cssi/SciSciGPT-SciSciNet huggingface dataset:
Platelet-activating factor acetylhydrolase: selective inhibition by potent n-alkyl methylphosphonofluoridates

Abstract Platelet-activating factor (PAF) is a potent endogenous phospholipid modulator of diverse biological activities, including inflammation and shock. PAF levels are primarily regulated by PAF acetylhydrolases (PAF-AHs). These enzymes are candidate secondary targets of organophosphorus (OP) pesticides and related toxicants. Previously known OP inhibitors of other serine hydrolases were tested with PAF-AH from mouse brain and testes of established functional importance compared with the structurally different human plasma enzyme. Several key OP pesticides and their oxon metabolites were very poor inhibitors of mouse brain and human plasma PAF-AH in vitro but moderately active for mouse brain and blood PAF-AH in vivo (e.g., tribufos defoliant and profenofos insecticide, presumably following oxidative bioactivation). OP compounds were then designed for maximum in vitro potency and selectivity for mouse brain PAF-AH vs. acetylcholinesterase (AChE). Lead compounds were found in a series of benzodioxaphosphorin 2-oxides. Ultrahigh potency and selectivity were achieved with n -alkyl methylphosphonofluoridates (long-chain sarin analogs): mouse brain and testes IC50 ≤ 5 nM for C 8 –C 18 analogs and 0.1–0.6 nM for C 13 and C 14 compounds; human plasma IC50 ≤ 2 nM for C 13 –C 18 analogs. AChE inhibitory potency decreased as chain length increased with maximum brain PAF-AH/AChE selectivity (>3000-fold) for C 13 –C 18 compounds. The toxicity of i.p.-administered PAF (LD50 ca. 0.5 mg/kg) was increased less than 2-fold by pretreatment with tribufos or the C 13 n -alkyl methylphosphonofluoridate. These studies with a mouse model indicate that PAF-AH is not a major secondary target of OP pesticide poisoning. The optimized PAF-AH inhibitors may facilitate investigations on other aspects of PAF metabolism and action.
Breeding success at the range margin of a desert species: implications for a climate-induced elevational shift

If the breeding range of a species is limited by biotic or abiotic environmental factors that depress breeding success at the range margin, then range expansion is expected when those limiting factors are alleviated. Over a three-year period, we measured breeding success of a desert species, black-throated sparrow Amphispiza bilineata, along a steep elevation gradient between the Peninsular Mountains and Colorado Desert (San Diego County, California) that is undergoing a warming trend. We compared breeding success at geographically marginal locations (higher-elevation chaparral sites) to more central locations (lower-elevation desert scrub sites) only a short distance apart. Breeding success was measured at the nest level, territory level, and population level. At each level measured, breeding success tended to be greater at higher-elevation chaparral sites at the distribution margin compared to lower-elevation sites where the bird was more common. Black-throated sparrows had 100% reproductive failure at lower-elevation sites during the two driest years of our study (2006–2007), but did relatively well at higher-elevation sites. Only in a wetter year (2008) was breeding success improved at lower-elevation sites. Surprisingly, there was no evidence of an upward elevational shift in distribution over a 26-year period despite a clear warming trend and drier conditions. Greater territory density at lower-elevation sites with reproductive failure during dry years suggests the possibility of an ecological trap in this system, which could prevent or delay climate-induced range shifts. A common presumption has been that desert species will undergo relatively mild negative impacts due to a warming climate, but it is possible that some desert species are already at or near their temperature and aridity tolerance limits within their current range and shifts may not always be possible.
Central dogma at the single-molecule level in living cells

Gene expression originates from individual DNA molecules within living cells. Like many single-molecule processes, gene expression and regulation are stochastic, that is, sporadic in time. This leads to heterogeneity in the messenger-RNA and protein copy numbers in a population of cells with identical genomes. With advanced single-cell fluorescence microscopy, it is now possible to quantify transcriptomes and proteomes with single-molecule sensitivity. Dynamic processes such as transcription-factor binding, transcription and translation can be monitored in real time, providing quantitative descriptions of the central dogma of molecular biology and the demonstration that a stochastic single-molecule event can determine the phenotype of a cell.
Tackling Tough Topics: Using Socio-Scientific Issues to Help Museum Visitors Participate in Democratic Dialogue and Increase Their Understandings of Current Science and Technology

AbstractIn a world of increasing scientific and technological complexity, where science and technology play an expanding role in our lives, there is need for a democratic citizenry that is skilled at discussing and making choices that are informed by science and shaped by individual and collective values. Although an oft argued rationale for teaching science is the need for informed citizens, few have connected science education goals to democratic dialogue. At the Museum of Science, taking on this task—to promote democratic dialogue and teach the public about current science and technology—has meant a change in our approach to science education over the past decade. We know that creating an informed citizenry prepared to address today's challenges requires educating the public about cutting edge science and technology research connected to the issues of the day, but it also requires moving beyond a public understanding of science model to a public engagement with science model in which the public's exper...
Should we routinely perform liver biopsy in suspected alcoholic liver disease

