bluuebunny/crossref_metadata_2025 huggingface dataset:
Colistin Resistance in a Clinical Acinetobacter baumannii Strain Appearing after Colistin Treatment: Effect on Virulence and Bacterial Fitness
Authors: López-Rojas Rafael , McConnell Michael J. , Jiménez-Mejías Manuel Enrique , Domínguez-Herrera Juan , Fernández-Cuenca Felipe , Pachón Jerónimo
Published: July 2013

The fitness and virulence costs associated with the clinical acquisition of colistin resistance by
Acinetobacter baumannii
were evaluated. The growth of strain CR17 (colistin resistant) was less than that of strain CS01 (colistin susceptible) when the strains were grown in competition (72-h competition index, 0.008). In a murine sepsis model, CS01 and CR17 reached spleen concentrations when coinfecting of 9.31 and 6.97 log
10
CFU/g, respectively, with an
in vivo
competition index of 0.016. Moreover, CS01 was more virulent than CR17 with respect to mortality and time to death.
Azole Heteroresistance in Cryptococcus neoformans: Emergence of Resistant Clones with Chromosomal Disomy in the Mouse Brain during Fluconazole Treatment
Authors: Sionov Edward , Chang Yun C. , Kwon-Chung Kyung J.
Published: July 2013

We have previously reported that
Cryptococcus neoformans
strains are innately heteroresistant to fluconazole
in vitro
, producing minor, highly resistant subpopulations due to adaptive formation of disomic chromosomes. Using a mouse model, we assessed the emergence of heteroresistant clones in the brain during fluconazole treatment and found that the occurrence of heteroresistant clones
in vivo
with chromosomal disomy is strain dependent. Interestingly, emergence of heteroresistant clones
in vivo
was unrelated to the strain's MIC to fluconazole.
Impaired Virulence and Fitness of a Colistin-Resistant Clinical Isolate of Acinetobacter baumannii in a Rat Model of Pneumonia
Authors: Hraiech Sami , Roch Antoine , Lepidi Hubert , Atieh Thérèse , Audoly Gilles , Rolain Jean-Marc , Raoult Didier , Brunel Jean-Michel , Papazian Laurent , Brégeon Fabienne
Published: July 2013

We compared the fitness and lung pathogenicity of two isogenic clinical isolates of
Acinetobacter baumannii
, one resistant (ABCR) and the other susceptible (ABCS) to colistin.
In vitro
, ABCR exhibited slower growth kinetics than ABCS. In a rat model of pneumonia, ABCR was associated with less pronounced signs of infection (lung bacterial count, systemic dissemination, and lung damage) and a better outcome (ABCR and ABCS mortality rates, 20 and 50%, respectively [
P
= 0.03]).
Genetic Basis for
In Vitro
and
In Vivo
Resistance to Lincosamides, Streptogramins A, and Pleuromutilins (LS
A
P Phenotype) in Enterococcus faecium
Authors: Isnard Christophe , Malbruny Brigitte , Leclercq Roland , Cattoir Vincent
Published: July 2013

As opposed to
Enterococcus faecalis
, which is intrinsically resistant to lincosamides, streptogramins A, and pleuromutilins (LS
A
P phenotype) by production of the ABC protein Lsa(A),
Enterococcus faecium
is naturally susceptible. Since this phenotype may be selected for
in vivo
by quinupristin-dalfopristin (Q-D), the aim of this study was to investigate the molecular mechanism of acquired LS
A
P resistance in
E. faecium
. Six LS
A
P-resistant
in vitro
mutants of
E. faecium
HM1070 as well as three different pairs of clinical isolates (pre- and postexposure to Q-D) were studied. The full genome sequence of an
in vitro
mutant (
E. faecium
UCN90B) was determined by using 454 sequencing technology and was compared with that of the parental strain. Single-nucleotide replacement was carried out to confirm the role of this mutation. By comparative genomic analysis, a point mutation was found within a 1,503-bp gene coding for an ABC homologue showing 66% amino acid identity with Lsa(A). This mutation (C1349T) led to an amino acid substitution (Thr450Ile). An identical mutation was identified in all
in vitro
and
in vivo
resistant strains but was not present in susceptible strains. The wild-type allele was named
eat
(A) (for

