cssi/SciSciGPT-SciSciNet huggingface dataset:
Interlimb reflex activity after spinal cord injury in man: strengthening response patterns are consistent with ongoing synaptic plasticity

Abstract Objective Previous reports from our laboratory have described short-latency contractions in muscles of the distal upper limb following stimulation of lower limb nerves or skin in persons with injury to the cervical spinal cord. It takes 6 or more months for interlimb reflexes (ILR) to appear following acute spinal cord injury (SCI), suggesting they might be due to new synaptic interconnections between lower limb sensory afferents and motoneurons in the cervical enlargement. In this study, we asked if once formed, the strength of these synaptic connections increased over time, a finding that would be consistent with the above hypothesis. Methods We studied persons with sub-acute and/or chronic cervical SCI. ILR were elicited by brief trains of electrical pulses applied to the skin overlying the tibial nerve at the back of the knee. Responses were quantified based on their presence or absence in different upper limb muscles. We also generated peri-stimulus time histograms for single motor unit response latency, probability, and peak duration. Comparisons of these parameters were made in subjects at sub-acute versus chronic stages post-injury. Results In persons with sub-acute SCI, the probability of seeing ILR in a given muscle of the forearm or hand was low at first, but increased substantially over the next 1–2 years. Motor unit responses at this sub-acute stage had a prolonged and variable latency, with a lower absolute response probability, compared to findings from subjects with chronic (i.e. stable) SCI. Conclusions Our findings demonstrate that interlimb reflex activity, once established after SCI, shows signs of strengthening synaptic contacts between afferent and efferent components, consistent with ongoing synaptic plasticity. Significance Neurons within the adult human spinal cord caudal to a lesion site are not static, but appear to be capable of developing novel—yet highly efficacious—synaptic contacts following trauma-induced partial denervation. In this case, such contacts between ascending afferents and cervical motoneurons do not appear to provide any functional benefit to the subject. In fact their presence may limit the regenerative effort of supraspinal pathways which originally innervated these motoneurons, should effort in animal models to promote regeneration across the lesion epicenter be successfully translated to humans with chronic SCI.
Analysis of MAP/PH1,PH2/1 queue with vacations and optional secondary services

Abstract In this paper we study a queueing model in which the customers arrive according to a Markovian arrival process ( MAP ). There is a single server who offers services on a first-come-first-served basis. With a certain probability a customer may require an optional secondary service. The secondary service is provided by the same server either immediately (if no one is waiting to receive service in the first stage) or waits until the number waiting for such services hits a pre-determined threshold. The model is studied as a QBD -process using matrix-analytic methods and some illustrative examples are discussed.
The decomposition of nitric oxide on a heated platinum wire

Abstract The catalytic rate of decomposition of pure nitric oxide on platinum (2NO → N 2 + O 2 ) was measured employing the batch, hot-wire technique at wire temperatures in the range 900–1200°C and at total pressures from 400–2260 torr. Chemisorbed oxygen is known to inhibit the rate of this reaction but very little surface oxygen is present at these elevated temperatures and thus an effectively clean platinum surface was realized. Also the experiments were limited to low conversions and thus low oxygen partial pressures ( P O 2 → O 2 ), again minimizing the likelihood of oxygen inhibition. A Rideal—Eley type rate expression: − r (moles NO reached/cm 2 . sec) = k 2 P 2 NO /(1 + K 1 P O 2 + K 2 P NO ) describes quite well the dependence of the measured rate of the NO partial pressure on P NO . In contrast the data are not fit well by a Langmuir—Hinshelwood type rate-expression, similar to that above except for a unimolecular term P NO in the numerator. Owing to the large values of P NO and low conversions used in the present study with P O 2 → O, the study focused on the kinetics with respect to NO itself. For the above Rideal—Eley mechanism: k 2 ≊ 4·63 × 10 −4 exp (−8,600/ RT ) mol/cm 2 . atm 2 . sec and K 2 ≊ 3 · 5 × 10 −2 exp (11,300/ RT ) atm −1 .
Hospital charges of potentially preventable pediatric hospitalizations.

Abstract Objectives Reducing the number of preventable hospitalizations represents a possible source of health care savings. However, the current literature lacks a description of the extent of potentially preventable pediatric hospitalizations. The study objectives are to (1) identify the charges and (2) demographic characteristics associated with potentially preventable pediatric hospitalizations. Methods Secondary analysis of the 2006 Kids' Inpatient Database (weighted N = 7,558,812). International Classification of Diseases, Ninth Revision, Clinical Modification codes for 16 previously validated pediatric ambulatory care-sensitive (ACS) conditions identified potentially preventable hospitalizations; seven additional conditions reflected updated care guidelines. Outcome variables included number of admissions, hospitalization days, and hospital charges. Demographic and diagnostic variables associated with an ACS condition were compared with regression analyses by the use of appropriate person-level weights. Results Pediatric ACS hospitalizations totaled $4.05B in charges and 1,087,570 hospitalization days in 2006. Two respiratory conditions—asthma and bacterial pneumonia—comprised 48.4% of ACS hospital charges and 46.7% of ACS hospitalization days. In multivariate analysis, variables associated with an ACS condition included: male gender (odds ratio [OR] 1.10; 95% confidence interval [95% CI] 1.07–1.13); race/ethnicity of black (OR 1.22; 95% CI 1.16–1.27) or Hispanic (OR 1.12; 95% CI 1.06–1.18); and emergency department as admission source (OR 1.37; 95% CI 1.27–1.48). Conclusions Respiratory conditions comprised the largest proportion of potentially preventable pediatric hospitalizations, totaling as much as $1.96B in hospital charges. Children hospitalized with an ACS condition tend to be male, non-white, and admitted through the emergency department. Future research to prevent pediatric hospitalizations should examine targeted interventions in the primary care setting, specifically around respiratory conditions and minority populations.
Post-cervical decompression parsonage-turner syndrome represents a subset of C5 palsy: six cases and a review of the literature: case report.

