cssi/SciSciGPT-SciSciNet huggingface dataset:
Simplification via aggregation for neural networks

Aggregation is a useful technique for simplifying multicomponent systems. We illustrate this by sim plifying a class of neural network models and com paring the behaviors of the simplified (lumped) model and the original (base) model. Naturally, in order for aggregation to be applicable, certain constraints on the neural network models are imposed. The lumped model obtained is a vastly simplified model and is deterministic, even though the base model is proba bilistic. Nevertheless, by experimenting with the lumped model and using the information obtained in the form of force field plots, we are able to cor rectly predict many aspects of base model behavior. A related probabilistic lumped model, similar to the deterministic lumped model, is also examined.
Silent left ventricular dysfunction during routine activity after thrombolytic therapy for acute myocardial infarction.

Abstract To investigate prospectively the occurrence and significance of postinfarction transient left ventricular dysfunction, 33 ambulatory patients who underwent thrombolytic therapy after myocardial infarction were monitored continuously for 187 ± 56 min during normal activity with a radionuclide left ventricular function detector at the time of hospital discharge. Twelve patients demonstrated 19 episodes off transient left ventricular dysfunction (>0.05 decrease in ejection fraction, lasting ≥ 1 min), with no change in heart rate. Only two episodes in one patient were associated with chest pain and electrocardiographic changes. The baseline ejection fraction was 0.52 ± 0.12 in patients with transient left ventricular dysfunction and 0.51 ± 0.13 in patients without dysfunction (p = NS). At follow-up study (19.2 ± 5.4 months), cardiac events (unstable angina, myocardial infarction or death) occurred in 8 of 12 patients with but in only 3 of 21 patients without transient left ventricular dysfunction (p 0.05 at peak exercise; neither had a subsequent cardiac event. These data suggest that transient episodes of silent left ventricular dysfunction at hospital discharge in patients treated with thrombolysis after myocardial infarction are common and associated with a poor outcome. Continuous left ventricular function monitoring during normal activity may provide prognostic information not available from submaximal exercise test results.
Caregiving and care receiving among a technologically dependent heart failure population.

This descriptive study investigated health-related quality of life (HRQOL) and caregiving/care receiving among 20 end-stage heart failure patients receiving community-based inotropic infusions and among their 18 family caregivers. The analysis revealed that care recipients perceived considerable impairment from their disease process and poor HRQOL despite the use of inotropic infusions. Perceived powerlessness was identified as a predictor of the recipients' mental health status, while caregiver esteem adversely affected recipient HRQOL. Although insufficient preparation to care and caregiving tasks significantly contributed to the negative aspects of care provision, the esteem and mental health of the caregiver significantly enhanced HRQOL among caregivers.
The Brooks Slave Ship Icon: A 'Universal Symbol'?

This contribution concerns the recuperation of the Brooks slave ship icon in late modern and contemporary art. Inspired by the Description of the Slave Ship, an eighteenth-century abolitionist drawing, twentieth- and twenty-first-century artists have transformed the image of the slaver into a dialogic and metaphoric site. For Thai-American artist Skowmon Hastanan, the slave ship relates not only to the transatlantic trade of the past, but also to contemporary human trafficking of Asian women. Whilst the slave ship retains its specificity, the art of Hastanan and others who are not of African descent indicates that it has become a functional and perhaps even ‘universal’ symbol of exploitation, oppression and injustice. This article considers what this phenomenon might mean for notions of universality and visual signs of blackness.
Asymmetric Deprotonation of N-Boc Piperidine: React IR Monitoring and Mechanistic Aspects

The high yielding asymmetric deprotonation trapping of N-Boc piperidine is successfully realized using s-BuLi and a (+)-sparteine surrogate. Monitoring of the lithiation by in situ React IR allowed the direct observation of a prelithiation complex.
Flooding alters apparent position of floodplain saplings on a light gradient.

It has been hypothesized that flooding, interacting with light availability, can determine spatial patterns of tree regeneration by causing differential germination or survival among seedlings in river floodplains. We conducted a canonical correspondence analysis (CCA, a form of direct gradient analysis) of sapling and environmental data collected from 1980 to 1990 to investigate this hypothesis. The CCA recovered two significant axes, and of the eight environmental variables included, only elevation and percentage sky explained significant portions of the variability in species location. Axis 1 was correlated with elevation, while Axis 2 was correlated with percentage sky. Comparison of first axis rankings with species flood tolerance rankings obtained from the literature showed substantial agreement, indicating that elevation was a surrogate for flood tolerance. Comparison of second axis rankings with species shade tolerance rankings obtained from the literature showed little correspondence between position on the light gradient and species shade tolerance rankings; several of the most shade-tolerant species were placed on the high-light end of the light gradient. These results suggest that sapling distributions are responding primarily to flooding and light. The failure of the species to assort along the light gradient in accordance with their shade tolerance suggests that flooding interacts with life history traits of individual species, especially shade tolerance, resulting in complex species-specific responses. When we attempt to tease apart the interaction between light and flooding, we find two components: flood tolerance may allow persistence of some species under lower light conditions than normal, and flood intolerance may limit some normally shade-tolerant species to high-light conditions, where growth is fast enough to allow escape from the flooding hazard.
Ifosfamide and Mesna in epithelial ovarian carcinoma