E

nterococcus
A
BC
t
ransporter), and its mutated allelic variant was named
eat
(A)
v
. The introduction of
eat
(A)
v
from UCN90B into HM1070 conferred the LS
A
P phenotype, whereas that of
eat
(A) from HM1070 into UCN90B restored susceptibility entirely. This is the first description of the molecular mechanism of acquired LS
A
P resistance in
E. faecium
. Characterization of the biochemical mechanism of resistance and the physiological role of this ABC protein need further investigations.
Fidaxomicin versus Conventional Antimicrobial Therapy in 59 Recipients of Solid Organ and Hematopoietic Stem Cell Transplantation with Clostridium difficile-Associated Diarrhea
Authors: Clutter Dana S. , Dubrovskaya Yanina , Merl Man Yee , Teperman Lewis , Press Robert , Safdar Amar
Published: July 2013

The feasibility of fidaxomicin versus vancomycin and metronidazole (conventional therapy) was assessed in 59 transplant recipients with 61 episodes of
Clostridium difficile
-associated diarrhea (CDAD). Overall clinical cure was achieved in 86% of episodes, and in 7% of episodes, infection recurred. Fidaxomicin was well tolerated. Clinical cures were not significantly different compared with conventional therapy (67% versus 89%, respectively;
P
= 0.06). Univariate analysis of predictors for lack of clinical cure included continued use of broad-spectrum systemic antibiotics (
P
= 0.026) and prior diagnosis of CDAD (95% confidence interval, 1.113 to 19.569; odds ratio, 4.667;
P
= 0.041). New-onset vancomycin-resistant
Enterococcus
(VRE) colonization was not noted after fidaxomicin therapy alone. However, this occurred in 10 of 28 patients (36%) following conventional therapy, and 2 of 3 patients with subsequent bacteremia died.
Complete Sequence of pSAM7, an IncX4 Plasmid Carrying a Novel
bla
CTX-M-14b
Transposition Unit Isolated from Escherichia coli and Enterobacter cloacae from Cattle
Authors: Stokes M. O. , AbuOun M. , Umur S. , Wu G. , Partridge S. R. , Mevius D. J. , Coldham N. G. , Fielder M. D.
Published: July 2013

The same plasmid carrying
bla
CTX-M-14b
was identified from an
Escherichia coli
isolate and an
Enterobacter cloacae
isolate collected from cattle in the United Kingdom by complete plasmid sequencing. This 35,341-bp plasmid, pSAM7, had an IncX4 backbone that is 99% identical to that of pJIE143 from a human isolate in Australia. PCR screening identified pSAM7-like plasmids in three other
E. coli
isolates of different multilocus sequence types isolated from cattle on different farms in the United Kingdom.
KpnEF, a New Member of the Klebsiella pneumoniae Cell Envelope Stress Response Regulon, Is an SMR-Type Efflux Pump Involved in Broad-Spectrum Antimicrobial Resistance
Authors: Srinivasan Vijaya Bharathi , Rajamohan Govindan
Published: July 2013

Klebsiella pneumoniae
has been frequently associated with nosocomial infections. Efflux systems are ubiquitous transporters that also function in drug resistance. Genome analysis of
K. pneumoniae
strain NTUH-K2044 revealed the presence of ∼15 putative drug efflux systems. We discuss here for the first time the characterization of a putative SMR-type efflux pump, an
ebrAB
homolog (denoted here as
kpnEF
) with respect to
Klebsiella
physiology and the multidrug-resistant phenotype. Analysis of hypermucoviscosity revealed direct involvement of
kpnEF
in capsule synthesis. The Δ
kpnEF
mutant displayed higher sensitivity to hyperosmotic (∼2.8-fold) and high bile (∼4.0-fold) concentrations. Mutation in
kpnEF
resulted in increased susceptibility to cefepime, ceftriaxone, colistin, erythromycin, rifampin, tetracycline, and streptomycin; mutated strains changed from being resistant to being susceptible, and the resistance was restored upon complementation. The Δ
kpnEF
mutant displayed enhanced sensitivity toward structurally related compounds such as sodium dodecyl sulfate, deoxycholate, and dyes, including clinically relevant disinfectants such as benzalkonium chloride, chlorhexidine, and triclosan. The prevalence of
kpnEF
in clinical strains broadens the diversity of antibiotic resistance in
K. pneumoniae
. Experimental evidence of CpxR binding to the efflux pump promoter and quantification of its expression in a
cpxAR
mutant background demonstrated
kpnEF
to be a member of the Cpx regulon. This study helps to elucidate the unprecedented biological functions of the SMR-type efflux pump in
Klebsiella
spp.
Malic Enzyme and Malolactic Enzyme Pathways Are Functionally Linked but Independently Regulated in Lactobacillus casei BL23
Authors: Landete José María , Ferrer Sergi , Monedero Vicente , Zúñiga Manuel
Published: July 2013