The traditional arguments for routinely performing liver biopsy in patients with suspected alcoholic liver disease are examined. These arguments may not withstand critical scrutiny and, in most substances, clinical diagnosis may suffice.
Physical and nutritional properties of baby food containing menhaden oil (Brevoortia tyrannus) and microencapsulated menhaden oil

Purified menhaden oil (PMO) was characterized and microencapsulated. Baby foods containing PMO and microencapsulated purified menhaden oil (MPMO) were evaluated and compared. PMO had higher total omega-3, total saturated, total monounsaturated, DHA, and EPA contents than MPMO. Emulsion containing PMO (EPMO) exhibited viscoelastic characteristic and droplet size of EPMO was around 2–10 μm. The DHA and EPA in the PMO were reduced in MPMO. All baby-food samples with added fish oils had similar FFA values and color. DHA and EPA of baby food were significantly increased by adding PMO and/or MPMO. Total percent values for omega-3 fatty acids of extracted fat from commercial baby food (CB), commercial baby food containing PMO (BPMO), and commercial baby food containing MPMO (BMPMO) were 4.5, 9.8 and 10.1%, respectively.
Towards massively-parallel analytic capabilities for multielectrode recordings

Multielectrode recordings now reliably deliver simultaneous signals from a hundred or more neurons or networks. However, many analytic techniques are presently computationally limited to smaller numbers of signals, severely hampering our ability to relate these neural signals to brain functions including sensation, perception, decision, and action. To address this imbalance, the Laboratory of Neuroinformatics has begun developing a new open source Neurophysiology Extended Analysis Tool [NEAT]. NEAT leverages existing code bases and new massively-parallel computational technology to enable any multielectrode lab to perform high-throughput informative analyses. The goal is to enable neurophysiologists using arrays in cortex and elsewhere to perform analyses online, in real time, that now can be done only offline, and to make possible analyses offline that are now impractical for the number of neurons routinely available to new recording methods. The method is to extend our neuroanalysis.org information-theoretic and other spike train analytics to new graphics-processor-derived computational engines [GPUs] supplied on inexpensive drop-in cards. We have begun by evaluating computational bottlenecks in analytic routines, many information-theoretic, developed for our existing Spike Train Analysis Toolkit [STAToolkit]. The STAToolkit is in wide use, having been distributed via neuroanalysis.org to over 1,700 sites [1]. Central to this effort is appreciation of the specific capabilities and restrictions of GPU-parallel platforms. Our experience, that of others in our project who have used GPUs for other areas of biomedicine, and reports from the EEGLab community, all confirm that generic or library-based solutions show only modest performance gains. We project a greater than order of magnitude speedup that will allow many offline analyses to be performed in real time during experiments, and now-impractical questions to be explored offline in reasonable compute times. For example, pairwise analyses now possible on 10 or fewer neurons may be extendible to 50 or more. We focus on information-theoretic measures and standard pair-wise correlations, JPSTHs, spectra, coherences, and new and significant analyses that present significant loads for multineuron recordings. To aid communities planning similar GPU-enabled analyses, we note that the complex, structured, and hierarchic GPU architecture requires special optimization strategies: • decomposing code into >1,000 simultaneous threads is needed to efficiently use the 448 cores on new GPUs, • data should be loaded into on-chip memory once and re-used, avoiding transfers to other memory layers, • kernel processes must optimize thread/kernel and thread/block instruction execution in few clock cycles, • flow control code should control multi-thread warps, not individual threads.
Building Statistical Language Models of code

We present the Source Code Statistical Language Model data analysis pattern. Statistical language models have been an enabling tool for a wide array of important language technologies. Speech recognition, machine translation, and document summarization (to name a few) all rely on statistical language models to assign probability estimates to natural language utterances or sentences. In this data analysis pattern, we describe the process of building n-gram language models over software source files. We hope that by introducing the empirical software engineering community to best practices that have been established over the years in research for natural languages, statistical language models can become a tool that SE researchers are able to use to explore new research directions.
Observer performance in the localization of tubes and catheters on digital chest images: The role of expertise and image enhancement

Rationale and Objectives. To determine whether observer performance in the localization of tubes and catheters on computed radiography (CR) chest images can be improved by using an automatic image-processing algorithm. Methods. Comparisons were made of CR hard-copy, CR soft-copy, and CR enhanced soft-copy images obtained with an image-processing algorithm. The enhanced images used gray-level optimization and nonlinear unsharp masking to emphasize the edges of the devices. Chest radiologists (n = 4), general radiologists (n = 4); and interns (n = 6) read 45 images that contained endotracheal tubes, pulmonary artery catheters, and central venous catheters. Results. Chest radiologists had the smallest mean interobserver localization variability (4 mm), followed by general radiologists (6 mm) and interns (8 mm). Localization variability was greatest for hard-copy images and least for enhanced soft-copy images. Conclusion. Use of an automatic imaging-processing algorithm reduced localization variability and enabled the medical interns to perform at approximately the same level as the chest radiologists.
Substantial Discrepancy Between Fluid and Weight Loss During Acute Decompensated Heart Failure Treatment.

