cssi/SciSciGPT-SciSciNet huggingface dataset:
Impact of immortal person-time and time scale in comparative effectiveness research for medical devices: a case for implantable cardioverter-defibrillators

Abstract Objectives To assess the extent of immortal time bias in estimating the clinical effectiveness of implantable cardioverter-defibrillators (ICDs) and the impact of methods of handling immortal time bias. Study Design and Setting Retrospective population-based cohort study of patients with heart failure in a national registry linked to Medicare claims (2003–2008). We compared three methods of handling immortal time bias, namely the Mantel–Byar (or time-dependent exposure assignment), the landmark, and the exclusion methods. Results Of the 5,226 study patients, 1,274 (24.4%) received ICD therapy. Total person-years in the Mantel–Byar method were 2,639, or 490 more than that in the exclusion method, reflecting potential immortal time in the study. The exclusion method yielded a hazard ratio of 0.71 (95% confidence interval [CI]: 0.63–0.80), which was 16% lower than the Mantel–Byar method (0.84; 95% CI: 0.75–0.95). The 120-day landmark method yielded similar results to those produced by the Mantel–Byar method (0.82; 95% CI: 0.72–0.95). Conclusions Immortal time bias was detected in the ICD clinical effectiveness study, which might have led to substantial bias overestimating the treatment effect if handled by exclusion. When an appropriate landmark was selected, that method yielded similar hazard ratios to those obtained by the Mantel–Byar method, supporting the validity of the landmark method.
Southwestern Internal Medicine Conference: Adult Respiratory Distress Syndrome

ABSTRACT The Adult Respiratory Distress Syndrome (ARDS) is a fulminant form of respiratory failure affecting many seriously ill patients. The early manifestations of ARDS are caused by increased permeability of the alveo-lo-capillary barrier leading to pulmonary edema, stiff lungs, and a large right-to-left intrapulmonary shunt. Polymorphonuclear leukocytes (PMNS) are involved in the pathogenesis of most ARDS, and multiple PMN mechanisms can effect pulmonary injury; interactions between PMN adherence, proteolytic enzyme release, and oxygen radical production are emphasized. ARDS therapy remains largely supportive and has had little impact on mortality. The complications of infection and multiorgan failure play important roles in determining ARDS outcome.
Pots and pox : The identification of protohistoric epidemics in the upper mississippi valley

Exogenous diseases represent one of the principal agents of culture change associated with the historic period, yet the timing of their initial influence remains undocumented in many regions of North America. Settlement variables, cooking pot volume, and mortality profiles from Oneota tradition occupations are used to investigate the possible occurrence of epidemics in the Upper Mississippi River valley. Synchronous fluctuations in settlement and ceramic variables indicate that following at least two centuries of population growth a significant population decline occurred in the early seventeenth century. Several factors provide support for the role of disease in this decline, including its timing, magnitude, and the documented presence of epidemics in adjacent regions combined with substantial evidence for extensive contact with those areas. This event, prior to direct, sustained contact, is associated with the increased intensity of intergroup exchange occurring with the fur trade. The ability to identify the occurrence of such epidemics is essential for understanding protohistoric cultural dynamics as well as the transmission of disease on a continental level.
Isolation and characterization of autotrophic, hydrogen-utilizing, perchlorate-reducing bacteria.

Recent studies have shown that perchlorate (ClO4 −) can be degraded by some pure-culture and mixed-culture bacteria with the addition of hydrogen. This paper describes the isolation of two hydrogen-utilizing perchlorate-degrading bacteria capable of using inorganic carbon for growth. These autotrophic bacteria are within the genus Dechloromonas and are the first Dechloromonas species that are microaerophilic and incapable of growth at atmospheric oxygen concentrations. Dechloromonas sp. JDS5 and Dechloromonas sp. JDS6 are the first perchlorate-degrading autotrophs isolated from a perchlorate-contaminated site. Measured hydrogen thresholds were higher than for other environmentally significant, hydrogen-utilizing, anaerobic bacteria (e.g., halorespirers). The chlorite dismutase activity of these bacteria was greater for autotrophically grown cells than for cells grown heterotrophically on lactate. These bacteria used fumarate as an alternate electron acceptor, which is the first report of growth on an organic electron acceptor by perchlorate-reducing bacteria.
Linear Contribution to Spatial Dispersion in the Spin-Wave Spectrum of Ferromagnets

The implications of magnetic symmetry on the spin-wave spectrum of ferromagnets are examined. Contrary to the usual result, the spin-wave dispersion relation is found to contain a term linear in the wave vector for a definite set of magnetic symmetries. This linear dispersion is shown to be a consequence of antisymmetric exchange.
An Infrared Reflection Spectroscopy Study of Orientational Behavior in Poly(3-methylthiophene) on a Pt Surface

Infrared reflection-absorption spectroscopy (IRRAS) has been used to obtain the vibrational spectra of thin films of poly(3-methylthiophene) electrochemically polymerized on a platinum surface. Clear orientational effects, with the thiophene rings oriented parallel to the platinum surface, were observed when the thickness of the polymer films were within a few hundred Angstroms. 17 refs., 4 figs.
Binaural response-specific bands in primary auditory cortex (AI) of the cat: Topographical organization orthogonal to isofrequency contours

