bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical Investigation of Thermal Fields Around Subsea Buried Pipelines
Authors: Bai Yanbin , Niedzwecki John M. , Sanchez Marcelo
Published: September 2014

Subsea pipelines transporting hydrocarbons from very deepwater wells or at arctic sites for long distances present some challenging technical problems. The ambient temperature at the seafloor in deepwater may be about 5°C (∼ 41°F or 278 K) and can be even lower in the arctic regions, while the wellhead hydrocarbon temperatures can be in excess of 149°C (∼ 300°F or 422 K). Insulation of these buried pipelines to mitigate this large temperature gradient can be only part of the solution as temperature losses over long distance may require heating systems to avoid deposition of impurities and clogging of the pipeline. The near field thermal gradient in surrounding soil is investigated using complementary 2-D numerical simulations of finite element and boundary element numerical models. A finite element hydraulic-thermal code designed for porous media was used to investigate the time evolution of the natural convection effects due to pipeline heating of the seawater in soil. For a seabed of clay under these conditions, it was determined that the boundary element model could be directed at steady state heat transfer about the pipeline in layered soil conditions addressing trenching and backfill consistent with the burial of the pipeline by a remotely operated vehicle. Parameters that may affect the thermal field around the subsea buried pipeline such as burial depth, thermal power loss and thermal properties of backfilling soils were investigated. It was shown that the thermal conductivity of the backfill has a critical influence on temperature distribution at the pipe wall, and that the pipe burial depth significantly affects temperature distribution on the seabed right above the pipe in deepwater.
Wave Spectra Partitioning and Identification of Wind Sea and Swell Events
Authors: Kpogo-Nuwoklo Komlan A. , Olagnon Michel , Guédé Zakoua
Published: September 2014

Wave spectra often exhibit several peaks due to the coexistence of wind sea generated by local wind conditions and swells originating from distant weather systems. For an accurate description of sea states, those spectra can be partitioned and the partitions can be interpreted physically as representing independent wave systems. Furthermore, partitions can be associated in time to track the evolutions of wave systems originating from the same meteorological event (storm, depression, etc).

This paper proposes a new method to identify temporal sequences of wave systems parameters, consistent with respect to the meteorological events that are the sources of the phenomena. This method, as many conventional partitioning ones, is based on the watershed algorithm which is however directly applied in our case to the whole time-history of wave spectra. Using appropriate criteria, the identified events are classified into swell or wind sea events. Field data from West Africa are used to illustrate the method and the results are compared with those of conventional software. Hindcast data from the Iroise Sea are also used to validate the proposed method and the results show a good identification of wave systems events with a good correlation between wind sea events and wind characteristics.
Response of a Circular Cylinder Fitted With Permeable Meshes Acting as VIV Suppressors
Authors: Cicolin Murilo M. , Assi Gustavo R. S.
Published: September 2014

Experiments have been carried out on models of rigid circular cylinders fitted with three different types of permeable meshes to investigate their effectiveness in the suppression of vortex-induced vibrations (VIV). Measurements of the dynamic response are presented for models with low mass and damping which are free to respond in the cross-flow direction. Results for two meshes made of ropes and cylindrical tubes are compared with the VIV response of a bare cylinder and that of a known suppressor called the “ventilated trousers” (VT). All three meshes achieved an average 50% reduction of the response when compared with that of the bare cylinder. The sparse mesh configuration presented a similar behaviour to the VT, while the dense mesh produced considerable VIV response for an indefinitely long range of reduced velocity. Reynolds number ranged from 1,000 to 10,000 and reduced velocity was varied between 2 and 13.
Gender difference in the affricate productions of young Seoul Korean speakers
Authors: Kong Eun Jong , Kang Soyoung , Seo Misun
Published: September 2014

This study explored gender-related differences in affricates' place of articulation of young Seoul Korean speakers. Word-initial and medial affricates before /a/ and /i/ collected from 42 adult Seoul speakers were compared with alveolar and palatalized fricatives in the same vowel conditions by examining spectral peak frequencies of the frication part of the consonants. Results showed evidence of gender differences in the acoustic realization of word-medial affricates, which implies a more anterior articulation in females' productions before /a/. Possibilities for sound change in affricates led by females or the use of anterior affricates as a socially indexed gender marker are discussed.
Physical Activity and the Association With Self-Reported Impairments, Walking Limitations, Fear of Falling, and Incidence of Falls in Persons With Late Effects of Polio
Authors: Winberg Cecilia , Brogårdh Christina , Flansbjer Ulla-Britt , Carlsson Gunilla , Rimmer James , Lexell Jan
Published: September 2014

The purpose of this study was to determine the association between physical activity and self-reported disability in ambulatory persons with mild to moderate late effects of polio (N = 81, mean age 67 years). The outcome measures were: Physical Activity and Disability Survey (PADS), a pedometer, Self-Reported Impairments in Persons with Late Effects of Polio Scale (SIPP), Walking Impact Scale (Walk-12), Falls Efficacy Scale-International (FES-I), and self-reported incidence of falls. The participants were physically active on average 158 min per day and walked 6,212 steps daily. Significant associations were found between PADS and Walk-12 (r = −.31, p < .001), and between the number of steps and SIPP, Walk-12, and FES-I (r = −.22 to −.32, p < .05). Walk-12 and age explained 14% of the variance in PADS and FES-I explained 9% of the variance in number of steps per day. Thus, physical activity was only weakly to moderately associated with self-reported disability.
Association of the EF-hand and PH domains of the guanine nucleotide exchange factor SLAT with IP
3
receptor 1 promotes Ca
2+
signaling in T cells
Authors: Fos Camille , Becart Stephane , Balancio Ann J. Canonigo , Boehning Darren , Altman Amnon
Published: September 2014