Ifosfamide is a cyclophosphamide analogue synthesized in the 1960s with antineoplastic activity demonstrated in early broad-ranging phase I studies conducted in Germany in the 1970s. Because of significant urothelial toxicity, phase II studies in ovarian cancer in this country were delayed until the urinary epithelial protector mesna became available in 1985. Since that time, two well-executed prospective trials have shown that this agent produces measurable responses in about 20% of women with ovarian epithelial cancer recurring after primary chemotherapy and in 12% of those with tumors refractory to first-line therapy with regimens including cisplatin. Toxicity includes moderate to severe hematologic toxicity, renal dysfunction which is usually reversible, and CNS abnormalities including lethargy, somnolence, and disorientation. The risk of toxicity may be increased in patients with compromised hepatic or renal function and in those with hydronephrosis or hypoalbuminemia.
Predictors of neurocognitive decline after carotid endarterectomy.

Carotid endarterectomy (CEA) reduces the risk of future stroke in patients with high-grade stenosis (5, 10, 15, 25). However, approximately 25% of CEA patients experience declines in postoperative neurocognitive function that are detected by a battery of neuropsychometric tests (NPMTs) (12, 13). Although the mechanism of post-CEA neurocognitive decline is poorly understood, it is thought to be ischemic in nature, and may be owing to hypoperfusion during carotid artery cross-clamping or the dislodgement of microemboli during vessel dissection and plaque removal. To date, no studies have thoroughly investigated the risk factors for these neurocognitive changes after CEA. With nearly 100,000 CEAs performed annually (5, 25), many for borderline indications with small absolute benefit (11, 35), understanding the variables that predispose to subtle changes in cerebral function is crucial in appropriate patient selection. We sought to identify factors that predict postoperative neurocognitive dysfunction.
Alternative Approach to Vehicle Element Processing

The National Space Transportation Policy (NSTP), describes the challenge facing today's aerospace industry. 'Assuring reliable and affordable access to space through U.S. space transportation capabilities is a fundamental goal of the U.S. space program'. Experience from the Space Shuttle Program (SSP) tells us that launch and mission operations are responsible for approximately 45 % of the cost of each shuttle mission. Reducing these costs is critical to NSTP goals in the next generation launch vehicle. Based on this, an innovative alternative approach to vehicle element processing was developed with an emphasis on reduced launch costs. State-of-the-art upgrades to the launch processing system (LPS) will enhance vehicle ground operations. To carry this one step further, these upgrade could be implemented at various vehicle element manufacturing sites to ensure system compatibility between the manufacturing facility and the launch site. Design center vehicle stand alone testing will ensure system integrity resulting in minimized checkout and testing at the launch site. This paper will addresses vehicle test requirements, timelines and ground checkout procedures which enable concept implementation.
The impact of respiration on left atrial and pulmonary venous anatomy: Implications for image-guided intervention

Background Image-guided intervention using pre-acquired CT/MR 3-dimensional images is an emerging strategy for atrial fibrillation (AF) ablation but may be limited by its use of static images to depict dynamic physiology. The effect of biologic factors such as respiration on the left atrial-pulmonary venous (LA-PV) anatomy is not well understood but is likely to have important implications. Conventional CT/MR imaging is performed during an inspiratory breath-hold, while electroanatomical mapping (EAM) during "quiet" breathing approximates an expiratory breath-hold. This study examined the effects of respiration on LA-PV anatomy and the error introduced by respiration on the integration of EAM with 3D MR imaging. Methods Pre-procedural MRI angiography was performed at both end-expiration (EXP) and end -inspiration (INSP) in 20 patients undergoing AF catheter ablation. 3D INSP and EXP surface reconstructions of the LA-PVs were compared. In selected pts, EAM data acquired during the ablation procedure (n=7) were integrated with the 3D MRI datasets. Results Qualitative assessment of the INSP and EXP 3D images revealed splaying of the PVs and reduction in PV caliber of the right-sided PVs during held inspiration. After aligning these two datasets, the average surface-to-surface distance calculated by region ranged from 1.99mm (right middle PV) to 3.79mm (left superior PV). Registration of the EAM to the MRI models was better for the EXP dataset (2.30±0.73mm) than the INSP dataset (3.03±0.57mm; p=0.004). Conclusion There are significant changes in LA-PV anatomy with respiration. MR images acquired during standard held inspiration may introduce unnecessary errors in registration during image-guided intervention.
The isotopic dependence of the spin–rotation interaction: the rotational spectrum of cadmium hydride in its X2Σ+ state