Abstract The spatial distribution of neurons with different binaural response properties has been studied within the three dimensions of the primary auditory cortex (AI) in the cat. Using dichotic stimulation, 92% of neurons encountered could be classified into either the excitatory/excitatory (EE) or excitatory/inhibitory (EI) interaction class. In nearly all of almost 800 penetrations introduced along radial axes, all neurons encountered along a given penetration were of the same binaural response class. Neurons of different binaural interaction classes were spatially segregated within the plane of the cortex. Electrode penetrations made parallel to isofrequency contours traversed the mediolateral extent of AI through the middle layers of the cortex. A sharp segregation of units by binaural response class was observed in these penetrations, i.e. sequences of neurons that were all of the EE class alternated with sequences of EI neurons. The regions of uniform response to binaural stimulation formed radially organized topographical subunits that were elongated along the rostrocaudal dimension of AI. These binaural interaction bands intersect the lines of re-representation of the cochlear sensory epithelium (‘isofrequency contours’) and, thus, create subdivisions of AI that each contain a representation of the entire audible frequency domain. The implications of these results for the concept of AI as a unitary element in auditory processing are discussed.
Neutrinos of Nonzero Rest Mass

Some implications of neutrinos having nonzero rest masses and having finite lifetimes are considered.
Laparoscopic laser perforation of the urinary bladder

Risk factors for urologic complications of gynaecologic surgery include pelvic adhesions, poor haemostasis, cancer and large pelvic masses. Newer minimally invasive technologies of laparoscopy and laser surgery are not without complications. We report a case of potassium titanyl phosphate laser perforation of the urinary bladder during laparoscopy. To our knowledge this is the first case report of such an occurrence. The mechanism of injury, diagnosis and management of laparoscopic bladder perforation is discussed.
Multipurpose plasma reactor for materials research and processing

The operation of the Bell Laboratories large capacity, multipurpose plasma reactor for materials research and processing is discussed. The design of the reactor is such that all the plasma parameters can be independently controlled. This device has been used for growing, deposition, etching, as well as charged‐particle‐beam milling of thin films.
Identification of Rat EMAP, a δ-Glutamate Receptor Binding Protein

While most subtypes of glutamate receptors have been studied extensively, less is known about the delta-glutamate receptors, delta1 and delta2. Although neither forms functional channels when expressed in heterologous cells, genetic analyses have demonstrated the physiological significance of delta2. We used the cytosolic C-terminus of the delta2 glutamate receptor subunit in a yeast two-hybrid screen of a rat brain cDNA library to identify delta-glutamate receptor binding proteins. We isolated rat EMAP, the rat homolog of a microtubule-associated protein initially isolated and characterized in echinoderms. Rat EMAP contains 10 WD-repeats, which are domains important for mediating protein-protein interactions in a wide variety of proteins. Rat EMAP binds to delta-glutamate receptor subunits within a 50-amino-acid segment of the delta C-terminus. It is widely expressed in both brain and peripheral tissues, including high expression in brainstem and enrichment in the postsynaptic density.
Effects ofd-Ala2-Met5-enkephalinamide microinjections placed into the bed nucleus of the stria terminalis upon affective defense behavior in the cat

This study examined the effects of intracerebral injections ofd-Ala2-Met5-enkephalinamide (DAME) upon hypothalamically eliited hissing behavior in the cat. The bed nucleus of the stria terminalis (BNST) was selected for investigation because of its anatomical connections with the medial hypothalamus, its relatively high concentrations of enkephalins and opiate receptors and its demonstrated ability to modulate hypothalamically elicited aggressive reactions in the cat. DAME microinjected into the BNST in 1.0 or 10.0 μg/0.5 μl quantities resulted in significant dose dependent increases in mean latencies for elicitation of the hissing response. Suppression of hissing following the 1.0 μg dose of DAME was selectively diminished by prior administration of naloxone. These findings suggest that the opiate receptors within the BNST play a role in the regulation of the hissing component of hypothalamically elicited affective defense behavior.
Clavicle fracture in labor: risk factors and associated morbidities.

OBJECTIVE Neonatal clavicle fracture has been previously reported to occur in association with shoulder dystocia, suggesting liability on behalf of the obstetrician. However, clavicle fracture is often inconsistently diagnosed, and shoulder dystocia commonly subjectively defined. Using a formal pediatric diagnosis protocol and an objective definition of shoulder dystocia, we sought to determine the incidence, antecedents, and associated morbidities of clavicle fracture and the potential association with shoulder dystocia. STUDY DESIGN All deliveries at Harbor-UCLA Medical Center complicated by clavicle fracture from January 1996 to March 1999 were studied. Deliveries with clavicle fracture were compared to all vaginal deliveries during this period. RESULTS Among 4297 deliveries, twenty-six were complicated by clavicle fracture (0.5%). Clavicle fracture was significantly associated with increased maternal age and birth weight greater than 4 kg, though not associated with shoulder dystocia or operative vaginal delivery. Clavicle fracture was associated with meconium passage and with neonatal orthopedic abnormalities. CONCLUSION Neonatal clavicle fracture is associated with infant birth weight greater than 4 kg, but not with the occurrence of objectively defined shoulder dystocia. However, infants with clavicle fracture may be at increased risk for additional complications.
Blood from stone.