BACKGROUND AND IMPORTANCE: Approximately 5% of cervical decompression cases are complicated by postoperative weakness. Parsonage-Turner syndrome (PTS) or neuralgic amyotrophy is known to be precipitated by surgery and unrelated to technical or structural issues. Our practice has seen a number of cases of PTS after cervical decompression surgery. In this case report, we discuss a series of such patients, highlighting the commonalities with the more frequently diagnosed C5 palsy. We conclude with our management algorithm. CLINICAL PRESENTATION: Six patients with post-cervical decompression PTS were referred to our institution during a 32-month period. All patients were examined physically, radiographically, and electromyographically and were followed for up to 2 years or until symptoms resolved. Conservative management was the rule, and surgical intervention, including nerve releases and nerve reconstruction, was undertaken in select circumstances. In the majority of patients (4 of 6 patients), pain management and physical therapy alone were used and achieved eventual resolution of pain and recovery of motor strength. The other 2 patients required adjunctive surgical procedures to maximize their outcomes. CONCLUSION: PTS accounts for a subset of patients experiencing postoperative weakness after cervical decompression operations. Although it is at times difficult to arrive at this diagnosis, an understanding of the history of PTS, among other causes of postoperative weakness, allows a structured approach to these patients. An evidence-based approach to management helps provide the best outcome for a given patient.
Assessment of proposed fighter agility metrics

This paper presents the results of an analysis of proposed metrics to assess fighter aircraft agility. A novel framework for classifying these metrics is developed and applied. A set of transient metrics intended to quantify the axial and pitch agility of fighter aircraft is evaluated with a high fidelity, nonlinear F-18 simulation. Test techniques and data reduction method are proposed, and sensitivities to pilot introduced errors during flight testing is investigated. Results indicate that the power onset and power loss parameters are promising candidates for quantifying axial agility, while maximum pitch up and pitch down rates are for quantifying pitch agility.
Role of gaseous neurotransmitters in the hypothalamic-pituitary-adrenal axis.

: Nitric oxide (NO) is an unstable gas that plays important roles in the brain in general and in neuroendocrine functions in particular. We have shown that NO exerts opposite effects within the median eminence-pituitary axis, where it inhibits ACTH responses to blood-borne signals [such as the systemic injection of proinflammatory cytokines or vasopressin (VP)], and structures protected by the blood-brain barrier, where it stimulates the synthesis of the hypothalamic peptides, corticotropin-releasing factor (CRF) and VP. As a result, when an animal is exposed to stimuli that acutely activate the paraventricular nucleus of the hypothalamus as well as the release of peptides from nerve terminals (such as mild inescapable foot shocks), the net influence of NO on the ACTH response will represent the balance between these two effects. Based on experiments conducted with rats, we propose that, in shocks of low intensity, ACTH release primarily depends, at least in the initial phase, on the interaction between NO and VP (and consequently is augmented by reagents that block NO formation); in shocks of higher intensity, the interaction between NO and the hypothalamus predominates (i.e., it is inhibited by reagents that block NO formation).
Community Participation and Empowerment in Rural Post-Communist Societies: Lessons from the Leader Approach in Pomerania, Poland

AbstractEmpowerment, community participation and social capital have all been heavily researched within tourism development, yet few have looked at how they apply in a post-communist rural society. Filling the gap, this work helps to understand the community participation and empowerment in rural post-communist communities. The study demonstrates that despite there being an agreement that sustainable tourism development must consider residents’ needs and involve them in planning processes, empowering communities in the post-communist Central and Eastern Europe (CEE) setting is challenging owing to the unique political culture of the CEE. The qualitative approach was used to better capture tourism stakeholders' perspectives and experiences of challenges to community participation in tourism development in a post-communist setting.
Hearing in American leaf-nosed bats. III: Artibeus jamaicensis