Abstract Far-infrared rotational transitions within the X 2 Σ + ( v =0) state of cadmium hydride (CdH) were recorded over the range N ″=2–17 for 12 different isotopomers, using the technique of tunable far-infrared (TuFIR) spectroscopy. The molecule was made by heating cadmium metal in the presence of a DC electric discharge in hydrogen. Fine structure arising from the electron spin–rotation interaction and hyperfine structure from the 111 Cd, 113 Cd, and 1 H nuclei were resolved and analyzed. All of the isotopic data were fitted together using a Hamiltonian containing mass-independent, Dunham-type rotational parameters U kl and small correction terms Δ kl described by Watson [J. Mol. Spectrosc. 80 (1980) 411]. The spin–rotation interaction was modeled in an analogous way using Dunham-like U γ , kl parameters, and fitting its isotopic dependence properly required the use of four Δ γ , kl correction terms.
Laser stark spectroscopy of13CH3F

The far-infrared laser Stark spectrum of13CH3F has been observed using the 190 μm line of the DCN laser. The spectrum was taken at room temperature for both parallel and perpendicular polarizations up to 60,000V/cm. We identify the transition as Jk=3214←3114 in the ground vibrational state. The measured zero-field frequency for this transition is in agreement with that calculated from the available molecular constants.
Heave-roll-pitch correction for hydrographic and multi-beam survey systems

Abstract The development of a new generation of Hydrographic and Bathymetric Survey Systems by the U.S. National Ocean Survey (NOS), is described. New Instrumentation in the form of Multi-Beam Swath Sonars, Heave-Roll-Pitch (HRP) Instrumentation, and power computer systems have been merged to provide a quantum step forward in bathymetric and hydrographic survey techniques. These new systems provide the capability to achieve 100 percent bottom coverage as compared to the 2–5 percent coverage typically achieved by conventional narrow beam survey techniques. Two Bathymetric Swath Survey Systems (BS 3 ) are now under development and approaching operational status within NOS. One utilizes the General Instrument Corporation BO'SUN Sonar as its principal sensor and is optimized for mapping water depths from 20 to 300 fathoms. BO'SUN/BS 3 has been in use for over a year on the NOAA Ship “Davidson” in Alaska and West Coast waters. The second system utilizes the General Instrument Corporation SEABEAM Sonar as its principal sensor. This sonar is designed for deep ocean mapping. SEABEAM/BS 3 is currently undergoing grooming and initial sea trials on board the NOAA Ship “Surveyor”. Functionally, the two systems are very similar. They both employ similar computer hardware and software. Software has been developed that automates the real time survey data acquisition and control as well as the post time processing and production of bottom maps. These systems, when fully groomed and operational, will provide a new dimension to hydrographic and bathymetric Surveys. Results to date have shown a significant improvement in the accuracy and completeness of survey data as compared to more conventional techniques.
Revealing the natural complexity of fluvial morphology through 2D hydrodynamic delineation of river landforms

Abstract Fluvial landforms at the morphological-unit scale (~ 1–10 channel widths) are typically delineated and mapped either by breaking up the one-dimensional longitudinal profile with no accounting of lateral variations or by manually classifying surface water patterns and two-dimensional areal extents in situ or with aerial imagery. Mapping errors arise from user subjectivity, varying surface water patterns when the same area is observed at different discharges and viewpoints, and difficulty in creating a complete map with no gaps or overlaps in delineated polygons. This study presents a new theory for delineating and mapping channel landforms at the morphological-unit scale that eliminates in-field subjective decision making, adds full transparency for map users, and enables future systemic alterations without having to remap in the field. Delineation is accomplished through a few basic steps. First, near-census topographic and bathymetric data are used in a two-dimensional hydrodynamic model to create meter-scale depth and velocity rasters for a representative base flow. Second, expert judgment and local knowledge determine the number and nomenclature of landform types as well as the range of base flow depth and velocity over each type. This step does require subjectivity, but it is transparent and adjustable at any time. Third, the hydraulic landform classification is applied to hydraulic rasters to quickly, completely, and objectively map the planform pattern of laterally explicit landforms. Application of this theory will reveal the true natural complexity, yet systematic organization, of channel morphology.
Coal liquids distillation tower corrosion. Analysis of SRC atmospheric distillation column samples for the presence of a highly corrosive organic chloride compound class

Abstract Samples from the Wilsonville, Alabama, demonstration plant were chemically separated into phenolic, amine and neutral fractions. Each fraction was analyzed for total chloride. The results indicate that the high corrosion rates in the atmospheric distillation tower were not due to the formation of a highly corrosive organic chloride.
Chemical Boundary Layers of the Mantle and Core [Abstract Only]

There is now sufficient information from seismological mapping of the Earth’s deep interior to draw some preliminary conclusions regarding nature of large-scale mantle flow. This paper examines three features of mantle heterogeneity. Seismological studies confirm the existence of a thick (more than 300 km) thermal boundary layer (tbl) beneath the ancient cratonic nuclei. Petrological and gravimetric data imply that the continental tbl is stabilized against convective disruption by a buoyant, viscous, chemical boundary layer (cbl) depleted in Fe and A1 relative to Mg. Geothermal constraints require high heat production within the cbl and low heat flow through its base, indicating that the cbl has been recharged by large-ion lithophile (lil) elements after primary depletion events. Formation of this continental tectosphere cannot be simple conductive cooling, as in the oceans, but must involve several stages characterized by different timescales, terminating with crustal stabilization; the advective thickening of a basalt-depleted, LiL-rich cbl in episodes of compressive orogenesis (e.g. supercontinent assembly) may be an important mechanism for tectospheric consolidation. The stability and low basal heat flow of the cratonic cbl are evidence that the positions of the continents through time are coupled to the upward flow of material from the deep mantle.
Assessing environmental support for better health: Active living opportunity audits in rural communities in the southern United States

