cssi/SciSciGPT-SciSciNet huggingface dataset:
Response to phosphorus limitation varies among lake populations of the freshwater snail Potamopyrgus antipodarum.

Local adaptation – typically recognized as higher values of fitness-related traits for native vs. non-native individuals when measured in the native environment - is common in natural populations because of pervasive spatial variation in the intensity and type of natural selection. Although local adaptation has been primarily studied in the context of biotic interactions, widespread variation in abiotic characteristics of environments suggests that local adaptation in response to abiotic factors should also be common. Potamopyrgus antipodarum, a freshwater New Zealand snail that is an important model system for invasion biology and the maintenance of sexual reproduction, exhibits local adaptation to parasites and rate of water flow. As an initial step to determining whether P. antipodarum are also locally adapted to phosphorus availability, we examined whether populations differ in their responses to phosphorus limitation. We found that field-collected juvenile P. antipodarum grew at a lower rate and reached an important size threshold more slowly when fed a relatively low vs. a relatively high- phosphorus diet. We also detected significant across-population variation in individual growth rate. A marginally significant population-by-dietary phosphorus interaction along with a two-fold difference across populations in the extent of suppression of growth by low phosphorus suggests that populations of P. antipodarum may differ in their response to phosphorus limitation. Local adaptation may explain this variation, with the implication that snails from lakes with relatively low phosphorus availability should be less severely affected by phosphorus limitation than snails from lakes with higher phosphorus availability.
Tree size, stand density, and the source of water used across seasons by ponderosa pine in northern Arizona.

Abstract Understanding the dynamic relationships between seasonal water use, stand density, and tree size in semi-arid forests of the southwestern US is important for predicting climate change impacts and for tailoring forest restoration prescriptions to mitigate such impacts. Using hydrogen stable isotope ratio (δD) analyses of precipitation, soil water, and stem water over a 2-year sampling period, we found that winter precipitation was the dominant water source for ponderosa pines (Pinus ponderosa Dougl.) in northern Arizona in all seasons. Soil and stem waters were isotopically more enriched in high- than low-density stands. Isotopic analyses indicated large trees were more reliant on deep soil water than small trees. Our results indicate that management actions that maintain or create low-density stands of large deeply-rooted trees increase tree access to winter precipitation via deep soil storage and thus may help mitigate impacts of climate warming on tree health. Our findings provide new understanding of the complex relationships among seasonal water use, stand density, and tree size in a region where a drying climate puts increasing stress on forests.
Thermodynamics of Na2SO4(aq) at temperatures T from 273 K to 373 K and of {(1-y)H2SO4+yNa2SO4}(aq) at T = 298.15 K

Abstract New isopiestic vapor-pressure measurements on {(1-y)H2SO4 + y Na2SO4}(aq) along with earlier experimental investigations that span the range from y = 0 to y = 1 and infinitely dilute to supersaturated molalities have been analyzed in terms of the Pitzer ion-interaction model. Refined ion-interaction parameters for Na2SO4(aq) valid over the temperature range 273 K to 373 K have been calculated and used for analyzing results for {(1-y)H2SO4 + y Na2SO4}(aq) at 298.15 K. Analysis of experimental results for these aqueous mixtures required explicit consideration of the dissociation reaction of HSO-4. Previous treatments of H2SO4(aq) and subsequently the equilibrium for the dissociation of HSO-4 valid in the range 273 K to 343 K were employed as a first approximation in representing the mixed solutions. Two sets of Pitzer ion-interaction parameters are presented for {(1-y)H2SO4 + y Na2SO4}(aq). The validity of the first set is limited in ionic strength and molality to supersaturated solution of y = 1 (I = 12 mol·kg-1). The second set corresponds to a slightly less precise representation but is valid over the entire range of experimental results considered. Both sets of parameters provide a more complete description of solution with y = 0 because of the removal of various redundancies in ion-interaction parameters. The specific ion-interaction terms used and the overall fitting procedure are described as well as selected examples of relevant thermodynamic calculations for {(1-y)H2SO4 + y Na2SO4}(aq).
Direct time integration of Maxwell's equations in linear dispersive media with absorption for scattering and propagation of femtosecond electromagnetic pulses

The initial results for femtosecond pulse propagation and scattering interactions for a Lorentz medium obtained by a direct time integration of Maxwell's equations are reported. The computational approach provides reflection coefficients accurate to better than 6 parts in 10,000 over the frequency range of dc to 3 x 10 to the 16th Hz for a single 0.2-fs Gaussian pulse incident upon a Lorentz-medium half-space. New results for Sommerfeld and Brillouin precursors are shown and compared with previous analyses. The present approach is robust and permits 2D and 3D electromagnetic pulse propagation directly from the full-vector Maxwell's equations.
Analysis of antigenic drift in recently isolated influenza A (H1N1) viruses using monoclonal antibody preparations.