Abstract Background Net fluid and weight loss are used ubiquitously to monitor diuretic response in acute decompensated heart failure research and patient care. However, the performance of these metrics has never been evaluated critically. The weight and volume of aqueous fluids such as urine should be correlated nearly perfectly and with very good agreement. As a result, significant discrepancy between fluid and weight loss during the treatment of acute decompensated heart failure would indicate measurement error in 1 or both of the parameters. Methods The correlation and agreement (Bland-Altman method) between diuretic-induced fluid and weight loss were examined in 3 acute decompensated heart failure trials and cohorts: (1) Diuretic Optimization Strategies Evaluation (DOSE) (n = 254); (2) Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness (ESCAPE) (n = 348); and (3) Penn (n = 486). Results The correlation between fluid and weight loss was modest (DOSE r = 0.55; ESCAPE r = 0.48; Penn r = 0.51; P P ≤ .002). A consistent pattern of baseline characteristics or in-hospital treatment parameters that could identify patients at risk of discordant fluid and weight loss was not found. Conclusions Considerable discrepancy between fluid balance and weight loss is common in patients treated for acute decompensated heart failure. Awareness of the limitations inherent to these commonly used metrics and efforts to develop more reliable measures of diuresis are critical for both patient care and research in acute decompensated heart failure.
Erratum to “Correcting reaction rates measured by saturation-transfer magnetic resonance spectroscopy” [J. Magn. Reson. 191 (2008) 248–258]

1090-7807/$ see front matter 2007 Elsevier Inc. All rights reserved. doi:10.1016/j.jmr.2012.02.010 DOI of original article: 10.1016/j.jmr.2007.12.015 ⇑ Corresponding author at: Division of MR Research, Dept of Radiology, The Johns Hopkins University, Park Bldg. 310, 600 North Wolfe St., Baltimore, MD 21287, USA. E-mail address: bottoml@mri.jhu.edu (P.A. Bottomley). Table 4 Coefficients of the correction polynomials used in Eq. (11) for the progressive saturation a
Regulating Automobile Pollution under Certainty, Competition, and Imperfect Information

Abstract This paper studies an integrated economic model of automobile emissions that incorporates consumer mileage, automobile feature, and fuel content choices. Subject to informational constraints that bind the government, optimal regulatory policies are shown to include fuel content standards, gasoline taxes, and direct automobile regulation or taxation. Optimal automobile taxes are tied to the mileage that regulators can anticipate will be driven on a given car. In dynamic environments, constrained efficiency can be achieved by periodic automobile taxes or, under some circumstances, a combination of new car regulation and accelerated vehicle retirement subsidies. Desired properties of vehicle retirement programs are discussed.
Diurnal variation of dissolved gaseous mercury (DGM) levels in a southern reservoir lake (Tennessee, USA) in relation to solar radiation

Abstract Variations of dissolved gaseous mercury (DGM) concentrations in a southern reservoir lake (Cane Creek Lake, Cookeville, TN, USA) in relation to solar radiation were investigated consecutively from June 2003 to May 2004. The daytime DGM levels in the lake exhibited a two-phase diurnal trend; the DGM concentrations rose in the morning, peaked around noontime and then fell in the afternoon through the evening; these trends followed the general pattern of diurnal solar radiation variations. The morning and afternoon phases appeared to be asymmetrical with the former relatively steep and the latter gradual. A variety of daytime DGM level variations other than the typical two-phase diurnal patterns were also observed. For the time spans studied, the daytime mean DGM concentrations of the lake ranged from 12 to 68 pg L − 1 (60–340 fM). The daytime mean DGM levels in the summertime (June, July, August) showed values above 30 pg L − 1 (150 fM) in most cases and a large number of peak DGM concentrations above 50 pg L − 1 (250 fM). The summer DGM levels in the lake appear to be comparable to those observed in the large northern lakes for the summertime. The daytime DGM levels in the lake were found to correlate with solar radiation to various degrees (cases of r values above 0.8: ∼ 12% and ∼ 18% of the total sampling days for correlation with global solar radiation and UVA radiation, respectively). Correlating trends are recognizable between the daytime mean DGM concentration and the corresponding mean global solar radiation ( r = 0.66, p r = 0.62, p
A novel small acid soluble protein variant is important for spore resistance of most Clostridium perfringens food poisoning isolates.