Abstract Objective Leisure-time physical activity in the United States is lower rural areas and the South and has been linked to socioeconomic and environmental aspects of where people live. The purpose of this study is to assess the built environment and policies for physical activity in rural communities. Methods Eight rural communities in Alabama and Mississippi were assessed in 2011 using the Rural Active Living Assessment (RALA) street segment (SSA), town-wide (TWA), and town program and policies (PPA) assessment tools. Community Health Advisors Trained as Research Partners (CHARPS) and local staff conducted the assessments. The TWA and PPA were scored by domain and total scores. Data were analyzed using descriptive and nonparametric statistics. Results 117 segments were assessed in 22 towns in 8 counties. Built environmental barriers existed in all communities. Sidewalks were available in only 10–40% of the segments. TWA identified parks and playgrounds as the most available community feature. PPA scores indicated few policies for physical activity outside of school settings with mean scores higher in Mississippi compared to Alabama (61 vs. 49, respectively). Conclusions Multiple components of rural communities can be successfully assessed by CHARPs using RALA tools, providing information about resources and barriers for physical activity.
Comparative evaluation of carcinoembryonic antigen and gross cystic disease fluid protein as plasma markers for human breast carcinoma

A comparative evaluation of carcinoembryonic antigen (CEA) and gross cystic disease fluid protein (GCDFP) as plasma markers for human breast carcinoma has been performed. Both assays appear to be useful in patients with metastatic breast carcinoma. Of 216 patients under treatment for metastatic disease, 111 (51%) had abnormal plasma levels of CEA and/or GCDFP. Abnormal plasma levels of CEA were present in 73 patients whereas abnormal GCDFP levels were present in 67. Twenty-nine patients had increased plasma levels of both markers simultaneously, 44 patients had increased CEA levels only and 38 patients had increased GCDFP levels only. Thus, of the 111 patients with elevated levels of either CEA or GCDFP, the two markers varied independently of each other in 74%. Utilizing both assays, abnormal plasma levels were present in 79% of patients with osseous metastasis, 53% of patients with visceral metastasis and 26% with soft tissue metastasis. Both assays, when performed serially in patients treated for metastatic breast carcinoma, were found to have utility in monitoring responsiveness; and increasing CEA or GCDFP plasma level indicated disease progression and a decreasing plasma level indicated regression.
The redox status of cystinotic fibroblasts

Abstract A key unresolved question in the pathogenesis of phenotype development in nephropathic cystinosis is whether intralysosomal cystine, the hallmark of this lethal inborn error of metabolism, alters cytoplasmic redox potential. Variable findings on this issue have been reported. This study of fetal and non-fetal skin and lung-derived cystinotic fibroblasts compared to origin and age-matched normal control fibroblasts reveals that cystinotic cells do not exhibit redox perturbations. We find that the steady-state redox status as assessed by the [GSH]/[GSSG] ratio, an indicator of the intracellular redox poise, is unchanged in cystinotic cells. Furthermore, the dependence of the intracellular GSH and cysteine pool sizes and the [GSH]/[GSSG] ratio are similarly dependent on the two major sources of cysteine, i.e. the transsulfuration pathway and the plasma membrane cystine transporter, xc − , in both cystinotic and control cells, and the presence of lysosomal cystine has no measurable effect on the redox status of these cells. Hence, mechanisms other than cytosolic redox perturbations are involved in the etiology of nephropathic cystinosis.
When is Motion ‘Motion’?

Examples of visual motion have become more and more abstract over the years, leading up to ‘third-order’ stimuli where direction is actually determined by the observer through top–down attention. But how far can this be pushed—are there motion stimuli that are yet more arbitrary and abstract? Actually, there is a broad class of ‘conceptual motion’ stimuli—things like a moving grating of faces, or a shifting pattern of words—that are perfect analogs to traditional ‘perceptual motion’ stimuli, solvable by the same motion computation and for which observers can readily make direction-of-motion judgments. Interestingly though, these do not produce a sensation of motion (among other automatic consequences of motion detection). Here we compare a luminance-based perceptual motion stimulus to a semantic-based conceptual motion stimulus to contrast the psychophysical hallmarks of these motion categories.
The Role of Photodynamic Therapy in the Esophagus

Photodynamic therapy (PDT) is a drug and device therapy using photosensitizer drugs activated by laser light for mucosal ablation. Porfimer sodium PDT has been used extensively with proven long-term efficacy and durability for the ablation of Barrett esophagus and high-grade dysplasia. and early esophageal adenocarcinoma. However, continued use is hampered by an associated stricture risk and prolonged photosensitivity (4-6 weeks). Promising single-center European studies using other forms of PDT, such as aminolevulinic acid PDT, have not been replicated elsewhere, limiting the widespread use of other forms of PDT. Future use of PDT in esophageal disease depends on the development of improved dosimetry and patient selection to optimize treatment outcomes, while minimizing adverse events and complications.
Large deformations of nonlinear viscoelastic and multi-responsive beams