Lactobacillus caseiis the only lactic acid bacterium in which two pathways forl-malate degradation have been described: the malolactic enzyme (MLE) and the malic enzyme (ME) pathways. Whereas the ME pathway enablesL. caseito grow onl-malate, MLE does not support growth. Themlegene cluster consists of three genes encoding MLE (mleS), the putativel-malate transporter MleT, and the putative regulator MleR. Themaegene cluster consists of four genes encoding ME (maeE), the putative transporter MaeP, and the two-component system MaeKR. Since both pathways compete for the same substrate, we sought to determine whether they are coordinately regulated and their role inl-malate utilization as a carbon source. Transcriptional analyses revealed that themleandmaegenes are independently regulated and showed that MleR acts as an activator and requires internalization ofl-malate to induce the expression ofmlegenes. Notwithstanding, bothl-malate transporters were required for maximall-malate uptake, although only anmleTmutation caused a growth defect onl-malate, indicating its crucial role inl-malate metabolism. However, inactivation of MLE resulted in higher growth rates and higher final optical densities onl-malate. The limited growth onl-malate of the wild-type strain was correlated to a rapid degradation of the availablel-malate tol-lactate, which cannot be further metabolized. Taken together, our results indicate thatL. caseil-malate metabolism is not optimized for utilization ofl-malate as a carbon source but for deacidification of the medium by conversion ofl-malate intol-lactate via MLE.
Peptidoglycan Fragment Release from Neisseria meningitidis
Authors: Woodhams Katelynn L. , Chan Jia Mun , Lenz Jonathan D. , Hackett Kathleen T. , Dillard Joseph P.
Published: July 2013

Neisseria meningitidis
(meningococcus) is a symbiont of the human nasopharynx. On occasion, meningococci disseminate from the nasopharynx to cause invasive disease. Previous work showed that purified meningococcal peptidoglycan (PG) stimulates human Nod1, which leads to activation of NF-κB and production of inflammatory cytokines. No studies have determined if meningococci release PG or activate Nod1 during infection. The closely related pathogen
Neisseria gonorrhoeae
releases PG fragments during normal growth. These fragments induce inflammatory cytokine production and ciliated cell death in human fallopian tubes. We determined that meningococci also release PG fragments during growth, including fragments known to induce inflammation. We found that
N. meningitidis
recycles PG fragments via the selective permease AmpG and that meningococcal PG recycling is more efficient than gonococcal PG recycling. Comparison of PG fragment release from
N. meningitidis
and
N. gonorrhoeae
showed that meningococci release less of the proinflammatory PG monomers than gonococci and degrade PG to smaller fragments. The decreased release of PG monomers by
N. meningitidis
relative to
N. gonorrhoeae
is partly due to
ampG
, since replacement of gonococcal
ampG
with the meningococcal allele reduced PG monomer release. Released PG fragments in meningococcal supernatants induced significantly less Nod1-dependent NF-κB activity than released fragments in gonococcal supernatants and tended to induce less interleukin-8 (IL-8) secretion in primary human fallopian tube explants. These results support a model in which efficient PG recycling and extensive degradation of PG fragments lessen inflammatory responses and may be advantageous for maintaining meningococcal carriage in the nasopharynx.
Animal Models for Studying Female Genital Tract Infection with Chlamydia trachomatis
Authors: De Clercq Evelien , Kalmar Isabelle , Vanrompay Daisy
Published: July 2013