Abstract Monoclonal antibodies to the hemagglutinin (HA) and neuraminidase (NA) of A/USSR/ 90/77(HlN1) were prepared and used to study antigenic drift in the H1N1 subtype of influenza viruses. The results obtained with five different monoclones to each molecule were compared with the results obtained with postinfection ferret sera. Monoclonal antibodies and postinfection ferret sera detected antigenic drift in the hemagglutinin and neuraminidase molecules of H1N1 viruses and monoclonal antibodies showed that the A/USSR/90/77, A/ Roma/1/49, and A/Fort Warren/1/50 viruses were identical at five sites on both the hemagglutinin and neuraminidase molecules. To further evaluate monoclonal antibodies, they were used in hemagglutination inhibition tests with recently isolated influenza A(HlNl) viruses, including some shown in tests with postinfection ferret sera to have undergone antigenic drift. Three patterns of reactivity with the monoclonal antibodies were detected with the variants: two variants differed at two of the five sites identified by the monoclonal antibodies and a third variant differed at only one of the five sites. Two of these variant groupings had not been distinguished from each other in HI tests with ferret sera, whereas ferret sera were capable of distinguishing between two groups of variants that had similar reaction patterns with the five monoclonal antibody preparations. Monoclonal antibodies failed to detect antigenic drift in the NA molecules of the recent isolates of H1N1 influenza viruses, suggesting that antigenic changes occur less frequently in this molecule. The observation that antigenic differences could be detected between the recent variants with such a small panel of monoclonal antibodies (less than 10% of the number obtained to the HA of A/PR/8/34) suggests that monoclonal antibodies may provide an exquisitely sensitive method for antigenic mapping of influenza viruses.
p53 Expression and DNA ploidy of cartilage lesions

The aim of this study was to investigate the expression of a tumor suppressor gene (p53) in cartilage lesions of bone and its relationship to their histological grade and DNA ploidy. An immunohistochemical assay for p53 and Feulgen-stained DNA preparations was subjected to computerized image analysis. Enchondromas, synovial chondromatosis, and low grade (grade I and II) chondrosarcomas were diploid. High grade (grade III) chondrosarcomas and high grade sarcomatous components of dedifferentiated chondrosarcomas were aneuploid. Well differentiated cartilaginous components of dedifferentiated chondrosarcomas were diploid. Microscopic examination showed weak focal positivity for p53 in one of 10 enchondromas one of six examples of synovial chondromatosis, and three of four low grade (grade I and II) chondrosarcomas. All three high grade (grade III) chondrosarcomas were strongly positive for p53. The high grade sarcomatous component of all four dedifferentiated chondrosarcomas was strongly positive for p53, whereas only focal weak positivity was noted in the well differentiated cartilaginous areas. These results were confirmed by quantitative computer-assisted image analysis, which showed that high grade aneuploid cartilage tumors demonstrated strikingly higher levels of p53 than did diploid low grade malignant tumors or benign cartilage lesions.
Extensive Green Roofs and Mosses: Reflections from a Pilot Study in Terra Alta, West Virginia

Abstract. Bryophytes are increasingly used in “green roofs” (especially in Europe), usually mixed with Sedum in prevegetated mats rolled onto roofs. In this paper, we briefly review the roof moss literature and also report our preliminary findings on voluntarily established roof moss communities near Terra Alta, West Virginia. We found 11 bryophyte species (including one liverwort) on four partly shaded roofs (differing in material, aspect, and pitch) that had apparently been relatively undisturbed for over 40 years. Species richness and composition varied considerably among roofs. The most frequent and abundant taxa were Hedwigia ciliata, Plagiomnium cuspidatum, Brachythecium laetum, and Platygyrium repens, each of which dominated a different roof. We suggest that Hedwigia merits further investigation as a candidate for extensive green roofs, based on drought-tolerance and a growth-form similar to that of Racomitrium -- which is used for green roofs in Japan. We hope that our review and preliminary data ...
Myristoylation Exerts Direct and Allosteric Effects on Gα Conformation and Dynamics in Solution

Coupling of heterotrimeric G proteins to activated G protein-coupled receptors results in nucleotide exchange on the Gα subunit, which in turn decreases its affinity for both Gβγ and activated receptors. N-Terminal myristoylation of Gα subunits aids in membrane localization of inactive G proteins. Despite the presence of the covalently attached myristoyl group, Gα proteins are highly soluble after GTP binding. This study investigated factors facilitating the solubility of the activated, myristoylated protein. In doing so, we also identified myristoylation-dependent differences in regions of Gα known to play important roles in interactions with receptors, effectors, and nucleotide binding. Amide hydrogen-deuterium exchange and site-directed fluorescence of activated proteins revealed a solvent-protected amino terminus that was enhanced by myristoylation. Furthermore, fluorescence quenching confirmed that the myristoylated amino terminus is in proximity to the Switch II region in the activated protein. Myristoylation also stabilized the interaction between the guanine ring and the base of the α5 helix that contacts the bound nucleotide. The allosteric effects of myristoylation on protein structure, function, and localization indicate that the myristoylated amino terminus of Gα(i) functions as a myristoyl switch, with implications for myristoylation in the stabilization of nucleotide binding and in the spatial regulation of G protein signaling.
Safety and pharmacokinetic analysis of methotrexate administered directly into the fourth ventricle in a piglet model