Targeting a T cell receptor–dependent protein-protein interaction at the endoplasmic reticulum inhibits T cell activation.
Focus Issue: TGF-β and the Mesenchymal Transition in Physiology and Disease
Authors: Ferrarelli Leslie K. , Gough Nancy R.
Published: September 2014

Understanding the complex regulation and context dependence of TGF-β signaling may lead to new therapies for cancer and fibrosis.
Autophagy Limits Innate Immune Signaling
Authors: Gough Nancy R.
Published: September 2014

Autophagy not only provides a source of nutrients but also limits toxic innate immune signaling.
Extracellular DNA Impedes the Transport of Vancomycin in Staphylococcus epidermidis Biofilms Preexposed to Subinhibitory Concentrations of Vancomycin
Authors: Doroshenko Natalya , Tseng Boo Shan , Howlin Robert P. , Deacon Jill , Wharton Julian A. , Thurner Philipp J. , Gilmore Brendan F. , Parsek Matthew R. , Stoodley Paul
Published: September 2014

Staphylococcus epidermidis
biofilm formation is responsible for the persistence of orthopedic implant infections. Previous studies have shown that exposure of
S. epidermidis
biofilms to sub-MICs of antibiotics induced an increased level of biofilm persistence. BODIPY FL-vancomycin (a fluorescent vancomycin conjugate) and confocal microscopy were used to show that the penetration of vancomycin through sub-MIC-vancomycin-treated
S. epidermidis
biofilms was impeded compared to that of control, untreated biofilms. Further experiments showed an increase in the extracellular DNA (eDNA) concentration in biofilms preexposed to sub-MIC vancomycin, suggesting a potential role for eDNA in the hindrance of vancomycin activity. Exogenously added,
S. epidermidis
DNA increased the planktonic vancomycin MIC and protected biofilm cells from lethal vancomycin concentrations. Finally, isothermal titration calorimetry (ITC) revealed that the binding constant of DNA and vancomycin was 100-fold higher than the previously reported binding constant of vancomycin and its intended cellular
d
-Ala-
d
-Ala peptide target. This study provides an explanation of the eDNA-based mechanism of antibiotic tolerance in sub-MIC-vancomycin-treated
S. epidermidis
biofilms, which might be an important factor for the persistence of biofilm infections.
New Colistin Population Pharmacokinetic Data in Critically Ill Patients Suggesting an Alternative Loading Dose Rationale
Authors: Grégoire N. , Mimoz O. , Mégarbane B. , Comets E. , Chatelier D. , Lasocki S. , Gauzit R. , Balayn D. , Gobin P. , Marchand S. , Couet W.
Published: September 2014

Colistin is an old antibiotic that has recently gained a considerable renewal of interest as the last-line defense therapy against multidrug-resistant Gram-negative bacteria. It is administered as colistin methanesulfonate (CMS), an inactive prodrug, and it was shown that due to slow CMS conversion, colistin plasma concentrations increase very slowly after treatment initiation, which constitutes the rationale for a loading dose in critically ill patients. However, faster CMS conversion was observed in healthy volunteers but using a different CMS brand, which may also have a major impact on colistin pharmacokinetics. Seventy-three critically ill patients not undergoing dialysis received multiple doses of CMS. The CMS concentrations were measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS), and a pharmacokinetic analysis was conducted using a population approach. We confirmed that CMS renal clearance and colistin concentrations at steady state are mostly governed by creatinine clearance, but we predict a typical maximum concentration of drug in serum (
C
max
) of colistin close to 2 mg/liter, occurring 3 h after an initial dose of 2 million international units (MIU) of CMS. Accordingly, the estimated colistin half-life (
t
1/2
) was relatively short (3.1 h), with rapid attainment of steady state. Our results are only partially consistent with other recently published results. We confirm that the CMS maintenance dose should be adjusted according to renal function in critically ill patients. However, much higher than expected colistin concentrations were observed after the initial CMS dose, with rapid steady-state achievement. These discrepancies challenge the pharmacokinetic rationale for a loading dose, which may still be appropriate for rapid bacterial eradication and an improved clinical cure rate.
A Novel Target and Approach for Identifying Antivirals against Molluscum Contagiosum Virus
Authors: Guan Hancheng , Nuth Manunya , Zhukovskaya Natalia , Saw Yih Ling , Bell Edward , Isaacs Stuart N. , Ricciardi Robert P.
Published: September 2014

