cssi/SciSciGPT-SciSciNet huggingface dataset:
Salivary gland development in Drosophila melanogaster

The Drosophila salivary gland is proving to be an excellent experimental system for understanding how cells commit to specific developmental programs and, once committed, how cells implement such decisions. Through genetic studies, the factors that determine where salivary glands will form, the number of cells committed to a salivary gland fate, and the distinction between the two major cell types (secretory cells and duct cells) have been discovered. Within the next few years, we will learn the molecular details of the interactions among the salivary gland regulators and salivary gland target genes. We will also learn how the early-expressed salivary gland genes coordinate their activities to mediate the morphogenetic movements required to form the salivary gland and the changes in cell physiology required for high secretory activity.
Frequency contribution to the click‐evoked auditory brain‐stem response in human adults and infants

The results of previous research reports have led some investigators to hypothesize that frequency contribution to the infant click‐evoked auditory brain‐stem response (ABR) is low‐frequency dominated and derived primarily from the apical cochlea. This is in contrast to latency and morphology of the adult click‐evoked ABR which reflects contributions from the basal cochlea. Recent research, however, has suggested that a simple low‐frequency first model of development does not adequately describe the infant auditory brain‐stem response. This experiment was conducted as a carefully controlled comparison of infant and adult click‐evoked ABRs restricted to narrow frequency ranges with notched‐noise masking. The primary objective of this experiment was to define frequency contribution to wave I and V click‐evoked ABR latency and morphology in adults and 3‐month‐old infants. Results indicate that 3‐month‐old infants have adultlike latency shifts (re: unmasked latency) when the ABR is recorded in the presence of notched‐noise masking with center frequencies ranging from 500–8000 Hz. With high‐frequency centered notches, latency, and morphology change are similar to the unmasked response, while low‐frequency centered notches induce an average latency shift of approximately 3.5 ms for wave I and V of both infant and adult subjects. These data suggest that by 3 months of age, in normal hearing infants, ABR latency and appearance are determined by high‐frequency spectral components in the broadband click which activate the basal cochlea. The adultlike pattern of latency shift observed in the ABR of these infants suggests that relatively mature tonotopic organization is established by 3 months of age.
pH-Dependent Conformational Changes in Bacterial Hsp90 Reveal a Grp94-Like Conformation at pH 6 That Is Highly Active in Suppression of Citrate Synthase Aggregation

The molecular chaperone Hsp90 depends upon large conformational rearrangements for its function. One driving force for these rearrangements is the intrinsic ATPase activity of Hsp90, as seen with other chaperones. However, unlike other chaperones, structural and kinetic studies have shown that the ATPase cycle of Hsp90 is not conformationally deterministic. That is, rather than dictating the conformational state, ATP binding and hydrolysis shift the equilibrium between a preexisting set of conformational states in an organism-dependent manner. While many conformations of Hsp90 have been described, little is known about how they relate to chaperone function. In this study, we show that the conformational equilibrium of the bacterial Hsp90, HtpG, can be shifted with pH. Using small-angle X-ray scattering, we identify a two-state pH-dependent conformational equilibrium for apo HtpG. Our structural modeling reveals that this equilibrium is observed between the previously observed extended state and a second state that is strikingly similar to the recently solved Grp94 crystal structure. In the presence of nonhydrolyzable 5'-adenylyl-beta,gamma-imidodiphosphate, a third state, which is identical with the solved AMPPNP-bound structure from yeast Hsp90, is populated. Electron microscopy confirmed the observed conformational equilibria. We also identify key histidine residues that control this pH-dependent equilibrium; using mutagenesis, we successfully modulate the conformational equilibrium at neutral pH. Using these mutations, we show that the Grp94-like state provides stronger aggregation protection compared to the extended apo conformation in the context of a citrate synthase aggregation assay. These studies provide a more detailed view of HtpG's conformational dynamics and provide the first linkage between a specific conformation and chaperone function.
Incidence of atrial fibrillation in whites and African-Americans: The Atherosclerosis Risk in Communities (ARIC) study

Objectives To define the incidence and cumulative risk of atrial fibrillation (AF) in a population-based cohort of whites and African Americans. Background African-Americans reportedly have a lower risk of AF than whites despite their higher exposure to AF risk factors. However, precise estimates of AF incidence in African Americans have not been previously published. Methods We studied the incidence of AF in the Atherosclerosis Risk in Communities (ARIC) study, which has followed up 15,792 men and women 45 to 65 years of age at baseline from 4 communities in the United States since 1987. Atrial fibrillation cases were identified from electrocardiograms conducted at baseline and 3 follow-up visits, and from hospitalizations and death certificates through the end of 2004. During follow-up, 1,085 new cases of AF were identified (196 in African Americans, 889 in whites). Results Crude incidence rates of AF were 6.7, 4.0, 3.9, and 3.0 per 1,000 persons per year in white men, white women, African-American men, and African-American women, respectively. Increasing age was exponentially associated with an elevated risk of AF. Compared to whites, African-Americans had a 41% (95% CI: 8%-62%) lower age- and sex-adjusted risk of being diagnosed with AF. The cumulative risk of AF at 80 years of age was 21% in white men, 17% in white women, and 11% in African-American men and women. Conclusion In this population-based cohort, African Americans presented a lower risk of AF than whites. Still, the burden of AF among the former is substantial, with 1 in 9 receiving a diagnosis of AF before 80 years of age.
Estimation of regression parameters in a semiparametric transformation model

