bluuebunny/crossref_metadata_2025 huggingface dataset:
On the use of Gegenbauer reconstructions for shock wave propagation modeling
Authors: Jing Yun , Clement Greg T.
Published: September 2011

In therapeutic ultrasound, the presence of shock waves can be significant due to the use of high intensity beams, as well as due to shock formation during inertial cavitation. Although modeling of such strongly nonlinear waves can be carried out using spectral methods, such calculations are typically considered impractical, since accurate calculations often require hundreds or even thousands of harmonics to be considered, leading to prohibitive computational times. Instead, time-domain algorithms which generally utilize Godunov-type finite-difference schemes are commonly used. Although these time domain methods can accurately model steep shock wave fronts, unlike spectral methods they are inherently unsuitable for modeling realistic tissue dispersion relations. Motivated by the need for a more general model, the use of Gegenbauer reconstructions as a postprocess tool to resolve the band-limitations of the spectral methods are investigated. The present work focuses on eliminating the Gibbs phenomenon when representing a steep wave front using a limited number of harmonics. Both plane wave and axisymmetric 2D transducer problems will be presented to characterize the proposed method.
Predicting speech intelligibility based on the signal-to-noise envelope power ratio after modulation-frequency selective processing
Authors: Jørgensen Søren , Dau Torsten
Published: September 2011

A model for predicting the intelligibility of processed noisy speech is proposed. The speech-based envelope power spectrum model has a similar structure as the model of Ewert and Dau [(2000). J. Acoust. Soc. Am. 108, 1181–1196], developed to account for modulation detection and masking data. The model estimates the speech-to-noise envelope power ratio, SNRenv, at the output of a modulation filterbank and relates this metric to speech intelligibility using the concept of an ideal observer. Predictions were compared to data on the intelligibility of speech presented in stationary speech-shaped noise. The model was further tested in conditions with noisy speech subjected to reverberation and spectral subtraction. Good agreement between predictions and data was found in all cases. For spectral subtraction, an analysis of the model’s internal representation of the stimuli revealed that the predicted decrease of intelligibility was caused by the estimated noise envelope power exceeding that of the speech. The classical concept of the speech transmission index fails in this condition. The results strongly suggest that the signal-to-noise ratio at the output of a modulation frequency selective process provides a key measure of speech intelligibility.
Numerical evidence of mixing in rooms using the free path temporal distribution
Authors: Billon Alexis , Embrechts Jean-Jacques
Published: September 2011

The ergodic propriety of a room has strong effects on its reverberation. If the room is ergodic, the reverberation can be broken up in two steps: a deterministic process followed by a stochastic one. The late reverberation can be then modeled by a reverberation algorithm instead of more computationally consuming methods. In this study, the free path temporal distribution obtained by ray-tracing is used as an indicator of the room’s mixing: the energetic average of the path lengths is computed at each time step. Ergodic rooms are thus characterized by rapidly convergent distributions. The free path value becomes independent of time. On the other hand, path selection mechanism and orbits are observed in non-ergodic rooms. The transition time from the deterministic process to the stochastic one is also studied through the evaluation of the room’s time constant. It is shown that its value depends only on the mean free path and the boundaries scattering value. An empirical expression is obtained which agrees well with simulations carried out in a concert hall. This transition time from a deterministic model to a stochastic one can be used to speed up the acoustical predictions and auralizations in ergodic rooms.
Standards Meetings Calendar–National
Authors: Blaeser Susan B. , Schomer Paul D.
Published: September 2011

American National Standards (ANSI Standards) developed by Accredited Standards Committees S1, S2, S3, and S12 in the areas of acoustics, mechanical vibration and shock, bioacoustics, and noise, respectively, are published by the Acoustical Society of America (ASA). In addition to these standards, ASA publishes catalogs of Acoustical Standards, both National and International. To receive copies of the latest Standards Catalogs, please contact Susan B. Blaeser.

Comments are welcomed on all material in Acoustical Standards News.

This Acoustical Standards News section in JASA, as well as the National and International Catalogs of Acoustical Standards, and other information on the Standards Program of the Acoustical Society of America, are available via the ASA home page: http://acousticalsociety.org.
Barcoded Primers Used in Multiplex Amplicon Pyrosequencing Bias Amplification
Authors: Berry David , Ben Mahfoudh Karim , Wagner Michael , Loy Alexander
Published: September 2011

“Barcode-tagged” PCR primers used for multiplex amplicon sequencing generate a thus-far-overlooked amplification bias that produces variable terminal restriction fragment length polymorphism (T-RFLP) and pyrosequencing data from the same environmental DNA template. We propose a simple two-step PCR approach that increases reproducibility and consistently recovers higher genetic diversity in pyrosequencing libraries.
Selective Utilization of Exogenous Amino Acids by Dehalococcoides ethenogenes Strain 195 and Its Effects on Growth and Dechlorination Activity
Authors: Zhuang Wei-Qin , Yi Shan , Feng Xueyang , Zinder Stephen H. , Tang Yinjie J. , Alvarez-Cohen Lisa
Published: September 2011