We have developed a piglet model to assess chemotherapy administration directly into the fourth ventricle as a potential treatment for medulloblastoma and other malignant posterior fossa tumors. The objective of this study was to assess safety and pharmacokinetics after methotrexate infusions into the fourth ventricle. Catheters were inserted into the fourth ventricle and lumbar cistern in five piglets. Two milligrams of Methotrexate (MTX) was infused into the fourth ventricle on five consecutive days. Safety was assessed by neurological examination, 4.7 T MRI, and post-mortem pathological analysis. MTX levels in serum and cerebrospinal fluid (CSF) were measured, and area under the concentration-time curve (AUC) was calculated for CSF samples. No neurological deficits were caused by MTX infusions. One piglet died from complications of anesthesia induction for MRI scanning. MRI scans showed accurate catheter placement without signal changes in the brainstem or cerebellum. One piglet had asymptomatic ventriculomegaly. Pathological analysis demonstrated meningitis and choroid plexitis consisting predominantly of CD-3 positive T-lymphocytes in all piglets and a small focal area of subependymal necrosis in one. In all piglets, mean peak MTX level in fourth ventricular CSF exceeded that in lumbar CSF by greater than five-fold. Serum MTX levels were undetectable or negligible. Statistically significant differences between fourth ventricle and lumbar AUC were detected at peaks (P = 0.01) and at all collection time points (P = 0.01) but not at troughs (P = 0.36). MTX can be infused into the fourth ventricle without clinical or radiographic evidence of damage. An inflammatory response without clinical correlate is observed. Significantly higher peak MTX levels are observed in the fourth ventricle than in the lumbar cistern.
Establishing public school programs for older adults

Educational programs for older adults will enhance any educational program, adding a constituency that will support the adult school, provide at with new challenges, and give it an intergenerational student body.
Web TANGO: towards automated comparison of information-centric web site designs

Web site usability is even more critical as the number of sites grows exponentially and the number of users increases dramatically. We describe a new automated methodology and tool, Web TANGO, being developed to allow designers to explore alternative designs of information-centric web sites prior to implementation.
Corrugated bicrystal grain-boundaries in cast aluminium and zinc

A ridging or corrugation structure has been found to form on grain-boundary surfaces in zinc and aluminium parallel to the solidification direction. The density and severity of this ridging is found to increase with increasing solidification rates. The ridging is associated with substructure in the bicrystals forming the grain-boundary. Previous experiments suggest that this ridging can impart a considerable amount of resistance to grain-boundary sliding perpendicular to the solidification direction.
Structural features and reactivity of (sparteine)PdCl2: a model for selectivity in the oxidative kinetic resolution of secondary alcohols.

The chiral ligand (−)-sparteine and PdCl_2 catalyze the enantioselective oxidation of secondary alcohols to ketones and thus effect a kinetic resolution. The structural features of sparteine that led to the selectivity observed in the reaction were not clear. Substitution experiments with pyridine derivatives and structural studies of the complexes generated were carried out on (sparteine)PdCl2 and indicated that the C1 symmetry of (−)-sparteine is essential to the location of substitution at the metal center. Palladium alkoxides were synthesized from secondary alcohols that are relevant steric models for the kinetic resolution. The solid-state structures of the alkoxides also confirmed the results from the pyridine derivative substitution studies. A model for enantioinduction was developed with C1 symmetry and Cl− as key features. Further studies of the diastereomers of (−)-sparteine, (−)-α-iso- and (+)-β-isosparteine, in the kinetic resolution showed that these C_2-symmetric counterparts are inferior ligands in this stereoablative reaction
Tetrahydrocannabinol inhibits adenyl cyclase in human leukemia cells.

▵9-tetrahydrocannabinol has been shown to induce incomplete maturation in ML2 human leukemia cell lines. We extend the observation of its induction of morphologic maturation to HL60 cells and of its induction of growth restriction to HL60 and K562 cells. We show that tetrahydrocannabinol reduces the cyclic AMP content of ML2 cells. Finally we demonstrate that this agent inhibits adenyl cyclase activity in ML2 cell membrane-enriched fractions. This finding in myeloid cells is compatible with one hypothesis of cannabinoid action in neuronal cells.
Contributions of the [NiFe]- and [FeFe]-hydrogenase to H2 production in Shewanella oneidensis MR-1 as revealed by isotope ratio analysis of evolved H2

Shewanella oneidensis MR-1 encodes both a [NiFe]- and an [FeFe]-hydrogenase. While the output of these proteins has been characterized in mutant strains expressing only one of the enzymes, the contribution of each to H2 synthesis in the wild-type organism is not clear. Here, we use stable isotope analysis of H2 in the culture headspace, along with transcription data and measurements of the concentrations of gases in the headspace, to characterize H2 production in the wild-type strain. After most of the O2 in the headspace had been consumed, H2 was produced and then consumed by the bidirectional [NiFe]-hydrogenase. Once the cultures were completely anaerobic, a new burst of H2 synthesis catalyzed by both enzymes took place. Our data are consistent with the hypothesis that at this point in the culture cycle, a pool of electrons is shunted toward both hydrogenases in the wild-type organisms, but that in the absence of one of the hydrogenases, the flux is redirected to the available enzyme. To our knowledge, this is the first use of natural-abundance stable isotope analysis of a metabolic product to elucidate substrate flux through two alternative enzymes in the same cellular system.
Development and evaluation of a full-scale spray scrubber for ammonia recovery and production of nitrogen fertilizer at poultry facilities