A semiparametric approach to model skewed/heteroscedastic regression data is discussed. We work with a semiparametric transform-both-sides regression model, which contains a parametric regression function and a nonparametric transformation. This model is adequate when the relationship between the median response and the explanatory variable has been specified by a theoretical result or a previous empirical study. The transform-both-sides model with a parametric transformation has been studied extensively and applied successfully to a number data sets. Allowing a nonparametric transformation function increases the flexibility of the model. In this article, we estimate the nonparametric transformation function by the conditional kernel density approach developed by Wang and Ruppert (1995), and then use a pseudo-maximum likelihood estimator to estimate the regression parameters. This estimate of the regression parameters has not been studied previously. In this article, the asymptotic distribution of this pseudo-MLE is derived. We also show that when σ, the standard deviation of the error, goes to zero (small σ asymptotics), this estimator is adaptive. Adaptive means that the regression parameters are estimated as precisely as when the transformation is known exactly. A similar result holds in the parametric approaches of Carroll and Ruppert (1984) and Ruppert and Aldershof (1989). Simulated and real examples are provided to illustrate the performance of the proposed estimator for finite sample size.
Effect of metal on 2,4,5-trihydroxyphenylalanine (topa) quinone biogenesis in the Hansenula polymorpha copper amine oxidase.

Abstract Previous studies of wild-type and mutant forms of a recombinant copper amine oxidase from Hansenula polymorpha, expressed in Saccharomyces cerevisiae, have indicated a self-processing mechanism for 2,4,5-trihydroxyphenylalanine (topa) quinone biogenesis involving the active site copper (Cai, D., and Klinman, J. P. (1994) J. Biol. Chem. 269, 32039–32042). In contrast to prokaryotic copper amine oxidases, however, it has not been possible to initiate topa quinone formation by the addition of exogenous copper to precursorH. polymorpha amine oxidase lacking copper. Metal analysis of copper-depleted wild-type enzyme reveals 0.2–0.3 mol copper, together with 0.6 mol zinc. Despite changes in the zinc and copper levels in growth media, the level of zinc in purified enzyme remains fairly constant. Further, we have been unable to displace protein-bound zinc by exogenously added copper. The H. polymorpha amine oxidase gene was subsequently expressed in Escherichia coliand found to be almost completely free of copper and zinc. In vitro reconstitution of this apoprotein confirms that zinc binds to H. polymorpha amine oxidase and prevents reconstitution with copper. By contrast, addition of copper first to apoprotein leads to formation of topa quinone and stable activity in the presence of added zinc. These findings indicate efficient binding of either zinc or copper to a site that undergoes little or no exchange. The data confirm that topa quinone biogenesis in the H. polymorpha system is catalyzed by copper and occurs in the absence of added factors. We conclude that the mechanisms of cofactor biogenesis in pro- and eukaryotic systems are likely to be similar or identical. The results described herein imply different pathways for the in vivoassembly of heterologously expressed amine oxidases in S. cerevisiae and E. coli.
Fatigue from high- and low-frequency muscle stimulation: role of sarcolemma action potentials

This study compared the effect of high- (75 Hz, 1 min) and low- (5 Hz, 1.5 min) frequency stimulation on sarcolemmal action potentials of rat phrenic nerve-diaphragm preparations, measured in vitro at 25 degrees C. High-frequency stimulation reduced peak tetanic tension to 21 +/- 1% (means +/- SE) of initial, whereas 5 Hz stimulation produced less of a decline (71 +/- 2% of initial). Despite an initial faster rate of force recovery after 75-Hz stimulation, tetanic tension was still significantly depressed at 0.25 and 1 min relative to the values after 5-Hz stimulation (P less than 0.05). Resting membrane potential, and action potential overshoot and area were not significantly altered by fatigue. Action potential amplitude (AMP) was initially depressed by repetitive stimulation but increased significantly during recovery (P less than 0.05). No significant difference occurred in AMP recovery between the high- vs. low-frequency stimulation groups. The rate of rise and fall of the action potential was reduced after fatiguing stimulation but increased significantly with time (P less than 0.05). Moreover, the time to peak height of the action potential was prolonged by fatigue but significantly declined to resting values with time (P less than 0.05). During recovery, fatigue from high-frequency stimulation was associated with a greater prolongation in duration and time to baseline of the action potential relative to low-frequency stimulation (P less than 0.05). Action potential variables altered by stimulation generally recovered within 1 to 3 min, whereas peak tetanic tension did not completely return to resting values until 10 to 15 min of recovery. We conclude that high- and low-frequency stimulation elicits virtually identical perturbations in sarcolemmal action potentials, and thus changes in surface membrane properties cannot explain the decreased tetanic tension that follows 75-Hz stimulation. It appears that events distal to the sarcolemma are responsible for fatigue from both high- and low-frequency stimulation.
Synchronous and Dichotomous Replications of the Bacillus subtilis Chromosome During Spore Germination

