cssi/SciSciGPT-SciSciNet huggingface dataset:
Characteristics of the applicant pool to vascular surgery residency programs

Objective Based on the significant number of unfilled vascular fellowship positions in the 2004 National Residency Matching Program (NRMP) and the perception of program directors that the quality of candidates is deteriorating, the Issues Committee of the Association of Program Directors in Vascular Surgery (APDVS) explored the characteristics and the trend of the applicant pool to develop recommendations for improvement. Methods The Electronic Residency Application Service (ERAS) database was queried for the total number of applicants, medical school, gender, and age, among other characteristics. The vascular surgery applicant pool was compared to the applicant pool for general surgery; the applicant pool for all fellowship positions, including a variety of medical subspecialties; the applicant pool for all residency positions; and the applicant pool for colorectal surgery, the only other surgical subspecialty participating in ERAS in 2004. NRMP data was used prior to 2004. The χ 2 test was used for statistical analysis, with significance set at P Results In the 2004 match for June 2005 positions, there were 100 applicants for 110 first-year vascular surgery positions in 90 programs. In 1989, there were 123 applicants for 56 positions in 49 programs. In 1989, 55% of vascular surgery applicants did not match; whereas in 2004, only 7% were unmatched. Although the overall number of vascular surgery applicants has remained relatively stable, the number of United States applicants has decreased from 89% in 1990 to 68% in 2004 ( P Conclusions The data from the ERAS database support the impression held by many in the vascular surgery education community that the size of the applicant pool for vascular surgery fellowship positions has remained stagnant, while the number of positions has significantly increased. Strategies to increase the size and quality of the applicant pool are needed.
A Helmet-Mounted Virtual Environment Display System

This paper presents a simple, inexpensive design of a helmet-mounted color display system. The sys-tem can be mounted on a variety of helmets, including a bicycle helmet. Color LCD displays are used. The optical decisions are discussed as well as limitations of the system. The entire helmet-mounted system cost about $1000 to build using off the shelf, readily available hardware, with the exception of the Polhemus tracking device. Issues of depth perception are discussed. Predictive tracking is implemented using a simple Kalman filter.
Pirmenol determination by high-performance liquid chromatography.

A method for the determination of pirmenol in serum is presented in this paper. The method consists of extraction of pirmenol and chlorodisopyramide (internal standard) from serum at an alkaline pH using methylene chloride. The organic extract was analysed using high-performance liquid chromatography. The mobile phase consisted of 0.01 M K2HPO4 (pH 2.4)—acetonitrile (94:6, v/v) delivered at ambient temperature and 2 ml/min through a 25 cm × 0.4 mm C18 reversed-phase column. Detection of the compounds of interest was achieved at 210 nm. The analytical method demonstrated low intra- and inter-assay variation. During the analysis of patient samples and a therapeutic drug mixture test serum, no substances that interfered with pirmenol detection were found. The method is shown to be stable, accurate, selective and sensitive enough to be utilized for the analysis of multiple samples such as may be encountered in clinical or research situations.
Characteristics of worker accidents on NYSDOT construction projects.

This study identifies major construction accident types that injure workers, both within the work area as well as outside the work area, in order to suggest cost-effective safety measures to protect these workers. A detailed analysis of work zone accidents involving 36 fatalities and 3,055 severe injuries to construction workers on New York Sate Department of Transportation construction projects from 1990 to 2001 was conducted. From this analysis, five accident types that accounted for 96% of the fatal accidents, almost 63% of the hospital-level injury accidents, and nearly 91% of the total costs were established. These accident types were: struck/pinned by large equipment; trip or fall (elevated); contact with electrical or gas utility; struck by moving/falling load; and crane/lift device failure. These construction work area accidents had a total cost of $133.8 million. Traffic accidents that involve contractors' employers were also examined. Statistical analysis established that five traffic accident types were responsible for nearly 86% of the fatal accidents, nearly 70% of the hospital-level and minor injury accidents, and 79.4% ($45.4 million) of the total accident costs. These five traffic accident types were: work space intrusion, worker struck by vehicle inside work space; flagger struck by vehicle; worker struck by vehicle entering/exiting work space; and construction equipment struck by vehicle inside work space. For each type of accident, potential prevention measures are suggested. This ranking of accident types can help highway contractors and owner agencies identify cost-effective remedial actions.
H+CO2→OH+CO: Yield versus HI photolysls wavelength and OH rotational distributions under single-collision conditions and with CO2HI complexes

Abstract The title reaction was studied under single-collision conditions using 227–285 nm HI photolysis. A large decrease in the OH yield was observed as the photolysis wavelength was increased. Rotational distributions were obtained at 227, 239, 251, 263 and 280 nm. Similar yield versus wavelength data were obtained for CO2HI complexes (233–263 nm). The OH rotational distribution obtained using 239 nm CO2HI photolysis differs markedly from its single-collision H+CO2 counterpart.
HIGH-PRESSURE CO OXIDATION ON PT(111) MONITORED WITH INFRARED-VISIBLE SUM FREQUENCY GENERATION (SFG)