Bacteria of the genusDehalococcoidesare important members of bioremediation communities because of their ability to detoxify chloroethenes to the benign end product ethene. Genome-enabled studies conducted withDehalococcoides ethenogenes195 have revealed that two ATP-binding cassette (ABC)-type amino acid transporters are expressed during its exponential growth stages. In light of previous findings that Casamino Acids enhanced its dechlorination activity, we hypothesized that strain 195 is capable of importing amino acids from its environment to facilitate dechlorination and growth. To test this hypothesis, we applied isotopomer-based dilution analysis with13C-labeled acetate to differentiate the amino acids that were taken up by strain 195 from those synthesizedde novoand to determine the physiological changes caused by the significantly incorporated amino acids. Our results showed that glutamate/glutamine and aspartate/asparagine were almost exclusively synthesized by strain 195, even when provided in excess in the medium. In contrast, phenylalanine, isoleucine, leucine, and methionine were identified as the four most highly incorporated amino acids, at levels >30% of respective proteinogenic amino acids. When either phenylalanine or all four highly incorporated amino acids were added to the defined mineral medium, the growth rates, dechlorination activities, and yields of strain 195 were enhanced to levels similar to those observed with supplementation with 20 amino acids. However, genes for the putative ABC-type amino acids transporters and phenylalanine biosynthesis exhibited insignificant regulation in response to the imported amino acids. This study also demonstrates that using isotopomer-based metabolite analysis can be an efficient strategy for optimizing nutritional conditions for slow-growing microorganisms.
Rapid, Transient, and Proportional Activation of σ
B
in Response to Osmotic Stress in Listeria monocytogenes
Authors: Utratna Marta , Shaw Iain , Starr Emily , O'Byrne Conor P.
Published: September 2011

The osmotic activation of sigma B (σ
B
) in
Listeria monocytogenes
was studied by monitoring expression of four known σ
B
-dependent genes,
opuCA
,
lmo2230
,
lmo2085
, and
sigB
. Activation was found to be rapid, transient, and proportional to the magnitude of the osmotic stress applied, features that underpin the adaptability of this pathogen.
Functional Analyses of Multiple Lichenin-Degrading Enzymes from the Rumen Bacterium Ruminococcus albus 8
Authors: Iakiviak Michael , Mackie Roderick I. , Cann Isaac K. O.
Published: September 2011

Ruminococcus albus
8 is a fibrolytic ruminal bacterium capable of utilization of various plant cell wall polysaccharides. A bioinformatic analysis of a partial genome sequence of
R. albus
revealed several putative enzymes likely to hydrolyze glucans, including lichenin, a mixed-linkage polysaccharide of glucose linked together in β-1,3 and β-1,4 glycosidic bonds. In the present study, we demonstrate the capacity of four glycoside hydrolases (GHs), derived from
R. albus
, to hydrolyze lichenin. Two of the genes encoded GH family 5 enzymes (Ra0453 and Ra2830), one gene encoded a GH family 16 enzyme (Ra0505), and the last gene encoded a GH family 3 enzyme (Ra1595). Each gene was expressed in
Escherichia coli
, and the recombinant protein was purified to near homogeneity. Upon screening on a wide range of substrates, Ra0453, Ra2830, and Ra0505 displayed different hydrolytic properties, as they released unique product profiles. The Ra1595 protein, predicted to function as a β-glucosidase, preferred cleavage of a nonreducing end glucose when linked by a β-1,3 glycosidic bond to the next glucose residue. The major product of Ra0505 hydrolysis of lichenin was predicted to be a glucotriose that was degraded only by Ra0453 to glucose and cellobiose. Most importantly, the four enzymes functioned synergistically to hydrolyze lichenin to glucose, cellobiose, and cellotriose. This lichenin-degrading enzyme mix should be of utility as an additive to feeds administered to monogastric animals, especially those high in fiber.
Effect of Genetically Modified Poplars on Soil Microbial Communities during the Phytoremediation of Waste Mine Tailings
Authors: Hur Moonsuk , Kim Yongho , Song Hae-Ryong , Kim Jong Min , Choi Young Im , Yi Hana
Published: September 2011

The application of transgenic plants to clean up environmental pollution caused by the wastes of heavy metal mining is a promising method for removing metal pollutants from soils. However, the effect of using genetically modified organisms for phytoremediation is a poorly researched topic in terms of microbial community structures, despite the important role of microorganisms in the health of soil. In this study, a comparative analysis of the bacterial and archaeal communities found in the rhizosphere of genetically modified (GM) versus wild-type (WT) poplar was conducted on trees at different growth stages (i.e., the rhizospheres of 1.5-, 2.5-, and 3-year-old poplars) that were cultivated on contaminated soils together with nonplanted control soil. Based on the results of DNA pyrosequencing, poplar type and growth stages were associated with directional changes in the structure of the microbial community. The rate of change was faster in GM poplars than in WT poplars, but the microbial communities were identical in the 3-year-old poplars. This phenomenon may arise because of a higher rate and greater extent of metal accumulation in GM poplars than in naturally occurring plants, which resulted in greater changes in soil environments and hence the microbial habitat.
Detection of Enterotoxigenic Clostridium perfringens in Meat Samples by Using Molecular Methods
Authors: Kaneko Ikuko , Miyamoto Kazuaki , Mimura Kanako , Yumine Natsuko , Utsunomiya Hirotoshi , Akimoto Shigeru , McClane Bruce A.
Published: September 2011

