cssi/SciSciGPT-SciSciNet huggingface dataset:
Gd-based protein cage nanoparticles provide enhanced r1 relaxivity and detect experimental atherosclerosis

Background A T1 nanoparticle contrast agent showing high r1 relaxivity is desired to provide more sensitive molecular/ cellular imaging with reduced Gd dose, and may have more clinical utility than T2* (e.g., iron-based) approaches. Tethering multiple Gd-chelates to a supramolecular platform is a promising strategy to increase r1 relaxivity, as rotational correlation time of the Gd ions can become significantly larger which is highly favorable for efficient r1 relaxivity. Here we utilize a small heat shock protein cage (Hsp) with a 12nm exterior diameter and a 9nm interior cavity, as a platform to anchor Gd-DTPA.
Optimal Short Desired Impulse Response for Maximum Likelihood Sequence Estimation

In Maximum Likelihood Sequence Estimation, the number of operations per symbol depends critically on the length of the Desired Impulse Response (DIR). In this paper it is shown that a short but complex DIR of length 2 may be sufficient to cope with most severe distortion impairments found in quadrature modulation systems, thus permitting MLSE data decoding at still manageable complexity.
Outcomes of Minimally Invasive Urologic Surgery in the Elderly Patient Population

The elderly patient is generally counseled with caution regarding open surgical procedures because of the relatively high morbidity and mortality associated when compared with similar procedures in younger patients with- out comorbidities. However, there is an ever-increasing utilization of minimally invasive surgical approaches to urological conditions with demonstrable benefits over open surgery in all patient populations, irrespective of age. We explore and present the various applications of minimally invasive surgery in urology, looking at the outcomes and current trends specifically as it applies to urologic surgery in elderly patients.
Fiber degeneration following lesions in the multipolar and globular cell areas in the ventral cochlear nucleus of the cat.

Abstract A previous study with the Nauta method showed that lesions involving the octopus cell and caudal parts of the multipolar cell areas of the posteroventral cochlear nucleus of the cat produce degenerated fibers in the intermediate acoustic stria and trapezoid body which arborize in periolivary cell groups of the superior olivary complex both ipsilaterally and contralaterally. In the present study, using similar methods, lesions involving the rostral part of the multipolar cell area and adjacent parts of the globular cell area produced fine and coarse degenerated fibers in the caudal trapezoid body, but none in the intermediate acoustic stria. Ipsilaterally, sites of preterminal degeneration were largely co-extensive with those seen following lesions of the octopus cell and caudal multipolar cell areas, but included at least two projections not previously found. Contralaterally, projections were, in part, overlapping with, but were much more extensive than those from the caudal posteroventral cochlear nucleus. These differences, which include the demonstration of degenerated calyces of Held from large fibers of the trapezoid body, and fine preterminal degeneration in the ventral nucleus of the trapezoid body, are interpreted with respect to existing literature on the structure of the ventral cochlear nucleus and superior olivary complex. The data suggest that the ventral cochlear nucleus may be a complex of sub-nuclei each of which has its own set of output projections.
Vibrational constants of the C2Π, A′2Δ and X2Σ+ electronic states of LaO

Abstract Band heads of the LaO C 2 Π r → A ′ 2 Δ r and C 2 Π r → X 2 Σ + electronic transitions have been measured. Band origins, calculated from the observed heads and known rotational constants, have been used to derive vibrational constants and electronic term energies T e for the C 2 Π, A ′ 2 Δ, and X 2 Σ + electronic states of LaO.
Digital signature with (t, n) shared verification based on discrete logarithms

The Letter presents a digital signature scheme based on the discrete logarithm problem which enables any t of the n verifiers to verify the validity of the signature.
Factors Affecting Turkey Meat Color

Abstract INTRODUCTION COLOR in poulty products strongly influences consumer acceptance. Two closely related heme pigments, myoglobin and hemoglobin, make uncooked poultry flesh pink to red. Consumers often object to variation from that normal appearance of uncooked meat or from the normal white to golden-brown of cooked turkey. Pool (1956) reported that turkey meat acquired a pink color when oven roasted in an uncovered container. He concluded this discoloration resulted from small amounts of nitric oxide and carbon monoxide (frequently found in oven atmosphere) combining with heme pigments of the bird. Froning and Hartung (1967) studied effects of age, sex and strain on color and texture of turkey meat, reporting that Gardner L values of uncooked and cooked meat decreased (meat darkened) with age of the bird. (Gardner L refers to light reflectance, aL to redness and bL to yellowness.) They found that uncooked dark meat had significantly more redness (higher aL…
Dynamic aspects of retinotectal map formation revealed by a vital-dye fiber-tracing technique