Chlamydia trachomatisis a Gram-negative obligate intracellular bacterial pathogen. It is the leading cause of bacterial sexually transmitted disease in the world, with more than 100 million new cases of genital tract infections withC. trachomatisoccurring each year. Animal models are indispensable for the study ofC. trachomatisinfections and the development and evaluation of candidate vaccines. In this paper, the most commonly used animal models to study female genital tract infections withC. trachomatiswill be reviewed, namely, the mouse, guinea pig, and nonhuman primate models. Additionally, we will focus on the more recently developed pig model.
Engineering considerations for large dam removals
Authors: Hepler Thomas E.
Published: July 2013

The removal of a large dam requires special engineering considerations not normally required for the removal of smaller dams. Large dams generally provide greater project benefits, but they represent a higher downstream hazard in the event of failure and greater challenges to fish passage. The reservoirs associated with large dams can impound more sediment and affect downstream water quality to a greater degree. The environmental compliance and decision-making process for a large dam removal project can take many years and will normally require the evaluation of a full range of project alternatives with estimated costs, the performance of a comprehensive environmental impact analysis, and the identification and implementation of extensive mitigation measures. Streamflow diversion and demolition plans for the removal of a large dam must ensure acceptable construction risks from start to finish, and produce reservoir drawdown at a controlled rate for sediment management purposes and to prevent instability of natural or embankment slopes. Large dams require more time for removal, at a higher cost, and contain greater volumes of materials for which disposal sites must be found.
Assessing sedimentation issues within aging flood-control reservoirs
Authors: Bennett Sean J. , Dunbar John A. , Rhoton Fred E. , Allen Peter M. , Bigham Jerry M. , Davidson Gregg R. , Wren Daniel G.
Published: July 2013

Flood-control reservoirs designed and built by federal agencies have been extremely effective in reducing the ravages of floods nationwide. Yet some structures are being removed for a variety of reasons, while others are aging rapidly and require either rehabilitation or decommissioning. The focus of the paper is to summarize collaborative research activities to assess sedimentation issues within aging flood-control reservoirs and to provide guidance on such tools and technologies. Ten flood-control reservoirs located in Oklahoma, Mississippi, and Wisconsin have been examined using vibracoring, stratigraphic, geochronologic, geophysical, chemical, and geochemical techniques and analyses. These techniques and analyses facilitated: (1) the demarcation of the pre-reservoir sediment horizon within the deposited reservoir sediment, (2) definition of the textural and stratigraphic characteristics of the sediment over time and space, (3) the accurate determination of the remaining reservoir storage capacity, (4) the quantification of sediment quality with respect to agrichemicals and environmentally important trace elements over both time and space, and (5) the determination of geochemical conditions within the deposited sediment and the potential mobility of associated elements. The techniques employed and discussed here have proven to be successful in the assessment of sediment deposited within aging flood-control reservoirs, and it is envisioned that these same approaches could be adopted by federal agencies as part of their national reservoir management programs.
Engineering Geology of Radioactive Waste Disposal
Authors: Laguna Wallace De
Published: July 2013

Disposal of the radioactive wastes from our coming nuclear power economy will be a difficult problem, for the wastes are corrosive and toxic and liberate heat slowly for a long time. In a few decades the amount of waste will represent a formidable problem, and one which must be solved with a high degree of certainty. Waste disposal at present is largely by tank storage, supplemented by release of some low- to intermediate-level waste to the ground. Tank storage will hardly be an answer to the disposal problems of the future, and release to the ground, even at the present small scale, is raising problems that have not been and perhaps cannot be answered and so may have elements of hazard.