To prevent food-borne bacterial diseases and to trace bacterial contamination events to foods, microbial source tracking (MST) methods provide important epidemiological information. To apply molecular methods to MST, it is necessary not only to amplify bacterial cells to detection limit levels but also to prepare DNA with reduced inhibitory compounds and contamination. Isolates carrying theClostridium perfringensenterotoxin gene (cpe) on the chromosome or a plasmid rank among the most important food-borne pathogens. Previous surveys indicated thatcpe-positiveC. perfringensisolates are present in only ∼5% of nonoutbreak food samples and then only at low numbers, usually less than 3 cells/g. In this study, four molecular assays for the detection ofcpe-positiveC. perfringensisolates, i.e., ordinary PCR, nested PCR, real-time PCR, and loop-mediated isothermal amplification (LAMP), were developed and evaluated for their reliability using purified DNA. For use in the artificial contamination of meat samples, DNA templates were prepared by three different commercial DNA preparation kits. The four molecular assays always detectedcpewhen >103cells/g ofcpe-positiveC. perfringenswere present, using any kit. Of three tested commercial DNA preparation kits, the InstaGene matrix kit appeared to be most suitable for the testing of a large number of samples. By using the InstaGene matrix kit, the four molecular assays efficiently detectedcpeusing DNA prepared from enrichment culture specimens of meat samples contaminated with low numbers ofcpe-positiveC. perfringensvegetative cells or spores. Overall, the current study developed molecular assay protocols for MST to detect the contamination of foods with low numbers of cells, and at a low frequency, ofcpe-positiveC. perfringensisolates.
Evolutionary Dynamics of Candida albicans during
In Vitro
Evolution
Authors: Huang Mian , McClellan Mark , Berman Judith , Kao Katy C.
Published: September 2011

While mechanisms of resistance to major antifungal agents have been characterized in
Candida albicans
, little is known about the evolutionary trajectories during the emergence of drug resistance. Here, we examined the evolutionary dynamics of
C. albicans
that evolved
in vitro
in the presence or absence of fluconazole using the visualizing evolution in real-time (VERT) method, a novel experimental approach that facilitates the systematic isolation of adaptive mutants that arise in the population. We found an increase in the frequency of adaptive events in the presence of fluconazole compared to the no-drug controls. Analysis of the evolutionary dynamics revealed that mutations that led to increased drug resistance appeared frequently and that mutants with increased levels of resistance arose in independent lineages. Interestingly, most adaptive mutants with increased fitness in the presence of the drug did not exhibit a significant fitness decrease in the absence of the drug, supporting the idea that rapid resistance can arise from mutations in strains maintained in the population prior to exposure to the drug.
The Surfactant of Legionella pneumophila Is Secreted in a TolC-Dependent Manner and Is Antagonistic toward Other Legionella Species
Authors: Stewart Catherine R. , Burnside Denise M. , Cianciotto Nicholas P.
Published: September 2011

When
Legionella pneumophila
grows on agar plates, it secretes a surfactant that promotes flagellum- and pilus-independent “sliding” motility. We isolated three mutants that were defective for surfactant. The first two had mutations in genes predicted to encode cytoplasmic enzymes involved in lipid metabolism. These genes mapped to two adjacent operons that we designated
bbcABCDEF
and
bbcGHIJK
. Backcrossing and complementation confirmed the importance of the
bbc
genes and suggested that the
Legionella
surfactant is lipid containing. The third mutant had an insertion in
tolC
. TolC is the outer membrane part of various trimolecular complexes involved in multidrug efflux and type I protein secretion. Complementation of the
tolC
mutant restored sliding motility. Mutants defective for an inner membrane partner of TolC also lacked a surfactant, confirming that TolC promotes surfactant secretion.
L. pneumophila
(
lspF
) mutants lacking type II protein secretion (T2S) are also impaired for a surfactant. When the
tolC
and
lspF
mutants were grown next to each other, the
lsp
mutant secreted surfactant, suggesting that TolC and T2S conjoin to mediate surfactant secretion, with one being the conduit for surfactant export and the other the exporter of a molecule that is required for induction or maturation of surfactant synthesis/secretion. Although the surfactant was not required for the extracellular growth, intracellular infection, and intrapulmonary survival of
L. pneumophila
, it exhibited antimicrobial activity toward seven other species of
Legionella
but not toward various non-
Legionella
species. These data suggest that the surfactant provides
L. pneumophila
with a selective advantage over other legionellae in the natural environment.
Phage-Borne Factors and Host LexA Regulate the Lytic Switch in Phage GIL01
Authors: Fornelos Nadine , Bamford Jaana K. H. , Mahillon Jacques
Published: September 2011