Clostridium perfringens is a major cause of food poisoning (FP) in developed countries. C. perfringens isolates usually induce the gastrointestinal symptoms of this FP by producing an enterotoxin that is encoded by a chromosomal (cpe) gene. Those typical FP strains also produce spores that are extremely resistant to food preservation approaches such as heating and chemical preservatives. This resistance favors their survival and subsequent germination in improperly cooked, prepared, or stored foods. The current study identified a novel α/β-type small acid soluble protein, now named Ssp4, and showed that sporulating cultures of FP isolates producing resistant spores consistently express a variant Ssp4 with an Asp substitution at residue 36. In contrast, Gly was detected at Ssp4 residue 36 in C. perfringens strains producing sensitive spores. Studies with isogenic mutants and complementing strains demonstrated the importance of the Asp 36 Ssp4 variant for the exceptional heat and sodium nitrite resistance of spores made by most FP strains carrying a chromosomal cpe gene. Electrophoretic mobility shift assays and DNA binding studies showed that Ssp4 variants with an Asp at residue 36 bind more efficiently and tightly to DNA than do Ssp4 variants with Gly at residue 36. Besides suggesting one possible mechanistic explanation for the highly resistant spore phenotype of most FP strains carrying a chromosomal cpe gene, these findings may facilitate eventual development of targeted strategies to increase killing of the resistant spores in foods. They also provide the first indication that SASP variants can be important contributors to intra-species (and perhaps inter-species) variations in bacterial spore resistance phenotypes. Finally, Ssp4 may contribute to spore resistance properties throughout the genus Clostridium since ssp4 genes also exist in the genomes of other clostridial species.
Cyclic light intensity threshold for retinal damage in albino rats raised under 6 Lx

This study determined the minimum cyclic (12L:12D) light intensity which produces retinal damage in albino (Sprague-Dawley) rats raised from birth to 15 weeks of age under 6 lx (12L:12D). Four experimental light intensities were tested, viz. 1345, 270, 130 and 65 lx. Control animals remained under 6 lx. After various durations of exposure to one of the intensities tested, the retinas of groups of six rats were evaluated for physiological and morphological evidence of light damage. The indices of damage were: (1) histological and morphometric changes in the retina, and (2) changes in the amplitude and latency of the b-wave of the electroretinogram. Light intensities of 1345- or 270 lx severely damage retinas of albino rats raised from birth under 6 lx within 3-7 days of the initiation of light exposure. Exposure to 130- or 65 lx produced much less dramatic changes in the responsiveness and morphology of the retina that did not appear to be permanent. Based on these results, a reasonable estimate for the threshold cyclic-light intensity which produces damage to retinas of albino rats raised under 6 lx lies between 65- and 130 lx, or slightly more than 1 log unit above the light intensity under which the animals were raised. The effects of an animal's light history on retinal susceptibility to light damage are discussed.
Time-dependent inhibition of neuronal nitric oxide synthase by N-propargylguanidine

Abstract N-Propargylguanidine was synthesized and found to be a time-dependent inhibitor of neuronal nitric oxide synthase from bovine brain. No inactivation occurs when NADP+ is substituted for NADPH, inhibition is blocked by L-arginine, but not D-arginine, and no enzyme reactivation occurs by dilution of inactivated enzyme with excess L-arginine.
Document search interface design for large-scale collections and intelligent access

As the universe of documents has enlarged from those available via the online catalog to a larger cluster of databases and web-accessible resources, interfaces are being created that can search multiple document collections simultaneously. Also, searching for document surrogates is losing favor as more documents are digitized and distributed in full-text form. Availability of full-text makes it possible for document components such as tables, illustrations, citations, and references -- components that traditionally remained outside the scope of document searching -- to be considered and exploited by search interface designers. Additionally, due to the popularity of web-hyperlinking people are beginning to expect linking of documents across different collections based on common semantic or non-semantic attributes. Increased research activity on artificial intelligence techniques for document access is leading to more fundamental changes in document searching. It is now possible to delegate 100% of the search effort to online search agents. Agents have been also created for performing tasks such as selecting appropriate collections, refining queries, and sorting results to assist with searches conducted in distributed environments. The broad scope of the workshop is on the impact of above technological changes on search interface design.
Magnetic-field-enhanced rf argon plasma for ionized sputtering of copper

A multipole magnetic field was used to increase the ion density of an inductively coupled rf (13.5 MHZ) argon plasma for ionized magnetron sputtering of copper (Cu). Langmuir probe measurements showed an increase of plasma density over a factor of 2 with the application of the magnetic field. At an argon pressure of 15 mTorr and a rf power of 600 W, an ion density of 1.2×1012 ions/cm3 was achieved. When this plasma was applied to ionize the magnetron sputtered Cu vapor, a high emission intensity ratio from the Cu+ ion line to the Cu neutral line was observed from the optical emission spectroscopy, suggesting a high ionization fraction for the sputtered Cu vapor.
Cytological and Cytogenetic Analysis of Large Circulating Cells from Blood