Significant ammonia emissions from animal facilities need to be controlled due to its negative impacts on human health and the environment. The use of acid spray scrubber is promising, as it simultaneously mitigates and recovers ammonia emission for fertilizer. Its low pressure drop contribution on axial fans makes it applicable on US farms. This study develops a full-scale acid spray scrubber to recover ammonia emissions from commercial poultry facilities and produce nitrogen fertilizer. The scrubber performance and economic feasibility were evaluated at a commercial poultry manure composting facility that released ammonia from exhaust fans with concentrations of 66–278 ppmv and total emission rate of 96,143 kg yr−1. The scrubber consisted of 15 spray scrubber modules, each equipped with three full-cone nozzles that used dilute sulphuric acid as the medium. Each nozzle was operated at 0.59 MPa with a droplet size of 113 μm and liquid flow rate of 1.8 L min−1. The scrubber was installed with a 1.3-m exhau...
Robust cuticular penetration resistance in the common bed bug (Cimex lectularius L.) correlates with increased steady-state transcript levels of CPR-type cuticle protein genes

Abstract Bed bug (Cimex lectularius L.) populations are increasing worldwide, with resistance to insecticides thought to be a major contributor. Several recent reports have documented widespread kdr-type mutations at the target site for pyrethroid insecticides, and there is substantial published evidence for metabolic resistance mediated through cytochrome P450-mediated oxidation. Here we report that resistance ratios for a bed bug strain collected in Richmond, VA, increase by three orders of magnitude when the route of insecticide treatment is changed from inoculation to topical. This increase suggests that reduced cuticular penetration plays a powerful role in bed bug resistance to insecticides. We identified 62 putative cuticle protein-encoding contigs from bed bug transcriptome data containing the Rebers and Riddiford consensus sequence. We classified these contigs as to CPR type, and compared the amino acid composition of the different types to that of the entire proteome. Quantitative PCR analysis indicated that many of these transcripts were substantially upregulated in resistant bed bugs, with some more than 20-fold higher than in the susceptible strain. These results suggest the possibility that thickening or remodeling of the bed bug cuticle may contribute to decreased insecticide penetration.
The Aural Fold and the Sonic Jump Cut: Godard's (Baroque) Sound

Even though he has been associated with the other four principal directors representing the core of the New Wave movement, Jean-Luc Godard has set himself apart from all categorization. His pioneer...
Going beyond the specifics: generalization of single actions, but not temporal order, at 9 months.

We examined generalization in 9-month-old infants after a 24-hour delay using deferred imitation. Infants flexibly applied their knowledge of sequence actions across changes in props even though they had no opportunity for immediate imitation.
Niobium-doped titanium oxide for fuel cell application

Abstract High surface area niobium-doped titanium oxide catalyst supports were synthesized through a chemical method using nano-sized polystyrene (PS) latex as a template. By varying the concentration of template with respect to titania and niobium precursors, we were able to produce niobium-doped titanium oxides with surface areas of 75–115 m 2 /g and sufficient electrical conductance to function as fuel cell catalyst supports. The oxides were subsequently platinized and evaluated as oxygen reduction catalysts using a rotating disk electrode. One of the samples showed a mass activity of 0.16 A/mg Pt and a specific activity of 170 μA/cm 2 Pt at 900 mV, which are comparable to our benchmark Pt/C electrocatalyst.
The diverse roles of community health workers: Cues for technology innovations

Abstract Abstract Community health workers (CHW) in rural Kenya have great influence in their society and the potential to affect positive change in community health, yet their training is largely inconsistent and their community role is not well understood. This study explores the role of CHW and considers their ability to operate a telemedicine system designed by the Humanitarian Engineering and Social Entrepreneurship (HESE) Program at Penn State. Methods Qualitative field research allowed exploration of CHWs in their natural environment in Nyeri, Kenya. Data were collected in the form of focus groups and direct observations, and analysis was performed using the constant comparative method. Results Nyeri CHWs report identifying with many roles including public health advocate, a teacher, a healthcare provider, and a community role model. Conclusions Nyeri CHWs are highly motivated to improve the health of their community, yet lack the knowledge and training required to meet the key objectives of the Ministry of Health. Through telemedicine utilization, CHWs could both increase their knowledge of diseases and provide an opportunity for large-scale health surveillance. While this study focused on one specific region, the observations are transferrable to CHW programs in similar resource-constrained settings around the world.
On the asymmetric development of magnetic storm fields in low and middle latitudes

Ring current effects on axisymmetric development of geomagnetic storm fields in low and middle latitudes
Tilletia Togwatii A New Bunt Species from Poa Reflexa