Abstract This study presents analyses of deformations in nonlinear viscoelastic beams that experience large displacements and rotations due to mechanical, thermal, and electrical stimuli. The studied beams are relatively thin so that the effect of the transverse shear deformation is neglected, and the stretch along the transverse axis of the beams is also ignored. It is assumed that the plane that is perpendicular to the longitudinal axis of the undeformed beam remains plane during the deformations. The nonlinear kinematics of the finite strain beam theory presented by Reissner [27] is adopted, and a nonlinear viscoelastic constitutive relation based on a quasi-linear viscoelastic (QLV) model is considered for the beams. Deformation in beams due to mechanical, thermal, and electric field inputs are incorporated through the use of time integral functions, by separating the time-dependent function and nonlinear measures of field variables. The nonlinear measures are formulated by including higher order terms of the field variables, i.e. strain, temperature, and electric field. Responses of beams under mechanical, thermal, and electrical stimuli are illustrated and the effects of nonlinear constitutive relations on the overall deformations of the beams are highlighted.
Declining cell-mediated immunity is associated with increased chronic disease burden

Abstract Rationale We used delayed type hypersensitivity (DTH) skin testing to examine the hypothesis that declining cell-mediated immunity is more closely linked to chronic disease burden than to chronological age. Methods 58 elderly subjects were tested for delayed type hypersensitivity (DTH) response to Candida antigen. Each subjects' disease burden was quantified using the Cumulative Illness Ratings Scale (CIRS). Higher CIRS score reflects greater disease burden. Mean DTH response by age group ( 79 yo) was compared with mean DTH response by CIRS score ( 15). Total serum IgE levels were measured and similarly stratified by age and CIRS score. Results Mean Candida DTH responsiveness declined progressively with increasing disease burden (increasing CIRS score). Mean DTH responses were 7.4 mm, 3.4 mm, and 0.0 mm for CIRS groups 15 respectively. Interestingly, Candida DTH response showed no progressive decline with advancing age. Mean DTH responses were 5.2 mm, 3.5 mm, and 5.0 mm in subjects 79 yo respectively. Total serum IgE levels increased with advancing age. Mean total IgE levels were 183, 249, and 342 in subjects >71 yo, 71-78 yo, and >79 yo respectively. No correlation was observed between mean total IgE levels and CIRS score. Conclusions We note an inverse relationship between Candida DTH response and CIRS score, suggesting that increased chronic disease burden is associated with diminished cell-mediated immune response. Surprisingly, advancing age did not predict a diminished DTH response in our subjects. No relationship was observed between disease burden and total serum IgE.
Fuzzy variable-branch decision tree

Decision trees and their variants recently have been proposed. All trees used are fixed M-ary tree structured, such that the training samples in each node must be artificially divided into a fixed number of branches. This work proposes a fuzzy variable-branch decision tree (FVBDT) based on the fuzzy genetic algorithm (FGA). The FGA automatically searches for the proper number of branches of each node according to the classification error rate and the classification time of FVBDT. Therefore, FGA reduces both the classification error rate and classification time, and then optimizes the FVBDT. In our experiments, FVBDT outperforms the traditional C-fuzzy decision tree (CFDT) based on the fuzzy C-means (FCM) algorithm.
Mapping model validation metrics to subject matter expert scores for model adequacy assessment

This paper develops a novel approach to incorporate the contributions of both quantitative validation metrics and qualitative subject matter expert (SME) evaluation criteria in model validation assessment. The relationship between validation metrics (input) and SME scores (output) is formulated as a classification problem, and a probabilistic neural network (PNN) is constructed to execute this mapping. Establishing PNN classifiers for a wide variety of combinations of validation metrics allows for a quantitative comparison of validation metric performance in representing SME judgment. An advantage to this approach is that it semi-automates the model validation process and subsequently is capable of incorporating the contributions of large data sets of disparate response quantities of interest in model validation assessment. The effectiveness of this approach is demonstrated on a complex real-world problem involving the shock qualification testing of a floating shock platform. A data set of experimental and simulated pairs of time history comparisons along with associated SME scores and computed validation metrics is obtained and utilized to construct the PNN classifiers through K-fold cross validation. A wide range of validation metrics for time history comparisons is considered including feature-specific metrics (phase and magnitude error), a frequency metric (shock response spectra), a time-frequency metric (wavelet decomposition), and a global metric (index of agreement). The PNN classifiers constructed using a Parzen kernel for the class conditional probability density function whose smoothing parameter is optimized using a genetic algorithm performs well in representing SME judgment.
Becoming Literate, Being Human: Adult Literacy and Moral Reconstruction in Botswana