In the visual system of Xenopus laevis, the axons from the retinal ganglion cells of the eye form a topographic projection onto the optic tectum. Many studies have focused on revealing the mechanisms responsible for this precise and regular projection pattern. In contrast to the static view of the system that one might expect from examining the regularity of the projection, recent work on its regeneration and its changes during larval development indicate that part of the patterning process involves the dynamic behavior of optic fibers. Typically, anatomical and electrophysiological techniques have been used to obtain static views of the developing retinotectal projection which then must be compiled to provide a glimpse of any dynamic behavior. Here we report on experiments using a newly developed fiber tracing technique to directly follow the emergence of topography in the developing retinotectal projection. Defined halves of the developing eyebud were labeled with a vital fluorescent dye which fills the growing axons, and the projection of the labeled cells was followed for up to 2 weeks in individual animals. The experiments confirm that dorsal and ventral optic nerve fibers sort out into an ordered projection early in development. In contrast, nasal and temporal fibers initially overlap, and the same sets of prelabeled fibers then sort out into the adult topography over a period of days.
Experimental evidence for a spontaneously generated effective mass lateral superlattice

Abstract Low-temperature photoluminescence, photoluminescence excitation, and photoreflectance modulation measurements are used to probe the electronic structure and the dielectric function of (001) ( Gap ) 2 ( InP ) 2 superlattices (grown on a GaInP2 buffer) that exhibit lateral composition modulation. An 8×8 Luttinger-model Hamiltonian, which includes the effects of coherency strain generated by the lateral composition modulation, is used to analyze the experimental results. These studies yield the first experimental evidence for a spontaneously generated effective mass superlattice.
Symptoms of posttraumatic stress disorder following myocardial infarction and coronary artery bypass surgery

Psychosocial adjustment, particularly posttraumatic stress disorder (PTSD) symptoms, was assessed in a sample of 50 men 6-12 months after initial myocardial infarction (MI) or coronary artery bypass (CABG) surgery. Mean scores on the adjustment measures indicated relatively low levels of distress for the entire group. However, a small number of patients reported clinically significant elevations in anxiety, depression, anger, and ruminative thinking. Using DSM-III-R criteria, four patients met the criteria for PTSD on a self-report checklist. Four patients met the criteria for major depressive disorder on the Inventory to Diagnose Depression. Overall, the findings suggest that posttraumatic stress disorder-like reactions may be an unrecognized problem for some men who sustain an MI or undergo CABG surgery. These traumatic reactions are highly correlated with emotional distress, including depression, generalized anxiety, and anger.
The action of hormones in insect cell and organ cultures.

Abstract A review of the literature of the action of hormones on insect tissues in vitro published between 1915 and 1970 indicates that research has been concerned with four main areas: studies of the development of imaginal discs, studies of morphogenesis and cuticle secretion in epidermal tissues, studies of the development of gonads, and studies of secretory activity in endocrine glands. The progress made in each field and the possibilities of further investigations are discussed.
Nonparametric Probability Density Estimation: I. A Summary of Available Methods

(1972). Nonparametric Probability Density Estimation: I. A Summary of Available Methods. Technometrics: Vol. 14, No. 3, pp. 533-546.
Numerical Analysis of Local Heat Transfer From a Flat Plate to a Pair of Circular Air Impingining Jets

Local heat transfer from a flat plate to a pair of circular air impinging jets is investigated numerically. A pair of impinging jets from fully-developed pipe flows are used for the numerical simulations. The Reynolds Averaged Navier-Stokes equations(RANS) and energy equation are solved for the three dimensional flow. Eddy-viscocity based turbulence models, RNG k-epsilon and V2F models, are used. Hybrid meshes are used for the three dimensional flows and mesh independent solutions are obtained. The flow Reynolds number, which is based on the jet diameter, is kept at 23,000. In the analysis, local heat transfer coefficients are obtained for the jet-to-plate distance, L/D, ranging from 2 to 10 and the jet-to-jet spacing, S/D, in the range of 1.75 to 7.0. Both local and average heat transfer coefficients are evaluated and compared with available experimental data under same flow conditions. The effect of using different turbulence models in the numerical analysis is evaluated and the selection of proper turbulence models under such a flow condition is suggested.Copyright © 2004 by ASME
Expression of the SUC2 Gene of Saccharomyces cerevisiae is Induced by Low Levels of Glucose

High levels of glucose repress expression of the SUC2 gene in the yeast Saccharomyces cerevisiae. We have discovered that low levels of glucose are required for maximal transcription of SUC2: SUC2 expression is induced about five- to ten-fold in cells growing on low levels of glucose (0.1%) compared to cells growing on galactose or glycerol. Two pieces of evidence suggest that this low-glucose-induced expression is mediated by a repression mechanism that involves an upstream repression site in the SUC2 promoter (URS(SUC2)). First, deletion of the URS(SUC2) results in expression of the SUC2 gene in the absence of glucose, and second the URS(SUC2) mediates a six-fold repression of a reporter gene when inserted into a heterologous promoter. However, this URS(SUC2) mediated repression occurs on all tested carbon sources, suggesting that this URS element acts in concert with all other promoter elements to respond to low concentrations of glucose. This repression requires the general repressor SSn6p. SNF3, which encodes a glucose transporter that appears to be a sensor of low levels of glucose, is also required for low-glucose-induced expression of SUC2.
Glycaemic control is improved by 7 days of aerobic exercise training in patients with type 2 diabetes