The dermatological disease molluscum contagiosum (MC) presents as lesions restricted solely to the skin. The poxvirus molluscum contagiosum virus (MCV) is responsible for this skin disease that is easily transmitted through casual contact among all populations, with greater frequency in children and immunosuppressed individuals. In addition, sexual transmission of MCV in adolescents and adults is a health concern. Although the skin lesions ultimately resolve in immunocompetent individuals, they can persist for extended periods, be painful, and result in scarring. Treatment is problematic, and there is no drug that specifically targets MCV. The inability of MCV to propagate in cell culture has impeded drug development. To overcome these barriers, we integrated three new developments. First, we identified a new MCV drug target (mD4) that is essential for processive DNA synthesis
in vitro
. Second, we discovered a small chemical compound that binds to mD4 and prevents DNA synthesis
in vitro
. Third, and most significant, we engineered a hybrid vaccinia virus (mD4-VV) in which the natural vaccinia D4 (vD4) gene is replaced by the mD4 target gene. This hybrid virus is dependent on mD4 for viral growth in culture and is inhibited by the small compound. This target system provides, for the first time, a platform and approach for the discovery and evaluation of new therapeutics that can be used to treat MC.
Differential Roles of RND Efflux Pumps in Antimicrobial Drug Resistance of Sessile and Planktonic Burkholderia cenocepacia Cells
Authors: Buroni Silvia , Matthijs Nele , Spadaro Francesca , Van Acker Heleen , Scoffone Viola C. , Pasca Maria Rosalia , Riccardi Giovanna , Coenye Tom
Published: September 2014

Burkholderia cenocepacia
is notorious for causing respiratory tract infections in people with cystic fibrosis. Infections with this organism are particularly difficult to treat due to its high level of intrinsic resistance to most antibiotics. Multidrug resistance in
B. cenocepacia
can be ascribed to different mechanisms, including the activity of efflux pumps and biofilm formation. In the present study, the effects of deletion of the 16 operons encoding resistance-nodulation-cell division (RND)-type efflux pumps in
B. cenocepacia
strain J2315 were investigated by determining the MICs of various antibiotics and by investigating the antibiofilm effect of these antibiotics. Finally, the expression levels of selected RND genes in treated and untreated cultures were investigated using reverse transcriptase quantitative PCR (RT-qPCR). Our data indicate that the RND-3 and RND-4 efflux pumps are important for resistance to various antimicrobial drugs (including tobramycin and ciprofloxacin) in planktonic
B. cenocepacia
J2315 populations, while the RND-3, RND-8, and RND-9 efflux systems protect biofilm-grown cells against tobramycin. The RND-8 and RND-9 efflux pumps are not involved in ciprofloxacin resistance. Results from the RT-qPCR experiments on the wild-type strain
B. cenocepacia
J2315 suggest that there is little regulation at the level of mRNA expression for these efflux pumps under the conditions tested.
Small-Molecule Inhibitors of the Pseudaminic Acid Biosynthetic Pathway: Targeting Motility as a Key Bacterial Virulence Factor
Authors: Ménard Robert , Schoenhofen Ian C. , Tao Limei , Aubry Annie , Bouchard Patrice , Reid Christopher W. , Lachance Paule , Twine Susan M. , Fulton Kelly M. , Cui Qizhi , Hogues Hervé , Purisima Enrico O. , Sulea Traian , Logan Susan M.
Published: September 2014

Helicobacter pylori
is motile by means of polar flagella, and this motility has been shown to play a critical role in pathogenicity. The major structural flagellin proteins have been shown to be glycosylated with the nonulosonate sugar, pseudaminic acid (Pse). This glycan is unique to microorganisms, and the process of flagellin glycosylation is required for
H. pylori
flagellar assembly and consequent motility. As such, the Pse biosynthetic pathway offers considerable potential as an antivirulence drug target, especially since motility is required for
H. pylori
colonization and persistence in the host. This report describes screening the five Pse biosynthetic enzymes for small-molecule inhibitors using both high-throughput screening (HTS) and
in silico
(virtual screening [VS]) approaches. Using a 100,000-compound library, 1,773 hits that exhibited a 40% threshold inhibition at a 10 μM concentration were identified by HTS. In addition, VS efforts using a 1.6-million compound library directed at two pathway enzymes identified 80 hits, 4 of which exhibited reasonable inhibition at a 10 μM concentration
in vitro
. Further secondary screening which identified 320 unique molecular structures or validated hits was performed. Following kinetic studies and structure-activity relationship (SAR) analysis of selected inhibitors from our refined list of 320 compounds, we demonstrated that three inhibitors with 50% inhibitory concentrations (IC
50
s) of approximately 14 μM, which belonged to a distinct chemical cluster, were able to penetrate the Gram-negative cell membrane and prevent formation of flagella.
Molecular Characteristics of Salmonella Genomic Island 1 in Proteus mirabilis Isolates from Poultry Farms in China
Authors: Lei Chang-Wei , Zhang An-Yun , Liu Bi-Hui , Wang Hong-Ning , Guan Zhong-Bin , Xu Chang-Wen , Xia Qing-Qing , Cheng Han , Zhang Dong-Dong
Published: September 2014

Six out of the 64 studied
Proteus mirabilis
isolates from 11 poultry farms in China contained
Salmonella
genomic island 1 (SGI1). PCR mapping showed that the complete nucleotide sequences of SGI1s ranged from 33.2 to 42.5 kb. Three novel variants, SGI1-W, SGI1-X, and SGI1-Y, have been characterized. Resistance genes
lnuF
,
dfrA25
, and
qnrB2
were identified in SGI1 for the first time.
Enhanced Transmission of Antibiotic Resistance in Campylobacter jejuni Biofilms by Natural Transformation
Authors: Bae Junghee , Oh Euna , Jeon Byeonghwa
Published: September 2014