This article draws on ethnographic research to examine relationships between literacy and identity for newly literate men and women in the southern African country of Botswana. Situating beliefs about literacy in the intersection of evangelical missionary discourse, colonial-era labor practices, and modernity rhetoric, I argue that literacy is attributed with the power to transform oneself and describe an adult learning community that based pedagogy in these shared beliefs about literacy. [literacy practices, adult education, southern Africa, ethnographic research]
Quantitative assessment of myocardial scar in delayed enhancement magnetic resonance imaging

Purpose To characterize the extent and distribution of left ventricular myocardial scar in delayed enhancement magnetic resonance imaging (MRI). Materials and Methods Delayed enhancement images from 18 patients were categorized into three groups based on myocardial scar appearance: discrete myocardial infarction (N = 10), diffuse fibrosis (N = 4), and circumferential endocardial scarring (N = 4). Images were segmented manually by two observers (twice by one observer) to identify nonviable myocardium. Scar was characterized by the following morphologic parameters: the relative area of nonviable myocardium (Percent Scar); a measure of scar cohesion (Patchiness); and the extent to which scar traversed the ventricle wall (Trans>50). Results The three scar parameters successfully discriminated between patient groups, although no one parameter was able to differentiate between all groups. The average bias between readers was approximately 3% for each parameter, and the average bias between repeated measurements was 1%. In addition, five patients exhibited regions of nonhyperenhanced nonviable myocardium that were expected to show hyperenhancement based upon their location within the infarct zone and appearance on cine images. Conclusion Quantitative characterization of myocardial scar showed good interobserver and intraobserver agreement. However, the appearance of nonhyperenhanced scar in chronic ischemia is problematic for segmentation of delayed enhancement images. J. Magn. Reson. Imaging 2003;18:434–441. © 2003 Wiley-Liss, Inc.
Apolipoprotein E: Essential Catalyst of the Alzheimer Amyloid Cascade

The amyloid cascade hypothesis remains a robust model of AD neurodegeneration. However, amyloid deposits contain proteins besides Aβ, such as apolipoprotein E (apoE). Inheritance of the apoE4 allele is the strongest genetic risk factor for late-onset AD. However, there is no consensus on how different apoE isotypes contribute to AD pathogenesis. It has been hypothesized that apoE and apoE4 in particular is an amyloid catalyst or “pathological chaperone”. Alternatively it has been posited that apoE regulates Aβ clearance, with apoE4 been worse at this function compared to apoE3. These views seem fundamentally opposed. The former would indicate that removing apoE will reduce AD pathology, while the latter suggests increasing brain ApoE levels may be beneficial. Here we consider the scientific basis of these different models of apoE function and suggest that these seemingly opposing views can be reconciled. The optimal therapeutic target may be to inhibit the interaction of apoE with Aβ rather than altering apoE levels. Such an approach will not have detrimental effects on the many beneficial roles apoE plays in neurobiology. Furthermore, other Aβ binding proteins, including ACT and apo J can inhibit or promote Aβ oligomerization/polymerization depending on conditions and might be manipulated to effect AD treatment.
Factors Affecting Growth Response of Turkeys Administered Estradiol-17-Monopalmitate

Abstract IN ORDER to evaluate further the role of a single subcutaneous injection of estradiol-17-monopalmitate (EMP) in polyethylene glycolic paste in young tom turkeys (Moreng and Hopwood, 1966) six additional growth trials were conducted to evaluate: (1) duration of treatment, (2) type of diet, (3) repeat treatment, (4) response by sex, and (5) variety response. The study involved six trials conducted during the 1965 growing season, July through December. Based upon previous results (Moreng and Hopwood, 1966) it was concluded that a 30 mg. level per bird of EMP should be utilized throughout the study. PROCEDURE The first portion was designed to evaluate the response of the Colorado Agricultural Experiment Station strain of Broad Breasted Bronze turkeys to two different dietary regimes over a growth period 16 to 24 weeks of age inclusive. This portion of the study (trial 1) involved four groups of 25 birds each; two groups were fed …
Extinction risks from climate change

Biologists worry that the rapid rates of warming projected for the planet ( 1 ) will doom many species to extinction. Species could face extinction with climate change if climatically suitable habitat disappears or is made inaccessible by geographic barriers or species' inability to disperse (see the figure, panels A to E). Previous studies have provided region- or taxon-specific estimates of biodiversity loss with climate change that range from 0% to 54%, making it difficult to assess the seriousness of this problem. On page 571 of this issue, Urban ( 2 ) provides a synthetic and sobering estimate of climate change–induced biodiversity loss by applying a model-averaging approach to 131 of these studies. The result is a projection that up to one-sixth of all species may go extinct if we follow “business as usual” trajectories of carbon emissions.
Proinflammatory Adipokine Leptin Mediates Disinfection Byproduct Bromodichloromethane-induced Early Steatohepatitic Injury in Obesity