We determined the audiogram of the Jamaican fruit-eating bat (Phyllostomidae: Artibeus jamaicensis), a relatively large (40-50 g) species that, like other phyllostomids, uses low-intensity echolocation calls. A conditioned suppression/avoidance procedure with a fruit juice reward was used for testing. At 60 dB SPL the hearing range of A. jamaicensis extends from 2.8 to 131 kHz, with an average best sensitivity of 8.5 dB SPL at 16 kHz. Although their echolocation calls are low-intensity, the absolute sensitivity of A. jamaicensis and other 'whispering' bats does not differ from that of other mammals, including other bats. The high-frequency hearing of A. jamaicensis and other Microchiroptera is slightly higher than expected on the basis of selective pressure for passive sound localization. Analysis suggests that the evolution of echolocation may have been accompanied by the extension of their high-frequency hearing by an average of one-half octave. With respect to low-frequency hearing, all bats tested so far belong to the group of mammals with poor low-frequency hearing, i.e., those unable to hear below 500 Hz.
Eastern Indians' Childbearing Practices and Nursing Implications

The purpose of this article is to assist nurses to understand and provide culturally sensitive perinatal care to Eastern Indians residing in the United States. Traditional practices during pregnancy, labor and delivery, and after delivery are described. The strategies that are culturally relevant and sensitive to the needs of the clients are suggested.
Development of a multidisciplinary approach to assess regional sustainability

There are a number of established, scientifically supported metrics of sustainability. Many of the metrics are data-intensive and require extensive effort to collect data and compute the metrics. Moreover, individual metrics do not capture all aspects of a system that are relevant to sustainability. A pilot project was initiated to create an approach to measure, monitor, and maintain prosperity and environmental quality of a regional system. The goal was to produce a straightforward, inexpensive methodology that is simple to use and interpret. This requires historical data be readily accessible, metrics must be applicable to the relevant scale, and results must meet the needs of decision-makers. Because sustainability is a multidimensional concept, the research group consisted of a multidisciplinary team that identified the major components of an environmental system. We selected metrics to capture the multidimensionality of sustainability in environmental systems and included: (1) emergy to capture the q...
Magnetic Fields in Quasar Cores

Multifrequency polarimetry with the Very Long Baseline Array telescope has revealed absolute Faraday rotation measures (RMs) in excess of 1000 rad m-2 in the central regions of the quasars 3C 273, 3C 279, and 3C 380. Beyond a projected distance of ~20 h-1 pc, however, the jets of all three sources are found to have RM < 100 rad m-2. Such sharp RM gradients cannot be produced by cluster or galactic-scale magnetic fields but rather must be the result of magnetic fields organized on scales of 1-100 pc. If associated with the region that produces the narrow optical emission lines, then magnetic fields of strength ~0.05 μG are required to be uniform over scales of ~10 pc. The direct detection of high RMs in these quasar cores can explain the low fractional-core polarizations usually observed in quasars at centimeter wavelengths as the result of irregularities in the Faraday screen on scales smaller than the telescope beam.
Changes in grapefruit flavedo cell wall noncellulosic neutral sugar composition

Abstract Analysis of grapefruit flavedo cell walls detected seven neutral sugars. Arabinosyl and galactosyl residues were most abundant, followed by xylosyl, mannosyl, glucosyl and fucosyl residues. The percentage of the cell wall composed of neutral sugars (38%) decreased during development and ripening to 27%. There was a change in cell wall neutral sugar composition from June to April with a reduced percentage of flavedo cell wall galactosyl and arabinosyl residues as the season progressed. Degreening of fruit accelerated the decrease in flavedo cell wall galactosyl and arabinosyl residues, and a single preharvest spray with gibberellic acid, three months prior to harvest, reduced the decrease in flavedo cell wall galactosyl and arabinosyl residues, as well as reducing the rate of peel softening and loss of green colour.
Gluing nanoparticles with a polymer bonding layer: the strength of an adhesive bond.

The adhesive joint between silica nanoparticles and ultrathin poly(vinylpyridine) (PVP) layers (thickness between 3 and 100 nm) was tested using the cantilever of an atomic force microscope. Specifically, the strength of the adhesive bond (or practical adhesion) was probed in a tearing contact mode, when the particle was removed by applying a tangential force parallel to the substrate surface. The effect of the polymer molecular weight and layer thickness on the particle (practical) adhesion was investigated. It was found that the particles were removed by destroying the cohesive contact zone and that the PVP layer thickness had a pronounced effect on the force needed to destroy the adhesive joint. In particular, the greater the layer thickness, the larger was the required break force. However, the strength of the adhesive joint was estimated to be higher for a thinner layer. It is suggested that mechanical properties of the system as well as molecular characteristics of the PVP layer are responsible for ...
“Conventions of Simultaneity” Time Standards, Public Clocks, and Nationalism in American Cities and Towns, 1871-1905

This article considers the saturation of American cities and towns with government-sponsored public clocks during the Gilded Age. In doing so, it seeks to establish that while clocks are part of th...
The 100 classic papers of pediatric orthopaedic surgery: a bibliometric analysis.