Catalytic CO oxidation on Pt(111) to CO2 was studied under atmospheric pressures of CO and O2 and at various temperatures. Surface vibrational spectroscopy by sum frequency generation was used to probe the surface species, while the reaction rate and gas composition were simultaneously monitored by gas chromatography. Correlation between the turnover rates and the surface coverage of various CO species were utilized to identify the active CO species in the reaction. Ignition, above which the reaction becomes self-sustained, divides the reaction into two reactivity regimes. Below ignition, atop bonded CO appears as the major species on the surface, but the reaction rate is inversely proportional to the surface coverage of this species, indicating that it is not the active species but rather an inhibitor. The observed activation energy for the reaction in this regime suggests that desorption of atop CO is the rate-limiting step in the reaction. Above ignition, the atop CO becomes hardly detectable and the a...
Experimental response functions spanning the gamma-ray energy range of 123.6 keV to 11.67 MeV and response matrix generation for bismuth germanate scintillation detectors

Abstract We report experimental response functions at 12 gamma-ray energies over the range of 123.6 keV to 11.67 MeV for a 2.54 cm diameter × 2.54 cm long and a 7.62 cm diameter × 7.62 cm long bismuth germanate scintillation detector. The measurements were made at, or corrected to correspond to, source-to-detector distances of 100 cm. The resolutions of the detectors at a gamma-ray energy of 661.6 keV are 11.6% for the small detector and 13.0% for the large detector. We also present an interpolation method for generating a response function at any gamma-ray energy in the range of 123.6 keV to 11.67 MeV for either scintillator using the experimental response functions. Additionally, this method is used in constructing response matrices for unfolding gamma-ray pulse-height distributions acquired with the detectors. A computer code written in FORTRAN-77 generates the response matrices.
Electronic structure of lithium beryllium hydride.

Hartree-Fock band-structure and cluster calculations have been performed to study the electronic structure of ${\mathrm{LiBeH}}_{3}$ in the cubic perovskite structure. The total energy, bulk modulus, band structure, density of states, charge densities, and x-ray structure factors are obtained. The energy minimum has been found for a lattice constant of 3.3 A\r{} in the band calculation (3.2 A\r{} in the cluster calculation), by far larger than the 2.545 A\r{} proposed by Overhauser for a fcc superstructure of ${\mathrm{LiBeH}}_{3}$ and used in a previous augmented-plane-wave calculation. The hydride is found to be an insulator. The essential features of the band structure can be understood in terms of the energy band of the ${\mathrm{BeH}}_{2}$ planes present in the perovskite structure. A metal, and possible high-temperature superconductivity often envisioned for metallic hydrogen, could be obtained if beryllium is replaced by boron.
Effect of sodium fluoride on catecholamine concentrations in tissues from developing rats.

Abstract Catecholamine concentrations were determined in newborn rats treated with large doses of sodium fluoride (10 mg/kg) for varying periods of time. When fluoride treatment was started on day 5 after birth and continued daily to day 35 of life, decreased catecholamine concentrations were observed in the heart, kidney and liver. Daily fluoride treatment from day 15 through day 35 after birth failed to influence cardiac, kidney or liver catecholamines. Neither treatment regimen affected adrenal epinephrine or norepinephrine levels. These experiments suggest that fluoride may be affecting catecholamine biosynthetic mechanisms which are developing during days 5–10 of life.
Studies of parkinsonian movement: 2. Initiation of fast voluntary eye movement during postural disturbance.

Delay in initiation of rapid voluntary eye movements (saccades) in brady-kinetic parkinsonian patients and normal subjects was recorded with and without postural disturbances (rotation of the body and head). Parkinsonian patients as a group exhibited longer delays in the initiation of saccades. The delay increased during postural disturbance in both the patients and the normal subjects. The study failed to substantiate the hypothesis that postural reflexes interfere with the initiation of voluntary movement in Parkinsonism.
Improvement of dose distributions in abutment regions of intensity modulated radiation therapy and electron fields

In recent years, intensity modulated radiation therapy(IMRT) is used to radiate tumors that are in close proximity to vital organs. Targets consisting of a deep-seated region followed by a superficial one may be treated with abutting photon and electron fields. However, no systematic study regarding matching of IMRT and electron beams was reported. In this work, a study of dose distributions in the abutment region between tomographic and step-and-shoot IMRT and electron fields was carried out. A method that significantly improves dose homogeneity between abutting tomographic IMRT and electron fields was developed and tested. In this method, a target region that is covered by IMRT was extended into the superficial target area by ∼2.0 cm. The length and shape of IMRT target extension was chosen such that high isodose lines bent away from the region treated by the electrons. This reduced the magnitude of hot spots caused by the “bulging effect” of electron field penumbra. To account for the uncertainties in positioning of the IMRT and electron fields, electron field penumbra was modified using conventional (photon)multileaf collimator(MLC). The electron beam was delivered in two steps: half of the dose delivered with MLCs in retracted position and another half with MLCs extended to the edge of electron field that abuts tomographic IMRT field. The experimental testing of this method using film dosimetry has demonstrated that the magnitude of the hot spots was reduced from ∼45% to ∼5% of the prescription dose. When an error of ±1.5 mm in field positioning was introduced, the dose inhomogeneity in the abutment region did not exceed ±15% of the prescription dose. With step-and-shoot IMRT, the most homogeneous dose distribution was achieved when there was a 3 mm gap between the IMRT and electron fields.
Digestive efficiencies of ex situ and in situ West Indian manatees (Trichechus manatus latirostris)