The
Bacillus thuringiensis
temperate phage GIL01 does not integrate into the host chromosome but exists stably as an independent linear replicon within the cell. Similar to that of the lambdoid prophages, the lytic cycle of GIL01 is induced as part of the cellular SOS response to DNA damage. However, no CI-like maintenance repressor has been detected in the phage genome, suggesting that GIL01 uses a novel mechanism to maintain lysogeny. To gain insights into the GIL01 regulatory circuit, we isolated and characterized a set of 17 clear plaque (
cp
) mutants that are unable to lysogenize. Two phage-encoded proteins, gp1 and gp7, are required for stable lysogen formation. Analysis of
cp
mutants also identified a 14-bp palindromic
dinBox
1 sequence within the
P1
-
P2
promoter region that resembles the known LexA-binding site of Gram-positive bacteria. Mutations at conserved positions in
dinBox
1 result in a
cp
phenotype. Genomic analysis identified a total of three
dinBox
sites within GIL01 promoter regions. To investigate the possibility that the host LexA regulates GIL01, phage induction was measured in a host carrying a noncleavable
lexA
(Ind
−
) mutation. GIL01 formed stable lysogens in this host, but lytic growth could not be induced by treatment with mitomycin C. Also, mitomycin C induced β-galactosidase expression from GIL01-
lacZ
promoter fusions, and induction was similarly blocked in the
lexA
(Ind
−
) mutant host. These data support a model in which host LexA binds to
dinBox
sequences in GIL01, repressing phage gene expression during lysogeny and providing the switch necessary to enter lytic development.
An ATP-Grasp Ligase Involved in the Last Biosynthetic Step of the Iminomycosporine Shinorine in Nostoc punctiforme ATCC 29133
Authors: Gao Qunjie , Garcia-Pichel Ferran
Published: September 2011

We investigated the genetic basis for mycosporine sunscreen biosynthesis by the cyanobacterium
Nostoc punctiforme
ATCC 29133. Heterologous expression in
Escherichia coli
of three contiguous
N. punctiforme
genes (NpR5600, NpR5599, and NpR5598, here named
mys
A
,
mys
B
, and
mys
C
, respectively) led to the production of mycosporine-glycine, an oxomycosporine. Additional expression of gene NpF5597 (
mys
D
) led to the conversion of mycosporine-glycine into iminomycosporines (preferentially shinorine but also others like mycosporine-2-glycine and porphyra-334). This represents a new mode of enzymatic synthesis for iminomycosporines, one that differs in genetic origin, mechanism, and apparent substrate specificity from that known in
Anabaena variabilis
ATCC 29413. These results add to the emerging profile of the protein family of ATP-dependent ligases, to which the
mys
C
product belongs, as important condensation enzymes in microbial secondary metabolism.
Modulation of Substrate Efflux in Bacterial Small Multidrug Resistance Proteins by Mutations at the Dimer Interface
Authors: Poulsen Bradley E. , Cunningham Fiona , Lee Kate K. Y. , Deber Charles M.
Published: September 2011

Bacteria evade the effects of cytotoxic compounds through the efflux activity of membrane-bound transporters such as the small multidrug resistance (SMR) proteins. Consisting typically of ca. 110 residues with four transmembrane (TM) α-helices, crystallographic studies have shown that TM helix 1 (TM1) through TM helix 3 (TM3) of each monomer create a substrate binding “pocket” within the membrane bilayer, while a TM4-TM4 interaction accounts for the primary dimer formation. Previous work from our lab has characterized a highly conserved small-residue heptad motif in the
Halobacterium salinarum
transporter Hsmr as
90
GLXLIXXGV
98
that lies along the TM4-TM4 dimer interface of SMR proteins as required for function. Focusing on conserved positions 91, 93, 94, and 98, we substituted the naturally occurring Hsmr residue for Ala, Phe, Ile, Leu, Met, and Val at each position in the Hsmr TM4-TM4 interface. Large-residue replacements were studied for their ability to dimerize on SDS-polyacrylamide gels, to bind the cytotoxic compound ethidium bromide, and to confer resistance by efflux. Although the relative activity of mutants did not correlate with dimer strength for all mutants, all functional mutants lay within 10% of dimerization relative to the wild type (WT), suggesting that the optimal dimer strength at TM4 is required for proper efflux. Furthermore, nonfunctional substitutions at the center of the dimerization interface that do not alter dimer strength suggest a dynamic TM4-TM4 “pivot point” that responds to the efflux requirements of different substrates. This functionally critical region represents a potential target for inhibiting the ability of bacteria to evade the effects of cytotoxic compounds.
Selective oxygenation of α-olefins by means of metalloporphyrin catalysts mimicking cytochrome P-450
Authors: Zachař Pavel , Petkova Galina , Sýkora David , Král Vladimír
Published: September 2011

A significant problem associated with synthetic metalloporphyrin catalysts used to mimic oxygenation function of cytochrome P-450 is their deactivation due to the formation of inactive μ-oxo dimer. We prepared a series of porphyrin-based catalysts mimicking cytochrome P-450 potentially resistant to deactivation by varying the central metal ion, porphyrin ring substitution, and catalyst support. The influence of the nature of a solid support, the type of central cation and the chemical modification of the porphyrin ring on the catalytic efficiency was studied. The oxygenation ability of the synthesized catalysts was tested using 1-hexene as a substrate and tert-butyl hydroperoxide as an oxidant under various reaction conditions. Identification of the oxygenation products was performed with gas chromatography-mass spectrometry (GC-MS). Quantification of the products formed was based on GC with flame ionization detection (FID). It was found that the application of low GC injection temperature (150 °C) was necessary to detect primary products of the oxygenation, peroxo alkenes, from which secondary oxygenation products, mainly epoxides, alcohols, aldehydes and ketones, were formed slowly. The efficiency of the individual catalysts depended on their structure and varied significantly. The most active catalysts were Fe(II)-tetraphenylporphyrin (TPP) immobilized on aminopolystyrene (aminoPS) and Mn(II)-TPP immobilized on aminoPS.
Exploring situational awareness in diagnostic errors in primary care
Authors: Singh Hardeep , Giardina Traber Davis , Petersen Laura A , Smith Michael W , Paul Lindsey Wilson , Dismukes Key , Bhagwath Gayathri , Thomas Eric J
Published: September 2011

Objective

Diagnostic errors in primary care are harmful but poorly studied. To facilitate the understanding of diagnostic errors in real-world primary care settings that use electronic health records (EHRs), this study explored the use of the situational awareness (SA) framework from aviation human factors research.