Background:Pediatric orthopaedic surgery owes its development to many pioneering individuals, and the studies that these individuals have undertaken form the basis for the clinical decisions made on the modern pediatric orthopaedic service. The aim of our study was to use citation analysis to identi
Plasticity of visual evoked potentials in kittens demonstrated by operant conditioning

Abstract Immature kittens, 14 to 21 days of age, were trained in a shock avoidance paradigm to raise or lower the amplitude of a cortical visual evoked potential. Very large conditioned amplitude shifts were induced in the primary visual cortex without corresponding changes in other cortical areas. The results demonstrate that the kitten is capable of modifying a response to visual stimulation as early as 2 weeks of age.
Examination of Drosophila Larval Tracheal Terminal Cells by Light Microscopy

Cell shape is critical for cell function. However, despite the importance of cell morphology, little is known about how individual cells generate specific shapes. Drosophila tracheal terminal cells have become a powerful genetic model to identify and elucidate the roles of genes required for generating cellular morphologies. Terminal cells are a component of a branched tubular network, the tracheal system that functions to supply oxygen to internal tissues. Terminal cells are an excellent model for investigating questions of cell shape as they possess two distinct cellular architectures. First, terminal cells have an elaborate branched morphology, similar to complex neurons; second, terminal cell branches are formed as thin tubes and contain a membrane-bound intracellular lumen. Quantitative analysis of terminal cell branch number, branch organization and individual branch shape, can be used to provide information about the role of specific genetic mechanisms in the making of a branched cell. Analysis of tube formation in these cells can reveal conserved mechanisms of tubulogenesis common to other tubular networks, such as the vertebrate vasculature. Here we describe techniques that can be used to rapidly fix, image, and analyze both branching patterns and tube formation in terminal cells within Drosophila larvae. These techniques can be used to analyze terminal cells in wild-type and mutant animals, or genetic mosaics. Because of the high efficiency of this protocol, it is also well suited for genetic, RNAi-based, or drug screens in the Drosophila tracheal system.
The “recall effect” in radiotherapy: Is subeffective, reparable damage involved?

Abstract It has been proposed that lethal mutations among the progeny of a surviving cell could be the basis for the recall effect when chemotherapy is applied subsequent to the repair of normal-tissue injury resulting from a course of radiation therapy. Because radiotherapy is usually multifractionated, the possibility exists that repair of heritable injury of this type could occur between fractions as is the case for sublethal damage. To examine this possibility, the endpoint small-colony formation was used—an endpoint which integrates the effects of a number of radiation-induced aberrancies including lethal mutations—and low-dose-rate irradiation. It was found that, even after net surviving fractions comparable to those sought in radiotherapy were reached, little damage remained expressible as a deficiency in the size of the colony generated from a surviving cell. We conclude that the damage expressible as a lethal mutation is reparable and therefore the recall effect must be attributed to some other cellular mechanism.
Application of proper orthogonal decomposition to the discrete Euler equations

The response of a fluid moving above a panel to localized oscillation of the panel is predicted using reduced-order modelling (ROM) with the proper orthogonal decomposition technique. The flow is assumed to be inviscid and is modelled with the Euler equations. These non-linear equations are discretized with a total-variation diminishing algorithm and are projected onto an energy-optimal subspace defined by an energy-threshold criterion applied to a modal representation of time series data. Results are obtained for a bump oscillating in a Mach 1.2 flow. ROM is found to reduce the degrees of freedom necessary to simulate the flowfield by three orders of magnitude while preserving solution accuracy. Other observed benefits of ROM include increased allowable time step and robustness to variation of oscillation amplitude. Published in 2002 by John Wiley & Sons, Ltd.
Assessment of arteriovenous blood flow during retrograde cerebral perfusion

Abstract Objective: This study examined arterial and venous blood flow during retrograde cerebral perfusion (RCP) to quantify what proportion of arterial inflow is not recovered as venous outflow. Design: Prospective. Setting: Community hospital, university setting, single institution. Participants: Twelve patients undergoing reconstructive aortic arch surgery with profound hypothermic circulatory arrest and RCP. Interventions: None. Measurements and Main Results: RCP arterial inflow and venous outflow measurements were recorded at 2-minute intervals for 10 minutes, averaged, and then compared. Only 44.9% ± 16.3% of RCP inflow returned through the aortic arch. The remainder was not recovered. Conclusion: Internal jugular venous valves, sequestration, and shunting may contribute to arterial inflow diversion during RCP.
Expression of Four Methionine Sulfoxide Reductases in Staphylococcus aureus

Staphylococcus aureus possesses three MsrA enzymes (MsrA1, MsrA2, MsrA3) that reduce the S-epimer of methionine sulfoxide (MetO) and an MsrB enzyme that reduces R-MetO. The four msr genes are expressed from three different promoters. The msrA1/msrB genes are coexpressed. To determine the expression pattern of msr genes, three independent reporter strains were constructed where msr promoter was cloned in front of a promoterless lacZ and the resulting construct was integrated in the chromosome. Using these strains, it was determined that the msrA1/B expression is significantly higher in S. aureus compared to msrA2 or msrA3. Expression of msrA1/B was highest during stationary phase growth, but the expression of msrA2 and msrA3 was highest during the early to midexponential growth phase. Expression of msrA1/B was induced by oxacillin and the expression of msrA3 was upregulated by salt. Expression of msrA2 remained unchanged under all tested conditions.
Incidence, Predictors, and Outcomes of Extubation Failure in Children After Orthotopic Heart Transplantation: A Single-Center Experience