Introduction: Cancer cells found in circulation are believed to disseminate from tumors and form secondary metastatic sites. These cells, termed circulating tumor cells (CTCs), can provide a crucial cell source for cytology and cytogenetic analysis or cancer diagnosis, treatment monitoring, and personalized therapy identification. However, CTCs are difficult to isolate from the large number of contaminating blood cells and occur at extremely low frequencies (1-500 CTCs/mL blood). Standard modes of isolation and analysis use antibodies targeted against epithelial protein markers. However, due to intra/ inter-tumor heterogeneity, there is a need for label-free isolation and analysis of alternative characteristics that may correlate more accurately with the malignant phenotype. Our approach isolates and concentrates larger circulating cells into a small volume, enabling facile downstream cytological and fluorescence in situ hybridization (FISH) analyses compared to previous approaches. Material and Methods: We use a recently introduced microfluidic device that generates size-dependent shear gradient forces to selectively concentrate larger cells from blood into fluid vortices (Figure 1). In contrast to label-intensive methods, the isolated cells can easily be released from the device and collected in suspension for downstream analysis. Results: We have successfully isolated and detected atypical cells from patients diagnosed with adenoand squamous cell carcinoma through conventional Papanicolau staining (Figure 2). Similar morphological features are also seen in the corresponding primary tumors. Furthermore, we have detected the anaplastic lymphoma kinase (ALK) chromosomal translocation in circulating cells isolated from patients with the same genetic abnormality in their primary tumors (Figure 3). Conclusions: The detection of circulating cells that share similar morphological and genetic signatures as the primary tumor indicates their common site of origin. This demonstrates the utility of enriching and analyzing these potentially malignant cells in a label-free fashion, which can provide a noninvasive method to monitor disease progression and help guide clinical decision-making. 177
Klippel-Trénaunay syndrome: spectrum and management.

• Objective To describe a series of 252 patients with Klippel-Trenaunay syndrome (KTS), a rare congenital malformation characterized by the triad of capillary malformations, atypical varicosities or venous malformations, and bony or soft tissue hypertrophy usually affecting one extremity. • Material and Methods We reviewed the clinical characteristics and findings in 136 female and 116 male patients with KTS who underwent assessment at Mayo Clinic Rochester between January 1956 and January 1995. In addition, management options are discussed. • Results Capillary malformations (port-wine stains) were found in 246 patients (98%), varicosities or venous malformations in 182 (72%), and limb hypertrophy in 170 (67%). AII three features of KTS were present in 159 patients (63%), and 93 (37%) had two of the three features. Atypical veins, including lateral veins and persistent sciatic vein, occurred in 182 patients (72%). Operations performed in 145 patients with KTS included epiphysiodesis, stripping of varicose veins or venous malformations, excision of vascular malformations, amputations, and debulking procedures. • Conclusion Most patients with KTS should be managed conservatively. The clearest indication for operation is a leg length discrepancy projected to exceed 2.0 cm at skeletal maturity, which can be treated with epiphysiodesis in the growing child. If a functioning deep vein system is present, removal of symptomatic varicosities or localized superficial venous malformations in selected patients can yield good results.
Vascular complications and diabetes: current therapies and future challenges.

Diabetic retinal complications, including macular edema (DME) and proliferative diabetic retinopathy (PDR), are the leading cause of new cases of blindness among adults aged 20–74. Chronic hyperglycemia, considered the underlying cause of diabetic retinopathy, is thought to act first through violation of the pericyte-endothelial coupling. Disruption of microvascular integrity leads to pathologic consequences including hypoxia-induced imbalance in vascular endothelial growth factor (VEGF) signaling. Several anti-VEGF medications are in clinical trials for use in arresting retinal angiogenesis arising from DME and PDR. Although a review of current clinical trials shows promising results, the lack of large prospective studies, head-to-head therapeutic comparisons, and potential long-term and systemic adverse events give cause for optimistic caution. Alternative therapies including targeting pathogenic specific angiogenesis and mural-cell-based therapeutics may offer innovative solutions for currently intractable clinical problems. This paper describes the mechanisms behind diabetic retinal complications, current research supporting anti-VEGF medications, and future therapeutic directions.
Vesicoureteral reflux in boys

Vesicoureteral reflux is seen less frequently in boys than in girls, but is more likely to present a higher grade than that seen in girls. In this series, 65% of the patients presented with reflux of grade III or greater. Despite this higher grade, recurring urinary infection has been less frequently encountered in these boys. This has prompted us to be more comfortable following these patients expectantly — without surgery or chemoprophylaxis — especially in older boys with milder grades of reflux.
Effect of CF3Br on C1–C3 ignition and laminar flame speed: Numerical and experimental evaluation