Aims/hypothesis Cardiovascular events and death are better predicted by postprandial glucose (PPG) than by fasting blood glucose or HbA1c. While chronic exercise reduces HbA1c in patients with type 2 diabetes, short-term exercise improves measures of insulin sensitivity but does not consistently alter responses to the OGTT. The purpose of this study was to determine whether short-term exercise training improves PPG and glycaemic control in free-living patients with type 2 diabetes, independently of the changes in fitness, adiposity and energy balance often associated with chronic exercise training.
Multiscale models of thrombogenesis

To restrict the loss of blood follow from the rupture of blood vessels, the human body rapidly forms a clot consisting of platelets and fibrin. However, to prevent pathological clotting within vessels as a result of vessel damage, the response must be regulated. Clots forming within vessels (thrombi) can restrict the flow of blood causing damage to tissues in the flow field. Additionally, fragments dissociating from the primary thrombus (emboli) may lodge and clog vessels in the brain (causing ischemic stroke) or lungs (resulting in pulmonary embolism). Pathologies related to the obstruction of blood flow through the vasculature are the major cause of mortality in the United States. Venous thromboembolic disease alone accounts for 900,000 hospitalizations and 300,000 deaths per year and the incidence will increase as the population ages (Wakefield et al. J Vasc Surg 2009, 49:1620–1623). Thus, understanding the interplay between the many processes involved in thrombus development is of significant biomedical value. In this article, we first review computational models of important subprocesses of hemostasis/thrombosis including coagulation reactions, platelet activation, and fibrin assembly, respectively. We then describe several multiscale models integrating these subprocesses to simulate temporal and spatial development of thrombi. The development of validated computational models and predictive simulations will enable one to explore how the variation of multiple hemostatic factors affects thrombotic risk providing an important new tool for thrombosis research. WIREs Syst Biol Med 2012 doi: 10.1002/wsbm.1160 For further resources related to this article, please visit the WIREs website.
Climate change impacts on snow water availability in the Euphrates-Tigris basin

Abstract. This study investigates the effects of projected climate change on snow water availability in the Euphrates-Tigris basin using the Variable Infiltration Capacity (VIC) macro scale hydrologic model and a set of regional climate-change outputs from 13 global circulation models (GCMs) forced with two greenhouse gas emission scenarios for two time periods in the 21st century (2050 and 2090). The hydrologic model produces a reasonable simulation of seasonal and spatial variation in snow cover and associated snow water equivalent (SWE) in the mountainous areas of the basin, although its performance is poorer at marginal snow cover sites. While there is great variation across GCM outputs influencing snow water availability, the majority of models and scenarios suggest a significant decline (between 10 and 60 percent) in available snow water, particularly under the high-impact A2 climate change scenario and later in the 21st century. The changes in SWE are more stable when multi-model ensemble GCM outputs are used to minimize inter-model variability, suggesting a consistent and significant decrease in snow-covered areas and associated water availability in the headwaters of the Euphrates-Tigris basin. Detailed analysis of future climatic conditions point to the combined effects of reduced precipitation and increased temperatures as primary drivers of reduced snowpack. Results also indicate a more rapid decline in snow cover in the lower elevation zones than the higher areas in a changing climate but these findings also contain a larger uncertainty. The simulated changes in snow water availability have important implications for the future of water resources and associated hydropower generation and land-use management and planning in a region already ripe for interstate water conflict. While the changes in the frequency and intensity of snow-bearing circulation systems or the interannual variability related to climate were not considered, the simulated changes in snow water availability presented here are likely to be indicative of climate change impacts on the water resources of the Euphrates-Tigris basin.
Enhancement factor in low-coherence enhanced backscattering and its applications for characterizing experimental skin carcinogenesis

We experimentally study potential mechanisms by which the enhancement factor in low-coherence enhanced backscattering (LEBS) can probe subtle variations in radial intensity distribution in weakly scattering media. We use enhanced backscattering of light by implementing either (1) low spatial coherence illumination or (2) multiple spatially independent detections using a microlens array under spatially coherent illumination. We show that the enhancement factor in these configurations is a measure of the integrated intensity within the localized coherence or detection area, which can exhibit strong dependence on small perturbations in scattering properties. To further evaluate the utility of the LEBS enhancement factor, we use a well-established animal model of cutaneous two-stage chemical carcinogenesis. In this pilot study, we demonstrate that the LEBS enhancement factor can be substantially altered at a stage of preneoplasia. Our animal result supports the idea that early carcinogenesis can cause subtle alterations in the scattering properties that can be captured by the LEBS enhancement factor. Thus, the LEBS enhancement factor has the potential as an easily measurable biomarker in skin carcinogenesis.
Validation of a Respirator Performance Model