AbstractDigestive efficiencies (Dm) of ex situ and in situ manatees (Trichechus manatus latirostris) were, for the first time, assessed using manganese (Mn2+) as a naturally occurring marker. The Dm of ex situ manatees determined using [Mn2+] did not differ significantly from the Dm assessed using lignin, supporting the efficacy of the manganese approach. Gastrointestinal tract samples, obtained from recently dead animals, showed [Mn2+] concentrations were lowest in the stomach and remained low in the duodenum and small intestine but increased in the cecum, colon, and rectum, consistent with colonic digestion and absorption. In situ manatees consuming marine vegetation had significantly lower Dm (mean ± SE, ; ) than did in situ manatees consuming freshwater vegetation (; ), which in turn had significantly lower values than did ex situ manatees consuming lettuce (; ). In situ manatees eating seagrasses had significantly higher Dm than did long-term ex situ animals consuming seagrass for short periods of ti...
Building an environment model using depth information

The environment model's volumetric level, where information about free and occupied space is represented explicitly, is considered. At this model level, updating operations use raw sensory data from range sensors or processed data from any stereo or other depth recovery technique. In addition, this type of model can be used directly by path planning and navigation modules as well as for object recognition and manipulation modules. A system that uses the sensor-built model mode, in which there is initially little or no knowledge available about the domain and a model is incrementally constructed using the information provided by a sensor, is demonstrated. This mode of operation makes it possible to deal with unknown or dynamic environments. >
Pseudotumors and Reactive Lesions

This article discusses reactive or degenerative processes in bone or periosteal soft tissue that occasionally masquerade as neoplasms. Presentation of the clinical, radiologic, and pathologic features of these processes is provided with an emphasis on the avoidance of overdiagnosis. Clinical, radiologic, and pathologic features of pseudotumors are presented in detail. This article approaches these tumor-like lesions in 2 categories: (1) those in the soft tissue next to bone and (2) those inside bones from the aspect of mineralization and calcification.
Visitors to Southeastern Hawkmoth Flowers

Abstract Despite global concern for the status of animal pollinators, studies on pollination systems in the southeastern United States are disproportionately low compared to the diversity of this region. For example, sphingophilous, or hawkmoth-attracting plants, occur in the southeastern US, but confirmation is lacking for the large, long-tongued hawkmoths predicted to visit these flowers by previous researchers. Hymenocallis coronaria (Shoals Spider Lily, or Cahaba Lily), H. occidentalis (Woodland Spider Lily), Oenothera biennis (Common Evening Primrose), and O. grandiflora (Large-flowered Evening Primrose) were studied to confirm this prediction. Manduca rustica (Rustic Sphinx) was confirmed as a frequent visitor to all four plant species studied. M. sexta (Carolina Sphinx) was confirmed for three of the four plants. To determine the range of animal visitors to these plants, three of the plant species were observed during day- and night-observation periods, and total visitation was compared between the...
Reducing vulnerability to retrograde amnesia treatment: Can new memory be deactivated?

Abstract A series of six experiments examined the “deactivation” of memory as indexed by the attenuation of retrograde amnesia (RA). Experiments la-c demonstrated that a surprising and highly arousing event (a life-threatening situation) during the training-amnestic agent interval does not attenuate RA, but rather, may potentiate it. However, Experiments 2a-c demonstrated that placement in a familiar environment (the home cage) during the training-amnestic treatment interval does attenuate RA. The results of these experiments are consistent with Miller and Marlin's [16] suggestion that novel postacquisition events maintain a memory in an active state, whereas familiar postacquisition events deactivate memory and thus protect it from the amnestic effects of a hypothermia treatment.
Backside illuminated high saturation current partially depleted absorber photodetecters

A high-saturation-current, backside-illuminated In0.53Ga0.47As photodiode with a partially depleted absorber has been fabricated and tested. The 1 dB small-signal compression current was 199 mA at 1 GHz for a 100 µm diameter photodiode. The 1 dB large-signal compression current was 24 mA at 48 GHz for an 8 µm-diameter photodiode. The responsivity was 0.6 A/ W at 1.55 µm.
The average area under correlated receiver operating characteristic curves : a nonparametric approach based on generalized two-sample Wilcoxon statistics

Summary. It is well known that, when sample observations are independent, the area under the receiver operating characteristic (ROC) curve corresponds to the Wilcoxon statistics if the area is calculated by the trapezoidal rule. Correlated ROC curves arise often in medical research and have been studied by various parametric methods. On the basis of the Mann-Whitney U-statistics for clustered data proposed by Rosner and Grove, we construct an average ROC curve and derive nonparametric methods to estimate the area under the average curve for correlated ROC curves obtained from multiple readers. For the more complicated case where, in addition to multiple readers examining results on the same set of individuals, two or more diagnostic tests are involved, we derive analytic methods to compare the areas under correlated average ROC curves for these diagnostic tests. We demonstrate our methods in an example and compare our results with those obtained by other methods. The nonparametric average ROC curve and the analytic methods that we propose are easy to explain and simple to implement.
Experimental bovine coccidiosis: Control with monensin