Teliospore morphology, teliospore germination and cytology between a bunt from Poa reflexa and Tilletia fusca from bromes and fescues are compared, and those of the P. reflexa bunt are distinct fro...
Another Source of VOR Omni Error

In the vicinity of reflecting objects, a VOR receiver picks up both the direct and reflected signals. This summation adds both amplitude and phase modulation to the signal that were not present at the transmitter. The error due to this phase modulation is fairly evident since the desired directional information is transmitted as a relative phase. What is not so evident is the fact that the amplitude modulation can also produce a phase error. This happens when asymmetrical filters are used to process the amplitude-modulated signal. The asymmetrical filter converts some of the amplitude-modulated sidebands into phase modulation which is recorded as a direct phase error.
Thermal postbuckling analysis of cylindrically curved composite laminates with a hole

A non-linear finite element analysis including a new flat shell element has been developed to examine the response of laminated panels going through large deflections and rotations under uniform temperature change. The equilibrium path describing the relationship between temperature and deflection is sensitive to the material system, hole size, in-plane boundary conditions and radius of curvature. Certain laminate configurations exhibit snap-through and bifurcation along this path. The accuracy of the results for a cylindrically curved panel is established by considering numerous validation problems with known solutions. The method has been demonstrated to be highly effective for predicting the non-linear response of thin composite shells subjected to uniform temperature change in the presence of large displacements and rotations and material anisotropy.
“Their Fingers Were too Fat to Weave”: Ancient Textiles and Academic Politics Today

In 1993, we recognized textile impressions on fragments of fired clay from Upper Paleolithic sites in Moravia, which documented the world's oldest weaving, net making, and basketry. We published this discovery first in Czech in their premier professional journal and in collaboration with Moravian colleagues. Subsequently, this evidence was augmented by new data from across Eurasia, the recognition of textile products on the “Venus” figurines, and the identification of tools used to make them. Our discovery received a bifurcate reception. While scholars outside of the Czech Republic accepted it readily, local academics split into feuding factions. Below we discuss the evidence for Paleolithic textiles and use its reception to illustrate that: 1) the deep past necessarily lives in the political present, and 2) the present is contested and multi-vocal. Our article also serves to raise the questions of whose voice to privilege, and why.
Racial Disparities in Head and Neck Oncology: The Effects of Hurricane Katrina

Results Our demographic yielded a mean age of 62.6 with 36.4% African Americans (AA) and 54.5% whites. 78.4% of patients were male and 21.6% female. Racial disparities were noted across all categories, with 31.8% of African Americans enrolled in Medicaid versus 18.9% of whites [p=.01]. 84.4% of AA presented with advanced stage disease versus 64.6% of whites [p=.04]. 6.2% of AA used the emergency room as their route of presentation compared to 2.1% of whites [p=.01]. 40.6% of AA hailed from an area with 4.7 – 16.5 feet of flooding, compared to 18.8% of whites [p=.06].
Reading Disability: A Model for the Genetic Analysis of Complex Behavioral Disorders

Family, linkage, and twin studies of reading disability are briefly reviewed, and evidence is presented from the twin component of the Colorado Reading Project that implicates genetic factors in the expression of reading disability. Recently developed behavioral genetic methodology is outlined, which provides an estimate of the magnitude of these genetic effects. The present report details the application of this methodology to reading performance data obtained from 96 identical twin pairs and 72 fraternal twin pairs in which at least one member of each pair was identified as reading disabled. Results indicate that approximately 50% of the reading deficit observed in the probands may be attributed to genetic factors. Although such an analysis assumes that reading disability is a homogeneous disorder, there may exist alternative forms with differing genetic etiologies. To test this hypothesis, the methodology can be extended to assess differential genetic etiology in alternative subgroups of disabled readers.
Associations Between Lower Extremity Muscle Mass and Multiplanar Knee Laxity and Stiffness: A Potential Explanation for Sex Differences in Frontal and Transverse Plane Knee Laxity

Background:Compared with men, women have disproportionally greater frontal (varus-valgus) and transverse (internal-external) plane laxity and lower stiffness, despite having similar sagittal (anterior-posterior) plane laxity and stiffness. While the underlying cause is unclear, the amount of lower extremity lean mass (LELM) may be a contributing factor.Hypothesis:Lower extremity lean mass would be a stronger predictor of frontal and transverse plane laxity and incremental stiffness than the sagittal plane. Associations between LELM and stiffness would be stronger at lower force increments.Study Design:Descriptive laboratory study.Methods:Sixty-three women and 30 men with no history of ligament injury were measured for knee laxity and incremental stiffness in the sagittal (−90- to 130-N posterior-to-anterior directed loads), frontal (±10-N·m varus-valgus torques), and transverse (±5-N·m internal-external rotation torques) planes and underwent dual-energy X-ray absorptiometry scans to measure LELM. Linear r...
Subgrid mixing and molecular transport modeling in a reacting shear layer