Campylobacter jejuni
is a leading food-borne pathogen, and its antibiotic resistance is of serious concern to public health worldwide.
C. jejuni
is naturally competent for DNA transformation and freely takes up foreign DNA harboring genetic information responsible for antibiotic resistance. In this study, we demonstrate that
C. jejuni
transfers antibiotic resistance genes more frequently in biofilms than in planktonic cells by natural transformation.
The
rpoS
Gene Is Predominantly Inactivated during Laboratory Storage and Undergoes Source-Sink Evolution in Escherichia coli Species
Authors: Bleibtreu Alexandre , Clermont Olivier , Darlu Pierre , Glodt Jérémy , Branger Catherine , Picard Bertrand , Denamur Erick
Published: September 2014

The
rpoS
gene codes for an alternative RNA polymerase sigma factor, which acts as a general regulator of the stress response. Inactivating alleles of
rpoS
in collections of natural
Escherichia coli
isolates have been observed at very variable frequencies, from less than 1% to more than 70% of strains.
rpoS
is easily inactivated in nutrient-deprived environments such as stab storage, which makes it difficult to determine the true frequency of
rpoS
inactivation in nature. We studied the evolutionary history of
rpoS
and compared it to the phylogenetic history of bacteria in two collections of 82 human commensal and extraintestinal
E. coli
strains. These strains were representative of the phylogenetic diversity of the species and differed only by their storage conditions. In both collections, the phylogenetic histories of
rpoS
and of the strains were congruent, indicating that horizontal gene transfer had not occurred at the
rpoS
locus, and
rpoS
was under strong purifying selection, with a ratio of the nonsynonymous mutation rate (Ka) to the synonymous substitution rate (Ks) substantially smaller than 1. Stab storage was associated with a high frequency of inactivating alleles, whereas almost no amino acid sequence variation was observed in RpoS in the collection studied directly after isolation of the strains from the host. Furthermore, the accumulation of variations in
rpoS
was typical of source-sink dynamics. In conclusion,
rpoS
is rarely inactivated in natural
E. coli
isolates within their mammalian hosts, probably because such strains rapidly become evolutionary dead ends. Our data should encourage bacteriologists to freeze isolates immediately and to avoid the use of stab storage.
Development, Antibiotic Production, and Ribosome Assembly in Streptomyces venezuelae Are Impacted by RNase J and RNase III Deletion
Authors: Jones Stephanie E. , Leong Vivian , Ortega Joaquin , Elliot Marie A.
Published: September 2014

RNA metabolism is a critical but frequently overlooked control element affecting virtually every cellular process in bacteria. RNA processing and degradation is mediated by a suite of ribonucleases having distinct cleavage and substrate specificity. Here, we probe the role of two ribonucleases (RNase III and RNase J) in the emerging model system
Streptomyces venezuelae
. We show that each enzyme makes a unique contribution to the growth and development of
S. venezuelae
and further affects the secondary metabolism and antibiotic production of this bacterium. We demonstrate a connection between the action of these ribonucleases and translation, with both enzymes being required for the formation of functional ribosomes. RNase III mutants in particular fail to properly process 23S rRNA, form fewer 70S ribosomes, and show reduced translational processivity. The loss of either RNase III or RNase J additionally led to the appearance of a new ribosomal species (the 100S ribosome dimer) during exponential growth and dramatically sensitized these mutants to a range of antibiotics.
Cytosolic Selection Systems To Study Protein Stability
Authors: Malik Ajamaluddin , Mueller-Schickert Antje , Bardwell James C. A.
Published: September 2014

Here we describe biosensors that provide readouts for protein stability in the cytosolic compartment of prokaryotes. These biosensors consist of tripartite sandwich fusions that link the
in vitro
stability or aggregation susceptibility of guest proteins to the
in vivo
resistance of host cells to the antibiotics kanamycin, spectinomycin, and nourseothricin. These selectable markers confer antibiotic resistance in a wide range of hosts and are easily quantifiable. We show that mutations within guest proteins that affect their stability alter the antibiotic resistances of the cells expressing the biosensors in a manner that is related to the
in vitro
stabilities of the mutant guest proteins. In addition, we find that polyglutamine tracts of increasing length are associated with an increased tendency to form amyloids
in vivo
and, in our sandwich fusion system, with decreased resistance to aminoglycoside antibiotics. We demonstrate that our approach allows the
in vivo
analysis of protein stability in the cytosolic compartment without the need for prior structural and functional knowledge.
Characterization of
p
-Hydroxycinnamate Catabolism in a Soil Actinobacterium
Authors: Otani Hiroshi , Lee Young-Eun , Casabon Israël , Eltis Lindsay D.
Published: September 2014

p
-Hydroxycinnamates, such as ferulate and
p
-coumarate, are components of plant cell walls and have a number of commercial applications.
Rhodococcus jostii
RHA1 (RHA1) catabolizes ferulate via vanillate and the β-ketoadipate pathway. Here, we used transcriptomics to identify genes in RHA1 that are upregulated during growth on ferulate versus benzoate. The upregulated genes included three transcriptional units predicted to encode the uptake and β-oxidative deacetylation of
p
-hydroxycinnamates:
couHTL
,
couNOM
, and
couR
. Neither Δ
couL
mutants nor Δ
couO
mutants grew on
p
-hydroxycinnamates, but they did grow on vanillate. Among several
p
-hydroxycinnamates, CouL catalyzed the thioesterification of
p
-coumarate and caffeate most efficiently (
k
cat
/