Abstract Halon 1301 (CF3Br) is a well-known flame inhibitor, the understanding of which can guide the search of novel compounds with similar capabilities. Despite its importance as a benchmark for new fire suppressants, there are comparatively few detailed data for CF3Br that can be used to fine tune its chemical kinetics or to use as a baseline for candidate suppressants, particularly when interacting with hydrocarbon fuels. This paper presents new experimental data on ignition delay times and laminar flame speeds for mixtures containing CH4, C2H6, or C3H8 over a range of equivalence ratios with various amounts of CF3Br added to the mixture. Reflected-shock experiments were performed with fuel–O2 mixtures highly diluted in Argon (98%) for temperatures between 1250 and 2250 K at an average pressure of 1.4 atm and equivalence ratios of 0.5, 1.0, and 2.0; Halon 1301 was added at levels up to about 10% of the fuel for each hydrocarbon studied. Data obtained from the shock-tube experiments included ignition delay times and OH* time histories. Laminar flame speeds were measured using a windowed, constant-volume bomb at initial pressures of 1 atm for fuel–air mixtures at equivalence ratios between 0.7 and 1.3; CF3Br was added at levels of 0.5% and 1.0% to each mixture. A chemical kinetics mechanism was used herein to compare with the data, assembled from a recent, well-studied C0–C5 hydrocarbon mechanism from NUI Galway and a recent CF3Br mechanism. The model is very accurate with regard to the methane ignition behavior (with CF3Br actually accelerating ignition). However, for ethane and propane, although the model correctly predicted that the halon should slow down ignition, the level of inhibition was drastically under-predicted for the entire range of conditions studied. For the OH* time histories, the correct trends with respect to the addition of CF3Br were predicted, but major improvements can be made for the relative effect of the suppressant. With regard to the laminar flame speed results, the model also correctly predicted the basic trends of lowering flame speed with increasing levels of CF3Br addition, but it rather poorly predicted the magnitude of the impact for all three fuels. Using the assembled mechanism, the relative thermal and chemical flame inhibition contributions of CF3Br were estimated for each fuel, with the experimental chemical effect ranging from 72% to 87%, being much larger than the thermal effect (from 13% to 28%). Finally, ignition delay time and flame speed sensitivity analyses were conducted to identify the rate-controlling reactions for the systems analyzed. Given the importance of CF3Br as a model fire suppressant, and based upon the results of this study, further improvements in its kinetics mechanism are warranted.
Phosvitin phosphate content. Implications for protein kinase assay.

Abstract The maximal rates of the protein kinase (ATP: protein phosphotransferase, EC 2.7.1.37) reaction studied with chicken egg yolk phosvitin as substrate are dependent on the level of dephosphorylation of phosvitin. 30% dephospho-phosvitin gives the optimal initial rates. With varying levels of dephosphorylation, the apparent K m for the substrate also changes in a biphasic manner. If this factor is taken into account, and a suitable adjustment is made for the concentration of dephospho-phosvitin in the reaction, it is possible to achieve maximal rates for the kinase reaction with phosvitin preparations of varying levels of dephosphorylation. Such a consideration is important for comparing the results of protein kinase studies using phosvitin as the substrate.
Laminar separation bubble characteristics on an airfoil at low Reynolds numbers

An experimental investigation was conducted in order to document the structure and behavior of laminar separation bubbles at low Reynolds numbers. Data of this type are necessary if the currently insufficient analytical and numerical models are to be improved. The laminar separation bubble that forms on a NACA 663-018 airfoil model was surveyed at chord Reynolds numbers of 50,000-200,000 at angles of attack of 8-12 deg. The effects of the various testing conditions on the separation bubble were isolated and the data were analyzed in relation to existing separation bubble correlations in order to test their low Reynolds number applicability. This analysis indicated that the chord Reynolds number and the disturbance environment strongly influence the experimental pressure distributions. These effects must be included in any analytic prediction technique applied to the low Reynolds number flight regime.
Update on vascular tumors of infancy.

Purpose of reviewAdvances have been made in the pathogenesis, diagnosis and management of vascular tumors of infancy in the past year. Propranolol therapy for infantile hemangiomas (IH) is now being used widely, and case reports, series, and adverse effects are reviewed. Kaposiform hemangioendotheli
Systems Biology of the qa Gene Cluster in Neurospora crassa

An ensemble of genetic networks that describe how the model fungal system, Neurospora crassa, utilizes quinic acid (QA) as a sole carbon source has been identified previously. A genetic network for QA metabolism involves the genes, qa-1F and qa-1S, that encode a transcriptional activator and repressor, respectively and structural genes, qa-2, qa-3, qa-4, qa-x, and qa-y. By a series of 4 separate and independent, model-guided, microarray experiments a total of 50 genes are identified as QA-responsive and hypothesized to be under QA-1F control and/or the control of a second QA-responsive transcription factor (NCU03643) both in the fungal binuclear Zn(II)2Cys6 cluster family. QA-1F regulation is not sufficient to explain the quantitative variation in expression profiles of the 50 QA-responsive genes. QA-responsive genes include genes with products in 8 mutually connected metabolic pathways with 7 of them one step removed from the tricarboxylic (TCA) Cycle and with 7 of them one step removed from glycolysis: (1) starch and sucrose metabolism; (2) glycolysis/glucanogenesis; (3) TCA Cycle; (4) butanoate metabolism; (5) pyruvate metabolism; (6) aromatic amino acid and QA metabolism; (7) valine, leucine, and isoleucine degradation; and (8) transport of sugars and amino acids. Gene products both in aromatic amino acid and QA metabolism and transport show an immediate response to shift to QA, while genes with products in the remaining 7 metabolic modules generally show a delayed response to shift to QA. The additional QA-responsive cutinase transcription factor-1β (NCU03643) is found to have a delayed response to shift to QA. The series of microarray experiments are used to expand the previously identified genetic network describing the qa gene cluster to include all 50 QA-responsive genes including the second transcription factor (NCU03643). These studies illustrate new methodologies from systems biology to guide model-driven discoveries about a core metabolic network involving carbon and amino acid metabolism in N. crassa.
Parathyroid function in paget's disease of bone