Methods

A mixed-methods study was conducted involving reviews of EHR data followed by semi-structured interviews of selected providers from two institutions in the USA. The study population included 380 consecutive patients with colorectal and lung cancers diagnosed between February 2008 and January 2009. Using a pre-tested data collection instrument, trained physicians identified diagnostic errors, defined as lack of timely action on one or more established indications for diagnostic work-up for lung and colorectal cancers. Twenty-six providers involved in cases with and without errors were interviewed. Interviews probed for providers' lack of SA and how this may have influenced the diagnostic process.

Results

Of 254 cases meeting inclusion criteria, errors were found in 30 of 92 (32.6%) lung cancer cases and 56 of 167 (33.5%) colorectal cancer cases. Analysis of interviews related to error cases revealed evidence of lack of one of four levels of SA applicable to primary care practice: information perception, information comprehension, forecasting future events, and choosing appropriate action based on the first three levels. In cases without error, application of the SA framework provided insight into processes involved in attention management.

Conclusions

A framework of SA can help analyse and understand diagnostic errors in primary care settings that use EHRs.
How practical are transmucosal fentanyl products for breakthrough cancer pain? novel use of placebo formulations to survey user opinion: Table 1
Authors: England Ruth , Maddocks Matthew , Manderson Cathann , Zadora-Chrzastowska Sonja , Wilcock Andrew
Published: September 2011

Background

Three transmucosal fentanyl products have recently been licensed for cancer-related breakthrough pain: a sublingual tablet, a buccal/sublingual tablet and a nasal spray. Limited comparative data hinder identifying the most appropriate to use and adopt onto a service formulary. However, the availability of placebo formulations provides a unique opportunity to compare the practical aspects of their use.

Methods

30 patients with cancer accessed and administered a placebo of each product and were asked to rate them using 1–7 Likert agree–disagree scales and free-text responses, with regard to ease of access and administration, palatability and overall impression. Participants rated their usual rescue analgesic similarly, based on recall. They also indicated whether they would be prepared to use the fentanyl product, and their most preferred.

Results

For accessibility, the usual rescue analgesic was rated best (median score 3), significantly better than the buccal/sublingual tablet (p=0.01) and nasal spray (p<0.01), but not the sublingual tablet. Conversely, the nasal spray was rated significantly worse (median score 7) than the others (p<0.01). For ease of administration, the usual rescue analgesic and sublingual tablet were rated equally best (median score 1), with only the latter being significantly different to the buccal/sublingual tablet (p=0.04) and nasal spray (p=0.05). For palatability, the sublingual tablet was rated the best (median score 2), but was significantly different only to the buccal/sublingual tablet (p<0.01). For overall impression, the sublingual tablet was rated significantly better (median score 3) than the others, with more patients prepared to use it and selecting it as their most preferred (27 and 18, respectively).

Conclusion

This survey provides valuable insight into the practical aspects of these three transmucosal fentanyl products for practitioners considering their use.
Outcome measures in major trauma care: a review of current international trauma registry practice: Table 1
Authors: Sleat Graham K J , Ardolino Antonella M , Willett Keith M
Published: September 2011

Multiple reports over the past 20 years have criticised the care delivered to major trauma patients in England. The setting up of regional trauma networks is well underway to address these deficiencies. Outcomes currently collected in major trauma are restricted to mortality rates and process measures; however, many patients are left with long-term disabilities and reduced quality of life (QoL), which are not measured at present. Trauma systems need to develop outcome measures that capture this important information to judge the quality of care and influence the development of services. This review aimed to identify the current practice of international trauma registries with regard to outcome measurement and review the literature surrounding these measures. An internet-based search of international trauma registry websites including data dictionaries and annual reports was carried out as well as a literature review to determine what outcome measures are routinely collected by trauma registries. All registries were found to look at mortality and process measures, but only one registry routinely collected morbidity outcome measures for both adults and children. There is a considerable amount of disability and reduced QoL in survivors of major trauma that lasts for years following the injury. At present only the Victorian State Trauma Registry collects outcome measures that evaluate the extent of this. English regional trauma networks and the Trauma Audit and Research Network have the opportunity to learn from this experience and routinely start to collect measures of outcome that can drive service improvement and reduce patient morbidity.
Patients who leave emergency departments without being seen: literature review and English data analysis
Authors: Clarey A J , Cooke M W
Published: September 2011

Objectives

The purpose of this review was to determine the rate of those that leave the emergency department (ED) without being seen and their reasons, to clarify if such behaviour poses a health risk, to analyse the impact initiatives have made on the leave without being seen (LWBS) rate, and to discuss the implications of using it as a national performance indicator within the NHS.

Methods

A combination of data sources was reviewed: a ‘realistic’ literature review, analysis of hospital episode statistics data from England and a local NHS trust audit.

Major Findings

LWBS rates vary across the world, from 15% to 0.36%. Also initiatives to reduce LWBS rates demonstrated mixed outcomes, with reductions in the rate by as much as 96%, while others were ineffective. The most common reason quoted for LWBS was long waiting times and there were few data to suggest LWBS posed a risk to patient health.