Young Holstein-Friesian bull calves were used in a controlled experiment to evaluate the efficacy of monensin against coccidiosis. The calves were given oocysts of Eimeria bovis and/or E. zurnii. Medication was started 3 days prior to inoculation and continued during the 30-day experimental period. Oocyst shedding was quantified prior to and throughout the experiment and demonstrated that monensin at the rate of 20 or 30 g ton-1 of feed significantly reduced oocyst shedding and clinical coccidiosis. Clinical infection with E. zurnii was very difficult to establish, even when calves were treated with 20 mg dexamethasone IM on Days 12, 15, and 16 post-inoculation.
Involvement of a calcineurin/ inhibitor-1 phosphatase cascade in hippocampal long-term depression

Long-term potentiation (LTP) is a synaptic mechanism thought to be involved in learning and memory. Long-term depression (LTD), an activity-dependent decrease in synaptic efficacy, may be an equally important mechanism which permits neural networks to store information more effectively. One form of LTD that has been observed in the hippocampus requires activation of postsynaptic NMDA (N-methyl-D-aspartate) receptors, a change in postsynaptic calcium concentration, and activation of postsynaptic serine/threonine protein phosphatase 1 (PP1) or 2A (PP2A). The mechanism by which PP1 or PP2A is regulated by synaptic activity is unclear because these protein phosphatases are not directly influenced by calcium concentration. LTD induction may require activation of a more complex protein phosphatase cascade consisting of the Ca2+/calmodulin-dependent protein phosphatase, calcineurin, its phosphoprotein substrate, inhibitor-1, and PP1. We tested this hypothesis using calcineurin inhibitors as well as different forms of inhibitor-1 loaded into postsynaptic cells. Our results suggest a signalling pathway in which calcineurin dephosphorylates and inactivates inhibitor-1. This in turn increases PP1 activity and contributes to the generation of LTD.
Molecular evolution of the aldo-keto reductase gene superfamily.

The aldo-keto reductase enzymes comprise a functionally diverse gene family which catalyze the NADPH-dependant reduction of a variety of carbonyl compounds. The protein sequences of 45 members of this family were aligned and phylogenetic trees were deduced from this alignment using the neighbor-joining and Fitch algorithms. The branching order of these trees indicates that the vertebrate enzymes cluster in three groups, which have a monophyletic origin distinct from the bacterial, plant, and invertebrate enzymes. A high level of conservation was observed between the vertebrate hydroxysteroid dehydrogenase enzymes, prostaglandin F synthase, and ρ-crystallin of Xenopus laevis. We infer from the phylogenetic analysis that prostaglandin F synthase may represent a recent recruit to the eicosanoid biosynthetic pathway from the hydroxysteroid dehydrogenase pathway and furthermore that, in the context of gene recruitment, Xenopus laevisρ-crystallin may represent a shared gene.
HIGH ENERGY BEHAVIOR OF THE SM AT UNITARY GAUGE

It is shown that in an axial-vector field theory the axial-vector field is always accompanied by a spin-0 field which has negative metric. Therefore, the theory has problem of negative probability and unitarity is broken. The same results are found in a theory of charged vector fields which are coupled to two fermions whose masses are different. These results are applied to the SM. It is found that both Z and W fields contain spin-0 component. Their masses are mϕ0 = mte28.4 = 3.78 × 1014 GeV and mϕ± = mte27 = 9.31 × 1013 GeV respectively. A new perturbation theory of the SM is proposed. The propagators of Z and W fields in this new perturbation theory are derived in "unitary gauge." A minus sign is obtained in front of the scalar part of the propagators of W and Z fields. The minus sign indicates that the scalar fields have negative metric which leads to negative probability. Therefore, the unitarity of the SM is broken at about ~ 1014 GeV.
Forecast for the Physician Payment Sunshine Act: Partly to Mostly Cloudy?

The Physician Payment Sunshine Act was intended to bring greater transparency to physician–industry relationships by establishing the Open Payments database. This commentary discusses areas where d...
Keynote address: light to heavy, snail to rocket

Abstract The purpose of this address is to acknowledge several, but not all, pioneers who made a significant contribution to the science of Contact Mechanics. It also highlights the universal nature of the laws of Contact Mechanics in all branches of wheel/rail based transportation systems, and encourages the participants in their efforts to further advance an understanding of the wheel/rail interface phenomena. The address covers three major topics—problems, theories and concepts, and potential solutions and resources available.
Effects of phenobarbital, dexamethasone, and 3-methylcholanthrene administration on the metabolism of 17 beta-estradiol by liver microsomes from female rats.

Female rats were treated with phenobarbital, dexamethasone, 3-methylcholanthrene, clofibrate, or isoniazid to induce different hepatic cytochromes P-450. The profile of hydroxylated metabolites of estradiol (E2) formed by liver microsomes was then determined using a new HPLC method for the separation of hydroxylated estrogen metabolites. Inhibition of liver microsomal E2 metabolism by monoclonal antibodies raised against specific cytochrome P-450 isozymes was also evaluated. Treatment of immature or adult female rats with phenobarbital caused a 3-fold increase in the 2-hydroxylation of E2 and a more than 5-fold increase in liver microsomal hydroxylation of E2 at the 4-, 6 alpha, 6 beta-, and 14 alpha-positions. Monoclonal antibody directed toward CYP2B1/2B2 completely inhibited the 6 alpha- and 6 beta-hydroxylation of E2 and partially inhibited the 2-hydroxylation of E2 by liver microsomes from phenobarbital-treated adult female rats. Antibodies directed toward CYP3A1/3A2 completely inhibited the 4- and 1...
The expanding spectrum of aetiologies causing retinal microcystic macular change.