The article discusses paleontological research findings regarding the persistence of organic substances including blood vessels, bone cells, and fingernail-like matter in dinosaur remains from millions of years ago. The fossil tyrannosaurus rex MOR 555 is noted for its organic content. Traditional paleontological wisdom had held that minerals ultimately replaced organic molecules in fossilized remains. The author provides a personal narrative on her experience in discovering such fossilized organics and substantiating their validity. INSETS: Ancient Organic Remains;Dissecting a Duckbill.
The dual-factor model of mental health further study of the determinants of group differences

Consistent with a positive psychology framework, this study examined the contributions of personality, environmental, and perceived social support variables in classifying adolescents using Greenspoon and Saklofske’s Dual-Factor model of mental health. This model incorporates information about positive subjective well-being (SWB), along with psychopathology (PTH), to identify four groups of adolescents: positive mental health (high SWB, low PTH), vulnerable (low SWB, low PTH), symptomatic but content (high SWB, high PTH) and troubled (low SWB, high PTH). Using multinomial logistic regression analyses, adolescents were accurately classified into the four groups above chance. The contribution of the personality, social support, and stressful life events variables differed across the groups. Differences in perceived parent social support statistically significantly differentiated (p < .05) the vulnerable and troubled groups from the positive mental health group. The experience of stressful life events signif...
Reaction of ozone with nicotinamide and its derivatives.

Abstract Reaction of ozone with NADH eliminated the 340 nm absorbance. The 260 nm absorbance increased initially and then slowly declined. Equimolar amounts of NADH and ozone reacted. Products were separated by ion exchange chromatography and were shown to contain only traces of NAD. The products were not active in the alcohol dehydrogenase assay and did not form cyanide complexes. There was no reaction of NAD with ozone. NADPH and NADP showed the same reactivities as NADH and NAD. The reactions were not influenced by pH in the range 4.6–9.0. When NADH and tryptophan, or NADH and methionine, or NADH and glutathione (at low concentration) were competitors for available ozone, NADH was preferentially oxidized. Treatment of aqueous solutions of 1,4-dihydro-1-methyl nicotinamide with ozone caused changes in the absorbance spectrum consistent with ozonolysis of the 5,6 double bond. The product has been isolated after ozonolysis in methylene chloride and characterized by uv, ir, mass spectroscopy, and elemental analysis. Results were consistent with the reaction: Further ozonolysis cleaved the 2,3 double bond. Reaction of NADH with ozone resulted in analogous reactions. The adenine moiety was resistant to ozonolysis, but this reaction was pH dependent, being greater at neutral and alkaline pH.
Excellent biocompatibility of semiconductor quantum dots encased in multifunctional poly(N-isopropylacrylamide) nanoreservoirs and nuclear specific labeling of growing neurons

Quantum dots (QDs) have received attention for labeling biomolecules; however, toxicity of these nanostructures in the intracellular environment has prevented a biomedical breakthrough. Here we report biocompatibility of a QD based multifunctional system on neuronal cells. Moreover, the designed nanostructures bind with high affinity in the cell nucleus. Nucleus specific binding and enhanced biocompatibility, coupled with no deleterious effects on neurite outgrowth, even at high dosages (500 μg/ml sphere conc.) suggest increased therapeutic potential of this system for specific targeting followed by controlled release of drugs in treating neurodegenerative disorders.
Measurement of cell-monolayer adhesion in cells transfected with N-CAM cDNAs

To measure the adhesion of cells expressing the neural cell adhesion molecule N-CAM, mouse Lmtk- fibroblast cells were transfected by a calcium phosphate precipitation technique with eucaryotic expression vectors encoding N-CAM polypeptides. We obtained cell lines expressing the 140-kDa transmembrane isoform of N-CAM at high levels by several rounds of selection by fluorescence-activated cell sorting and compared the adhesion of these cells to that of untransfected cells using a centrifugal removal assay that measures the centrifugal force required to remove radiolabeled probe cells from a cell monolayer. The adhesion of cells prepared from embryonic chicken neural retinas also was examined. Retinal probe cells remained associated with a retinal cell monolayer with an adhesive force of approximately 5 x 10(-6) dyn/cell, and this force was not reduced by treatment with specific anti-N-CAM antibody fragments. Transfected and untransfected mouse L cells each were dislodged from transfected cell monolayers with a removal force of 5 x 10(-5) dyn/cell and thus did not differ in their adhesion. These results support the hypothesis that N-CAM-mediated homophilic adhesion in retinal cells and transfected fibroblasts is relatively weak and that the major adhesive interaction involved in N-CAM-mediated cell-cell adhesion is heterophilic.
Phthalocyanine 4 (Pc 4) photodynamic therapy of human OVCAR-3 tumor xenografts.