Conclusions

LWBS is an issue experienced in many countries that has responded in a varying manner to many initiatives in attempts to reduce it; however, it is clearly associated with the waiting times experienced in ED and therefore working within a packet of performance measures it would assess the effect of waiting times from another perspective.
ACCELERATING DARK ENERGY MODELS IN BIANCHI TYPE-V SPACETIME
Authors: PRADHAN ANIRUDH , AMIRHASHCHI HASSAN
Published: September 2011

Some new exact solutions of Einstein's field equations in a spatially homogeneous and anisotropic Bianchi type-V spacetime with minimally interaction of perfect fluid and dark energy components have been obtained. To prevail the deterministic solution we choose the scale factor [Formula: see text], which yields a time-dependent deceleration parameter (DP), representing a model which generates a transition of the universe from the early decelerating phase to the recent accelerating phase. We find that for n ≥ 1, the quintessence model is reproducible with present and expected future evolution of the universe. The other models (for n < 1), we observe the phantom scenario. The quintessence as well as phantom models approach to isotropy at late time. For different values of n, we can generate a class of physically viable DE models. The cosmic jerk parameter in our descended model is also found to be in good concordance with the recent data of astrophysical observations under appropriate condition. The physical and geometric properties of spatially homogeneous and anisotropic cosmological models are discussed.
GRAVITATIONAL POTENTIAL EVOLUTION IN UNIFIED DARK MATTER SCALAR FIELD COSMOLOGIES: AN ANALYTICAL APPROACH
Authors: PIATTELLA OLIVER F. , BERTACCA DANIELE
Published: September 2011

We investigate the time evolution of the gravitational potential Φ for a special class of non-adiabatic Unified Dark matter Models described by scalar field Lagrangians. These models predict the same background evolution as in the ΛCDM and possess a non-vanishing speed of sound. We provide a very accurate approximation of Φ, valid after the recombination epoch, in the form of a Bessel function of the first kind. This approximation may be useful for a future deeper analysis of Unified Dark Matter scalar field models.
LEPTON FLAVOR VIOLATING DECAY $Z\to\ell^\pm_i\ell^\mp_j$ IN THE 331 MODEL
Authors: CORTÉS-MALDONADO I. , MOYOTL A. , TAVARES-VELASCO G.
Published: September 2011

We study the lepton flavor violating (LFV) decays [Formula: see text](ℓi,j = e,μ,τ) in the framework of the minimal 331 model. The main contributions arise at the one-loop level via a doubly charged bilepton with general LFV couplings. We obtain an estimate for the corresponding branching ratios by using the bounds on the LFV couplings of the doubly charged bilepton from the current experimental limits on the decays ℓi → ℓjγ and [Formula: see text]. A bound on the bilepton mass is also obtained through the current limit on the anomalous magnetic moment of the muon. It is found that the bilepton contributions to LFV Z decays are not expected to be at the reach of experimental detection. In particular, the branching ratio for the Z → μ±τ∓ decay is below the 10-10 level for a bilepton mass of the order of 500 GeV.
Strategic Asset Allocation: The Role of Corporate Bond Indices?
Authors: Sangvinatsos Antonios
Published: September 2011

This paper studies dynamic asset allocations across stocks, Treasury bonds, and corporate bond indices. We employ a new model where liquidity plays an important role in forecasting excess returns. We document the significant utility benefits an investor gains by optimally including corporate bond indices in his portfolio. The benefits are bigger for lower-grade bonds. We also find that investment-grade indices are different from high-yield indices in that different risks are priced in these two asset classes. One important difference is that there exist positive "flight-to-liquidity" premia in investment-grade bonds, but we find no such premia in high-yield bonds. We calculate the portfolio behavior and the utility benefits for three types of investors, the "sophisticated", the "average" and the "lazy" investor. We provide practical portfolio advice on investing throughout the business cycle and we study how the total allocations and hedging demands vary with the business conditions. In addition, utilizing our model, we evaluate the significance of the liquidity variable information for the investor. We find that the liquidity information greatly enhances the investor's portfolio performance. Finally, further support in the optimality of the strategies is provided by calculating their in- and out-of-sample realized returns for the last decade.
Laser Induced Blue Luminescence Phenomenon
Authors: Zhu Haiyong , Duan Yanmin , Zhang Ge , Zhang Yaoju , Yang Fugui
Published: September 2011

Laser induced strange blue luminescence in several Raman crystals has been investigated. The blue luminescence at about 473 nm has the characteristic of no orientation and only produced in the crystal where the fundament laser oscillated. The experimental results show that the blue luminescence must result from the fundamental laser around 1.0 µm rather than Stokes-shifting. The spectrum detected is similar for different crystals. This blue luminescence is obviously strange and inconsistent with traditional luminescence theories, which maybe a brand-new luminescence theory.
Splanchnic sympathetic nerves in the development of mild DOCA-salt hypertension
Authors: Kandlikar Sachin S. , Fink Gregory D.
Published: September 2011