In this issue of Brain , John Kisimbi et al. (2013) describe spectral domain optical coherence tomography (OCT) findings in a cohort of patients with Tanzanian endemic optic neuropathy, a disorder of unknown aetiology, leading to severe bilateral subacute optic neuropathy. They describe severe retinal nerve fibre layer (RNFL) thinning and concomitant microcystic macular changes in 12.5% of this cohort. The authors describe a parafoveal annular or semi-lunar pattern of the microcystic (perhaps a misnomer but the term will be used for consistency in the literature) changes with a predilection for the nasal aspect of the macula visible using en face infrared imaging. This distribution of microcystic macular change is consistent with that described in previous contexts (Abegg et al. , 2012; Kaufhold et al. , 2013; Wolff et al. , 2013). The current study by Kisimbi et al. (2013) adds Tanzanian endemic optic neuropathy to a growing list of aetiologies causing microcystic macular changes. Histopathological changes similar in appearance to microcystic macular change were described as early as 1963 by John Van Buren, who observed cystic changes in the retinal inner nuclear layer of non-human primates following optic nerve injury. Similar changes to the inner nuclear layer of human eyes with optic nerve lesions were subsequently demonstrated by Gills and Wadsworth (1966). A more recent study demonstrated inner nuclear layer cavitation and cystic changes in rhesus macaques with bilateral idiopathic optic atrophy (Fortune et al. , 2005). Microcystic macular changes on OCT were described in patients with multiple sclerosis and correlated with disease severity (Gelfand et al. , 2012; Saidha et al. , 2012). These studies were followed by a flurry of Letters to the …
Intraoral features and considerations in face transplantation

Face transplantation (FT) is a unique and novel addition to the field of reconstructive surgery, which offers new hope to facially disfigured individuals. This review provides an overview of FT, including clinical indications, immunological principles, and functional outcomes, as well as an in-depth characterization of the intraoral hard and soft tissue findings in the six patients transplanted to date at Brigham and Women's Hospital in Boston, MA, USA. Six FT recipients underwent comprehensive clinical and radiographic evaluation to assess their intraoral status, function, and overall health. The extra- and intraoral soft tissue was assessed via quantitative sensory testing. The vitality of the transplanted dental hard tissue was evaluated with clinically available testing methods. Native teeth and prostheses were also assessed. Sensation of transplanted oral mucosa varied based on time elapsed from FT, ranging from minimal at 3 months post-FT, to nearly complete recovery by approximately 24 months. There was mixed success with the integration of donor teeth (Patients 1, 4 and 6), including associated occlusal discrepancies. Mucosal complications included constriction at the donor/recipient interface (Patients 2 and 5) and solitary episodes of mucosal rejection presenting as lichenoid inflammation (Patients 2 and 4). Face transplantation represents a pivotal moment in the history of reconstructive surgery and transplant medicine, providing new optimism to patients with gross facial deformities. This report highlights the successes of FT, but also the challenges of transplanting hard and soft tissues to restore complex stomatognathic function. Further attention directed toward comprehensive oral rehabilitation in FT will contribute to improved outcomes, with the ultimate goal of restoring and optimizing patient quality of life.
Diurnal variation in nicotine sensitivity in mice: role of genetic background and melatonin.

Abstract Despite the evidence that there is a daily rhythm in smoking behavior and that the effects of drugs of abuse exhibit diurnal variations, very few studies have explored the extent to which sensitivity to the effects of nicotine vary over the course of the day. In the studies described in this report, the melatonin proficient mouse strain C3H/Ibg and the melatonin deficient mouse strains C57BL/6J and DBA/2J were assessed for diurnal variations in sensitivity to the effects of nicotine. Results indicated that there is significant variation in sensitivity to both activity and body temperature depressant effects of nicotine in the melatonin proficient C3H/Ibg strain with maximal sensitivity occurring during the latter third of the light period of the light cycle and minimal sensitivity taking place during the last third of the dark phase of the light cycle. The melatonin deficient strains did not exhibit diurnal differences in sensitivity to the effects of nicotine suggesting a potential role for melatonin in modulating the effects of nicotine. Experiments with knockout mice lacking both the Mtnr1a and Mtnr1b melatonin receptors confirmed that the reduced sensitivity observed during the dark phase is melatonin dependent. Diurnal variation in nicotinic receptor expression also was measured in cortex, hippocampus, hypothalamus and striatum using [125I]-α-bungarotoxin and [125I]-epibatidine. [125I]-α-bungarotoxin binding in hypothalamus of C3H mice exhibited a diurnal pattern with maximal binding observed in the latter third of the light portion of the light cycle. No other significant differences in binding were detected.
A brief review of ventricular assist devices and a recommended protocol for pathology evaluations.