The objective of this study is to describe the incidence, etiologies, predictors, and outcomes of extubation failure in children undergoing orthotopic heart transplantation (OHT). A Retrospective, observational study was designed to evaluate clinical outcomes. . The study was conducted in a cardiovascular intensive care unit (CVICU) setting at a single, tertiary care, academic children’s hospital. We collected demographic, pre-operative, intra-operative, post-operative and peri-extubation data in a retrospective, observational format from patients who underwent OHT at our institution. Clinical outcomes evaluated included the success or failure of extubation, CVICU length of stay (LOS), hospital LOS, and in-hospital mortality. We utilized descriptive and univariate statistics to compare the group with extubation failure to the group with extubation success. There were no interventions in this study. During the study period, 127 patients qualified for inclusion. The median age of patients was 108 months [interquartile range (IQR): 25–169] and median weight was 23 kg (IQR: 10.6–48). Extubation failure occurred in 12.5 % (16/127) of the patients. Median duration of mechanical ventilation was 2 days (IQR: 1–4.5), median CVICU LOS was 7 days (IQR: 5–13), and the median hospital LOS was 36 days (IQR: 20–74). Overall in-hospital mortality was 2 % (2/127). There was a significant improvement in blood pressure (p < 0.001) with a decrease in inotropic score (p < 0.001) after removal of positive pressure ventilation among the patients with extubation success. Independent factors associated with extubation failure included lower body weight, need for mechanical ventilation prior to heart transplantation, renal failure prior to extubation attempt, and right ventricular diastolic dysfunction prior to extubation attempt. Our study demonstrates that extubation failure in patients after OHT is infrequent and the causes are diverse. Extubation success in children after OHT is associated with improvement in mean arterial blood pressure, decrease in inotropic support, and decrease in supplemental oxygen requirement.
A variable relaxation scheme for multiphase, multicomponent flow

We propose a variable relaxation scheme for the simulation of 1D, two-phase, multicomponent flow in porous media. For these strongly nonlinear systems, traditional high order upwind schemes are impractical: Riemann solutions are not directly available when the phase behavior is complex, and the systems are weakly hyperbolic at isolated points. Relaxation schemes avoid the dependency on the eigenstructure and nonlinear Riemann solvers by approximating the original system with a strongly hyperbolic linear system. We exploit the known information about the eigenvalues to construct first order and second order variable relaxation schemes with much reduced numerical diffusion as compared to the standard relaxation formulations. The proposed second order variable relaxation scheme is competitive in accuracy and efficiency with a third order component-wise ENO reconstruction, and performs at least as well as second order component-wise TVD schemes.
Cognitive-behavioral stress management reduces distress and 24-hour urinary free cortisol output among symptomatic HIV-infected gay men.

Background Stress management interventions can reduce symptoms of distress as well as modulate certain immune system components in persons infected with human immunodeficiency virus (HIV). These effects may occur in parallel with reductions in hypothalamic-pituitary-adrenal (HPA) axis hormones such as cortisol, which has been related in other work to a down-regulation of immune system components relevant to HIV infection. The present study tested the effects of a multimodal cognitive-behavioral stress management (CBSM) intervention on 24-hour urinary free cortisol levels and distressed mood in symptomatic HIV+ gay men.
Endodontic dowel retention with resinous cements

This study compared the capability of three composite resin cements to sustain a standard endodontic dowel. All of the systems incorporated some form of smear layer removal on the dentin of the endodontic channel. One system that used a methyl ethyl ketone drying agent provided inadequate clinical resistance to dislodgment of 5.4 DaN. A second cementing system that used only smear layer removal resisted loads at 54.7 DaN. The third cementing regimen that included a surface-initiated dentinal adhesive and smear layer removal recorded retention of 77.4 DaN. This study supported the concept that passively cemented dowels with composite resin can be as effective as actively seated dowels.
A study of successful projects, unsuccessful projects, and projects in process in West Germany

This study is concerned with eleven successful and eleven unsuccessful innovations as well as ten innovations in progress. The data were gathered by the author in West Germany in 1974-1975. The earlier findings on the effects of demand pull and technology push are augmented with this study, which offers further evidence that the high number of successful innovations start from demand pull, while the high number of unsuccessful projects start from technology push. The successful and unsuccessful projects are compared in level of effort and elapsed time, and the process versus product R&D decision is examined. Ten current projects are examined and the social forces are found to be diffuse. Two examples demonstrate the importance of the necessary integration between technology and the environment.
Yahoo! Do You Google? Virtual Reference Overview