Abstract This article presents results of an experimental validation of a model for predicting the performance of half-mask respirators. The model predicts respirator performance for protection against aerosols. It uses as input the measured fit factor, an estimated work rate, the exposure particle size distribution, and known performance characteristics for the type and brand of filter used. The validation tests involved the measurement of respirator performance, using human subjects, under simulated use conditions with known fit, work rate, particle size distribution, and filter performance. Comparison is made between measured and predicted performance for two conditions each of fit, particle size, and work rate. Fit factors ranged from 5 to 231, test aerosol mass median aerodynamic diameters from 0.6 to 1.3 μm, and work rates from 0 to 50 W. Based on tests conducted here, the predictive model does a reasonable job of predicting penetration under simulated use conditions where fit factor, size distribut...
Comparison of polybutadiene-coated alumina and octadecyl-bonded silica for separations of proteins and peptides by reversed-phase high-performance liquid chromatography

Abstract The chromatographic retention and separations of proteins and peptides on a novel polybutadiene-coated alumina (PBDA) high-performance liquid chromatographic stationary phase are compared to those obtained on a widely-used polymeric octadecylsilane (ODS) phase. Using acetonitrile-water mobile phase gradients containing 0.1% trifluoroacetic acid, the average peak capacities (which are inversely proportional to average peak widths) and peak resolutions obtained for chromatograms of mixtures of ribonuclease A, cytochrome c, lysozyme and carbonic anhydrase are five times lower on a column packed with PBDA than on one packed with ODS. Irreversible adsorption causes increases in column backpressure during successive analyses of protein solutions on PBDA phases and 50% reductions in protein peak areas on the PBDA phase compared to ODS. In contrast to those results, peak capacities, resolutions and peaks areas for synthetic octapeptides on the PBDA and ODS phases are more comparable to each other. Chromatographic capacity factors of 31 low-molecular-weight organic compounds on PBDA and ODS columns are shown to correlate well. The critical concentrations of organic modifier required to elute proteins and octapeptides from PBDA columns are lower than that required for ODS, but still correlate linearly with corresponding values from ODS columns. It is concluded from these results that the retentions of peptides, proteins and smaller molecules on both the PBDA and ODS phases are governed by similar hydrophobic interaction mechanism, while peak broadening due to mass transfer resistance increases more rapidly with solute size on the PBDA stationary phase than it does on ODS. The increase in solute mass transfer resistance with solute size on the PBDA column is attributed to solute interactions with the uniquely-shaped PBDA particles.
Effect of early plasma transfusion on mortality in patients with ruptured abdominal aortic aneurysm.

Background The ratio of red blood cell (PRBC) transfusion to plasma (FFP) transfusion (PRBC:FFP ratio) has been shown to impact survival in trauma patients with massive hemorrhage. The purpose of this study was to determine the effect of the PRBC:FFP ratio on mortality for patients with massive hemorrhage after ruptured abdominal aortic aneurysm (RAAA). Methods A retrospective review was performed of patients undergoing emergent open RAAA repair from January 1987 to December 2007. Patients with massive hemorrhage (≥10 units of blood products transfused prior to conclusion of the operation) were included. The effects of patient demographics, admission vital signs, laboratory values, peri-operative variables, amount of blood products transfused, and the PRBC:FFP ratio on 30-day mortality were analyzed by multivariate analysis. Results One hundred and twenty-eight of the 168 (76%) patients undergoing repair for RAAA received at least 10 units of blood products within the peri-operative period. Mean age was 73.1 ± 9.1 years, and 109 (85%) were men. Thirty-day mortality was 22.6% (29/128), including 11 intra-operative deaths. By multivariate analysis, 30-day mortality was markedly lower (15% vs 39%; P 2:1 (LOW FFP), and the likelihood of death was more than 4-fold greater in the LOW FFP group (odds ratio 4.23; 95% confidence interval, 1.2–14.49). Patients in the HIGH FFP group had a significantly lower incidence of colon ischemia than those in the LOW FFP group (22.4% vs 41.1%; P = .004). Conclusion For RAAA patients requiring massive transfusion, more equivalent transfusion of PRBC to FFP (HIGH FFP) was independently associated with lower 30-day mortality. The lower incidence of colonic ischemia in the HIGH FFP group may suggest an additional benefit of early plasma transfusion that could translate into further mortality reduction. Analysis from this study suggests the potential feasibility for a more standardized protocol of initial resuscitation for these patients, and prospective studies are warranted to determine the optimum PRBC:FFP ratio in RAAA patients.
Who needs an IV? Retrospective service analysis in a tertiary pediatric hospital