Three possible methods for future waste disposal are now being investigated: fixation in or as solids, disposal into salt, and disposal into deep porous formations. The fixation methods now under investigation all involve heating the waste, are expensive, and are dangerous to the operators, but the solid product once formed would probably be no further hazard. Disposal into salt can be arranged by mining the salt through shafts, which is expensive and will require shaft maintenance. Alternatively, cavities can be dissolved in salt by pumping fresh water down wells, but either such cavities must be small, or their use must be restricted to the disposal of medium-level waste if they are not to overheat. Cavities in salt should provide safe storage, for salt is quite impermeable, but the use of salt as a structural material raises questions. Disposal through deep wells also appears to have serious limitations. The wastes will have to be filtered and diluted and perhaps treated to reduce corrosion of the disposal wells. Heat-generation problems will prevent the disposal of fresh, high-level waste. However, the very large potential storage capacity of deep porous formations suggests that the method may be applicable for the very large amounts of waste that will eventually be produced. Recently an investigation has begun of the possibility of disposing of waste mixtures into shale by fracturing. The subject is controversial, and although the initial experiments look promising it will take much experience with low-level waste before the future of the method can be evaluated.
Stabilization of Rock by Bolting
Authors: Thomas Edward
Published: July 2013

During the past 10 years rock bolting has evolved into a systematic method of underground roof, wall, and floor support, which is generally accepted wherever ground can be consolidated economically and efficiently. Although the method was known and used occasionally over a long period of time, apparently acceptance was contingent upon the improvements in drilling and mechanized loading that have taken place just before and concurrent with the development. Rock bolting effects a general improvement in safety by reducing roof-fall accidents, increases efficiency, and makes for conservation in mining.

This paper attempts a logical classification of rock bolts from the standpoint of utilization and provides current criteria for designing and testing installations.
Land Subsidence Due to the Application of Water
Authors: Lofgren Ben E.
Published: July 2013

Loose, dry, low-density deposits that compact when they are wetted mantle extensive areas in North America, Europe, and Asia. This process, here referred to as hydrocompaction, has produced widespread subsidence of the land surface. Hydrocompaction may occur under natural overburden load or may occur only with the addition of a surcharge load.

Deposits that subside because of hydrocompaction are generally one of two types: (1) loose, moisture-deficient alluvial deposits; and (2) moisture-deficient loess and related eolian deposits. Such deposits occur in regions where seasonal rainfall seldom, if ever, is sufficient to penetrate below the root zone; thus, they have remained moisture deficient throughout their postdepositional history and are readily susceptible to hydrocompaction when they are artificially wetted.

Subsidence due to hydrocompaction is of serious concern in the design and maintenance of aqueducts, buildings, pipe lines, highways, and other major engineering structures. Damage usually can be minimized by precompacting the deposits before construction begins.
Geologic Settings of Subsidence
Authors: Allen Alice S.
Published: July 2013

This paper reviews the role of geologic processes that contribute to subsidence in order to aid those starting investigations of ground-surface subsidence. Subsidence occurs, or at least is discovered, only infrequently, and little organized information has been available. In order to assess our present state of knowledge, the author gathered fragmentary bits of information from many sources widely scattered in the literature of geology and other earth sciences.

The author cites examples for each geologic process that is a potential contributor to ground-surface subsidence together with geologic evidence for diagnosing their causes. The geologic processes involved are: (1) solution of gypsum and salt and redistribution of transient fill materials through solution cavities in calcareous rocks; (2) underground erosion of uncemented or lightly cemented silt and sand through temporary underground passageways; (3) lateral plastic flow of salt, gypsum and anhydrite, shale, and clay under loading; (4) compaction of sediments by loading, drainage, vibration, and hydrocompaction; (5) tectonic movements including primary and secondary effects of earthquakes, folding, and warping; and (6) volcanic activity. Because the first four processes may be accelerated by various engineering activities, examples have been selected to illustrate subsidence both under natural conditions and under conditions modified by man's activities.

Although this extensive search for existing information on the role of geologic factors in subsidence indicates that much detailed work remains to be done, the future prospects for advancing our geologic knowledge are excellent. Methods of measuring ground-surface displacements are improving rapidly. Also, broadly based investigations of known areas of major subsidence throughout the world are developing new methods of diagnosis and treatment and are yielding quantitative data that will aid our evaluation of the rates and magnitude of present-day geologic processes.
Failure of anti-TNF therapy to reactivate previously septic prosthetic joints
Authors: Manolios Nicholas , Burneikis Anthony , Spencer David , Howe Graydon
Published: July 2013