Abstract The Internet is fast becoming the world's largest public li brary. Reference librarians are using Web resources rather than print to an swer many reference queries. This article provides an overview of topics relating to virtual reference services: search engines, subject directories, virtual reference desks, the invisible Web, electronic journal publishing, virtual reference services, and reference librarian skills.
Behavioral Variability through Stochastic Choice and Its Gating by Anterior Cingulate Cortex

Behavioral choices that ignore prior experience promote exploration and unpredictability but are seemingly at odds with the brain's tendency to use experience to optimize behavioral choice. Indeed, when faced with virtual competitors, primates resort to strategic counter prediction rather than to stochastic choice. Here, we show that rats also use history- and model-based strategies when faced with similar competitors but can switch to a "stochastic" mode when challenged with a competitor that they cannot defeat by counter prediction. In this mode, outcomes associated with an animal's actions are ignored, and normal engagement of anterior cingulate cortex (ACC) is suppressed. Using circuit perturbations in transgenic rats, we demonstrate that switching between strategic and stochastic behavioral modes is controlled by locus coeruleus input into ACC. Our findings suggest that, under conditions of uncertainty about environmental rules, changes in noradrenergic input alter ACC output and prevent erroneous beliefs from guiding decisions, thus enabling behavioral variation. PAPERCLIP:
Dispositional Factors Affecting Motivation during Learning in Adult Basic and Secondary Education Programs.

Research indicates that about a quarter of adult students separate from formal adult basic and secondary education (ABE/ASE) programs before completing one educational level. This retrospective study explores individual dispositional factors that affect motivation during learning, particularly students’ goals, goal-directed thinking and action based on hope theory and attendance behaviors, and self-perceptions of competency based on affective domain attributions about external and internal obstacles to learning and employment, and demographic factors. Among 274 ABE/ASE students, those learners who made an education gain in 1 year significantly differed from those who did not in only a few dispositional or demographic variables; and by educational level they significantly differed in a wide variety of dispositional and demographic variables. These findings suggest researchable questions and programmatic considerations that may lead to future innovations that improve learner persistence.
Effects of diphenhydramine on human eye movements

Peak saccadic eye movement velocity (SEV) and average smooth pursuit gain (SP) are reduced in a dose-dependent manner by diazepam and provide reliable, quantitative measures of benzodiazepine agonist effects. To evaluate the specificity of these eye movement effects for agents acting at the central GABA-benzodiazepine receptor complex and the role of sedation in benzodiazepine effects, we studied eye movement effects of diphenhydramine, a sedating drug which does not act at the GABA-benzodiazepine receptor complex. Ten healthy males, aged 19–28 years, with no history of axis I psychiatric disorders or substance abuse, received 50 mg/70 kg intravenous diphenhydramine or a similar volume of saline on separate days 1 week apart. SEV, saccade latency and accuracy, SP, self-rated sedation, and short-term memory were assessed at baseline and at 5, 15, 30, 45, 60, 90 and 120 min after drug administration. Compared with placebo, diphenhydramine produced significant SEV slowing, and increases in saccade latency and self-rated sedation. There was no significant effect of diphenhydramine on smooth pursuit gain, saccade accuracy, or short-term memory. These results suggest that, like diazepam, diphenhydramine causes sedation, SEV slowing, and an increase in saccade latency. Since the degree of diphenhydramine-induced sedation was not correlated with changes in SEV or saccade latency, slowing of saccadic eye movements is unlikely to be attributable to sedation alone. Unlike diazepam, diphenhydramine does not impair smooth pursuit gain, saccadic accuracy, or memory. Different neurotransmitter systems may influence the neural pathways involved in SEV and smooth pursuit gain.
Intrahepatic hematoma requiring hepatic artery embolization: a rare complication of extracorporeal shock wave lithotripsy

Extracorporeal shock wave lithotripsy is a well-established treatment modality for renal calculi since the 1980s (Urology 1984;23(5):59–66). In general, it is a safe and effective noninvasive therapeutic modality for treatment of urolithiasis. Bleeding complications of this procedure are rare and usually involve the kidneys. In this case report, a 56-year-old woman developed severe abdominal pain with signs of hemorrhagic shock 2 days post–extracorporeal shock wave lithotripsy procedure. Computed tomography of the abdomen and pelvis showed a large intrahepatic hemorrhage that required hepatic artery embolization.
Accelerator-driven systems ; Their application to the incineration of long-lived radioactive waste

Actinides, mainly responsible for the long term risk of spent fuel, are the principal candidates to transmutation due to their large absorption cross sections. Systems driven by particle accelerators have been investigated in the past to produce fissile material. Recently these systems have been reconsidered to destroy minor actinides (MA) and long-lived fission products (LLFP), reducing the need for the traditional final confinement of radioactive waste. Two Monte Carlo calculation models have been developped to determine the criticality safety conditions and the burning capability of MAS and of Pu. A Pu burner, whose core is poisoned with Th to compensate by producing 233U the burnup reactivity due to the even Pu isotopes, can operate at a low proton current using perhaps a cyclotron, incinerating 70% of the charged Pu; its burning capability would be the production of about 1.5 PWRs. Liquid fuel accelerator driven systems can be used in the future (due to the accelerator dimensions) for MA burning usin...
Trypanosoma cruzi: quantification and analysis of the infectivity of cloned stocks.