In order to determine the prevalence of secondary hyperparathyroidism in patients with Paget's disease of bone, we measured serum parathyroid hormone levels (N-terminal assay) in 39 patients with a wide range of pagetic activity. All patients had normal serum calcium levels. A total of 30 patients were either untreated or had received no treatment for 6 months or longer when studied; the other 9 were receiving either salmon calcitonin (3) or EHDP (6). The results showed that in 7 of the 39 patients (18%) parathyroid hormone levels were increased above normal. These were among the most severely affected cases, as manifested by the degree of elevation of three pagetic biochemical indices: serum alkaline phosphatase, plasma bone Gla protein, and 24 h urinary hydroxyproline-creatinine ratios. Levels of 25-hydroxyvitamin D3 and 1,25-dihydroxyvitamin D3 were normal. We examined the relationships between parathyroid hormone and each of the three pagetic indices as well as serum calcium for the entire group of 39 patients. Parathyroid hormone values did not correlate with serum calcium measurements (r = -0.241, p = NS) but did correlate significantly with serum alkaline phosphatase (r = 0.496, p less than 0.001), plasma bone Gla protein (r = 0.537, p less than 0.001), and urinary hydroxyproline (r = 0.450, p less than 0.011). We conclude that relative or absolute increases in parathyroid hormone may occur in moderately active Paget's disease, possibly in the setting of greater calcium demands during periods of increased pagetic new bone formation.(ABSTRACT TRUNCATED AT 250 WORDS)
Posture balancing control of smart mobile walker for uneven terrain

This paper introduces a posture control of smart mobile walker, where the controller adjusts four linear actuators based on the measurement of orientation and ground forces to balance manipulator and to keep wheel contact with ground. It is an important feature for this walker to adapt its pose to uneven terrains such as ramp or slope since it aims to assist elderly and disabled safely. Control scheme is based on PID impedance control where sensor noise and wind-up due to low actuator performance are considered. Hardware implementation and its experimental result are presented.
Dysphagia in Old-Old Women: Prevalence as Determined According to Self-Report and the 3-Ounce Water Swallowing Test

Objectives To determine whether symptoms and clinical signs of swallowing dysfunction could be easily identified in community-dwelling elderly adults and to examine the association between self-report and direct observation of symptoms and signs of swallowing dysfunction. Design Physiological substudy conducted as a home visit within an observational cohort study. Setting Baltimore City and County, Maryland. Participants Community-dwelling elderly women without history of dysphagia or neurological disease aged 85 to 94 enrolled in the Women's Health and Aging Study II (N = 47). Measurements Three trials of the 3-ounce water swallowing test, swallowing function questionnaire, and frailty status. Results Thirty-four (72%) subjects demonstrated swallowing dysfunction in at least one swallowing trial and 16 (34%) in all three trials. The most common signs of dysfunction were throat clear and wet voice. Conversely, participants reported few symptoms of dysphagia on a swallowing function questionnaire. The most common symptom, reported by approximately 15% of participants, was the sensation of the food going “down the wrong way,” 8.5% or fewer participants reported other symptoms. Conclusion Signs of swallowing dysfunction were present in a large majority of community-dwelling old-old women, but they were largely unrecognized and reported. Formal evaluation of swallowing function in community-dwelling elderly adults is necessary to determine the clinical consequences of these findings.
A Political Approach to Organizations: A Review and Rationale

In ignoring the implications of systems thinking at the intra-organizational level of analysis, organizational literature has obscured the fact that organizational behavior (OB) occurs as a result of subunit dynamics within the organization. Several assumptions are basic to a political approach to OB. Organizational development literature is discussed from a political perspective.
The Z-plasty transposition flap for reconstruction of the middle cheek

Abstract Background: Large defects of the middle cheek may prove difficult to repair. Too wide for primary closure, such defects pose challenging reconstructive options because there are no cosmetic unit boundaries in which to camouflage incision lines without resorting to widely undermined flaps. Objective: This article summarizes our experience with the Z-plasty and double Z-plasty transposition flaps for reconstruction of the cheek. Methods: The Z-plasty transposition flap was used immediately after Mohs micrographic surgery to repair 14 defects of the middle cheek caused by basal cell carcinoma (n = 12) or squamous cell carcinoma (n = 2). In all cases, primary closure of the defect would have resulted in excessively long scars, scars oriented perpendicular to relaxed skin tension lines, and/or free-margin distortion. In 4 of these cases, a double Z-plasty was used. Results: The cosmetic and functional outcomes were judged from good to excellent by patient and surgeon. No cases of infection occurred. In one patient, minor superficial tip necrosis healed without incident. A "spit" subcutaneous suture at one flap tip of another patient left a small nodular scar, which was primarily excised and healed well. Conclusions: The Z-plasty and double Z-plasty transposition flaps offer excellent primary reconstructive modalities for the repair of geographically isolated defects of the cheek that are large or misoriented for primary side-to-side closure. The theoretical and practical geometric characteristics of the Z-plasty transposition require preparation and practice to achieve consistently satisfying results. (J Am Acad Dermatol 2002;46:738-42.)
Use of imaging for procedural guidance during transcatheter aortic valve replacement.