Summary Aims: The question if it is possible and safe to anesthetize children for short procedures without intravenous (IV) access provokes strong opinions among pediatric anesthetists. However, only limited data are available to support either side of the arguments. This pediatric university hospital provides anesthesia to a community dental service, led by staff anesthesiologists. A rapid turnover system based on inhalational induction and maintenance of anesthesia without mandatory IV access has been employed since 2005. Methods: A retrospective service analysis was performed to identify the incidence of adverse anesthesia events. Results: A total of 6440 children with an average (±sd) age of 8.1 (±4.1) years and weight of 29.6 (±13.5) kg were cared for over the 5-year period. The total number of children refusing to undergo inhalational induction was 81 (1.26%) and 19 (0.3%) elected for an IV induction. One-third received cannulation for delivery of IV analgesia. There were no adverse anesthesia events requiring emergency cannulation and/or intubation over the 5-year period. Conclusions: This service review indicates that general anesthesia for outpatient dental anesthesia may be safely performed without mandatory IV access. The technique employed in this center emphasizes the need for the clinician to primarily concentrate on pediatric airway management in a safe environment with experienced assistance. It supports the hypothesis that instrumentation of the airway (insertion of laryngeal mask airway) can be satisfactorily achieved without prior IV access.
Responses of a eutrophic pond community to separate and combined effects of N:P supply and planktivorous fish: a mesocosm experiment

We conducted an outdoor mesocosm experiment of factorial design consisting of three levels of nutrient supply (no nutrient addition and additions of nitrogen and phosphorus in ratios of 10:1 and 45:1) cross-classified with two levels of bluegill (Lepomis macrochirus) (presence and absence). Nutrient supply significantly affected total phosphorus (TP), total nitrogen (TN), TN: TP ratio, turbidity, Secchi depth, phytoplankton chlorophyll, filamentous blue-green algae, periphyton chlorophyll, Asplanchna and non-predatory rotifers. The presence of bluegill significantly increased TP, turbidity, diatoms, unicellular green algae, colonial blue-green algae, filamentous blue-green algae, periphyton chlorophyll, Asplanchna and non-predatory rotifers, and decreased Secchi depth, cladocerans, cyclopoid copepodids, copepod nauplii and chironomid tube densities. Nutrient supply and fish effects were not independent of each other as shown by significant nutrient × fish interaction effects for TP, Secchi depth, filamentous blue-green algae, periphyton chlorophyll, Asplanchna and non-predatory rotifers.
An Oncology Patient's Choice to Forgo Nonvolitional Nutrition Support: Ethical Considerations

A 76-year-old patient with metastatic carcinoid tumor who had difficulty tolerating an oral diet and jejunostomy feedings became dehydrated and failed to thrive. His jejunostomy feeding regimen was manipulated to improve tolerance without success. Although his medical condition was untreatable, he was not considered terminally ill, and he was determined to be a reasonable candidate for home total parenteral nutrition (HTPN). However, he thought HTPN was an "excessive measure," and despite lengthy discussions with him by members of both the Hematology/Oncology and Nutrition Support services about the potential benefits of HTPN, he refused any further interventions involving nonvolitional nutrition support (jejunostomy feedings and HTPN). He was discharged to home receiving an oral diet as tolerated in the care of his family and hospice. This case illustrates the ethical considerations surrounding a patient's decision to forgo medical care that might prolong life.
A PIV study of co-rotating disks flow in a fixed cylindrical enclosure

Abstract This study investigates the coherent flow between enclosed co-rotating disks using flow visualization and particle image velocimetry (PIV). To simulate the 3.5-inch hard disks the tested disks have a diameter of 275 mm and a gap-to-disk radius ratio of 0.09. In the flow measurements the Reynolds number is fixed at Re = 5.25 × 10 5 corresponding to a disk rotating speed of 12,000 rpm. The rotation speed and disk space selected above is for the next generation hard disk consideration, and the related parameters are determined through the Reynolds dynamic similarity Re ( model , water 30 ° C ) = Re ( prototype , air 30 ° C ) . The results show that the flow between the disks can be characterized by eight sub-flow regions: namely 1st solid body rotation region, 2nd large-scale vortex structure region, 3rd detached shear layer region, 4th boundary layer region, 5th core region, 6th Ekman layer region, 7th Stewartson layer region, and 8th shroud shear layer region. Among these sub-flow regions the 5th to 7th flow regimes are not identified previously. In addition, the additional measurements of the circumferential velocity component in the 5th core region reveal that a pair of circular flow structure acts like an annular chain to surround the 2nd sub-region large-scale vortex. This finding is also not reported in the literature. Moreover, the present PIV phase velocity measurements provide the physical explanation of the cyclic variation in the 1st solid body rotation region reported previously by our Laser Doppler Velocimetry spectra measurements.
The impact of a policy of amnioinfusion for meconium-stained amniotic fluid.