K
m

= ∼400 mM
−1
s
−1
).
p
-Coumarate was also RHA1's preferred growth substrate, suggesting that CouL is a determinant of the pathway's specificity. CouL did not catalyze the activation of sinapate, in similarity to two
p
-coumaric acid:coenzyme A (CoA) ligases from plants, and contains the same bulged loop that helps determine substrate specificity in the plant homologues. The
couO
mutant accumulated 4-hydroxy-3-methoxyphenyl-β-ketopropionate in the culture supernatant when incubated with ferulate, supporting β-oxidative deacetylation. This phenotype was not complemented with a D257N variant of CouO, consistent with the predicted role of Asp257 as a metal ligand in this amidohydrolase superfamily member. These data suggest that CouO functionally replaces the β-ketothiolase and acyl-CoA thioesterase that occur in canonical β-oxidative pathways. Finally, the transcriptomics data suggest the involvement of two distinct formaldehyde detoxification pathways in vanillate catabolism and identify a eugenol catabolic pathway. The results of this study augment our understanding of the bacterial catabolism of aromatics from renewable feedstocks.
An Aerobic Exercise: Defining the Roles of Pseudomonas aeruginosa Terminal Oxidases
Authors: Jo Jeanyoung , Price-Whelan Alexa , Dietrich Lars E. P.
Published: September 2014

The opportunistic pathogen
Pseudomonas aeruginosa
encodes a large and diverse complement of aerobic terminal oxidases, which is thought to contribute to its ability to thrive in settings with low oxygen availability. In this issue,
Arai et al.
(J. Bacteriol. 196:4206–4215, 2014, doi:
http://dx.doi.org/10.1128/JB.02176-14
) present a thorough characterization of these five complexes, enabling a more detailed understanding of aerobic respiration in this organism.
Agreement between routine and research measurement of infant height and weight
Authors: Bryant M , Santorelli G , Fairley L , Petherick E S , Bhopal R , Lawlor D A , Tilling K , Howe L D , Farrar D , Cameron N , Mohammed M , Wright J
Published: September 2014

In many countries, routine data relating to growth of infants are collected as a means of tracking health and illness up to school age. These have potential to be used in research. For health monitoring and research, data should be accurate and reliable. This study aimed to determine the agreement between length/height and weight measurements from routine infant records and researcher-collected data.

Methods

Height/length and weight at ages 6, 12 and 24 months from the longitudinal UK birth cohort (born in Bradford; n=836–1280) were compared with routine data collected by health visitors within 2 months of the research data (n=104–573 for different comparisons). Data were age adjusted and compared using Bland Altman plots.

Results

There was agreement between data sources, albeit weaker for height than for weight. Routine data tended to underestimate length/height at 6 months (0.5 cm (95% CI −4.0 to 4.9)) and overestimate it at 12 (−0.3 cm (95% CI −0.5 to 4.0)) and 24 months (0.3 cm (95% CI −4.0 to 3.4)). Routine data slightly overestimated weight at all three ages (range −0.04 kg (95% CI −1.2 to 0.9) to −0.04 (95% CI −0.7 to 0.6)). Limits of agreement were wide, particularly for height. Differences were generally random, although routine data tended to underestimate length in taller infants and underestimate weight in lighter infants.

Conclusions

Routine data can provide an accurate and feasible method of data collection for research, though wide limits of agreement between data sources may be observed. Differences could be due to methodological issues; but may relate to variability in clinical practice. Continued provision of appropriate training and assessment is essential for health professionals responsible for collecting routine data.
Raised levels of immunoglobulin G, A and M are associated with an increased risk of total and cause-specific mortality: the Vietnam Experience Study
Authors: Phillips Anna C , Carroll Douglas , Drayson Mark T , Batty G David
Published: September 2014

Background

Immunoglobulins (Ig) are essential for combating infectious disease. However, high levels are associated with a range of diseases and/or poor health behaviours, such as autoimmune diseases, chronic infection, HIV and excessive alcohol consumption. In the present analyses, we extend this body of work by examining whether higher levels of serum Ig G, A and M are associated with increased mortality risk.

Methods

Participants were 4255 Vietnam-era, former US army personnel (the Vietnam Experience Study). From military service files, telephone interviews in 1983 and a medical examination in 1986, sociodemographic, and health data were collected. Contemporary morning fasted blood samples were taken from which IgG, IgA and IgM concentrations were determined. Mortality surveillance over 15 years gave rise to deaths ascribed to all-causes, cardiovascular disease mortality, all cancers combined mortality, external cause and ‘other’ causes (predominantly comprising deaths due to infectious disease). Cox proportional hazard models were utilised to compute HRs per SD increase in Ig which were first adjusted for age and then additionally adjusting for a range of candidate confounders.

Results

In multiply adjusted analyses, in general, the higher the immunoglobulin concentration, the greater the risk of death. Thus, IgA (HR=2.0 95% CI 1.47 to 2.73), IgM (HR=1.5 95% CI 1.11 to 1.91) and IgG (HR=5.8 95% CI 3.38 to 9.95) were positively related to all-cause mortality. Corresponding results for ‘other’ causes of mortality were 4.7 (2.64 to 8.19), 3.5 (2.29 to 5.45) and 33.4 (15.13 to 73.64).