The importance of molecular transport in high-Reynolds number reacting flows is now well accepted because of incontrovertible experimental evidence. However, most mixing models neglect this small-scale process and, as a result, fail to predict the observed variation of the mean mixed composition and the Reynolds number, Schmidt number, and Damkohler number dependence observed in the experiments. A mixing model that explicitly accounts for the small-scale mixing, molecular transport, and chemical kinetics processes was developed earlier as a stand-alone method by Kerstein. Here, this linear eddy model (LEM) is implemented as a subgrid model within a configuration-independent simulation methodology based on large eddy simulation (LES) and used to study scalar mixing in a low-heat release mixing layer. The ability of the present method to capture correctly the small-scale mixing and molecular transport effects is demonstrated by carrying out both qualitative and quantitative comparisons with experimental data obtained in high-Reynolds number flows. The present method provides a unique modeling capability to handle the small-scale processes within the context of a general LES approach without any ad hoc closure of the scalar equations.
Late potential at the high ventricular septal level in a patient with Brugada: possible mechanisms and clinical implications

The Brugada syndrome (BS) accounts for approximately 20% of cases of sudden cardiac death in patients with structurally normal hearts. The electrophysiologic basis for ST-segment elevation in the precordial electrocardiogram (ECG) leads that characterize the Brugada phenotype and its strong linkage to ventricular tachycardia (VT)/ventricular fibrillation is still a subject of controversy. Electrocardiographic manifestations of the syndrome have been attributed to one of two basic mechanisms: (1) conduction delay in the right ventricular (RV) epicardial-free wall in the region of the outflow tract or (2) premature repolarization of the RV epicardial action potential secondary to loss of the action potential dome. Signal-averaged ECG recordings have demonstrated late potentials that extend beyond the QRS complex in patients with the BS, especially in the anterior wall of the RV outflow tract. The basis for these epicardial late potentials remains a subject of interest among basic and clinical electrophysiologists. Endocardial late potentials in BS are even less well understood. We present a case of a patient with Brugada syndrome with a distinct endocardial late potential in the high ventricular septum coinciding with the ST-segment elevation. We discuss the possible mechanisms for this intracardiac finding and its clinical significance. We also review the effect of isoproterenol infusion on both the late potential and the surface ECG.
Inhibition of insulin secretion: A fail-safe system

Insulin secretion from the β-cells of the endocrine pancreas is subject to a pot-pourri of stimulatory, modulatory and inhibitory influences. β-Cell secretion is reduced or blocked by a variety of inhibitors (including galanin, somatostatin and noradrenaline) which reach the cells either via the islet vascular system or are released locally from sympathetic and peptidergic nerves terminating in the pancreas. It is now becoming clear that among these many inhibitors, several have multiple mechanisms by which they inhibit release at the cellular level. Indeed, with multiple inhibitors (some of which are co-secreted) and multiple mechanisms of inhibition, the latter including a late effect in stimulus secretion coupling (perhaps on the exocytotic step per se), inhibition of insulin secretion has the characteristics of a fail-safe system.
Tracing 15N with chemical reaction interface mass spectrometry: a demonstration using 15N-labeled glutamine and asparagine substrates in cell culture.

This research demonstrates how the chemical reaction Interface mass spectrometry (CRIMS) approach works for a study of amino acid metabolism in cell culture. 15N-selective chromatograms from both the culture medium and the cytosol of human hepatoma Hep G2 cells that were incubated in the presence of either 12 mM (α-15N)glutamine or (α-15N)asparagine have been produced. The time course of the distribution of 15N among different amino acids, as well as the enrichment for each amino acid, were observed over a 144 h period. Labeled glutamine was quickly converted into glutamate. After 144 h of incubation, the total amount of 15N was distributed primarily among alanine (50%), proline (28%) and glutamate (21%). The 15N enrichment of alanine and proline reached 44% and 41% respectively. Asparagine was only slowly metabolized by the cells. In addition to the 82% that was retained in asparagine, the remaining 15N in the media at 144 h was found primarily in alanine (8%), glutamate (6.8%) and proline (2.2%). Their enrichments were 20%, 36% and 19% respectively. The minimum detectable amount was 17 pg of 15N entering the CRI. CRIMS appears to be a powerful, facile approach for 15N-tracer experiments.
Development of the professional role behaviors survey (PROBES).

Background and Purpose. This study examined the content validity, internal consistency, and underlying dimensions of the Professional Role Behaviors Survey (PROBES) for its use in future research. Methods. Using the 26-item PROBES, 253 clinical managers reported on the direction and magnitude of change in the role behaviors of physical therapists following hospital restructuring. Results. Descriptive and correlational statistics of the responses indicated that the nature of the role behavior changes was consistent with those identified in the literature and that the survey instrument had good internal consistency. A principal component factor analysis yielded 5 underlying role behavior dimensions: “evaluating and planning,” “productivity,” “inter-acting,” “information sharing,” and “administration/clinical.” This factor structure was found to provide a good fit with role classification schemes and a clear differentiation of physical therapist role behaviors. In addition, the finding supports viewing the professional role behaviors as a single construct rather than as multiple constructs. Discussion and Conclusion. The PROBES was found to have good content validity and internal consistency. It provides a useful tool for the study of the changing roles of professional practitioners and a link in the study of the effect of organizational change on organizational outcomes such as job satisfaction and organizational commitment.
Munc18a Scaffolds SNARE Assembly to Promote Membrane Fusion