Synchronous and Dichotomous Replications of the Bacillus subtilis Chromosome During Spore Germination
Phylogenetic and Functional Classification of Mitogen- and Stress-Activated Protein Kinases

All currently sequenced stress-activated protein kinases (SAPKs), extracellular signal-regulated kinases (ERKs), and other mitogen-activated protein kinases (MAPKs) were analyzed by sequence alignment, phylogenetic tree construction, and three-dimensional structure modeling in order to classify members of the MAPK family. Based on this analysis the MAPK family was divided into three subgroups (SAPKs, ERKs, and MAPK3) that consist of at least nine subfamilies. Members of a given subfamily were exclusively from animals, plants, or yeast/fungi. A single signature sequence, [LIVM][TS]XX[LIVM]XT[RK][WY]YRXPX[LIVM] [LIVM], was identified that is characteristic for all MAPKs and sufficient to distinguish MAPKs from other members of the protein kinase superfamily. This signature sequence contains the phosphorylation site and is located on loop 12 of the three-dimensional structure of MAPKs. I also identified signature sequences that are characteristic for each of the nine subfamilies of MAPKs. By modeling the three-dimensional structure of three proteins for each MAPK subfamily based on the resolved atomic structures of rat ERK2 and murine p38, it is demonstrated that amino acids conserved in all MAPKs are located primarily in the center of the protein around the catalytic cleft. I conclude that these residues are important for maintaining proper folding into the gross structure common to all MAPKs. On the other hand, amino acids conserved in a given subfamily are located mainly in the periphery of MAPKs, indicating their possible importance for defining interactions with substrates, activators, and inhibitors. Within these subfamily-specific regions, amino acids were identified that represent unique residues occurring in only a single subfamily and their location was mapped in three-dimensional structure models. These unique residues are likely to be crucial for subfamily-specific interactions of MAPKs with substrates, inhibitors, or activators and, therefore, represent excellent targets for site-directed mutagenesis experiments.
The preparation and properties of thin polycrystalline GaAs solar cells with grain boundary edge passivation

This paper describes the preparation and properties of thin-film (9-µm) polycrystalline GaAs solar cells, fabricated on molybdenum substrates by the metalorganic process. These cells, of a Schottky structure, have an efficiency of 5.7 percent under simulated AM1 conditions, with no antireflective (AR) coating. This is achieved by passivating the grain boundary edges, resulting in a reduction of shunt leakage by five to six decades. The effect of treatments on the resulting electrical properties is described; both treatments during fabrication as well as on complete devices are considered here. These include a critic acid etch treatment prior to anodization, and hydrochloric acid treatments on completed devices. The effect of annealing is also described briefly together with techniques by which full recovery of cell performance can be achieved. Finally, transport properties are outlined briefly in order to highlight the primary current transport mechanisms in these cells.
Statistical issues in trial design and personalized medicine

“New and general statistical methods are needed to analyze clinical data for personalized medicine. Specifically, it is important to address the following questions: are the most classical statistical methods ... still valid? Can one use some nonparametric methods, such as rerandomization tests? How does one perform subgroup statistical ana lysis?”
From acoustic scattering models of zooplankton to acoustic surveys of large regions

The bioacoustics research group at the Woods Hole Oceanographic Institution is actively conducting field surveys, laboratory acoustic scattering experiments, and theoretical modeling of acoustic scattering. While the focus of the research has been on zooplankton, we have also investigated the scattering by internal waves and suspended sediment. The field surveys are taking advantage of the newly developed towed instrument, BIOMAPER-II, that contains a suite of acoustical (43 kHz to 1 MHz), optical, and environmental sensors. The system has been used to map portions of Georges Bank near Cape Cod, MA, US. Our laboratory contains a wide range of acoustic transducers (24 kHz to 1.4 MHz, some of which are broadband) that are used to measure the acoustic backscattering as a function of acoustic frequency and animal orientation. The system has been used to measure the acoustic scattering properties of live tethered animals, either at sea on the deck of a ship with freshly caught animals or on land with live animals that have been maintained. The laboratory data have provided a basis for the development of physics-based acoustic scattering models of the zooplankton which have been used to interpret the field surveys. The models take into account the material properties of the animals, size, shape, and orientation, as well as acoustic frequency. Broadband echo classification methods have been developed based on the models and data. Finally, two new systems are under development: one is used to measure target strength of individuals in situ and the other is to be used to measure sound speed of the animals in situ.
The interaction of high-speed turbulence with flames: Global properties and internal flame structure