Conclusions

In the present study, high levels of Ig are associated with an elevated risk of death from total and ‘other’ causes, mainly infectious disease. High levels of Ig, particularly IgG, may signal subclinical disease.
Utilizing a zwitterionic approach for the synthesis of late transition metal – triphosphenium ion coordination compounds
Authors: Dube Jonathan W. , Béland Vanessa A. , Boyle Paul D. , Ragogna Paul J.
Published: September 2014

Zwitterionic dicoordinate phosphorus(I) compounds (1 and 2), formally a charge neutral triphosphenium ion or phosphanide, are shown to coordinate to a variety of late transition metals. The reaction of the phosphanide proligands with {Rh(COD)Cl}2 results in an equilibrium process that varies as a function of temperature or reaction stoichiometry. Palladium(II) compounds have a tendency to chlorinate the borate backbone while giving dimeric coordination compounds (1Pd) and also a decomposition product (3) where the P(I) atom was replaced. Both “lone pairs” of electrons on phosphorus are utilized simultaneously in the dominant product from the reaction of 1 and [PtMe2(μ-SMe2)]2, while each platinum center ortho-metallated a phenyl substituent on the flanking phosphorus atoms (1Pt). Stable, isolable, and fully characterized dimeric mercury complexes (1Hg and 2Hg) are produced nearly quantitatively from the reaction of the phosphanide proligand with HgCl2. All compounds described were structurally characterized using single crystal X-ray diffraction and represent a growing series of zwitterionic P(I) coordination compounds that cannot be isolated when a cationic triphosphenium ion is used.
Juvenile salmon and steelhead occupancy of stream pools treated and not treated with restoration structures, Entiat River, Washington
Authors: Polivka Karl M. , Steel E. Ashley , Novak Jenni L.
Published: September 2014

We observed habitat occupancy by juvenile Chinook salmon (Oncorhynchus tschawytscha) and steelhead trout (Oncorhynchus mykiss) at in-stream habitat restoration structures constructed in the Entiat River, Washington, USA. In 2009–2013, fish abundance measurements during rearing (July–October) showed high temporal variability in pools with restoration structures. Both species were more abundant at restored pools than at natural pools in early summer (July), but this difference was typically absent by September. Fish response to restoration structures also varied across years. When looking only at restored pools, there were strong seasonal fluxes in parameters describing the effects of temperature, water depth, and current velocity on fish abundance. Significant interaction terms such as current velocity × depth and temperature × current velocity were present for both species, suggesting that these may be important physical attributes improved by restoration. Through extensive sampling in untreated habitat, both within the treated segment and in nearby control segments, we found that when higher Chinook abundance was observed at restored pools, it was apparently attributable to an increase in habitat capacity and not due to depletion of fish from natural habitat in the same segment. Steelhead habitat selection was too inconsistent for conclusions about capacity, but we did not observe evidence that structures depleted untreated habitat.
Evidence for multiple paternity in two species of Orconectes crayfish
Authors: Kahrl A.F. , Laushman R.H. , Roles A.J.
Published: September 2014

Multiple mating is expected to be common in organisms that produce large clutches as a mechanism by which sexual reproduction can enrich genetic variation. For freshwater crayfish, observation of multiple mating suggests the potential for high rates of multiple paternity, but genetic confirmation is largely lacking from natural populations. We studied paternity within wild-caught broods of two crayfish species in the genus Orconectes (Sanborn’s crayfish (Orconectes sanbornii (Faxon, 1884)) and the Allegheny crayfish (Orconectes obscurus (Hagen, 1870))). Although females have been observed mating with multiple males, this is the first genetic confirmation of multiple paternity in broods of these two species. Berried females were collected in the field and maintained in aquaria until their eggs hatched. We amplified and genotyped extracted DNA from maternal and hatchling tissue for several microsatellite loci. For both species, paternity reconstruction (GERUD 2.0) yielded 2–3 sires per brood and no single paternity clutches. We discuss these results from natural populations in light of the body of work on reproductive ecology of decapod crustaceans and in the context of changes in life history following the transition from marine to freshwater habitats.
Modeling the influence of the Casimir force on the pull-in instability of nanowire-fabricated nanotweezers
Authors: Farrokhabadi Amin , Mokhtari Javad , Rach Randolph , Abadyan Mohamadreza
Published: September 2014

The Casimir force can strongly interfere with the pull-in performance of ultra-small structures. The strength of the Casimir force is significantly affected by the geometries of interacting bodies. Previous investigators have exclusively studied the effect of the Casimir force on the electromechanical instability of nanostructures with planar geometries. However no work has yet considered this effect on the pull-in instability of systems with cylindrical geometries such as nanotweezers fabricated from nanotube/nanowires. In our present work, the influence of the Casimir attraction on the electrostatic response and pull-in instability of nanotweezers fabricated from cylindrical conductive nanowires/nanotubes is theoretically investigated. An asymptotic solution, based on scattering theory, is applied to consider the effect of vacuum fluctuations in the theoretical model. The Euler–Bernoulli beam model is employed, in conjunction with the size-dependent modified couple stress continuum theory, to derive the governing equation of the nanotweezers. The governing nonlinear equations are solved by two different approaches, i.e., the modified Adomian–Padé method (MAD–Padé) and a numerical solution. Various aspects of the problem, i.e., the variation of pull-in parameters, effect of geometry, coupling between the Casimir force and size dependency effects and comparison with the van der Waals force regime are discussed.
An AOP-Based Fault Injection Environment for Cryptographic SystemC Designs
Authors: Mestiri Hassen , Lahbib Younes , Machhout Mohsen , Tourki Rached
Published: September 2014