Munc18a is an SM protein required for SNARE-mediated fusion. The molecular details of how Munc18a acts to enhance neurosecretion have remained elusive. Here, we use in vitro fusion assays to characterize how specific interactions between Munc18a and the neuronal SNAREs enhance the rate and extent of fusion. We show that Munc18a interacts directly and functionally with the preassembled t-SNARE complex. Analysis of Munc18a point mutations indicates that Munc18a interacts with helix C of the Syntaxin1a NRD in the t-SNARE complex. Replacement of the t-SNARE SNAP25b with yeast Sec9c had little effect, suggesting that Munc18a has minimal contact with SNAP25b within the t-SNARE complex. A chimeric Syntaxin built of the Syntaxin1a NRD and the H3 domain of yeast Sso1p and paired with Sec9c eliminated stimulation of fusion, suggesting that Munc18a/Syntaxin1a H3 domain contacts are important. Additionally, a Syntaxin1A mutant lacking a flexible linker region that allows NRD movement abolished stimulation of fusion. These experiments suggest that Munc18a binds to the Syntaxin1a NRD and H3 domain within the assembled t-SNARE complex, positioning them for productive VAMP2 binding. In this capacity, Munc18a serves as a platform for trans-SNARE complex assembly that facilitates efficient SNARE-mediated membrane fusion.
Optimal nonuniform deployment of sensors for distributed detection in wireless sensor networks

We determine the optimal nonuniform spatial density of nodes in a single-hop Wireless Sensor Network (WSN) whose task is the distributed detection of a target within its sensing field. The optimization approach accounts for such factors as the Medium Access Control (MAC) protocol being used, the wireless channel's propagation characteristics, a randomized sleep/wake-up scheduling protocol, network coverage constraints, the energy consumed, the time to reach a decision, and the number of nodes in the network. The node density that minimizes the average Decision Error Probability (DEP) when a node at the center of the network serves as the Cluster Head (CH) is shown to be a function of the distance from this CH. The solution of this optimization problem and simulations demonstrate both the significant performance improvement provided by nonuniform spatial densities and the trade-offs that are possible amongst energy, network lifetime, detection performance, and time to reach a decision.
Deficiencies of Cardiovascular Risk Prediction Models for Type 1 Diabetes

OBJECTIVE —Cardiovascular risk prediction models are available for the general population (Framingham) and for type 2 diabetes (U.K. Prospective Diabetes Study [UKPDS] Risk Engine) but may not be appropriate in type 1 diabetes, as risk factors including younger age at diabetes onset and presence of diabetes complications are not considered. Therefore, our objective was to examine the accuracy of Framingham and UKPDS models for predicting coronary heart disease (CHD) in a type 1 diabetic cohort. RESEARCH DESIGN AND METHODS —Ten-year follow-up data from the Pittsburgh Epidemiology of Diabetes Complications (EDC) study, a prospective cohort study of 658 subjects with childhood-onset type 1 diabetes diagnosed between 1950 and 1980 first seen in 1986–1988, were analyzed. EDC study data were used to calculate the 10-year probability of CHD (fatal CHD, nonfatal myocardial infarction, or Q-waves) applying to the Framingham and UKPDS equations. RESULTS —Mean age at CHD onset was 39 years. When fatal/nonfatal myocardial infarction and CHD death were modeled, both the UKPDS and Framingham models showed significant lack of calibration ( P CONCLUSIONS —Currently available CHD models poorly predict events in type 1 diabetes. Future research should focus on determining the risk factors accounting for the lack of fit and developing prediction models specific to this high-risk group.
LDL oxidized by hypochlorous acid causes irreversible platelet aggregation when combined with low levels of ADP, thrombin, epinephrine, or macrophage-derived chemokine (CCL22).

The in vitro oxidation of low-density lipoprotein (LDL) by hypochlorous acid produces a modified form (HOCl-LDL) capable of stimulating platelet function. We now report that HOCl-LDL is highly effective at inducing platelet function, causing stable aggregation and α-granule secretion. Such stimulation depended on the presence of low levels of primary agonists such as adenosine diphosphate (ADP) and thrombin, or others like epinephrine (EPI) and macrophage-derived chemokine (MDC, CCL22). Agonist levels, which by themselves induced little or reversible aggregation, caused strong stable aggregation when combined with low levels of HOCl-LDL. Platelet activation by HOCl-LDL and ADP (1 μM) caused P-selectin (CD62P) exposure, without serotonin or adenosine triphosphate (ATP) secretion. Intracellular calcium levels rose slowly (from 100 to 200 nM) in response to HOCl-LDL alone and rapidly when combined with ADP to about 300 nM. p38 mitogen-activated protein kinase (MAPK) became phosphorylated in response to HOCl-LDL alone. This phosphorylation was not blocked by the protein kinase C (PKC) inhibitor bisindolylmaleimide, which reduced the extent of aggregation and calcium increase. However, the p38 MAPK inhibitor SB203580 blocked platelet aggregation and phosphorylation of p38 MAPK. These findings suggest that HOCl-LDL exposed during atherosclerotic plaque rupture, coupled with low levels of primary agonists, can rapidly induce extensive and stable thrombus formation. (Blood. 2004;104:380-389)
Excited‐state lifetime studies of the three tryptophan residues in the N‐lobe of human serum transferrin