We study the dynamics and properties of a turbulent flame, formed in the presence of subsonic, high-speed, homogeneous, isotropic Kolmogorov-type turbulence in an unconfined system. Direct numerical simulations are performed with Athena-RFX, a massively parallel, fully compressible, high-order, dimensionally unsplit, reactive flow code. A simplified reaction-diffusion model represents a stoichiometric H2–air mixture. The system being modeled represents turbulent combustion with the Damkohler number Da=0.05 and with the turbulent velocity at the energy injection scale 30 times larger than the laminar flame speed. The simulations show that flame interaction with high-speed turbulence forms a steadily propagating turbulent flame with a flame brush width approximately twice the energy injection scale and a speed four times the laminar flame speed. A method for reconstructing the internal flame structure is described and used to show that the turbulent flame consists of tightly folded flamelets. The reaction zone structure of these is virtually identical to that of the planar laminar flame, while the preheat zone is broadened by approximately a factor of two. Consequently, the system evolution represents turbulent combustion in the thin reaction zone regime. The turbulent cascade fails to penetrate the internal flame structure, and thus the action of small-scale turbulence is suppressed throughout most of the flame. Finally, our results suggest that for stoichiometric H2–air mixtures, any substantial flame broadening by the action of turbulence cannot be expected in all subsonic regimes.
Protocol-level reconfigurations for infusion of resilience in distributed network services

The paper describes a network service model where a service provider (SP) maintains multiple protocol modules to exercise the infrastructure resources under various environment conditions. Each protocol exhibits a certain degree of performance optimality and service resilience in distinct operating regions of the network infrastructure and the environment. During run-time, the SP selects one of the protocol modules that can meet the application-requested Quality of Service (QoS) obligation against the prevailing operating conditions. Under normal conditions when the external disturbances are benign (e.g., low packet loss in the network), an optimal usage of the network resources is important. Under adverse conditions however (e.g., heavy packet loss), a sustained access to the network service at some minimum acceptable level becomes more important than a resource-optimal service offering. Often, a resilient protocol incurs more resource usage to tackle the hostile environment conditions than a performance-conscious protocol tuned for the normal case operations. Accordingly, a protocol selection by the SP considers the trade-off between ‘service resilience’ under extreme operating conditions and ‘resource optimality’ under normal operations. Our model allows a dynamic switching from one protocol module to another at run-time based on the changing environment conditions.
Load Transfer Mechanisms between Underground Structure and Surrounding Ground: Evaluation of the Failure of the Daikai Station

The Daikai Station, a cut and cover structure in the subway system in Kobe, collapsed during the Hyogoken-Nambu earthquake of January 17, 1995 in Japan. The Daikai Station is the first well-documented underground structure not crossing an active fault that has completely collapsed during an earthquake without liquefaction of the surrounding soil. What makes this case even more interesting is that tunnel sections adjacent to the station, with similar structural characteristics and analogous soil conditions, did not collapse. Dynamic numerical analyses have been conducted to investigate the load transfer mechanisms between the underground structure and the surrounding soil and to identify the causes for different behavior of similar sections of the station subjected to the same seismic loading. A hysteretic nonlinear soil model has been used for the analysis. The model captures well the soil's shear modulus degradation and the increase of damping with strain. The results from the analyses show that, for a given earthquake, there are two key factors that determine the response of an underground structure: the relative stiffness between the structure and the degraded surrounding ground, and the frictional characteristics of the interface. A stiff structure has small deformations; because the adjacent soil movement is restricted by the structure, the shear modulus degradation of the soil is limited which contributes to reduce further deformation of the soil and thus decreases the displacement demand on the structure. A strong interface is capable of transmitting larger shear to the structure but in turn increases the confinement of the soil surrounding the structure which limits the soil's shear modulus degradation. The model predicts larger deformations in the section that collapsed because this section had a smaller stiffness, and thus triggered drifts in critical structural elements which were larger than at other sections of the station which remained stable.
Deposition of DDE and Polychlorinated Biphenyls in Dated Sediments of the Santa Barbara Basin

Analysis of dated oceanic sediments from the Santa Barbara Basin of the Southern California Bight has shown that deposition of polychlorinated biphenyls (PCB) began about 1945 and that DDE [1,1-dichloro-2-2-bis(p-chloro-phenyl)ethylene] first appeared in sediments deposited about 1952. Concentrations of both show a progressive increase through 1967; estimated deposition rates (in grams per square meter per year) in 1967 of DDE and PCB were 1.9 x 10(-4) and 1.2 x 10(-4), respectively.
On the Origins of German Uvular [R]: The Yiddish Evidence

Yiddish provides a compelling argument that uvular [R] was present early in German (well before any possible French influence). Eastern European Yiddish r was uvular despite the fact that the r of eastern European languages sharing territory with Yiddish has always been overwhelmingly apical. Jews came from Germany to eastern Europe between 1100 and 1650. Thus, the testimony of Yiddish provides independent confirmation of other recent arguments for early uvular [R] on German-speaking territory. The weight of all the evidence leads to one conclusion: the theory that German uvular [R] came from France is no longer tenable.
Quick Reference Dictionary for Occupational Therapy (5th ed.), by K. Jacobs and L. Jacobs