Purpose of review Transcatheter aortic valve replacement (TAVR) has recently emerged as an alternative to surgical aortic valve replacement for patients with severe, symptomatic aortic stenosis who are at a 'high risk' or deemed inoperable. Multiple imaging modalities are integral to procedural success and recent studies may help establish the role of each modality. Recent findings Procedural guidance includes preimplantation device selection, intraprocedural guidance of valve positioning and post-implantation assessment of procedural success. Numerous studies have suggested that three-dimensional (3D) assessment of the aortic annulus and adjacent structures by multislice computed tomography (MSCT) or cardiac MRI can improve annular sizing and reduce complications. Subsequent studies suggest that 3D transesophageal echocardiography (TEE) can also accurately measure the annular aortic annulus. New imaging techniques help with coaxial fluoroscopic positioning. Finally, the use of intraprocedural TEE allows imaging of complications. Summary Multimodality imaging is indispensable for procedural guidance during TAVR. MSCT is a fundamental part of preprocedural planning, including the assessment of peripheral vasculature, the aortic root and the annulus and optimal fluoroscopic positioning. Echocardiography, particularly two-dimensional (2D) and 3D TEE, is an integral part of preprocedural, intraprocedural and immediate postprocedural assessment. MRI remains at this time an adjunctive imaging modality for procedural guidance, but may have an essential role in postprocedural valve assessment.
A Survey of Learning Styles of Engineering Students

This study examined the learning styles of engineering students using the Index of Learning Styles (ILS) developed by Soloman and Felder (Soloman & Felder, 2002), the Cognitive Styles Analysis (CSA) developed by Riding (Riding, 1991), and the Learning Style Inventory (LSI) developed by Kolb (Kolb, 1993). Thirty-five graduate and thirty-six undergraduate engineering students took each of the assessments. There was a strong preference for the visual category on the ILS, but an even split for the imagery/verbal dimension on the CSA. Scores were also evenly split on the active/reflective and sequential/global dimensions on the ILS. Another strong preference was seen for the analytic category on the CSA. On the LSI, most students' scores indicated a preference for the convergent category and no student scores were in the divergent category. An overview of each of the instruments as well as a summary of student learning needs for each of the dimensions is presented.
Variance Components for Yield and Specific Gravity in a Diploid Potato Population after Two Cycles of Recurrent Selection

The potato(Solanum tuberosum L.) processing industry needs cultivars with high tuber specific gravity and acceptable color of processed product. All of the cultivars with high specific gravity currently grown in the U.S. are very closely related, which increases their genetic vulnerability and results in inbreeding as efforts are made to improve these traits. The use of diploidSolanum sp. in breeding may resolve these problems. The purposes of this study were (1) to estimate narrow-sense heritability for yield and specific gravity in random-mating diploid hybrid potato populations ofS. phureja - S. stenotomum (PHU-STN) following two cycles of recurrent selection, (2) to examine phenotypic variances for yield and specific gravity following two cycles of recurrent selection within PHU-STN, (3) to compare the yield and specific gravity of individual PHU-STN clones with Atlantic, and (4) to screen these PHU-STN clones for the presence of 2n pollen. Four clones from each of 72 maternal half-sib families were evaluated for yield and specific gravity in replicated field tests in 1990 and 1991. A second selection cycle, using a randomly mated population obtained from the highest specific gravity clone in each maternal half-sib family, was similarly evaluated for yield and specific gravity in replicated field tests in 1995 and 1996. Narrow-sense heritability for specific gravity was estimated as 0.37 ± 0.25 and 0.43 ± 0.27, in the first and second selection cycles, respectively, with a 27% decrease in phenotypic variance. Narrow-sense heritability for yield was estimated as 0.60 ± 0.26 and 0.06 ± 0.24, in the first and second selection cycles, respectively, with a 73% decrease in phenotypic variance. There were significant correlations between yield and specific gravity in 1990 (r=0.32) and 1996 (r=0.37), but not 1991 (r=0.08) and 1995 (r=0.05). These results indicate that additional breeding efforts in this PHU-STN population could result in improvements in specific gravity. However, the amount of variation for yield in this population is decreasing and may indicate that the yield potential of this population is rapidly approaching its limit. In the second selection cycle, many of the 288 clones were significantly higher in specific gravity than the high-specific-gravity cultivar Atlantic, but none were higher yielding. Fifty-eight clones from the second selection cycle produced at least 5% 2n pollen. When used in tetraploid x diploid hybridizations, this diploid population could furnish new genetic material to the tetraploid potato germplasm base for simultaneously increasing specific gravity and yield.
Near homeomorphisms and G-like continua

Abstract It is shown that for a given finite, connected, planar graph, G , containing a branch point, the set of surjective, continuous maps of G which cannot be extended to a near homeomorphism on any neighborhood of G is open and dense in the set of all such maps, with the C 0 -topology. Also, an example of a map which cannot be extended to a near homeomorphism for which the inverse limit can be embedded as an attractor in the plane is given.