Abstract Heart failure is a leading cause of death in human populations, and as people live longer, it is becoming an increasingly prominent problem. Because of the insufficient numbers of donor hearts, physicians and engineers are turning to mechanical circulatory support in the form of ventricular assist devices (VADs). Their clinical performance and increasing availability of various types, sizes, and functions are increasing VAD recognition. However, for any implantable medical device, especially one that is life supporting, performance and safety must be evaluated both pre- and postmarket. It has been demonstrated that specific pathology analysis can provide unique and important information to augment the evaluation of performance and safety. To help ensure the safety and efficacy of a device, we propose that regulatory agencies include pathology analysis by experienced, independent pathologists with relevant expertise as an integral component of device submissions. We believe that this analysis should include both gross and microscopic components and, when warranted, supplementary data obtained through radiography, electron microscopy, or both. The pathology data acquired through these analyses should be correlated with clinical data to yield a more thorough data set for submission to the governing regulatory body. Submitting this coordinated analysis of data will demonstrate to regulatory agencies (United States Food and Drug Administration, Therapeutic Goods Administration, Brazilian Health Surveillance Agency, etc.) that the device manufacturer shares their objective: making medical devices as safe and effective as possible. Summary This review of ventricular assist devices introduces a recommended protocol for pathology evaluations of devices from organizations or researchers seeking approval by a governing regulatory agency.
Biosynthesis and processing of lysosomal acid phosphatase in cultured human cells

Abstract The biosynthesis of lysosomal acid phosphatase was studied in a normal human embryonic lung cell line, WI-38. Cells were labeled with radioactive leucine under a variety of conditions, the enzyme was immunoprecipitated using a monospecific antiserum raised against human liver lysosomal acid phosphatase, and the products were separated by electrophoresis and were visualized by fluorography. Lysosomal acid phosphatase constitutes 60% of the total tartrate-inhibitable acid phosphatase in WI-38. It is initially synthesized as a high-molecular-weight precursor polypeptide of 69 kDa. The precursor polypeptide is rapidly glycosylated and processed to a mature enzyme of 53-45 kDa via intermediates of 65 and 60 kDa in WI-38 cells. The 69-kDa precursor polypeptide is also converted to larger precursor polypeptides of 74 and 80 kDa. The multiplicity of precursor polypeptides is due at least in part to differences in the glycosylation and phosphorylation of the polypeptides. Sensitivity of phosphorylated oligosaccharide chains from precursor, mature and small polypeptides to endo-β-hexosaminidase H-catalyzed cleavage suggests the presence of high-mannose phosphorylated oligosaccharide chains similar to those present on many other lysosomal enzymes. The effects of tunicamycin and ammonium chloride were also studied. In contrast to the effect of ammonium chloride on arylsulfatase A secretion, the lysosomal acid phosphatase in WI-38 cells was not secreted in the presence of NH 4 Cl. This is consistent with the existence of an alternate route for the transfer of lysosomal acid phosphatase into lysosomes. This alternate route may be the reason that I-cell fibroblasts contain a normal level of lysosomal acid phosphatase.
Gravitating 't Hooft Monopoles

The 't Hooft magnetic monopole solution of the SO(3) Higgs model generates, when coupled to gravity, a geometry which for large distances is of the Reissner-Nordstr\"om form corresponding to a (magnetic) charge $\frac{1}{e}$. The Higgs fields can contribute a cosmological term. In the absence of scalar fields the corresponding Wu-Yang solution of the SO(3) gauge theory still generates the Reissner-Nordstr\"om geometry.
Predicting ecosystem dynamics at regional scales: an evaluation of a terrestrial biosphere model for the forests of northeastern North America

Terrestrial biosphere models are important tools for diagnosing both the current state of the terrestrial carbon cycle and forecasting terrestrial ecosystem responses to global change. While there are a number of ongoing assessments of the short-term predictive capabilities of terrestrial biosphere models using flux-tower measurements, to date there have been relatively few assessments of their ability to predict longer term, decadal-scale biomass dynamics. Here, we present the results of a regional-scale evaluation of the Ecosystem Demography version 2 (ED2)-structured terrestrial biosphere model, evaluating the model's predictions against forest inventory measurements for the northeast USA and Quebec from 1985 to 1995. Simulations were conducted using a default parametrization, which used parameter values from the literature, and a constrained model parametrization, which had been developed by constraining the model's predictions against 2 years of measurements from a single site, Harvard Forest (42.5° N, 72.1° W). The analysis shows that the constrained model parametrization offered marked improvements over the default model formulation, capturing large-scale variation in patterns of biomass dynamics despite marked differences in climate forcing, land-use history and species-composition across the region. These results imply that data-constrained parametrizations of structured biosphere models such as ED2 can be successfully used for regional-scale ecosystem prediction and forecasting. We also assess the model's ability to capture sub-grid scale heterogeneity in the dynamics of biomass growth and mortality of different sizes and types of trees, and then discuss the implications of these analyses for further reducing the remaining biases in the model's predictions.
Elastic scattering of deuterons by 6Li and 7Li at 8.0–12.0 MeV