Photodynamic therapy (PDT) is a cancer treatment modality utilizing a photosensitizer, light and oxygen. Photodynamic therapy with Photofrin has been approved by the U.S. Food and Drug Administration for treatment of advanced esophageal and early lung cancer. Because of certain drawbacks associated with the use of Photofrin, there is a need to identify new photosensitizers for human use. The photosensitizer Pc 4 (HOSiPc-OSi[CH3]2[CH2]3N[CH3]2) has yielded promising PDT effects in many in vitro and in vivo systems. The aim of this study was to assess the usefulness of Pc 4 as a PDT photosensitizer for a human tumor grown as a xenograft in athymic nude mice. The ovarian epithelial carcinoma (OVCAR-3) was heterotransplanted subcutaneously in athymic nude mice. Sixty mice bearing OVCAR-3 tumors (approximately 80-130 mm3) were divided into six groups of 10 animals each, three for controls and three for treatment. The Pc 4 was given by tail vein injection, and 48 h later a 1 cm area encompassing the tumor was irradiated with light from a diode laser coupled to a fiberoptic terminating in a microlens (lambda = 672 nm, 150 J/cm2, 150 mW/cm2). Tumors of control animals receiving no treatment, light alone or Pc 4 alone continued to grow. Of animals receiving 0.4 mg/kg Pc 4 and light, one (10%) had a complete response and was cured (no regrowth up to 90 days post-PDT), while all others (90%) had a partial response and were delayed in regrowth. Of animals receiving 0.6 mg/kg Pc 4 and light, eight (80%) had a complete response, and two of these were cured. Of animals receiving 1.0 mg/kg Pc 4 and light, six (60%) had a complete response, and two of these were cured. In additional experiments, tumors from animals treated with Pc 4 (1 mg/kg) and light were removed 15, 30, 60 and 180 min post-PDT, and from these tumors DNA and protein were extracted. Agarose gel electrophoresis revealed the presence of apoptotic DNA fragmentation as early as 15 min post-PDT. Western blotting showed the cleavage of the 116 kDa native poly(ADP-ribose) polymerase (PARP) into fragments of approximately 90 kDa, another indication of apoptosis, and the presence of p21/WAF1/CIP1 (p21) in all PDT-treated tumors. These changes did not occur in control tumors. Pc 4 appears to be an effective photosensitizer for PDT of human tumors grown as xenografts in nude mice. Early apoptosis, as revealed by PARP cleavage, DNA fragmentation and p21 overexpression, may be responsible for the excellent Pc 4-PDT response. Clinical trials of Pc 4-PDT are warranted.
The efficacy of postoperative perineural infusion of bupivacaine and clonidine after lower extremity amputation in preventing phantom limb and stump pain.

We report the efficacy of perioperative infusion of clonidine and bupivacaine for above-knee amputation in a patient with a history of phantom limb pain in the same extremity after a previous below-knee amputation. The patient underwent general anesthesia. Before transection, the sciatic nerve was infiltrated with 0.25% bupivacaine 5 mL and clonidine 50 μg. After the nerve was severed, a 20-gauge epidural catheter was inserted into the nerve sheath and externalized laterally through a separate skin incision. Before closure, 0.25% bupivacaine 10 mL and clonidine 50 μg was injected, and 0.1% bupivacaine and clonidine two μg/mL was infused at 10 mL/h for the first 96 hours postoperatively. There were no incidents of hypotension, bradycardia, or sedation during the infusion period. The mean postoperative pain score (from 0 to 10) for 96 hours was 1.2 ± 0.7. The patient required a total of 10 mg of oxycodone postoperatively. The patient did not report either stump or phantom pain for 12 months after surgery.
Globalization and North—South Inequality, 1870—2000: A Factor for Convergence, Divergence or Both?

Analysts continue to debate the nature of the relationship between globalization and global inequality between states, with some arguing that globalization increases inequality, others saying that ...
Predicted Outcomes in a National Sample: A Source of Comparison for Program Evaluation.

Abstract The lack of comparison groups is a common problem for researchers conducting evaluations of small, specialized programs. When conventional comparison groups are not available, the authors suggest a possible alternative approach which involves: (a) locating a sub-group in a national study for whom relevant variables have been measured; (b) generating a statistical model which predicts the outcome of interest in the national data; and (c) applying the predictive model to program data, in order to estimate outcomes in the absence of progam intervention. The authors illustrate this new application by presenting the results of an analysis of data from Project Talent, a national manpower study, and discuss its application to the evaluation of a medical training program in New York City.
Transport coefficients and Lyapunov exponents

Abstract After introducing the viscosity of a fluid macroscopically and microscopically as well as the Lyapunov exponents of the fluid, the SLLOD equations of motion with a Gaussian thermostat and Lees-Edwards boundary conditions for the motion of particles in a sheared fluid in a nonequilibrium stationary state are discussed. An explicit expression, due to Posch and Hoover, for the viscosity is then derived in terms of the sum of all Lyapunov exponents, illustrating the direct connection between irreversible entropy production (due to viscous heating) and phase space contraction. A symmetry of the Lyapunov spectrum allows this expression to be reduced to a simple relation between the viscosity and the two maximal Lyapunov exponents of the fluid in the stationary state. A numerical check of this relation for fluids consisting of 108 and 864 particles is presented. Finally, similar relations for other transport coefficients and the connection with other work are discussed.
Microsomal metabolism of carbon tetrachloride: participation of pyridine nucleotide synergism.