The energy transfer from the three Trp residues at positions 8, 128, and 264 within the human serum transferrin (hTF) N-lobe to the ligand to metal charge transfer band has been investigated by monitoring changes in Trp fluorescence emission and lifetimes. The fluorescence emission from hTF N-lobe is dominated by Trp264, as revealed by an 82% decrease in the quantum yield when this Trp residue is absent. Fluorescence lifetimes were determined by multifrequency phase fluorometry of mutants containing one or two Trp residues. Decays of these samples are best described by two or three discrete lifetimes or by a unimodal Lorentzian distribution. The discrete lifetimes and the center of the lifetime distribution for samples containing Trp128 and Trp264 are affected by iron. The distribution width narrows on iron removal and is consistent with a decrease in dynamic mobility of the dominant fluorophore, Trp264. Both the quantum yield and the lifetimes are lower when iron is present, however, not proportionally. The greater effect of iron on quantum yields is indicative of nonexcited state quenching, i.e., static quenching. The results of these experiments provide quantitative data strongly suggesting that Forster resonance energy transfer is not the sole source of Trp quenching in the N-lobe of hTF.
Determination of approximate size of maxillary anterior denture teeth when mandibular anterior teeth are present. Part II: Mold selection.

Consequently, when mandibular anterior teeth are present, the arch width from distal-of-canine to distalof-canine can be measured, and this measurement times 1.3 equals the required arch width of maxillary anterior teeth to produce a Class I canine relationship. To allow for intentional disclusion of the maxillary anterior teeth arrangement, the ratio can be slightly modified. A ratio of 1.38 will usually yield the desired result. There is an acceptable range of minimum and maximum for the mesiodistal width of the selected maxillary anterior teeth mold.
Physical layout algorithms for computer generated holograms in optoelectronic MCM systems design

The fundamental computer generated hologram (CGH) fabrication and design limitations that greatly influence optoelectronic multichip module (OE-MCM) design are discussed. Physical models of free-space optical interconnects for OE-MCM are identified. Logical and mathematical models for analysis are then derived from these models. These cases are analyzed and an iterative algorithm to solve the layout problem is presented. The results of applying the algorithm to the OE-MCM design of a twin butterfly interconnection network are discussed. >
Endoscopic Management of Gastrointestinal Leaks and Fistulae

Gastrointestinal leaks and fistulae can be serious acute complications or chronic morbid conditions resulting from inflammatory, malignant, or postsurgical states. Endoscopic closure of gastrointestinal leaks and fistulae represents major progress in the treatment of patients with these complex presentations. The main goal of endoscopic therapy is the interruption of the flow of luminal contents across a gastrointestinal defect. In consideration of the proper endoscopic approach to luminal closure, several basic principles must be considered. Undrained cavities and fluid collections must often first be drained percutaneously, and the percutaneous drain provides an important measure of safety for subsequent endoscopic luminal manipulations. The size and exact location of the leak/fistula, as well as the viability of the surrounding tissue, must be defined. Almost all complex leaks and fistulae must be approached in a multidisciplinary manner, collaborating with colleagues in nutrition, radiology, and surgery. Currently, gastrointestinal leaks and fistulae may be managed endoscopically by using 1 or more of the following modalities: stent placement, clip closure (including through-the-scope clips and over-the-scope devices), endoscopic suturing, and the injection of tissue sealants. In this article, we discuss these modalities and review the published outcomes data regarding each approach as well as practical considerations for successful closure of luminal defects.
Chronic Subdural Hematoma After Neurosurgical Procedures

hronic subdural hematomas (CSDHs) are commonly seen in elderly people and in younger people with brain C involution, and only 50% of patients give a history of head injury, often a mild injury. Other risk factors include alcohol abuse, seizures, coagulopathies, anticoagulant therapy, some physical conditions that predisposes to falls, and low intracranial pressure due to different causes (1). This last condition may be connected with the main subject of this Perspective, that is the CSDH secondary to an intracranial surgery.
Diaphragm muscle shortening modulates kinematics of lower rib cage in dogs

We tested the hypothesis that diaphragm muscle shortening modulates volume displacement and kinematics of the lower rib cage in dogs and that posture and mode of ventilation affect such modulation....
Antibody Response After Influenza Immunization in Renal Transplant Patients Receiving Cyclosporin A or Azathioprine

Nineteen renal transplant recipients receiving cyclosporin A and prednisone, eight kidney recipients receiving azathioprine and prednisone, and 12 healthy volunteers were immunized with 0.5 ml of trivalent influenza vaccine containing A/Bangkok/1/79 (H(3)N(2)), A/Brazil/11/78 (H(1)N(1)), and B/Singapore/222/79. Nine patients (47%) in the cyclosporin A group and five (63%) in the azathioprine group showed fourfold rises in titer to at least one virus strain compared with 12 (100%) in the control group.