The purpose of the Quick Reference Dictionary for Occupational Therapy is to provide the occupational therapy student and practitioner a quick reference to commonly used terminology. Appendixes foc...
Responsiveness of Health Status Measures to Change among Older Adults

Author(s): Wagner, EH; LaCroix, AZ; Grothaus, LC; Hecht, JA | Abstract: ObjectiveThis study examines the ability of commonly used self-reported health status measures to detect important changes in health (responsiveness) in older adults.DesignWe compared changes in health status measures over the year among subgroups of a cohort of seniors: those who experienced an intervening illness, hospitalization or increase in drug regimen, and those who didn't. Differences between the two groups in changes in the measures were quantitated using Guyatt's responsiveness statistic and receiver operating characteristic curves (ROC).SettingStaff model HMO.Participants1379 senior HMO enrollees who were participants in a health promotion trial and provided complete information at baseline and one year later.MeasurementsThe following self-reported health status measures were evaluated: restricted activity days, bed disability days, the Medical Outcomes Study physical function scale, self-evaluated health, and a positive affect scale.Main resultsAll measures except the positive affect scale were able to discriminate significantly between seniors who were or were not hospitalized and/or reported a major illness in the intervening year. The two disability days measures showed the best responsiveness for all indicators of worsening health and included 70%-80% of the area under the ROC curves for major illness defined by hospitalization or self-report.ConclusionsCommonly used, brief self-reported physical health status measures are responsive to intervening illness among relatively healthy seniors supporting their use in longitudinal geriatric research.
Multifield optimization intensity-modulated proton therapy (MFO-IMPT) for prostate cancer: Robustness analysis through simulation of rotational and translational alignment errors.

To evaluate the dosimetric consequences of rotational and translational alignment errors in patients receiving intensity-modulated proton therapy with multifield optimization (MFO-IMPT) for prostate cancer. Ten control patients with localized prostate cancer underwent treatment planning for MFO-IMPT. Rotational and translation errors were simulated along each of 3 axes: anterior-posterior (A-P), superior-inferior (S-I), and left-right. Clinical target-volume (CTV) coverage remained high with all alignment errors simulated. Rotational errors did not result in significant rectum or bladder dose perturbations. Translational errors resulted in larger dose perturbations to the bladder and rectum. Perturbations in rectum and bladder doses were minimal for rotational errors and larger for translational errors. Rectum V45 and V70 increased most with A-P misalignment, whereas bladder V45 and V70 changed most with S-I misalignment. The bladder and rectum V45 and V70 remained acceptable even with extreme alignment errors. Even with S-I and A-P translational errors of up to 5 mm, the dosimetric profile of MFO-IMPT remained favorable. MFO-IMPT for localized prostate cancer results in robust coverage of the CTV without clinically meaningful dose perturbations to normal tissue despite extreme rotational and translational alignment errors.
Integrating Sheep Grazing into Cereal-Based Crop Rotations: Spring Wheat Yields and Weed Communities

Published in Agron. J. 107:104–112 (2015) doi:10.2134/agronj14.0086 Copyright © 2015 by the American Society of Agronomy, 5585 Guilford Road, Madison, WI 53711. All rights reserved. No part of this periodical may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. ABSTRACT
Rapid intensification and propagation of the dayside aurora: Large scale interplanetary pressure pulses (fast shocks)

We present two cases of abrupt dayside auroral brightenings and very fast auroral propagation using the POLAR UV imaging data. The brightenings occur first at noon and then propagate along the auroral oval towards dawn and dusk. Ionospheric speeds of 6 to 11 km/s are determined. The auroral brightenings and motion are associated with the arrival and propagation of interplanetary shocks/pressure waves. The brightening at noon occurs within minutes of the shock compression of the noon-time magnetopause. The speed of the auroral propagation in the ionosphere towards dawn and dusk corresponds extremely well to the solar wind downstream flow. Our model assumes that shocks/pressure waves compress the outer dayside magnetosphere, and plasma contained therein. This plasma compression leads to the loss cone instability, wave-particle interactions, and concomitant particle loss into the ionosphere.
A sedimentary-based history of hurricane strikes on the southern Caribbean coast of Nicaragua

Multi-millennial hurricane landfall records from the western North Atlantic indicate that landfall frequency has varied dramatically over time, punctuated by multi-centennial to millennial scale periods of hyperactivity. We extend the record geographically by presenting a paleostrike record inferred from a four-core transect from a marsh on the Caribbean coast of Nicaragua. Fossil pollen indicates that the site was a highly organic wetland from ~ 5400–4900 cal yr BP, at which time it became a shallow marine lagoon until ~ 2800 cal yr BP when it transitioned back into swamp/marsh, freshening over time, with the present fresh-to-brackish Typha marsh developing over the very recent past. Hurricane Joan, 1988, is recorded as a distinctive light-colored sand–silt–clay layer across the top of the transect, identifiable by abrupt shifts in color from the dark marsh deposits, increased grain size, and two upward-fining sequences, which are interpreted as representing the storm's traction and suspension loads. The six layers identified as hurricane-generated display temporal clustering, featuring a marked increase in landfall frequency ~ 800 cal yr BP. This pattern is anti-phase with the activity pattern previously identified from the northern Caribbean and the Atlantic coast of North America, thereby opposing the view that hyperactivity occurs simultaneously across the entire basin.
Redox Changes during Fertilization and Maturation of Marine Invertebrate Eggs