The role of pyridine nucleotide synergism in CCl4 metabolism was evaluated for its potential contribution to enhanced lipid peroxidation. Male Sprague-Dawley rats receiving either no treatment (control) or treatment with phenobarbital (PB) were used to prepare hepatic microsomes. Metabolism was evaluated in the presence and absence of an NADPH generator system and in the presence and absence of NADH. The generator system produced a greater extent of metabolism for both control and PB microsomes. NADH-catalyzed CCl4 metabolism occurred to a similar extent in control and PB microsomes, amounting to 9–10% and 5–6% of the NADPH rate in control and PB microsomes, respectively. Synergism by NADH occurred at the lowest concentrations of NADPH, apparently decreasing the Km for NADPH and having little effect on the Vmax. Addition of NAD+ produced synergism, as did the addition of 5′AMP, an inhibitor of nucleotide pyrophosphatase. Thus, the synergistic increase in CCl4 metabolism produced by NADH may occur in part from an increased availability of NADPH, as a result of decreased degradation, rather than by electron donation from NADH.
Management of Cervical Facet Dislocations

Optimal management of unilateral and bilateral cervical facet fractures remains controversial. This article explores the evaluation and treatment options available, focusing on the controversy surrounding prereduction magnetic resonance imaging (MRI) and the choice of surgical approach. In addition, the authors propose a treatment protocol for cervical facet dislocations. Acute disk herniation and disruption is highly prevalent in traumatic cervical facet injury. Some authors maintain the necessity of prereduction MRI to identify those at risk for further prolapse of a herniated disk during closed reduction maneuvers. Others maintain the risk of neurologic deterioration is small in the appropriate patient. To date, no permanent neurological worsening has ever been documented following a closed cervical spine reduction in an awake, cooperative patient. The need for open internal fixation following reduction is widely accepted; however, surgical treatment options are diverse and include anterior, posterior, and combined approaches. Closed reduction of cervical facet dislocations without baseline MRI is appropriate in the awake, cooperative patient. Postreduction MRI is essential in identifying herniated disks and tailoring a surgical approach. An anterior approach is classically employed with a concurrent disk herniation, although a combined anterior and posterior approach is sometimes chosen due to the severity of ligamentous disruption associated with bilateral cervical facet dislocations.
Identifying Personality-Related Problems in Living: The Multi-Context Problems Checklist

The Multi-Context Problems Checklist (MCPC) is a new measure of personality-related problems designed for a young adult population. Previously published problem checklists either have little supporting empirical documentation to support their validity or focus on specific kinds of difficulties in specific contexts (e.g., interpersonal, close relationships). The MCPC is a straightforward and easy-to-use instrument covering 6 domains of functioning, takes about 5 minutes to complete, and is intended for young adults ages 18 to 29. Psychometric data are presented in 3 studies. In Study 1, correlations with self- and observer ratings showed scores on the MCPC to be consensually valid, and associations with measures of well-being and personality provided evidence of construct validity. Study 2 added to these findings by identifying specific personality-related problems associated with each pole of each trait of the five-factor model of personality, demonstrating moderate to high test-retest reliability of problem endorsements, and showing strong associations with measures of psychological distress. Study 3 indicated that the MCPC is sufficiently sensitive to capture more frequent problem reporting among individuals undergoing counseling. Problem-trait associations are related to a broader literature on global personality dimensions and psychosocial outcomes at the individual, interpersonal, and social and institutional levels. The MCPC deserves attention from both researchers and clinicians who are interested in assessing personality-related problems in living.
Developing an institution-based assessment of resident communication and interpersonal skills

AbstractPurposeThe authors describe the development and validation of an institution-wide, cross-specialty assessment of residents' communication and interpersonal skills, including related components of patient care and professionalism.MethodResidency program faculty, the department of medical educ
Combined effects of fast treadmill walking and functional electrical stimulation on post-stroke gait

Gait dysfunctions are highly prevalent in individuals post-stroke and affect multiple lower extremity joints. Recent evidence suggests that treadmill walking at faster than self-selected speeds can help improve post-stroke gait impairments. Also, the combination of functional electrical stimulation (FES) and treadmill training has emerged as a promising post-stroke gait rehabilitation intervention. However, the differential effects of combining FES with treadmill walking at the fast versus a slower, self-selected speed have not been compared previously. In this study, we compared the immediate effects on gait while post-stroke individuals walked on a treadmill at their self-selected speed without FES (SS), at the SS speed with FES (SS-FES), at the fastest speed they are capable of attaining (FAST), and at the FAST speed with FES (FAST-FES). During SS-FES and FAST-FES, FES was delivered to paretic ankle plantarflexors during terminal stance and to paretic dorsiflexors during swing phase. Our results showed improvements in peak anterior ground reaction force (AGRF) and trailing limb angle during walking at FAST versus SS. FAST-FES versus SS-FES resulted in greater peak AGRF, trailing limb angle, and swing phase knee flexion. FAST-FES resulted in further increase in peak AGRF compared to FAST. We posit that the enhancement of multiple aspects of post-stroke gait during FAST-FES suggest that FAST-FES may have potential as a post-stroke gait rehabilitation intervention.
Novel metal/semiconductor nanocomposite and superlattice materials and devices for thermoelectrics