Today's developed world faces a major public health challenge in the rise in the obese population and the increased incidence in fatty liver disease. There is a strong association among diet induced obesity, fatty liver disease and development of nonalcoholic steatohepatitis but the environmental link to disease progression remains unclear. Here we demonstrate that in obesity, early steatohepatitic lesions induced by the water disinfection byproduct bromodichloromethane are mediated by increased oxidative stress and leptin which act in synchrony to potentiate disease progression. Low acute exposure to bromodichloromethane (BDCM), in diet-induced obesity produced oxidative stress as shown by increased lipid peroxidation, protein free radical and nitrotyrosine formation and elevated leptin levels. Exposed obese mice showed histopathological signs of early steatohepatitic injury and necrosis. Spontaneous knockout mice for leptin or systemic leptin receptor knockout mice had significantly decreased oxidative stress and TNF-α levels. Co-incubation of leptin and BDCM caused Kupffer cell activation as shown by increased MCP-1 release and NADPH oxidase membrane assembly, a phenomenon that was decreased in Kupffer cells isolated from leptin receptor knockout mice. In obese mice that were BDCM-exposed, livers showed a significant increase in Kupffer cell activation marker CD68 and, increased necrosis as assessed by levels of isocitrate dehydrogenase, events that were decreased in the absence of leptin or its receptor. In conclusion, our results show that exposure to the disinfection byproduct BDCM in diet-induced obesity augments steatohepatitic injury by potentiating the effects of leptin on oxidative stress, Kupffer cell activation and cell death in the liver.
Focal Plane Testing From A Production Point Of View: A Tutorial

Abstract Focal plane production testing to be cost and schedule effective involves many tradeoffs which appear very difficult to optimize. This optimization appears particularly difficult for the more sophisticated devices which have detailed and interactive specifications. These tradeoffs will be broken down into major categories with clear optimization procedures and guidelines provided so that their individual impacts will be more easily understood.Production yields of focal planes can be significantly increased and costs reduced - the technology and techniques are at hand. The manufacturers ability can be further optimized through wise, concise testing at cryogenic temperatures which has long been an industry bottleneck.The six major categories to be discussed are: 1) Go/No Go Testing; 2) Characterization; 3) Specification Ys Performance and Cost Tradeoffs; 4) Earliest Significant Testing; 5) Room and Cryogenic Temperature Testing and 6) Self and Diagnostic Testing. Practical examples will be shown to demonstrate the basic techniques so that a firm foundation of each of the major categories will be obtained.IntroductionBefore we get started let's review the typical device evolution from feasibility to focal plane delivery. The major steps are indicated in Figure 1. The focal plane test require­ ments are more involved than most devices due to mainly the addition of both a flux and a low temperature cooling requirement. These requirements are listed in Table 1.
The effect of intraocular tetrodotoxin on the postnatal reduction in the numbers of optic nerve axons in the rat

We have examined the effects of blocking retinal ganglion cell activity with the sodium channel blocker tetrodotoxin (TTX) on the postnatal reduction in the number of optic nerve axons (and, by interference, the degree of ganglion cell loss in the retina). TTX was injected every other day into the left eyes of a series of albino rats beginning on the day of birth, continuing through the 3rd, 7th, 12th or 14th days when the animals were killed and the optic nerves from both eyes were prepared for electron microscopy. The numbers of axons in the TTX treated and untreated optic nerves from the opposite side were determined from electron micrographs, and compared to the number seen in normal rats at the same ages. Both the magnitude and the time course of the reduction in the number of axons in the TTX-treated and untreated nerves were found to be similar to those seen in normal animals. However, there was a slight reduction in the loss of optic axons in the untreated nerves on the side opposite the TTX injections; this attenuation in axon loss could be mimicked by large systemic injections of TTX, and is probably attributable to a general systemic effect following repeated intraocular injections. These findings indicate that blocking ganglion cell activity with intraocular injections of TTX has little effect on the normal rate of axon loss from the optic nerve and on the numbers of ganglion cells that die during the first two weeks of postnatal life.
An environmental approach to informal evaluation in preschools

Informal evaluation need not be restricted to evaluation of children; evaluation ofthe extent to which classrooms provide settings conductive to development may also be valuable. This article reports a set of instruments used for the evaluation of aspects of preschool classrooms hypothesized to have important effects on children's literacy and literacy-related language development. Results from observations using these instruments in 22 classrooms serving low-income children reveal frequent efforts to provide a broad curriculum (e.g., science and social studies) and standard preschool literacy experiences (e.g, book area, book reading), but great variability in the extent to which teachers support literacy through involving children in producing text displayed in the room, and in the amount of time spent reading books. When additional data are available from a variety of classrooms, such instruments could be of value to program directors interested in evaluating their classroom's language and literacy environment.
Immunoscintigraphy with a new indium-111-labeled monoclonal antibody (MAb 1A3) in patients with colorectal cancer

