results. On the other hand, an approximate Roe splitting of the implicit operator (the complete Roe splitting is too complicated for practical use) proves to be the least robust with regard to convergence to the steady state. In this respect, the Steger-Warming splitting is the most robust: it leads to convergence when combined with any of the splittings in the explicit operator, although not necessarily in the most efficient way.
The quest for very low-mass planets

The statistical results gathered on exoplanet properties over the past decade provide strong constraints for planet-formation models. They now prove to be especially important for the new category of very low-mass solid planets recently revealed by improved radial velocities, obtained mainly with the HARPS spectrograph. We review here the emerging properties of this newly discovered population, in the light of results from state-of-the-art planet-formation models. We also discuss the limitations of the radial-velocity method and the associated optimistic perspectives for the future detection of Earth-like planets in the Habitable Zone of solar-type stars, with radial velocities alone or in complement to space photometry.
A Rat Model for Chemotherapy-Induced Male Infertility

The effects of chronic administration of cyclophosphamide and procarbazine on testicular function in the rat were examined. Cyclophosphamide produced disruption of the normal spermatogenic architecture that was dose and time dependent. Total ablation of the germinal epithelium was not achieved. Procarbazine produced more specific testicular damage. Multiple weekly injections of 100-200 mg/kg of procarbazine caused complete destruction of the spermatogenic cells, with no effect on Sertoli cells. Treated animals remained infertile for more than 4 months and showed no histologic evidence of recovery. This model may be useful for examining possible mechanisms to prevent spermatogenic damage associated with cancer chemotherapy in man.
Student perceptions of using a human patient simulator for basic cardiac assessment

Abstract Objectives To discern the level of satisfaction of Doctor of Pharmacy students after using a Human Patient Simulator (HPS) to develop cardiovascular assessment skills. Design A survey was developed and sent to all students who used the HPS for cardiac assessment. Student responses were anonymous and participation in the survey was voluntary. The survey design allowed students to describe initial expectations, reflections after use, and interest in future HPS use. Assessment Two-hundred seventy-seven students completed the survey. Student responses were overall positive, showing a high degree of satisfaction and increased confidence in performing cardiovascular assessment skills. Conclusions The integration of HPS into a Doctor of Pharmacy curriculum is beneficial for enhanced learning and increased student confidence, and is extremely well received by students.
Long-term follow-up of redo pull-through procedures for Hirschsprung's disease: efficacy of the endorectal pull-through.

Abstract Background/Purpose: The purpose of this study was to review the authors' 25-year experience with redo pull-through procedures for Hirschsprung's disease including surgical technique and long-term outcome. Methods: From 1974 to now, over 325 patients with Hirschsprung's disease have been treated at C.S. Mott Children's Hospital. This includes 30 patients referred after an unsuccessful pull-through at another hospital and 2 patients with an unsuccessful pull-through from C.S. Mott. All redo pull-throughs (n = 19) were performed in these patients, and their clinical courses are reviewed. Results: Twelve patients required reoperation secondary to a mechanical problem with their first pull-through. The other 7 patients had evidence of residual segments of dilated colon leading to functional failure of their initial operation including 5 patients with documented aganglionic bowel present at the second pull-through. Ten of the patients requiring reoperation initially had an endorectal pull-through (ERPT), 5 had a Duhamel procedure, 3 had a Swenson procedure, and 1 had a Rehbein procedure. Choice of revision was an ERPT in 8 patients in whom an adequate rectal cuff could be developed. Additional redo procedures included a Duhamel in 8 patients and a Swenson in 3 patients. Follow-up ranges from 3 months to 23 years (mean, 13.8 years). There were no deaths in the series, and 1 patient required a third pull-through. All patients who are not neurologically impaired and are over age 3 are continent except one (94%). Stools per day range from 1 to 10 (mean, 3.2). Conclusions: Redo pull-through operations for Hirsch-sprung's disease appear to be as effective as primary procedures in terms of continence and stooling frequency. Distinct from other series, we found an ERPT to be the procedure of choice if an adequate rectal cuff was present. J Pediatr Surg 35:829-834. Copyright © 2000 by W.B. Saunders Company.
Conductivity and mechanical properties of well-dispersed single-wall carbon nanotube/polystyrene composite