Previous studies on sea urchin eggs indicate that activation of NAD kinase is one of the earliest Ca2+-mediated events of fertilization. The subsequently produced NADP is converted to NADPH by the pentose shunt pathway, and some of this NADPH is used by an NADPH oxidase for generation of H2O2. To examine whether these changes apply generally, we have analyzed changes in pyridine nucleotide content during meiotic maturation and fertilization in eggs from four phyla. Surprisingly, fertilization-associated increases in NAD kinase were found only in echinoid eggs. The ratio of NADPH/NADP (redox ratio) increased from 1-1.6 to 2.5-6 following fertilization of echinoid and also clam eggs. However, the ratio is already >2 for unfertilized asteroid, tunicate and echiuroid eggs, and this ratio is unaffected by fertilization. We conclude that activation of NAD kinase and shifts in pyridine nucleotide metabolism and thereby cellular redox status may have roles that vary between species. In echinoids, a major role is in providing NADPH for H2O2 production, but there may be other yet unappreciated signaling functions for this change.
Analysis of 16S-23S intergenic spacer regions of the rRNA operons in Edwardsiella ictaluri and Edwardsiella tarda isolates from fish.

V.S. PANANGALA, V.L. VAN SANTEN, C.A. SHOEMAKER AND P.H. KLESIUS. 2005. Aims: To analyse interspecies and intraspecies differences based on the 16S–23S rRNA intergenic spacer region (ISR) sequences of the fish pathogens Edwardsiella ictaluri and Edwardsiella tarda. Methods and Results: The 16S-23S rRNA spacer regions of 19 Edw. ictaluri and four Edw. tarda isolates from four geographical regions were amplified by PCR with primers complementary to conserved sequences within the flanking 16S–23S rRNA coding sequences. Two products were generated from all isolates, without interspecies or intraspecific size polymorphisms. Sequence analysis of the amplified fragments revealed a smaller ISR of 350 bp, which contained a gene for tRNA Glu , and a larger ISR of 441 bp, which contained genes for tRNA Ile and tRNA Ala . The sequences of the smaller ISR of different Edw. ictaluri isolates were essentially identical to each other. Partial sequences of larger ISR from several Edw. ictaluri isolates also revealed no differences from the one complete Edw. ictaluri large ISR sequence obtained. The sequences of the smaller ISR of Edw. tarda were 97% identical to the Edw. ictaluri smaller ISR and the larger ISR were 96–98% identical to the Edw. ictaluri larger ISR sequence. The Edw. tarda isolates displayed limited ISR sequence heterogeneity, with ‡97% sequence identity among isolates for both small and large ISR. Conclusions: There is a high degree of size and sequence similarity of 16S–23S ISR both among isolates within Edw. ictaluri and Edw. tarda species and between the two species. Significance and Impact of the Study: Our results confirm a close genetic relationship between Edw. ictaluri and Edw. tarda and the relative homogeneity of Edw. ictaluri isolates compared with Edw. tarda isolates. Because no differences were found in ISR sequences among Edw. ictaluri isolates, sequence analysis of the ISR will not be useful to distinguish isolates of Edw. ictaluri. However, we identified restriction sites that differ between ISR sequences of Edw. ictaluri and Edw. tarda, which will be useful in distinguishing the two species.
Cooperation with the corporation? CNN and the hegemonic cooptation of citizen journalism through iReport.com

The literature on online citizen journalism tends to construe user-generated citizen media as inherently counter-hegemonic, as the emerging, as yet unformed but nonetheless virile antithesis to the traditional media. This article argues that while the vigorous profusion of web-based citizen media has the potential to inaugurate an era of dynamic expansion of the deliberative space and even serve as a counterfoil to the suffocating dominance of the discursive space by the traditional, mainstream media, we are now witnessing a trend toward the aggressive cooptation of these citizen media by corporate media hegemons. To demonstrate this, I study ‘iReport.com,’ a YouTube-type, user-generated citizen news site launched by the Cable News Network (CNN). I argue that the trend toward corporate-sponsored citizen media may, in the final analysis, blur the distinction between citizen and mainstream journalism.
Eddy-Induced Diapycnal Fluxes and Their Role in the Maintenance of the Thermocline