The increasing complexity of cryptographic devices requires fast simulation environment in order to test their security against fault attacks. SystemC is one promising candidate in Electronic System Level that allows models to reach higher simulation speed. However in order to enable both fault injection and detection inside a SystemC cryptographic models, its code modification is mandatory. Aspect-Oriented Programming (AOP), which is a new programming paradigm, can be used to test the robustness of the cryptographic models without any code modifications. This may replace real cryptanalysis schemes. In this paper, we present a new methodology to simulate the security fault attacks of cryptographic systems at the Electronic System Level. A fault injection/detection environment is proposed to test the resistance of cryptographic SystemC models against fault injection attacks. The fault injection technique into cryptographic SystemC models is performed using weaving faults by AspectC++ as an AOP programming language. We validate our methodology with two scenarios applied to a SystemC Advanced Encryption Standard case study: the first is related to the impact of the AOP on fault detection capabilities, while the second refers to the impact of the AOP on simulation time and size of the executable files. Simulation results show that this methodology can evaluate perfectly the robustness of a cryptographic design against fault injection attacks. They show that the impact of AOP on simulation time is not significant.
DETECTION OF NON-GRANULOMATOUS LESIONS OFMYCOBACTERIUMSPECIES IN CULTURED FRESHWATER HYBRID STURGEON
Authors: Chang P. H. , Chen Y. C. , Hsu W. L. , Chen M. S. , Chen M. M.
Published: September 2014

A disease outbreak with 71% (cumulative) mortality was reported in a freshwater hybrid sturgeon farm located in Hualien County, Taiwan. The moribund fish showed signs of lethargy, anorexia, diffuse external hemorrhages around mouth and anus, and on the base of fin and abdomen surface accompanied with abdomen swelling. Post-mortem examination revealed multiple red patches ranging from 1 to 5 cm in size on the liver. The histopathology revealed extensive coagulative to liquefied necrosis of various sizes in the liver and spleen. Focal necrosis of kidney was also evident. The lesions were positive with Ziehl-Neelsen acid fast staining. A rapid growth of nontuberculous mycobacteria (NTM) was isolated from liver of moribund sturgeon and the polymerase chain reaction (PCR) studies using primer sets derived from Mycobacterium sp. suggested this NTM was closely related to Mycobacterium marinum. There was only one bacterial colony been isolated in brain heart infusion agar (BHI Agar) and been identified as Streptococcus iniae. These findings suggest that a bacterium identified as belonging to M. marinum might cause heavy mortality.
Mathematical analysis of a model for thymus infection with discrete and distributed delays
Authors: Prakash M. , Balasubramaniam P.
Published: September 2014

In this paper, the dynamics of mathematical model for infection of thymus gland by HIV-1 is analyzed by applying some perturbation through two different types of delays such as in terms of Hopf bifurcation analysis. Further, the conditions for the existence of Hopf bifurcation are derived by evaluating the characteristic equation. The direction of Hopf bifurcation and stability of bifurcating periodic solutions are determined by employing the center manifold theorem and normal form method. Finally, some of the numerical simulations are carried out to validate the derived theoretical results and main conclusions are included.
Hybrid Porous Silicon- Rhodamine B Derivative Nanostructures as Chemical Sensor for Hg(II) Detection
Authors: De la Cruz Guzman Paola Mayela , Aguilar-Aguilar Angelica , Bañuelos-Frias Alan , Chazaro-Ruiz Luis Felipe , Palestino Gabriela
Published: September 2014

Sensing of heavy metals in aqueous solutions has been performed by developing porous silicon (PSi) hybrid materials. The Rhodamine organosilane derivative (Rh-UTES) was used as metal receptor through formation of luminescence chelates within the porous silicon microcavities (PSiMc). The attachment of organic derivative into PSiMc was confirmed by FTIR, specular reflectance and scanning electron microscopy (SEM). The complexing ability of Rh-UTES receptor to Hg+2 detection was investigated by fluorescent spectroscopy and microscopy. We found that the fluorescent intensity of the PSiMc hybrid device is metal concentration dependent. Similar behavior was observed in liquid and solid phase. Metal-Ligand affinity was study by electrochemical techniques.
Influence of Alkyl Chain on a Neutral-Carrier for Use in Selective Membranes Mercury Ions
Authors: Juarez-Gomez Jorge , Ramirez-Silva Maria Teresa , Perez-Garcia Francisco , Palomar-Pardavé Manuel , Romero-Romo Mario , Rojas-Hernández Alberto
Published: September 2014

Regarding the ISEs, their recognition element or ionophore is the main parameter to be considered at their building time, which is the reason to synthesize four molecules of the same family, all of them candidates to be the best recognition element for building a novel Hg(II) ions selective electrode with a solid inner contact. The difference between the four structures is the alkyl group bound to one of the sulphur donating groups, the aliphatic chain can be: methyl, ethyl, propyl or butyl. Electrodes were prepared for each of the ionophores synthesized using the composition (%) of the ionophore membrane: o-NPOE:PVC:NaTPB with 5:62:33:1.0mg. The best neutral-carrier for the selective determination of mercury ions proves to be the ionophore containing the methyl in its structure, as its detection limit of (9.1 ± 0.8)x10−10 mol L-1, linear range (1.0x10−9 a 1.0x10−1) mol L-1 and Nernstian response (29.8 ± 0.4) mV decade-1 demonstrated.
Determination of the Antioxidant Capacity of "Pistache Amargo" Using a Biosensor Based on Laccase Trametes Versicolor
Authors: Juarez-Gomez Jorge , Ramirez-Silva Maria Teresa , Palomar-Pardavé Manuel , Romero-Romo Mario , Salinas-Hernández Pastora , Morales-Anzures Fernando
Published: September 2014