Objective To evaluate the impact of an amnioinfusion (AI) policy for thick or moderate meconium-stained amniotic fluid (AF) on neonatal outcome, specifically meconiumaspiration syndrome and its complications. Methods We reviewed maternal and neonatal charts of 937 vertex, singleton pregnancies complicated by moderate or thick meconium-stained AF during a 3-year period. The patients were divided into groups according to whether AI was performed. Demographic characteristics, risk factors, mode of delivery, pregnancy outcome, and neonatal complications, including meconium-aspiration syndrome, were analyzed. Results Four hundred forty patients (47%) received AI (AI group); 497 (53%) did not, for the following reasons: imminent delivery (310 patients), occult meconium (141), or emergency cesarean delivery (46) (no-AI group). Our study did not show any reduction in the incidence of 5-minute Apgar scores of 7 or less (8 versus 7%), meconium below the vocal cords (28 versus 29%), meconium aspiration syndrome (4.5 versus 3.8%), ventilation requirement (4.3 versus 2.4%), or neonatal death (0.7 versus 0.2%) in the AI and no-AI groups, respectively. The AI group had a higher incidence of fetal heart rate abnormalities in labor (48 versus 31%, P P P P = .004). Conclusions With the policy of routine AI for moderate or thick meconium-stained AF, AI was not clinically feasible in 53% of the cases. We were unable to demonstrate any improvement in neonatal outcome in those who received AI for moderate or thick meconium.
Alternative access for balloon-expandable transcatheter aortic valve replacement: comparison of the transaortic approach using right anterior thoracotomy to partial J-sternotomy

Objectives For transcatheter aortic valve replacement (TAVR), transaortic (TAo) and transapical (TA) approaches are major alternatives in cases unsuitable for the transfemoral approach. Partial J-sternotomy is a widely used access for TAo. However, redo sternotomy or right-sided aorta may preclude this access, and right anterior thoracotomy is potentially beneficial in these cases. This study sought to evaluate the TAo approach using thoracotomy (T-TAo) and compare it to the TAo approach using a sternotomy (S-TAo) and a TA approach. Methods In a large single-center series, consecutive TAVR patients were studied. Procedural/clinical outcomes of the T-TAo, S-TAo, and TA groups were compared up to a 30 days follow-up period. Results Of 872 TAVR patients, 22 (2.5%) were T-TAo, 29 (3.3%) were S-TAo, and 86 (9.9%) were TA approaches. The TA group showed the shortest intensive care unit stay, with a median 2.0 (interquartile range 1.0-3.0) days: for T-TAo it was 3.0 (2.0-5.3) and for S-TAo, 3.0 (3.5-5.0) ( P P = .30), with no difference in other endpoints, including stroke/transient ischemic attack, rehospitalization, and paravalvular leak. Additionally, computed tomographic assessment revealed that T-TAo facilitated a more coaxial approach than S-TAo: 20.4° ± 8.2° versus 30.6° ± 8.2° ( P Conclusions T-TAo is a feasible approach that can provide greater coaxiality. This option allows tailored and optimal access to the individual patient and facilitates a treatment strategy in nontransfemoral TAVR patients.
The Impact of Nationalisation

One of the most important developments in the last decade has been the movement by Africans to recover control of their own economy. A recent article in this Journal, XVI, 3, September 1976, gave a factual account of the extent to which foreign-owned industry in black Africa has been nationalised and indigenised, and discussed the inability of international law to provide guidelines for the settlement of this ongoing struggle between alien owners and host countries. Predictably, it was written by a lawyer because this field has been captured by lawyers almost to the exclusion of all others. But there is much that economists, sociologists, and political scientists could contribute concerning nationalisation, particularly in analysing its causes and effects, although up to now they have had little to say.1 This note makes a start on the question of the impact of nationalisation upon Africa and Africans, in the hope that the tentative conclusions reached here will lead to treatment of the subject by those with the tools for a deeper appraisal.
Agency budgets and the use of eligibility rules

The practice of limiting program benefits to specific groups in the population through the specification of eligibility and targeting rules is relatively common among government sponsored programs. In some cases, such as Social Security, Supplemental Security Income, and Medicaid, the eligibility criteria are established by Federal and state regulations. The local community and the local administrators of the program can exercise some discretion in the enforcement of these regulations, but they are seldom able to change the specific eligibility rules. This situation contrasts with decentralized programs in which both the specification and enforcement of eligibility and targeting rules are determined at the local level. The result of this decentralization in rule making has been the generally predictable variation in the development and use of eligibility and targeting rules by local organizations. While this observed variation has been both praised and criticized, relatively little research has been done to determine the sources of this observed variation in rule use. Efforts to associate rule use with measures of decentralization are an exception to this generalization. Previous studies of bureaucratic behavior, especially studies which have employed a rational actor approach, have argued that decisions by administrators will depend on their individual preference functions and on various constraints limiting their choices (Tullock, 1965; Niskanen, 1975; Allison, 1971). Although not the central focus of these studies, explanations for the observed variation in rule use by local agencies have been suggested. However, only limited attempts have been made to explore the reasonableness of these suggestions. The objective of this paper is to formalize a rational actor model of bureaucratic behavior designed to explore variations in the use of eligibility rules, and to test this model using data collected on the use of eligibility rules by local organizations. Part 1 presents the theoretical model designed
Kinetics of Heparin Removal from Circulation of the Minipig