PURPOSE: This study was designed to evaluate a new anticolorectal carcinoma monoclonal antibody (1A3), conjugated with the bifunctional chelating agent N,N′-bis (2-hydroxybenzyl) 1 (4-bromoacetamidobenzyl) 1,2-ethylenediamine-N,N′-diacetic acid and labeled with indium-111, in a Phase I/II study involving 38 patients with localized or advanced colorectal cancer. METHODS: Patients were injected with indium-111-N,N′-bis(2-hydroxybenzyl) 1 (4-bromoacetamidobenzyl) 1,2-ethylenediamine-N, N′-diacetic acid-monoclonal antibody 1A3 (1–50 mg, 1–5 mCi) and imaged at two or three sessions one to five days later. Scintigraphic findings were compared with radiologic, pathologic, surgical, and other clinical findings to assess the accuracy of radioimmunoscintigraphy. RESULTS: At least one known tumor site was clearly defined by planar scintigraphy in 29 (76 percent) patients. Increased radioactivity was seen in 40 of 63 known tumor sites (37/43 abdominal-pelvic, 3/15 hepatic, and 0/5 pulmonary sites) without any apparent dose-related effects. Nineteen previously undetected sites were considered positive by imaging, and, of these, six were biopsy-proven tumor sites, four were probable tumor sites, three were definitely false positive sites, and six were probable false positive sites. Radioimmunoscintigraphy detected proven tumor in 15 of 16 patients with negative or equivocal computed tomography results. Of the 28 patients with rectosigmoid cancer, 25 (89 percent) had positive studies with 34 of 47 tumor sites showing definite uptake on the scintigrams. This included 3 of 9 hepatic metastases. The only adverse reaction occurred in one patient who developed transient hives. Human anti-mouse antibody responses occurred in approximately one-half of the patients injected with doses of 10 or 50 mg. CONCLUSION: This study shows that radioimmunoscintigraphy with this indium-111-labeled monoclonal antibody is safe, it can detect most nonhepatic abdominalpelvic tumors with a positive predictive value of 83 (44/ 53) percent, and it should prove to be useful, particularly in the diagnosis of recurrent rectal carcinoma.
Redefining Men's Sexuality, Resignifying Male Bodies: The Argentine Law of Anti‐Venereal Prophylaxis, 1936

By analysing governmental, legal and medical sources, this article examines Argentina's first national law of anti-venereal prophylaxis enacted in 1936. It argues that two aspects of the law, the abolition of legalised prostitution and the mandatory prenuptial medical exam and certificate for men, especially signalled a shift in the state's concern for men's sexuality. The essay demonstrates that this shift was based on the legal and medical recognition of men's reproductive role, its impact on the health of the family and the biological destiny of the nation, and the consideration of the male body as a carrier of venereal diseases and an agent of contagion. This interest in men's sexuality was also the result of the limits the state confronted in its attempts to target women. The law imposed new controls over men because the medical surveillance of prostitutes had proved to be a sanitary failure, and the medical examination and certificate for single women was rejected since it went against beliefs regarding female purity and virginity. This article shows how, under the influence of eugenics, the state turned to the sanitary surveillance of men to prevent venereal contagion and to assure healthy procreation by assuming a new interventionist and paternalist role as the guarantor of public health, the promoter of the hygienic family, and the entity responsible for the protection of wives and children through the control of the male body.
Site specific constraints on shell selection behavior in the hermit crab, Clibanarius vittatus

Site‐specific constraints on shell selection behavior in the hermit crab Clibanarius vittatus were studied with both laboratory and field experiments at two sites along the Louisiana coast. At both sites, crabs selected larger Stramonita haemastoma shells in field experiments. Although discarded shells were often no smaller than selected shells, they did show heavy damage by predators. Crabs in both populations inhabited shells that were on average larger than those of living 5. haemastoma as well as those discarded in experiments. Although these results suggest that larger, undamaged shells may be a limiting resource, crabs collected from a site with few intermediate sized 5. haemastoma actually selected smaller shells in the laboratory. Clibanarius vittatus also selected the stronger, higher spired shell of S. haemastoma over Polinices duplicatus in both laboratory and field experiments, suggesting predation risk plays a role in shell choice. Although crabs in P. duplicatus shells were no more vulnerabl...
C-MYC Transcriptionally Amplifies SOX2 Target Genes to Regulate Self-Renewal in Multipotent Otic Progenitor Cells

Sensorineural hearing loss is caused by the loss of sensory hair cells and neurons of the inner ear. Once lost, these cell types are not replaced. Two genes expressed in the developing inner ear are c-Myc and Sox2. We created immortalized multipotent otic progenitor (iMOP) cells, a fate-restricted cell type, by transient expression of C-MYC in SOX2-expressing otic progenitor cells. This activated the endogenous C-MYC and amplified existing SOX2-dependent transcripts to promote self-renewal. RNA-seq and ChIP-seq analyses revealed that C-MYC and SOX2 occupy over 85% of the same promoters. C-MYC and SOX2 target genes include cyclin-dependent kinases that regulate cell-cycle progression. iMOP cells continually divide but retain the ability to differentiate into functional hair cells and neurons. We propose that SOX2 and C-MYC regulate cell-cycle progression of these cells and that downregulation of C-MYC expression after growth factor withdrawal serves as a molecular switch for differentiation.
The effects of immigration on children in the Mexican-American community

Effects of immigration on Mexican-American immigrant children and families can be lifelong. This article describes conditions contributing to immigration and its effects on poor families, describing and illustrating developmental disruptions, and emphasizing effects on school participation and family dynamics.