We previously reported that mild deoxycorticosterone acetate (DOCA)-salt hypertension develops in the absence of generalized sympathoexcitation. However, sympathetic nervous system activity (SNA) is regionally heterogeneous, so we began to investigate the role of sympathetic nerves to specific regions. Our first study on that possibility revealed no contribution of renal nerves to hypertension development. The splanchnic sympathetic nerves are implicated in blood pressure (BP) regulation because splanchnic denervation effectively lowers BP in human hypertension. Here we tested the hypothesis that splanchnic SNA contributes to the development of mild DOCA-salt hypertension. Splanchnic denervation was achieved by celiac ganglionectomy (CGX) in one group of rats while another group underwent sham surgery (SHAM-GX). After DOCA treatment (50 mg/kg) in rats with both kidneys intact, CGX rats exhibited a significantly attenuated increase in BP compared with SHAM-GX rats (15.6 ± 2.2 vs. 25.6 ± 2.2 mmHg, day 28 after DOCA treatment). In other rats, whole body norepinephrine (NE) spillover, measured to determine if CGX attenuated hypertension development by reducing global SNA, was not found to be different between SHAM-GX and CGX rats. In a third group, nonhepatic splanchnic NE spillover was measured as an index of splanchnic SNA, but this was not different between SHAM (non-DOCA-treated) and DOCA rats during hypertension development. In a final group, CGX effectively abolished nonhepatic splanchnic NE spillover. These data suggest that an intact splanchnic innervation is necessary for mild DOCA-salt hypertension development but not increased splanchnic SNA or NE release. Increased splanchnic vascular reactivity to NE during DOCA-salt treatment is one possible explanation.
Metabolic stress in isolated mouse ventricular myocytes leads to remodeling of t tubules
Authors: Cheng Lu-Feng , Wang Fuzhen , Lopatin Anatoli N.
Published: September 2011

Cardiac ventricular myocytes possess an extensive t-tubular system that facilitates the propagation of membrane potential across the cell body. It is well established that ionic currents at the restricted t-tubular space may lead to significant changes in ion concentrations, which, in turn, may affect t-tubular membrane potential. In this study, we used the whole cell patch-clamp technique to study accumulation and depletion of t-tubular potassium by measuring inward rectifier potassium tail currents ( IK1,tail), and inward rectifier potassium current ( IK1) “inactivation”. At room temperatures and in the absence of Mg2+ ions in pipette solution, the amplitude of IK1,tail measured ∼10 min after the establishment of whole cell configuration was reduced by ∼18%, but declined nearly twofold in the presence of 1 mM cyanide. At ∼35°C IK1,tail was essentially preserved in intact cells, but its amplitude declined by ∼85% within 5 min of cell dialysis, even in the absence of cyanide. Intracellular Mg2+ ions played protective role at all temperatures. Decline of IK1,tail was accompanied by characteristic changes in its kinetics, as well as by changes in the kinetics of IK1 inactivation, a marker of depletion of t-tubular K+. The data point to remodeling of t tubules as the primary reason for the observed effects. Consistent with this, detubulation of myocytes using formamide-induced osmotic stress significantly reduced IK1,tail, as well as the inactivation of inward IK1. Overall, the data provide strong evidence that changes in t tubule volume/structure may occur on a short time scale in response to various types of stress.
Mitochondrial autophagy by Bnip3 involves Drp1-mediated mitochondrial fission and recruitment of Parkin in cardiac myocytes
Authors: Lee Youngil , Lee Hwa-Youn , Hanna Rita A. , Gustafsson Åsa B.
Published: September 2011

The Bcl2/adenovirus E1B 19-kDa interacting protein 3 (Bnip3) is an atypical BH3-only protein that is associated with mitochondrial dysfunction and cell death. Bnip3 is also a potent inducer of mitochondrial autophagy, and in this study we have investigated the mechanisms by which Bnip3 induces autophagy in cardiac myocytes. We found that Bnip3 induced mitochondrial translocation of dynamin-related protein 1 (Drp1), a protein involved in mitochondrial fission in adult myocytes. Drp1-mediated mitochondrial fission correlated with increased autophagy, and inhibition of Drp1 reduced Bnip3-mediated autophagy. Overexpression of Drp1K38E, a dominant negative of Drp1, or mitofusin 1 prevented mitochondrial fission and autophagy by Bnip3. Also, inhibition of mitochondrial fission or autophagy resulted in increased death of myocytes overexpressing Bnip3. Moreover, Bnip3 promoted translocation of the E3 ubiquitin ligase Parkin to mitochondria, which was prevented in the presence of a Drp1 inhibitor. Interestingly, induction of autophagy by Bnip3 was reduced in Parkin-deficient myocytes. Thus our data suggest that induction of autophagy in response to Bnip3 is a protective response activated by the cell that involves Drp1-mediated mitochondrial fission and recruitment of Parkin.
Sepiapterin enhances angiogenesis and functional recovery in mice after myocardial infarction
Authors: Shimazu Takayuki , Otani Hajime , Yoshioka Kei , Fujita Masanori , Okazaki Toru , Iwasaka Toshiji
Published: September 2011