The morphologies, electrical and mechanical properties and structure of polystyrene (PS) composites with varying concentrations of single-wall carbon nanotubes (SWNT) are analyzed. Using Raman spectroscopy and electron microscopy, we demonstrate that initial thermal annealing of SWNT significantly improves their dispersion in PS. In dielectric measurements, the annealed SWNT/PS composites show higher electrical conductivity and a lower percolation threshold (less than 0.3 wt%) than the raw SWNT/PS composites, which provides further evidence of good dispersion of the annealed SWNT in PS. Raman spectra of composites under tension show good transfer of an applied stress from the polymer matrix to SWNT. However, mechanical moduli of the annealed SWNT/PS composites are only increased slightly. The reason for this discrepancy remains unclear.
Emergency Care and the National Quality Strategy: Highlights From the Centers for Medicare & Medicaid Services

The Centers for Medicare & Medicaid Services (CMS) of the US Department of Health and Human Services seeks to optimize health outcomes by leading clinical quality improvement and health system transformation through a variety of activities, including quality measure alignment, prioritization, and implementation. CMS manages more than 20 federal quality measurement and public reporting programs that cover the gamut of health care providers and facilities, including both hospital-based emergency departments (EDs) and individual emergency physicians. With more than 130 million annual visits, and as the primary portal of hospital admission, US hospital-based EDs deliver a substantial portion of acute care to Medicare beneficiaries. Given the position of emergency care across clinical conditions and between multiple settings of care, the ED plays a critical role in fulfilling all 6 priorities of the National Quality Strategy. We outline current CMS initiatives and future opportunities for emergency physicians and EDs to effect each of these priorities and help CMS achieve the triple aim of better health, better health care, and lower costs.
Engineering the development of optical fiber sensors for adverse environments

Optical fiber sensors and measurement systems must be engineered to meet tough environmental requirements necessary for applications outside the laboratory. No generalized computer-aided tools exist to help advance the development, design and use of these systems in the field. Computer-aided design tools currently being developed are described. Structural finite element analyses are coupled with opto-elastic analyses of all-fiber interferometers and serial microbend sensors for the distributed measurement of various physical quantities. The combined analyses are parameterized and implemented on personal computers or workstations for use as design and development tools to determine the performance of different sensor configurations in various environments. Potentially, these computer-aided tools could be used for failure diagnosis and redesigning of existing optical fiber sensors. Performances predicted by the computer simulations are verified with experimental data and numerical analyses from the literature. The long-term goal is to develop user-friendly software packages for sensor manufacturers and end-users.
Can radiofrequency ablation get on your nerves

sprouting was observed at sites both near and remote from the site of radiofrequency ablation. In contrast, in the right ventricle, no increase in nerve density was observed near the ablation sites, but nerve density increased at remote sites 2 hours following ablation. One month after ablation, nerve sprouting remained present in the atrium but not in the ventricle. The reason for the discrepancy in response between the atrium and ventricle is not clear. The control group did not display significant changes in GAP-43. The authors concluded that nerve sprouting can occur as a result of radiofrequency ablation. Although not examined in this report, nerve sprouting has been shown to be arrhythmogenic in other studies. 5,6 Some minor technical issues regarding the report should be noted. The target temperatures in the atrium and ventricle were different, making comparison of neural remodeling in the atrium vs the ventricle difficult. Only five animals were
Measurement Characteristics and Clinical Utility of the Stroke Rehabilitation Assessment of Movement Among Stoke Patients

The Stroke Rehabilitation Assessment of Movement (STREAM) is an outcome measure that examines voluntary limb movement of the arm and leg and basic mobility after stroke. The 2 limb subscales are scored on a 3-point ordinal scale. Scoring considers the excursion and quality of limb movement compared with the less impaired side. The mobility subscale is scored on a 4-point ordinal considering the quality of movement, whole versus part completion of the task, use of a device, and assistance required. A total of 20 points is available for each limb scale, and 30 points are available for the mobility scale. Scores are converted to percentages to allow for items that were not tested. The measure can be completed in 15 minutes with equipment typically found in the clinic. Excellent reliability, concurrent validity with other commonly used clinical tests, minimal detectable change data, and normative values have been established. The STREAM has been reported to be responsive to change in acute stroke. A full review of the STREAM as well as reviews of nearly 200 other instruments can be found at www.rehabmeasures.org. Please address correspondence to rehabmeasures@ric.org.
Twenty-first century plant biology: impacts of the Arabidopsis genome on plant biology and agriculture.

In the late 1980s and early 1990s, Arabidopsis ( Arabidopsis thaliana ) rapidly emerged as a model system for plant biology due to the ease of genetic approaches to study development, physiology, and gene function coupled with a highly collaborative community. Arabidopsis’s position as the