Efficiency of thermoelectric materials is generally discussed in terms of the dimensionless figure-of-merit, ZT = S 2 σT/κ, Many researchers have found that it is possible to reduce the lattice thermal conductivity by incorporating nanostructures (i.e. nanoparticles or heterobarriers) into materials, thereby scattering phonons. At the same time, it has been theoretically predicted and experimentally demonstrated that barriers can be used to "filter" the distribution of carriers which contribute to conduction. By doing so, it is possible to significantly increase the Seebeck coefficient while only modestly decreasing the electrical conductivity. As a result of this energy-dependent scattering of carriers, the thermoelectric power factor is increased. We present theoretical and experimental results for metal/semiconductor nanocomposites consisting of metallic rareearth- group V nanoparticles within III-V semiconductors (e.g. ErAs:InGaAlAs) demonstrating both an increase in thermoelectric power factor and a decrease in thermal conductivity, resulting in a large figure of merit. We also discuss metal/semiconductor superlattices made of lattice-matched nitride materials for electron filtering and the prospects of these materials for efficient thermoelectrics, especially at high temperatures. Finally, we will discuss both various synthesis techniques for these materials, including the prospects for bulk growth, and also devices fabricated from these materials.
Device and circuit simulation of quantum electronic devices

Quantum electronic devices such as resonant tunneling diodes and transistors are now beginning to be used in ultrafast and compact circuit designs. These devices exhibit negative differential resistance (NDR) and/or negative transconductance in their I-V characteristics and have active dimensions of a few nanometers. Since the conventional drift-diffusion approximation is not valid for simulation of device behavior at this microscopic scale, quantum simulation models based on the Schrodinger equation are required to accurately predict the behavior of the device. However, these models are too slow for circuit simulation. This paper describes a modeling scheme that maintains the accuracy of the quantum simulation while achieving satisfactory speed for circuit simulation, and is applicable to a wide range of two and three terminal resonant tunneling devices and may also be extended to future scaled-down MOS and bipolar devices. A self-consistent solution of the Poisson and the Schrodinger equations for various bias points is used to build up tables of conductances, capacitances and other parameters. Table-lookup methods are then used during circuit simulation. Convergence techniques have been developed to overcome the problems caused by the NDR characteristics and the lookup-table model in simulation. While implementation details are presented for a resonant tunneling transistor (RTT), models for several other quantum electronic devices have also been implemented in NDR-SPICE. >
Glutamine: More Evidence, More Promise

Pancreatitis is a nasty disease. It attacks young and old alike, often occurring without warning signs. Fortunately, most cases are rather mild and resolve spontaneously. However, a subpopulation of patients develops life-threatening disease, spending a month (usually longer) in the hospital with a large part of the stay spent in the intensive care unit (ICU). The disease poses several management problems for the clinician. First, the patients are hypermetabolic, rapidly immobilizing lean tissues in an aggressive catabolic state. Second, infectious complications—both respiratory and intra-abdominal (infected pancreatic tissue, retroperitoneal abscesses, etc)—present a difficult management problem requiring aggressive ICU care, antibiotic (often multiple) therapy, respiratory support, and frequently, surgical debridement. Although enteral access can be safely obtained during laparotomy and successfully used for postoperative enteral nutrition, 1 operative therapy occurs weeks rather than days into the course of the disease process. During the acute preoperative phase, a massive retroperitoneal phlegmon impairs gastric emptying, precluding any form of intragastric nutrition support. The inflamed, edematous duodenum usually makes advancement of a nasojejunal tube technically impossible. Hence, in addition to hemodynamic, respiratory, and other critical care therapies, parenteral nutrition provides the primary method of nutrition support for these patients, often for prolonged periods of time. Even if enteral access is obtained at laparotomy, advancement of jejunostomy feedings is often slow, requiring a very gradual transition from parenteral to enteral therapy.
Nitric oxide mediates seasonal muscle potentiation in clam gills

The physiology and timing of gill muscle potentiation were explored in the clam Mercenaria mercenaria. When isolated demibranchs were exposed twice (with an intervening wash) to the same concentration of 5-hydroxytryptamine, the second contraction was larger than the first. This potentiation was seasonal: it was present from November through June, and absent from July through October. Potentiation was not affected by the geographic origin of the clams, nor by their acclimation temperature. Potentiation was inhibited by the nitric oxide synthase (NOS) inhibitor L-NAME and mimicked by the nitric oxide (NO) donor DEANO. During the season of potentiation, immunoreactive NOS appeared in the gill muscles and the gill filament epithelium, but during the off-season, the enzyme occurred at the base of the gill filaments. Potentiation was inhibited by ODQ, which inhibits soluble guanylate cyclase (sGC), and it was mimicked by dibutyryl-cGMP, an analog of cyclic GMP (cGMP). Moreover, potentiation was inhibited by the protein kinase G (PKG) inhibitor Rp-8-CPT-cGMPS. During the season of potentiation, immunoreactive sGC was concentrated in the gill muscles and the gill filament epithelium; but during the off-season, immunoreactive sGC was found in the gill filament epithelium. These data suggest that the potentiation of gill muscle is mediated by a NO/cGMP/PKG signaling pathway.
Asthma and the risk of panic attacks among adults in the community.