The infection of bovine embryo skin and muscle cells by trypomastigotes of four Trypanosoma cruzi clones (CA-I/71, /72, Miranda/76, /80) was quantified. Stable and reproducible intra-isolate differences were observed; an almost 70-fold difference in infectivity occurred between clones. The CA-I/71 clone was not susceptible to N-acetyl-D-glucosamine at a concentration that inhibits the infection of vertebrate cells by Ernestina and Y-strain parasites. Eight other monosaccharides that are common constitutents of vertebrate cell surface glycoproteins also failed to inhibit the infection of vertebrate cells by the CA-I/71 clone.
Harmonic sources and filtering approaches

This article presents 22 configurations of power filters for the harmonic compensation of nonlinear loads. Some of these configurations are novel and result from the newly discovered characteristics of nonlinear loads and circuitry duality, while the others are well known and used in practice. Nonlinear loads can be characterized into two types of harmonic sources: current-source nonlinear loads and voltage-source nonlinear loads. These two types of harmonic sources have completely distinctive and dual properties and characteristics. Based on their properties and characteristics, the current-source nonlinear loads and voltage-source nonlinear loads have their own suitable filter configurations, respectively.
Myocardial contrast echocardiography: Enhancement of perfusion images by color coding

To determine whether real-time color coding enhances the detection of myocardial perfusion through the use of echocardiographic contrast agents, we used a recently developed real-time color system during contrast injection in six open-chest dogs. Small amounts of echocardiographic contrast were injected into the left atrium. Short-axis epicardial images were obtained with a 5-MHz transducer before and after left anterior descending artery ligation. Gray-scale and rainbow-color map images were obtained for each contrast agent. The color map allowed detection of small increment in echo intensity that were not evident with routine gray-scale imaging. Thus, realtime color coding may improve the detection of myocardial perfusion with echocardiographic contrast agents. © 1994 John Wiley & Sons, Inc.
The Aharonov-Bohm effect as a manifestation of the Zeeman interaction

It is shown that the Aharonov-Bohm effect in the region exterior to an infinite solenoid is a necessary consequence of the Zeeman interaction in the interior region. The Zeeman interaction energy is a part of the electron's kinetic energy. As a consequence, the electron's energy must be renormalized in the exterior region. This leads to a change in the canonical angular momentum as the electron crosses the solenoid wall, in spite of the cylindrical symmetry of the problem.
Comparison of measured inherent optical properties with estimates determined from reflectance in coastal waters off Cape Hatteras, North Carolina, USA

The ability to acquire information about inherent optical properties such as total spectral absorption (a((lambda) ), m-1) and scattering (b((lambda) ), m-1) from reflectance properties of oceanic waters is fundamental to the development of remote sensing algorithms. While considerable success has been achieved in relatively clear oceanic waters, inversion methods to determine a((lambda) ) and b((lambda) ) in conjunction with profiles of in situ radiance reflectance at various locations off Cape Hatteras, North Carolina during spring 1996. Our objective was to evaluate measurment and model closure among the different methods that were applied. Spectral a and b were determined using a WETLabs ac-9. Independent estimates of a were also determined in discrete samples using a spectrophotometer. In situ upwelling radiance (Lu) and downwelling irradiance (Ed) were determined using a Satlantic SeaWiFS Profiling Multichannel Radiometer. Inverse methods provided estimates of a and b from reflectance (Lu/Ed). For the mid- shelf station characterized by relatively low b/a ratios, agreement among the different methods for estimating a((lambda) ) was quite good. At the inner shield station, higher b/a ratios were encountered and larger discrepancies were observed between the different methods. The results illustrate the utility of multi-faceted measurement strategies for evaluating the reliability of estimates of optical properties.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
TH‐C‐BRD‐03: Determining the Optimal Collimator Position for Collimated Pencil Beam Scanning Proton Therapy

Purpose: There has been a growing interest in applying collimation to pencil beam scanning (PBS) proton therapy in order to sharpen the lateral dose falloff out of the target, especially at low energies. Currently, there is not a method to optimally determine the collimation position or margin around the target. A uniform margin would not be ideal due to the fact that an incoming symmetric pencil beam, after being intercepted by a collimator near the target boundary, will become asymmetric and experience a lateral shift away from its original spot location, leaving the target insufficiently covered. We demonstrate a method that optimally determines the collimator position on a per-spot basis, in order to maximize target dose while minimizing normal tissue dose. Methods: A library of collimated pencil beams were obtained through Monte Carlo simulation with a collimator placed at varying distances from the central axis of an incoming symmetrical pencil beam of 118 MeV and 5 mm sigma-in-air. Two-dimensional treatment plans were then created using this library of collimated pencil beams. For each spot position in a treatment plan, the collimator position was optimally determined in such a way that the resultant pencil beam maximized the ratio of in-target dosemore » and out-of-target dose. For comparison, un-collimated treatment plans were also computed. Results: The spot-by-spot optimally determined collimator positions allowed the reduction of normal tissue dose while maintaining the same target coverage as un-collimated PBS. Quantitatively, the mean dose outside of the target was reduced by approximately 40% as compared to the plan without collimation. Conclusion: The proposed method determines the optimal collimator position for each spot in collimated PBS proton therapy. The use of a collimator will improve PBS dose distributions achievable today and will continue to be the subject of future investigations.« less
Ancestry and Severity of Disability A National Study