Uncoupling of nitric oxide synthase (NOS) has been implicated in left ventricular (LV) remodeling and dysfunction after myocardial infarction (MI). We hypothesized that inducible NOS (iNOS) plays a crucial role in LV remodeling after MI, depending on its coupling status. MI was created in wild-type, iNOS-knockout (iNOS−/−), endothelial NOS-knockout (eNOS−/−), and neuronal NOS-knockout (nNOS−/−) mice. iNOS and nNOS expressions were increased after MI associated with an increase in nitrotyrosine formation. The area of myocardial fibrosis and LV end-diastolic volume and ejection fraction were more deteriorated in eNOS−/− mice compared with other genotypes of mice 4 wk after MI. The expression of GTP cyclohydrolase was reduced, and tetrahydrobiopterin (BH4) was depleted in the heart after MI. Oral administration of sepiapterin after MI increased dihydrobiopterin (BH2), BH4, and BH4-to-BH2 ratio in the infarcted but not sham-operated heart. The increase in BH4-to-BH2 ratio was associated with inhibition of nitrotyrosine formation and an increase in nitrite plus nitrate. However, this inhibition of NOS uncoupling was blunted in iNOS−/− mice. Sepiapterin increased capillary density and prevented LV remodeling and dysfunction after MI in wild-type, eNOS−/−, and nNOS−/− but not iNOS−/− mice. Nω-nitro-l-arginine methyl ester abrogated sepiapterin-induced increase in nitrite plus nitrate and angiogenesis and blocked the beneficial effects of sepiapterin on LV remodeling and function. These results suggest that sepiapterin enhances angiogenesis and functional recovery after MI by activating the salvage pathway for BH4 synthesis and increasing bioavailable nitric oxide predominantly derived from iNOS.
Restricted Algebras on Inverse Semigroups—Part II: Positive Definite Functions
Authors: Amini Massoud , Medghalchi Alireza
Published: September 2011

The relation between representations and positive definite functions
is a key concept in harmonic analysis on topological groups. Recently this relation has been studied on topological groupoids. In this paper, we investigate the concept of restricted positive definite functions and their relation with restricted representations of an inverse semigroup. We also introduce the restricted Fourier and Fourier‐Stieltjes algebras of an inverse semigroup and study their relation with the corresponding algebras on the associated groupoid.
A Game Theoretic Approach for Interuser Interference Reduction in Body Sensor Networks
Authors: Wu Guowei , Ren Jiankang , Xia Feng , Yao Lin , Xu Zichuan , Shang Pengfei
Published: September 2011

As a kind of small-scale cyber-physical systems (CPSs), body sensor networks (BSNs) can provide the pervasive, long-term, and real-time health monitoring. A high degree of quality-of-service (QoS) for BSN is extremely required to meet some critical services. Interuser interference between different BSNs can cause unreliable critical data transmission and high bite error rate. In this paper, a game theoretic decentralized interuser interference reduction scheme for BSN is proposed. The selection of the channel and transmission power is modeled as a noncooperative game between different BSNs congregating in the same area. Each BSN measures the interference from other BSNs and then can adaptively select the suitable channel and transmission power by utilizing no-regret learning algorithm. The correctness and effectiveness of our proposed scheme are theoretically proved, and the extensive experimental results demonstrate that the effect of inter-user interference can be reduced effectively with low power consumption.
Oral Health-Related Quality of Life of Greek Adults: A Cross-Sectional Study
Authors: Papaioannou William , Oulis Constantine J. , Latsou Demetra , Yfantopoulos John
Published: September 2011

Purpose. The aim of the present study was to investigate the impact of oral health status on the quality of life of adults in different regions of Greece, using the Oral Health Impact Profile-short form (OHIP-14).Methods. A random sample consisting of a total of 504 Greek adults between the ages of 35–44 years (mean 39.1 ± 3.5) was selected from different urban and rural areas, and face-to-face interviews were conducted using the validated Greek language OHIP-14. Associations of the total OHIP-14 score and its 7 sub-scales along with the self-perceived quality of life were evaluated with Spearman's correlations.Results. The subjects had an overall weighted OHIP-14 score of 1.1 (sd 1.9). No significant differences were found for either rural or non-metropolitan areas when compared to urban or metropolitan regions. High scores of above 2 were determined for functional limitation, physical pain, handicap, and the psychological discomfort scales. The education level of the subjects had a significant positive impact on the quality of life of the subjects.Conclusions. Dental and oral health conditions are factors that do impact on the quality of life of individuals.
Altered Expression of Somatostatin Receptors in Pancreatic Islets from NOD Mice Cultured at Different Glucose ConcentrationsIn Vitroand in Islets Transplanted to Diabetic NOD MiceIn Vivo
Authors: Ludvigsen Eva , Stridsberg Mats , Janson Eva T. , Sandler Stellan
Published: September 2011

Somatostatin acts via five receptors (sst1-5). We investigated if the changes in pancreatic islet sst expression in diabetic NOD mice compared to normoglycemic mice are a consequence of hyperglycemia or the ongoing immune reaction in the pancreas. Pancreatic islets were isolated from NOD mice precultured for 5 days and further cultured for 3 days at high or low glucose before examined. Islets were also isolated from NOD mice and transplanted to normal or diabetic mice in a number not sufficient to cure hyperglycemia. After three days, the transplants were removed and stained for sst1-5and islet hormones. Overall, changes in sst islet cell expression were more common in islets cultured in high glucose concentrationin vitroas compared to the islet transplantationin vivoto diabetic mice. The beta and PP cells exhibited more frequent changes in sst expression, while the alpha and delta cells were relatively unaffected by the high glucose condition. Our findings suggest that the glucose level may alter sst expressed in islets cells; however, immune mechanisms may counteract such changes in islet sst expression.