Objective. The study was designed to determine the association between self-reported asthma and the risk, persistence and severity of panic attacks among adults in the community.Method. Data were drawn from waves 1 and 2 of the Baltimore site of the Epidemiologic Catchment Area (ECA) Study (N=2768), which included self-report information on asthma, treatment for asthma and panic attacks in 1981 and 1982. Multiple logistic regression analyses were used to calculate odds ratios comparing the prevalence of panic attack at baseline and follow-up by asthma status at baseline. Linear regression analyses were used to examine the relationship between self-reported asthma status and the number of panic symptoms during a panic attack.Results. Self-report asthma was associated with significantly increased likelihood of having panic attacks at baseline (1981) (12·1% v. 7·3%, P<0·05) and of having panic attacks at both baseline and follow-up (15·9% v. 7·3%, P<0·05), compared to those without asthma at baseline. Adults receiving treatment for asthma at baseline had an increased risk of incident panic attacks at follow-up (OR=2·65 (1·11, 6·34)) and at baseline and follow-up (OR=5.88 (2·21, 15.62)), though untreated asthma did not appear to increase risk of incident panic at follow-up. Similarly, the risk of panic at follow-up was not increased among those with asthma at baseline who did not report asthma at follow-up, compared with those without asthma at baseline. Treated asthma was associated with having more panic symptoms during panic attacks, compared to those without asthma (P<0·001).Conclusion. These findings are consistent with and extend previous results suggesting that self-reported asthma is associated with an increased risk of panic attacks among adults in the general population, and that there is a consistent relation between severity and persistence of asthma and panic attacks. The lack of association between remitted asthma and panic attack may reveal a need for further research to determine whether asthma may be a causal risk factor for panic attacks, or whether a third factor (genetic or environmental) may be associated with increased risk of the co-occurrence of asthma and panic attacks. Replication of these results using alternative methodology with corroborative data on asthma and panic attacks is needed next.
Antimicrobial nanomaterials for water disinfection and microbial control: Potential applications and implications

The challenge to achieve appropriate disinfection without forming harmful disinfection byproducts by conventional chemical disinfectants, as well as the growing demand for decentralized or point-of-use water treatment and recycling systems calls for new technologies for efficient disinfection and microbial control. Several natural and engineered nanomaterials have demonstrated strong antimicrobial properties through diverse mechanisms including photocatalytic production of reactive oxygen species that damage cell components and viruses (e.g. TiO2, ZnO and fullerol), compromising the bacterial cell envelope (e.g. peptides, chitosan, carboxyfullerene, carbon nanotubes, ZnO and silver nanoparticles (nAg)), interruption of energy transduction (e.g. nAg and aqueous fullerene nanoparticles (nC(60))), and inhibition of enzyme activity and DNA synthesis (e.g. chitosan). Although some nanomaterials have been used as antimicrobial agents in consumer products including home purification systems as antimicrobial agents, their potential for disinfection or microbial control in system level water treatment has not been carefully evaluated. This paper reviews the antimicrobial mechanisms of several nanoparticles, discusses their merits, limitations and applicability for water disinfection and biofouling control, and highlights research needs to utilize novel nanomaterials for water treatment applications.
Elastohydrodynamic Analysis of an Elastomeric Hydraulic Rod Seal During Fully Transient Operation

A soft elastohydrodynamic model of a reciprocating elastomeric hydraulic rod seal has been developed. It consists of coupled fluid mechanics, contact mechanics, and deformation analyses. The model has been used to analyze a U-cup lip seal in an injection molding application with a time-varying sealed pressure and rod velocity. Results include the histories of the hydraulic fluid flow rate, fluid transport, mean shear stress on rod, sealing zone length, and friction force on rod, as well as distributions of the fluid pressure, film thickness, and contact pressure.
A simplified interface for concurrent processing

Teaching the concepts of concurrency is a task requiring an understanding of how the operating system allocates resources for the processes and how concurrent processes may share data. The difficulty of trying to understand the asynchronous execution behavior of processes is compounded by the need to understand the syntax and required parameters for making the system calls. Providing wrappers for system calls that make move intuitive function calls to allocate and manage resources can help students understand the issues involved with shared memory multiprocessing and message passing systems without having to understand the details of the syntax associated with making the system calls. This paper describes a library of C functions, the Parallel Library, that can be used to introduce the concepts of shared memory multiprocessing, message passing, and related synchronization issues, but hide the details of the actual system calls used to implement them. This library has been successfully used to introduce students with minimal operating system knowledge and programming skills to the ideas associated with concurrent processing.
Cultural standing in expression of opinion