High-resolution numerical experiments are diagnosed to study the integral effects of geostrophic eddy fluxes on the large-scale ocean circulation. Three characteristic large-scale flows are considered: 1) an anticyclonic single gyre, 2) a double gyre, and 3) an unblocked zonal flow, a simple analog of the Antarctic Circumpolar Current. It is found that buoyancy and potential vorticity budgets in the presence of eddies are dominated by a balance between vertical advection into the control volume by Ekman pumping and eddy transfer across the density surfaces achieved by diapycnal eddy fluxes, with small-scale mixing making only a minor contribution. Possible oceanographic implications of the results are discussed. In this paper we discuss the role of time-dependent geostrophic eddy motions in the buoyancy and potential vorticity budgets diagnosed from numerical models of large-scale ocean flows. The ocean is full of energetic eddies that, as suggested by the numerical experiments herein, may be very effective in balancing global buoyancy and potential vorticity budgets. The possible role of eddies in this manner has been discussed in highly idealized laboratory and numerical studies by Marshall et al. (2002), Karsten et al. (2002), and Radko and Marshall (2003)—see also the discussion in Hughes (2002). Radko and Marshall (2003) considered an idealized abstraction of a subtrobical ocean gyre: the equilibration of a warm-pumped lens on a b plane. By construction, geostrophic eddies play a central role in the volume budget of the lens: warm fluid pumped down from the surface is fluxed away laterally by geostrophic eddies formed as a result of the baroclinic instability of a large-scale current in the region of western intensification. Here we consider more complex and perhaps more realistic configurations in which the downward flux of buoyancy from the Ekman layer could either be balanced by eddies, explicit dissipation, or by advective fluxes. Three-dimensional eddy-resolving numerical experiments of ocean gyres are diagnosed to quantify the roles of eddy buoyancy, momentum, and potential vorticity transfer. While many previous eddy-resolving studies have focused on the properties of isopycnal
Cranberry cocktail juice, cranberry concentrates, and proanthocyanidins reduce reovirus infectivity titers in African green monkey kidney epithelial cell cultures.

Studies were performed to investigate the effect of several cranberry and grape juice extracts on the inhibition of reovirus infectivity following cell culture inoculation. Infectivity testing was performed utilizing cranberry juice extracts NutriCran-100TM and NutriCran-90TM. At 5% extract concentrations, titers were reduced by ca. 50%. Cranberry cocktail juice caused an infectivity loss of ca. 10%. We ascribe these data to higher concentrations of proanthocyanidins (PACs) in the cranberry extracts. Further testing was performed utilizing purified high and low molecular weight cranberry PAC fractions (CB HMW and CB LMW, respectively), a cranberry flavonol glycoside (CB EToAc), cranberry anthocyanins (CB CA), and a grape PAC extract. Reovirus titers were reduced to undetectable levels at PAC concentrations ≤0.2%. CB CA had no effect on the inhibition of infectivity titers. Loss of infectivity titers was in the order: GP PAC>CB HMW>CB LMW>CB EToAc. Probe homogenization of CB HMW enhanced the extract to efficacy levels equal to that of grape PAC. Reovirus dsRNA segments were undetectable 96-h postcranberry cocktail juice pretreatment of MA-104 cell cultures. This study indicates an inhibition of reovirus infectivity titers by cranberry or grape juices or their purified PAC extracts. Viral inhibition probably occurs at the host cell surface.
Detailed modeling of fault-tolerant processor arrays

Detailed modeling of fault-tolerant processor arrays entails not only an explosive growth in the model state space but also a difficult model construction process. The latter problem is addressed, and a systematic method to construct Markov models for evaluating the reliability of processor arrays is proposed. This method is based on the premise that the fault behavior of a processor array can be modeled by a stochastic Petri net. However, in order to obtain a more compact representation, a set of attributes is associated with each transition in the Petri net model. This set of attributes allows the construction of the corresponding Markov model as the generation of the reachability graph takes place. Included in these attributes is a discrete probability distribution such that the effect of faulty spares in the reconfiguration algorithm is captured each time a configuration change occurs. This distribution includes the probabilities of survival given that a number of components required by the reconfiguration process are faulty. Depending on the type of component and the reconfiguration scheme, probabilities of survival are determined using simulation or closed-form expressions. >
Pressure-based viscous flow computation using multiblock overlapped curvilinear grids

A pressure-based multiblock computational method is developed for solving the incompressible Navier-Stokes equations in general curvilinear grid systems. A conservative interface scheme is devised with desirable accuracy to handle the information transfer between blocks. The scheme is based on the semiimplicit-type flow solver with the staggered grid. Issues concerning discontinuous grids, global mass conservation, viscous term treatment, and boundary conditions at the grid interface are addressed. The method is tested for two flow problems, a curved channel flow and a bifurcated channel flow. The calculations demonstrate that, besides maintaining desirable solution characteristics across discontinuous grid interfaces, the present multiblock algorithm can achieve convergence rates comparable to that of the single-block algorithm, yielding an improved computational capability for treating complex flow problems.
(GaIn)(NAsSb): the challenges and successes for long wavelength lasers

We have developed a new structure using GaInNAsSb quantum wells (QWs) with strain compensating GaNAs barriers which has produced 1.5 /spl mu/m lasers with threshold currents of 450 A/cm/sup 2/ and the first 1.5 /spl mu/m VCSELs. This material is grown by solid source MBE with a RF plasma source and both growth temperature and ion damage from the plasma source have turned out to be critical issues. The paper focuses on the successes to date on long wavelength lasers and integrated photonic crystal structures as well as the remaining challenges to achieve a viable technology for next generation high speed optical networks.
Quality indicators for the management of medical conditions in nursing home residents.