The effects of ancestry and severity of disability of vocational rehabilitation consumers (as measured by cost, time in rehabilitation, number of services received, receipt of assistive technology, and disability severity [the Rehabilitation Services Administration definition]) were examined by applying a logistic regression to the RSA-911 national database from 1998. The best model was identified and interpreted. European Americans, individuals with higher costs, and persons who received assistive technology were more likely to be closed rehabilitated. Individuals from other ancestry groups, who were coded severely disabled, or who had been in the system for longer periods of time were less likely to be closed rehabilitated. Model limitations and suggestions for future research are presented.
Paleoclimatic and paleomagnetic constraints on the Paleozoic reconstructions of south China, north China and Tarim

Abstract Paleomagnetic and paleoclimatic data provide the most useful latitudinal constraints for plate reconstructions. Distributions through the Paleozoic of five types of climatically sensitive sediments (coals, evaporites, reefs, dolomites and limestones) for south China, north China and Tarim are shown on 15 maps that include 1578 reliable data points. These paleoclimatic data agree reasonably well with available paleomagnetic directions, although significant divergence between the two exists for the Early Paleozoic. These data indicate the following: 1. (1) South China was in low latitudes during the entire Paleozoic, with a subtropical position in the Cambrian. 2. (2) North China also remained near the equator in the Early and Late Paleozoic, except for the Ordovian and the Late Permian when extensive evaporites suggest slightly higher latitudinal positions, while its Middle Paleozoic position is uncertain due to the missing stratigraphie record. 3. (3) In south China, local tectonics appears to have played a dominant role in determining paleogeography and therefore marine sedimentation, especially after the Late Ordovician-Early Silurian, because the areal coverage of marine sediments through time is distinctly different from what would be expected from published global sea-level curves. 4. (4) Paleoclimatic and paleomagnetic data are compatible with biogeographic data which suggest that south China was part of eastern Gondwana in the Early Paleozoic, but was widely separated from Gondwana in the Late Paleozoic, and the split between the two probably happened in the Devonian, giving rise to a major break-up unconformity in central south China.
A reference solution for phase change with convection

A reference solutions for phase change involving convection in the melt is currently missing. In the present study, we focus on the problem of melting of pure tin in a square cavity heated from the side, which is used as a benchmark test problem. The mathematical model used for the simulations is based on the enthalpy formulation. Extensive numerical computations are performed with grids as fine as 800 × 800. The convergence of the numerical solution is demonstrated and its level assessed. Data values and plots are provided for use as a reference solution. Copyright © 2005 John Wiley & Sons, Ltd.
Viral infections of the developing nervous system

Abstract Both clinical and experimental studies indicate that viruses can interact with the developing nervous system to produce a spectrum of neurological damage and brain malformations. Following infection of the pregnant woman, virus may indirectly or directly involve the fetus. Direct involvement is generally due to transplacental passage of the virus and invasion of fetal tissue. Resultant disease is determined by a variety of virus-host factors, including the developmental stage of the fetus at the time it is infected, the neural cell populations which are susceptible to infection, the consequent virus-infected cell interactions, and the mechanism and timing of viral clearance. There is a growing list of human viruses which injure the developing nervous system. There are also several experimental models in which congenital viral infections have been shown to result in a variety of brain malformations but with no evidence of the prior infection remaining at the time of birth.
Fanconi anemia strikes early in utero.

In this issue of Blood , Tulpule and colleagues[1][1] describe the use of lentiviral vectors to knock down FANCA and FANCD2 in hESC lines, which results in early hematopoietic defects reminiscent of the human disease. Fanconi anemia (FA) is an autosomal recessive disorder characterized by bone
Psychoneural models of the auditory masking process.

Abstract Two mathematical models are presented which describe perception of the loudness of a tone masked by noise. The designation “psychoneural” indicates that the models are consistent with accepted findings in the fields of neuroanatomy, neurophysiology, and psychophysics. Each of the models consists of two channels, one which responds only to noise and another which responds to a weighted sum of tone and noise. Each channel is functionally equivalent to the model proposed by MacKay to explain intensity perception. In the first of the two masking models, it is assumed that the noise decreases the perceived loudness of the tone by lateral inhibition at a central location. In the second model, it is assumed that the noise decreases the loudness of the tone by efferent inhibition which acts at the periphery. The quantitative predictions of both models are identical and, with the appropriate adjustment of certain parameters, can be brought into close agreement with psychophysical masking data. The relative merits and handicaps of the models are discussed in the context of a more complex representation of the masking process in which a separate channel is assigned to each critical frequency band.