Techniques were developed for kinetic studies in unanesthetized, unrestrained minipigs weighing less than 45.4 kg (100 Ib). By using 35S-heparin and 3H-heparin, the disappearance from the plasma of different amounts of heparin injected intravenously into the minipig was determined. Serial plasma samples were assayed for radioactivity, and the resulting plasma radioactivity-time curves were analyzed for calculation of half-lives of disappearance (t1/2) and volume of distribution (Vd). The plasma radioactivity followed a monoexponential decay. Over the 1–50-mg heparin range, an increase in t1/2 from 3.4 to 39 min was observed. Essentially no differences in the Vd were observed among the various doses. This volume was approximately 1.5 times the estimated plasma volume. The observed kinetics are consistent with previous suggestions that the reticuloendothelial system may be involved in the diposition of heparin.
Explanatory models in expert systems

The problem considered here concerns the situation in which we are interested in the degree to which a set of elements called the diagnosis set explains another set called the evidence set. A measure is suggested to calculate the degree of explanatory power the diagnosis set has for the evidence set. We also concern ourselves with the problem of minimizing the diagnosis set.
Normalization of a spatially variant image reconstruction problem in electrical impedance tomography using system blurring properties

The electrical impedance tomography (EIT) image reconstruction problem is ill posed and spatially variant. Because of the problem's ill-posed nature, small amounts of measurement noise can corrupt reconstructed images. The problem must be regularized to reduce image artifacts. In this paper, we focus on the spatially variant characteristics of the problem. Correcting errors due to spatial variance should improve reconstruction accuracy. In this paper, we present methods to normalize the spatially variant image reconstruction problem by equalizing the point spread function (PSF). In order to equalize the PSF, we used the reconstruction blurring properties obtained from the sensitivity matrix. We compared three mathematical normalization schemes: pixel-wise scaling (PWS), weighted pseudo-inversion (WPI) and weighted minimum norm method (WMNM) to equalize images. The quantity index (QI), defined as the integral of pixel values of an EIT conductivity image, was considered in investigating spatial variance. The QI values along with reconstructed images are presented for cases of two-dimensional full array and hemiarray electrode topologies. We found that a spatially invariant QI could be obtained by applying normalization methods based on equalization of the PSF using conventional regularized reconstruction methods such as truncated singular value decomposition (TSVD) and WMNM. We found that WMNM normalization applied to WMNM regularized reconstruction was the best of the methods tested overall, for both hemiarray and full array electrode topologies.
Damage detection using scanning laser vibrometer

A damage detection algorithm based on the principle of curvature changes has been developed at CFC-WVU. However, the algorithm requires accurate mode shapes with adequate spatial density. Existing contact sensors can not provide adequate spatial density without adding excessive mass. Hence, non-contact scanning techniques, such as scanning laser vibrometer (SLV) has adequate sensitivity and accuracy is yet to be proven. The applicability of SLV on large structures is also questionable. To assess the suitability of using SLV for damage detection, a beam specimen has been tested using an existing system. The results confirm that damage detection using vibration measurements from SLV is successful. Due to more spatial density, the SLV data is shown to be more sensitive than the contact sensor test.
Grain-Focused Microstructure Simulations: Stress-Induced Evolution of Polycrystalline Films

We discuss simulations of grain boundary motion utilizing a grain-continuum approach to representing polycrystalline films; i.e., as a system of distinct but interacting continua. Field variables are computed as functions of position in each grain; e.g., internal stresses and concentrations. Grain boundaries are represented and tracked using multiple level sets, providing a method to evolve the grain structure in time. We demonstrate the approach using stress-driven grain boundary migration in polycrystalline copper films, assuming that migration is due to vacancy migration. The anisotropic elastic constants of single crystal copper are used for each grain, under specified rotations (grain orientations). Stresses and stress gradients are thermally induced in a film with texture, with the exception of a single grain on a silicon dioxide film on a silicon substrate. Grain boundary velocities are calculated from the fluxes of vacancies to grain boundaries. The computed velocities are then used to update the level sets that represent the grain boundaries.
Altering States: Ethnographies of Transition in Eastern Europe and the Former Soviet Union

Altering States: Ethnographies of Transition in Eastern Europe and the Former Soviet Union. Daphne Berdahl. Matti Bunzl. and Martha Lampland. eds. Ann Arbor: University of Michigan Press, 2000. vii. 252 pp., maps, photographs, references, index,
Long-Term Consequences of Drugs on the Paediatric Cardiovascular System