Purpose The purpose of this study was to develop a set of specific care processes associated with better outcomes for general medical conditions identified as quality improvement targets for institutionalized vulnerable elders. Methods A national panel of nursing home experts used a modified-Delphi process to rate the validity (process linked to improved outcomes) and feasibility (of implementation and measurement) of candidate measures for depression, diabetes, hearing impairment, heart failure, hypertension, ischemic heart disease, osteoarthritis, osteoporosis, pneumonia, stroke, and vision impairment. Each quality indicator was written as an "if" statement, describing persons to whom the quality indicator applied followed by a "then" statement identifying the care process to be provided. A separate clinical committee reviewed the resulting set of indicators. Results One hundred fourteen quality indicators were identified across the 11 medical conditions. The quality indicators capture a broad range of medical care addressing assessment, management, and follow up. Fifty-five indicators (48%) were identical to quality measures for community-dwelling vulnerable elders. A limited number were rated as questionably feasible to implement or measure (6 and 2, respectively). Thirty-eight (33%) would not be applied to measures of care quality for persons with advanced dementia or poor prognosis. Conclusions Explicit care processes linked to improved nursing home outcomes for general medical conditions can be identified. Most of these care processes can be measured by medical records or interview. Nursing home quality measures for medical conditions must account for exclusions related to poor prognosis and advanced dementia.
A Case of Hermaphroditism and Viviparity in Echinocardium cordatum

In May, 1933, during routine gonad examinations, a hermaphrodite specimen of Echinocardium cordatum was observed. It was collected in the sandy beach of Port Erin Bay at low water of ordinary spring tides, and was 4.7 cm. in length, which corresponds, in a normal specimen, to an age of about four years. The external colour was dark, although not more so than in other specimens in the batch, but the gonad was exceptionally pigmented—almost black. In this locality the colour of the test and gonad becomes progressively darker with increasing age, and affords some measure of the latter.The specimen was examined within half an hour of being collected, and portions of the gonad were fixed within ten minutes of being opened, so that fertilization and segmentation could not have advanced in the laboratory to the stage found. Smears from the gonad showed ova, of which about 50% were ripe, together with ripe spermatozoa. The gonoduct contained ripe ova, together with segmenting ova and early embryos. Figure 1 is a photograph of the contents of the gonoduct, taken immediately after opening, and showing ova with a four-cell stage and a blastula. Cultures were set up in sterile sea-water, from the contents of the gonoduct, and also from the gonad itself, as well as a control fertilization from normal urchins, and from all of these normal early plutei were reared. Those cultures from the hermaphrodite specimen did not, however, develop much further, possibly owing to premature fertilization in the abnormal conditions in the gonad.
Ensuring the quality of conceptual representations

High quality data and process representations are critical to the success of system development efforts. Despite this importance, quantitative methods for evaluating the quality of a representation are virtually nonexistent. This is a major shortcoming. However, there is another approach. Instead of evaluating the quality of the final representation, the representation process itself can be evaluated. This paper views the modeling process as a communication channel. In a good communication channel, sufficient error prevention, error detection, and error correction mechanisms exist to ensure that the output message matches the input message. A good modeling process will also have mechanisms for preventing, detecting, and correcting errors at each step from observation to elicitation to analysis to final representation. This paper describes a theoretically-based set of best practices for ensuring that each step of the process is performed correctly, followed by a proof of concept experiment demonstrating the utility of the method for producing a representation that closely reflects the real world.
Perspectives on Tiered Older Driver Assessment in Primary Care Settings

Purpose of the Study: Widespread screening of older dri vers, with in-depth evaluation only of those who screen positive (“tiered assessment”), might efficiently balance driver safety and mobility. To inform program development, we sought to examine the perspectives of older drivers and clinicians on the concept of tiered assessment in primary care settings. Design and Methods: Iterati ve focus groups and interviews with 33 community-dwelling current drivers aged ≥65 years and 8 primary care providers. We used inductive and deductive theme analysis to explore driver and clinician perspectives and to identify barriers and facilitators to establishing a tiered older driver assessment program in primary care settings. Results: F our dominant themes emerged. Two themes addressed the overall concept: (a) support for the concept of tiered older driver assessment and (b) concerns about the consequences of older driver assessment and how these could affect program viability. Two themes addressed screening: (c) tension inherent in using a generalized approach to the highly individualized issue of driving and (d) logistical considerations for screening in primary care settings. Implications: Standardiz ed older driver screening and referral might improve clinician– driver communication, but screening should occur in a context that includes personalized mobility counseling.