This article explores an underappreciated pragmatic constraint on the expression of opinions: When expressing an opinion on a topic that has been previously discussed, a speaker should correctly indicate the cultural standing of that view in the relevant opinion community. This Bakhtinian approach to discourse analysis is contrasted with conversation analysis, politeness theory (Brown & Levinson 1987), and analysis of epistemic modality. Finally, indicators of four points on the cultural standing continuum (highly controversial, debatable, common opinion, and taken for granted) are illustrated with examples from American English usage. (Opinion display, discourse analysis, argumentation, hedges, modality, welfare discourse)* “. . . Prose discourse—in any of its forms, quotidian, rhetorical, scholarly—cannot fail to be oriented toward the ‘already uttered,’ the ‘already known,’ the ‘common opinion’ and so forth.” Mikhail Bakhtin, “Discourse in the Novel” (1981:279)
Exploiting Temporal Geometry for Moving Camera Background Subtraction

In this paper, we introduce a new method for background subtraction for freely moving cameras and arbitrary scene geometry. Instead of relying on frame-to-frame estimation, we simultaneously estimate the epipolar geometries induced by a moving camera in a temporally consistent manner for a number of frames using the temporal fundamental matrix (TFM). The TFM is robustly estimated from the track lets generated by dense point tracking and used to compute the probability of each track let belonging to the background. In order to ensure the color, spatial, and temporal consistencies of track let labeling, we minimize spatiotemporal labeling cost in locality of track lets. Extensive experiments with challenging videos show that the proposed method is comparable and, in most cases, outperforms the state-of-the-art.
Restoration of Cough Reflex in Lung Transplant Recipients

Background Lung transplantation involves vagal nerve interruption resulting in sensory airway denervation and impairment of the cough reflex. Following lung transplantation, it is unclear whether functional recovery of the cough reflex occurs over time. Our objective was to evaluate the afferent limb of the cough reflex in lung transplant recipients. Methods The assessment of cough reflex involved upper airway anesthesia, conscious sedation, and fiberoptic bronchoscopy; the biopsy forceps and a 5% dextrose solution were applied through the bronchoscope to the airway mucosa at the main carina, proximal and distal to the anastomosis. A cross-sectional group of seven subjects underwent a single assessment, while eight subjects in a longitudinal group underwent assessment at 1.5 and 12 months. Cough frequency was determined by counting the number of audible coughs and abdominal muscle contractions measured with a surface electromyogram recorder. The airway anastomosis from deceased subjects in the longitudinal group was examined for nerves. Results All seven subjects from the cross-sectional group demonstrated a similar cough frequency after mechanical and chemical irritation of all airway sites. All subjects in the longitudinal group who were evaluated at 1.5 weeks had a cough response at all sites except distal to the anastomosis. Twelve months after transplantation, cough was present at all sites. Immunohistochemical staining for protein gene product 9.5, low-affinity neurotrophin, and vanilloid receptors demonstrated nerves in subepithelial regions proximal and distal to the airway anastomosis. Conclusion In human lung transplant recipients, recovery of the cough reflex was noted 12 months after lung transplantation.
The Impact of the Self-Directed Search Form R Internet Version on Counselor-Free Career Exploration

College students (N = 125) volunteered to participate in a study of career exploratory behavior. Participants were randomly assigned to complete the Self-Directed Search Form R (SDS: R) Internet ve...
Image reconstruction in optoacoustic tomography accounting for frequency-dependent attenuation

In this work, we show how to incorporate attenuation into the optoacoustic tomography (OAT) imaging equation and develop a strategy for compensating for this attenuation during image reconstruction. In OAT, one exposes a sample to pulses of electromagnetic radiation that cause small amounts of heating in the specimen. The heating engenders thermal expansion which, in turn, gives rise to acoustic waves. The resulting acoustic pressure signal is generally measured by transducers arrayed around the object, and these data may be used to reconstruct images of the original electromagnetic absorption. Frequency-dependent absorption of the acoustic waves can lead to blurring and distortion in reconstructed images. We show that in the temporal frequency domain, the optoacoustic wave equation incorporating attenuation is equivalent to the inhomogeneous Helmholtz equation with a complex wave number. While some work has been done in other fields on directly solving Helmholtz equations with complex wave numbers, these are generally computationally intensive numerical approaches. We pursue a different approach, deriving an integral equation that relates the temporal optoacoustic signal at a given transducer location in the presence of attenuation to the ideal signal that would have been obtained in the absence of attenuation. This equation is readily discretized and the resulting linear system of equations involves a matrix that need only be inverted once, at which point the inverse can be used to correct all of the measured time signals prior to reconstruction by conventional methods.
CTH03-5: Optimal Resource Allocation via Geometric Programming for OFDM Broadcast and Multiple Access Channels

For multi-user orthogonal frequency division multiplexing (OFDM) systems, efficient optimal rate and power allocation algorithms are presented via geometric programming (GP), a special form of convex optimization problem for which very efficient interior point methods exist. Both multiple access channel (MAC) and broadcast channel (BC) are considered and the following two resource allocation problems are of main interest: weighted sum-rate maximization (WSRmax) and weighted sum-power minimization (WSPmin). Utilizing degradedness of BC on each tone, WSRmax and WSPmin in the BC can be all formulated as GP. By using the duality relation between MAC and BC, it is shown that the above resource allocation problems in the MAC can be converted into GP problems as well. This GP perspective of multi-user OFDM resource allocation problems provides numerical efficiency as well as strong scalability for any additional constraints of GP form.