Many pharmacological and toxicological actions of drugs in children cannot be fully predicted from adult clinical experience or from standard non-clinical toxicology studies. Numerous drugs have direct or indirect pharmacological effects on the heart and are prescribed for children of all ages. Toxicity or secondary effects may be immediate or delayed for years after drug exposure has ceased. Originally, the aim of this review was to compile information on the effect of specific drugs on the post-natal development of the cardiovascular system and to examine long-term follow-up of the use of cardio-active drugs in children. The limited database of published information caused the original question to evolve into an examination of the medical literature for three areas of information: (i) whether vulnerable developmental windows have been identified that reflect the substantial functional development that the cardiovascular system undergoes after birth; (ii) what is known about pharmacological perturbation of development; and (iii) what the likelihood is of drug exposure during childhood. We examined different scenarios for exposure including random, isolated exposure, conditions historically associated with adults, primary or secondary cardiac disease, psychiatric and neurological conditions, asthma, cancer and HIV. Except for random, isolated drug exposures, each category of possible exposure contained numerous drugs known to have either primary or secondary effects on the cardiovascular system or to influence factors associated with atherosclerosis. It is likely that a significant number of children will be prescribed drugs having either direct or indirect effects upon the immature cardiovascular system. A confounding factor is the simultaneous use of over-the-counter medications and herbal or nutraceutical preparations that a patient, parent or guardian does not mention to a prescribing physician. Metabolism is also important in assessing drug effects in children. Differences in body water : body fat ratio, age-related gastrointestinal absorption, distribution, excretion, renal function and drug metabolizing capabilities make it possible for children to have a different metabolite profile for a drug compared with adults. There is little examination of drug effects on the interdependent processes of cardiac maturation and less examination of metabolite effects. It is difficult to identify delayed toxicities in children as these adverse events may take years to manifest with many patients lost to follow-up. Clearly this is an area of study where intermediate endpoints and surrogate markers would be of great benefit. Pharmacogenomics may be useful in providing markers of increased risk or susceptibility. A perspective must be kept in balancing the possibility of a problem with the very real benefits that many children experience from the use of these pharmaceuticals.
Cardiac Pacing and ICDs, 3rd edition.

Kenneth A. Ellenbogen, Mark A. Wood, eds. 530 pp. Malden, Mass: Blackwell Science, Inc; 2002. $49.95. ISBN 0-86542-586-8 This 530-page paperback text is divided into 10 chapters written by twelve authors, including the co-editors. The majority of the book emphasizes the basics, indications, electrocardiography, and follow-up of pacemakers. Two chapters are limited …
Mucocutaneous neuromas: an underrecognized manifestation of PTEN hamartoma-tumor syndrome.

Background The spectrum of clinical findings associated with PTEN tumor suppressor gene germline mutations, referred to as PTEN hamartoma-tumor syndrome (PHTS), includes Cowden and Bannayan-Riley-Ruvalcaba syndromes. Although the skin is the ectodermal structure most often affected by these autosomal dominant genodermatoses, abnormalities of neural tissues are frequently observed. Observations We describe a 5-year-old boy with macrocephaly, prominent corneal nerves, and progressive development of multiple painful, dome-shaped, translucent pink to skin-colored papules on the vermilion portion of the upper lip, fingers, palms, and shins. Histologic evaluation demonstrated dermal proliferation of well-demarcated nerve bundles associated with abundant mucin and surrounded by a distinct perineural sheath, findings diagnostic of a nonencapsulated neuroma. Genetic analysis revealed a novel heterozygous germline nonsense mutation in PTEN , predicted to result in a truncated PTEN protein. To our knowledge, this represents the first report of multiple neuromas as the sole mucocutaneous manifestation of PHTS. Conclusions This article highlights neuromas as a cutaneous sign of PHTS, drawing attention to manifestations of PHTS in neural tissues of the skin, eye, gastrointestinal tract, and brain. Along with multiple endocrine neoplasia type 2B, PHTS should be considered in the differential diagnosis of multiple mucocutaneous neuromas, particularly those involving extrafacial sites.
SCIENTISTS’ PARTICIPATION IN TEACHER PROFESSIONAL DEVELOPMENT: THE IMPACT ON FOURTH TO EIGHTH GRADE TEACHERS’ UNDERSTANDING AND IMPLEMENTATION OF INQUIRY SCIENCE

The impact of a professional development experience involving scientists and fourth to eighth grade teachers of science was explored. Teachers attended a summer program at a research facility where they had various experiences such as job shadowing and interviewing scientists. They also participated in authentic inquiry investigations and planned inquiry units for their classrooms. Data on teachers’ understanding and implementation of inquiry were collected through surveys, questionnaires, and classroom observations. Findings show that the teachers’ understanding of inquiry improved and most participants were able to successfully implement inquiry science in their classrooms. Barriers to the implementation of inquiry practices and the impact of specific experiences with the scientists were explored.
Phase behavior of rigid objects on a cubic lattice

Grand canonical Monte Carlo simulations were carried out to examine phase transitions of rigid lattice objects. The objects studied are coarse representations of planar, spherical, cubic, and cylin...