Abstract Absolute differential cross sections for the elastic scattering of protons and deuterons by 6 Li and 7 Li have been measured with an error of ≈ 2% at selected angles and bombarding energies. The optical model is used to describe the angular distributions of the deuteron scattering at E d = 8.0, 10.0 and 12.0 MeV. The model parameters found when one uses a real potential radius between 3 fm and 4 fm are more nearly constant with changes in bombarding energy than are those obtained using a value ≈ 2 fm. The two sets of parameters represent a phase equivalent ambiguity.
Computational and Experimental Investigation of Thermal Coupling Between Superlattice Coolers

Thermal coupling between superlattice coolers (SLCs) in an array adversely affects performance of an each individual cooler compared with an isolated device. Here, we have developed an electrothermal model to study this coupling between SLCs and how it is affected by geometric parameters such as separation between the superlattice structure and a ground electrode, and operating parameters such as the convective heat transfer coefficient and the activation current applied for driving the SLC. Complementary to the modeling efforts, we have also experimentally studied thermal coupling between SLCs in a microfabricated array under various conditions. Simulation results are critically compared against the experimental data and yield the conclusions of importance for an optimized design of the hybrid microfluidic SLC cooling scheme for thermal management of multiple clustered hotspots in microprocessors. We have observed more than 60% reduction in cooler performance, when placed within the few characteristic diameters of the ground electrode, due to thermal coupling effect. Thermal properties of the working fluid have even more pronounced effect on the thermal coupling between the coolers.
The Influence of an Obesogenic Diet on Oxysterol Metabolism in C57BL/6J Mice

Our current understanding of oxysterol metabolism during different disease states such as obesity and dyslipidemia is limited. Therefore, the aim of this study was to determine the effect of diet-induced obesity on the tissue distribution of various oxysterols and the mRNA expression of key enzymes involved in oxysterol metabolism. To induce obesity, male C57BL/6J mice were fed a high fat-cholesterol diet for 24 weeks. Following diet-induced obesity, plasma levels of 4 β -hydroxycholesterol, 5,6 α -epoxycholesterol, 5,6 β -epoxycholesterol, 7 α -hydroxycholesterol, 7 β -hydroxycholesterol, and 27-hydroxycholesterol were significantly (P < 0.05) increased. In the liver and adipose tissue of the obese mice, 4 β -hydroxycholesterol was significantly (P < 0.05) increased, whereas 27-hydroxycholesterol was increased only in the adipose tissue. No significant changes in either hepatic or adipose tissue mRNA expression were observed for oxysterol synthesizing enzymes 4 β -hydroxylase, 27-hydroxylase, or 7 α -hydroxylase. Hepatic mRNA expression of SULT2B1b, a key enzyme involved in oxysterol detoxification, was significantly (P < 0.05) elevated in the obese mice. Interestingly, the appearance of the large HDL1 lipoprotein was observed with increased oxysterol synthesis during obesity. In diet-induced obese mice, dietary intake and endogenous enzymatic synthesis of oxysterols could not account for the increased oxysterol levels, suggesting that nonenzymatic cholesterol oxidation pathways may be responsible for the changes in oxysterol metabolism.
Index of Refraction of Methane in the Infra-Red and the Dipole Moment of the CH Bond

The index of refraction of methane has been measured for 49 different wave-lengths in the infra-red between 1 and $15\ensuremath{\mu}$. These data have been interpreted in terms of the active infra-red frequencies of methane, and yield what may be considered estimates of the dipole moment of the CH bond and the rate of change of this moment with CH distance. The measurements show that the infra-red bands are only about one-sixth as strong as would be necessary to remove the discrepancy between ${n}_{\ensuremath{\infty}}\ensuremath{-}1$ as obtained from indices of refraction measured at optical wave-lengths and extrapolated to infinite wave-length, and $\ensuremath{\epsilon}\ensuremath{-}1$ as determined from dielectric constant measurements.
Polarization-entangled photon pairs from a periodically poled crystalline waveguide

A proposal is made for the generation of polarization-entangled photon pairs from a periodically poled crystal allowing for high collection efficiency, high entanglement, and stable operation. The theory is formulated for colinear propagation for application to waveguides. The key feature of the theory is the use of type II phase matching using both the +1 and −1 diffraction orders of the poling structure. Although these conditions are fairly restrictive in terms of operating parameters, practical operating conditions can be found. For example, we find that a HeNe pump laser may be used for a periodically poled rubidium-doped potassium titanyl phosphate (Rb:KTP) waveguide to yield single mode polarization-entangled pairs. Fidelities of 0.98 are possible under practical conditions.
Facile Preparation of Active Glassy Carbon Electrodes with Activated Carbon and Organic Solvents

Pretreatment of glassy carbon (GC) electrodes with 2-propanol, acetonitrile, or cyclohexane had a significant effect on electrode kinetics, adsorption, and capacitance. Reagent grade solvents slowed electron transfer rates for dopamine, ascorbic acid, Fe3+/2+, and Fe(CN)63-/4- and decreased adsorption of anthraquinone-2,6-disulfonate (AQDS) and methylene blue (MB). However, if activated carbon (AC) was present in the solvent during pretreatment, the result was increased electron transfer rates and adsorption for several commonly studied redox systems. The large surface area of AC acts as a “getter” for solvent impurities and for species desorbed from the GC surface, leading to a carbon electrode surface with higher capacitance, higher adsorption of AQDS and MB, and faster electron-transfer rates for Fe(CN)63-/4-, dopamine, and ascorbic acid. In addition, the treated surfaces were more reproducible, and aged electrodes were reactivated by AC in 2-propanol. The results imply that large, polar organic impuri...
Peacemaking and Philosophy: A Critique of Justice for Hero and Now