In the region of the Itsmo of Tehuantepec, Oaxaca, México, grows a variety of Pistache of the Anacardiaceae family, the fruit is composed of about 68% oil by weight and is rich in polyphenolic compounds. These are antioxidant molecules of great interest today for their beneficial effects to human health, so there is a strong interest in finding natural sources of antioxidants. For this reason, the present work shows the spectrophotometric studies using the DPPH radical method for the determination of the antioxidant capacity equivalent to caffeic acid in different extracts of the "Pistache Amargo" residual pulp. The spectrophotometric method is contrasted with an electrochemical method using a biosensor based on the enzyme Laccase Trameters Versicolor immobilized on a polyvinyl alcohol polymeric membrane.
Discriminative Detection of Neurotoxins by a Layer-by-Layer Based Carbon Nanotube/bi-enzyme Biosensor
Authors: Zhang Yuanyuan , Arugula Mary , Simonian Aleksandr
Published: September 2014

Multi-enzyme systems have attracted considerable interests due to the versatility for multiplexed detection of different analytes. In this study, a layer-by-layer (LbL) assembled carbon nanotube/multi-enzyme electrochemical biosensor incorporating acetylcholinesterase (AChE) and organophosphate hydrolase (OPH) was established for discriminative detection of paraoxon and carbaryl. The parameters used for assembling of the LbL structure on glassy carbon electrode were previously optimized. Flow mode amperometric and cyclic voltammetry (CV) analyses were proposed for discriminative detection between paraoxon and carbaryl.
Autonomous Magnetoelastic Biosentinels for the Detection and Capture of Invasive Pathogens
Authors: Horikawa Shin , Chai Yating , Wikle Howard Clyde , Chin Bryan A.
Published: September 2014

This paper investigates phage-coated magnetoelastic (ME) biosentinels that capture and detect low-concentration pathogenic bacteria in stagnant liquid. These biosentinels are composed of a freestanding, strip-shaped ME resonator coated with a landscape phage that specifically binds with the pathogen of interest. The biosentinels can be moved through a liquid by externally applied magnetic fields. When a time-varying magnetic field is applied, the biosentinels can be placed into mechanical resonance by magnetostriction. As soon as the biosentinels bind with the target pathogen, a change in the biosentinel's resonant frequency occurs, and thereby the presence of the target pathogen can be detected. Detection of Bacillus anthracis spores under stagnant flow conditions was demonstrated.
Selection of Materials for Cascaded Thermoelectric Generators under Transient Thermal Loading
Authors: Fergus J. W.
Published: September 2014

Materials for thermoelectric devices should have a large Seebeck coefficient, high electrical conductivity and low thermal conductivity as indicated by the thermoelectric figure of merit (ZT). The figure of merit is temperature dependent, so multiple materials can be used in cascaded thermoelectric devices, in which each material is located according to its properties at the temperature expected at its location during operation. Numerical modeling has shown that the energy conversion efficiencies of materials with the same figures of merit but different electrical/thermal conductivities depend on the position of the materials in the device (i.e. hot or cold region). The differences in performance are larger under transient heating and cooling, but there are differences even under steady-state conditions. In this paper, results of numerical modeling of thermoelectric generators will be presented to demonstrate how strategic materials placement can be used to improve device performance.
Effect of Cation Demixing on the Electrochemical Performance of LSCFO Cathodes for SOFCs
Authors: Baqué Laura Cecilia , Soldati Analía , Troiani Horacio , Serquis Adriana
Published: September 2014

The commercialization of Solid oxide fuel cells (SOFCs) is still hindered by their cost and long term degradation. One of the most common degradation mechanisms of La1-xSrxFe1-yCoyO3-d (LSCFO) cathodes reported in literature is element demixing. In this work, the degradation of LSCFO cathodes deposited on Ce1-xGdxO2-d electrolytes at 800°C in air for 50 h was investigated by electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). EIS spectra from LSCFO cathodes present two contributions: one at high frequency and another at low frequency. The high frequency contribution remains invariable during the ageing treatment while the low frequency contribution continuously increases. The formation of small segregates was observed after the ageing treatment. Energy dispersive spectroscopy analysis reveals that these segregates were particularly poor in Sr.
NiO/YSZ Reduction for SOFC/SOEC Studied In Situ by Environmental Transmission Electron Microscopy
Authors: Simonsen Søren Bredmose , Agersted Karsten , Hansen Karin Vels , Jacobsen Torben , Wagner Jakob Birkedal , Hansen Thomas Willum , Kuhn Luise Theil
Published: September 2014

A typical anode for solid oxide fuel cells (SOFC) or cathode for solid oxide electrolysis cells (SOEC) is a complex porous structure of Ni and yttria-stabilized zirconia (YSZ). The porous Ni/YSZ is usually prepared from powder mixtures of NiO and YSZ, tape casted and sintered into a dense structure and finally reduced during start-up of the SOFC/SOEC in H2 at the operating temperature of the cell (ca. 800 °C). This contribution presents environmental transmission electron microscopy (ETEM) nanoscale observations of the reduction process of a NiO/YSZ powder in H2 at temperatures up to almost 1000 °C. The study focusses on the temperature dependent dynamical morphology of the NiO/YSZ and on the possible influence of YSZ on the NiO reduction.