Critique de l'ouvrage de J. Sterba intitule «Justice for Here and Now» (1998) qui developpe deux projets distincts: 1) le projet methodologique de substituer le modele pacificiste au modele belleciste de l'activite philosophique; 2) le projet ethique d'etablir la rationalite comme exigence de la moralite, d'une part, et de reconcilier les perspectives de differentes positions sur la justice, telles que le liberalisme-providence, le libertarisme, le socialisme, le feminisme, le multiculturalisme, l'ethique environnementale anthropocentriste et non anthropocentriste, le pacifisme et la theorie de la guerre juste, d'autre part
Xcellog: A deductive spreadsheet system

The promise of rule-based computing was to allow end-users to create, modify, and maintain applications without the need to engage programmers. But experience has shown that rule sets often interact in subtle ways, making them difficult to understand and reason about. This has impeded the widespread adoption of rule-based computing. This paper describes the design and implementation of XcelLog, a user-centered deductive spreadsheet system, to empower non-programmers to specify and manipulate rule-based systems. The driving idea underlying the system is to treat sets as the fundamental data type and rules as specifying relationships among sets, and use the spreadsheet metaphor to create and view the materialized sets. The fundamental feature that makes XcelLog suitable for non-programmers is that the user mainly sees the effect of the rules; when rules or basic facts change, the user sees the impact of the change immediately. This enables the user to gain confidence in the rules and their modification, and also experiment with what-if scenarios without any programming. Preliminary experience with using XcelLog indicates that it is indeed feasible to put the power of deductive spreadsheets for doing rule-based computing into the hands of end-users and do so without the requirement of programming or the constraints of canned application packages.
Pericardial Thickness Measured With Transesophageal Echocardiography: Feasibility and Potential Clinical Usefulness

Abstract Objectives. This study assessed the reliability of transesophageal echocardiographic measurements of pericardial thickness and the potential diagnostic usefulness of this technique. Background. Transthoracic echocardiography cannot reliably detect thickened pericardium. The superior resolution achieved with transesophageal echocardiography should allow better pericardial definition. Methods. Pericardial thickness measured at 26 locations in 11 patients with constrictive pericarditis who underwent intraoperative transesophageal echocardiography was compared with pericardial thickness measured with electron beam computed tomography. Intraobserver and interobserver variabilities were determined. Pericardial thickness was then measured in 21 normal subjects. With these values as a guide, two observers reviewed 37 transesophageal echocardiographic studies to determine whether echocardiographic measurement of pericardial thickness could be used to distinguish diseased from normal pericardium. Results. The correlation between echocardiographic and computed tomographic measurements (r ≥ 0.95, SE ≤ 0.06 mm, p Conclusions. Measurement of pericardial thickness with transesophageal echocardiography is reproducible and should be a valuable adjunct in assessing constrictive pericarditis. (J Am Coll Cardiol 1997;29:1317–23)
Effect of membrane lipid alteration on the growth, phospholipase C activity and G protein of HT-29 tumor cells

The objective of the present study was to examine the effect of modifying the fatty acid composition of membranes on cell growth and phosphoinositide specific phospholipase C (PLC) activity in HT-29 colon cancer cells. Cells were seeded at a density of 12 x 10(3) cells/cm2 and supplemented with 30 microM of either 18:0, 18:2 (n6) or 18:3 (n3) complexed to bovine serum albumin (BSA) in DMEM medium. Cell growth was followed for 12 days. The 18:0 supplemented cells (control) reached maximum growth at day nine which was greater than either 18:2 (n6) or 18:3 (n3) supplemented cells. There was no difference between the latter two groups in their growth. To investigate the fatty acid incorporation of the supplemented fatty acid and how they may influence composition in the cell membrane, we examined the fatty acid composition of each phospholipid (PL) species. Both phosphatidylcholine (PC) and phosphatidylethanolamine (PE) were significantly influenced by the type of fatty acid supplemented. Supplementation with 18:0 resulted in HT-29 cell membranes having more monounsaturated fatty acids than the cells grown in the other fatty acids. Polyunsaturated fatty acid (PUFA) supplementation (both 18:2 and 18:3) resulted in the enrichment of PUFA in the PL fractions. Cells supplemented with 18:3 (n3) had the highest unsaturation index in membrane PE as compared to the other phospholipid species. PLC activity of the membranes was measured using PIP2 as a substrate in the presence of 15 micrograms alamethicin and 42 microM free calcium. The contribution of G protein to the activity of the enzyme was assessed using GTP gamma(S). PLC activity of HT-29 cells was 16% higher in the presence of GTP gamma(S) response. GTP gamma(S)-activated PLC activity of 18:3 (n3) supplemented cells was 81% of those supplemented with either 18:0 or 18:2 (n6) cells. It is concluded that the decrease in cell proliferation with supplementation with 18:3 (n3) may be mediated through its inhibitory effect on PLC, which provides the second messengers for protein kinase C (PKC) activation. PLC may be influenced by an increased unsaturation index of the PE fraction of the HT-29 tumor cell membranes.