A patient with long-standing rheumatoid arthritis was admitted withStreptococcus pneumoniaesepticaemia and bilateral septic knee joints. He was treated conservatively with intravenous antibiotics and arthroscopic washouts and discharged home on oral antibiotics. Six months posthospital discharge, following re-exacerbation of arthritis, an informed consent was given by the patient to continue antitumour necrosis factor therapy. After 5 years of observation, there has been no recurrence of sepsis and the rheumatoid arthritis remains in remission.
An exceptionally large giant lipoma of the hand
Authors: Chatterton Benjamin Dougal , Moores Thomas Steven , Datta Praveen , Smith Kevin David
Published: July 2013

Lipomas are benign tumours that consist of mature adipocytes. They are the commonest soft tissue tumours, most frequently seen in the trunk and proximal extremities. Lesions in the hand are uncommon, and giant lipomas of the hand, defined as greater than 5 cm in size, are particularly rare. We present a case of an exceptionally large giant lipoma of the hand, presenting as an extremely large inconvenient swelling of the palm in a 67-year-old woman. The diagnosis of lipoma was suggested via ultrasonography, and confirmed via MRI and histology. The lesion was successfully excised with no postoperative neurovascular deficit. The excised lesion measured 8×6×3 cm, one of the largest giant lipomas of the hand reported to date. When patients present with large lesions such as these a malignant cause must always be considered, and appropriate early imaging is essential when assessing these patients.
Time for bed: associations with cognitive performance in 7-year-old children: a longitudinal population-based study
Authors: Kelly Yvonne , Kelly John , Sacker Amanda
Published: July 2013

Background

Little is known about the links between the time that young children go to bed and their cognitive development. In this paper we seek to examine whether bedtimes in early childhood are related to cognitive test scores in 7-year-olds.

Methods

We examined data on bedtimes and cognitive test (z-scores) for reading, maths and spatial abilities for 11 178 7-year-old children from the UK Millennium Cohort Study.

Results

At age 7, not having a regular bedtime was related to lower cognitive test scores in girls: reading (β: −0.22), maths (β: −0.26) and spatial (β: −0.15), but not for boys. Non-regular bedtimes at age 3 were independently associated, in girls and boys, with lower reading (β: −0.10, −0.20), maths (β: −0.16, −0.11) and spatial (β: −0.13, −0.16) scores. Cumulative relationships were apparent. Girls who never had regular bedtimes at ages 3, 5 and 7 had significantly lower reading (β: −0.36), maths (β: −0.51) and spatial (β: −0.40) scores, while for boys this was the case for those having non-regular bedtimes at any two ages (3, 5 or 7 years): reading (β: −0.28), maths (β: −0.22) and spatial (β: −0.26) scores. In boys having non-regular bedtimes at all three ages (3, 5 and 7 years) were non-significantly related to lower reading, maths and spatial scores.

Conclusions

The consistent nature of bedtimes during early childhood is related to cognitive performance. Given the importance of early child development, there may be knock on effects for health throughout life.
THE MECHANISM AND PROPERTIES OF ELECTRON TRANSFER IN THE BIOLOGICAL ORGANISM
Authors: PANG XIAO-FENG
Published: July 2013

The mechanism and properties of electron transfer along protein molecules at finite temperature T ≠ 0 in the life systems are studied using nonlinear theory of bio-energy transport and Green function method, in which the electrons are transferred from donors to acceptors in virtue of the supersound soliton excited by the energy released in ATP hydrolysis. The electron transfer is, in essence, a process of oxidation–reduction reaction. In this study we first give the Hamiltonian and wavefunction of the system and find out the soliton solution of the dynamical equation in the protein molecules with finite temperature, and obtain the dynamical coefficient of the electron transfer. The results show that the speed of the electron transfer is related to the velocity of motion of the soliton, distribution of electrons in the donor and acceptor as well as the interaction strength among them. We finally concluded the changed rule of electric current, arising from the electron transfer, with increasing time. These results are useful in molecular and chemical biology.
THE 2-D SEXTIC HAMILTONIAN OSCILLATOR
Authors: MOLERO F. J. , VAN DER MEER J. C. , FERRER S. , CÉSPEDES F. J.
Published: July 2013

The 2-D sextic oscillator is studied as a family of axial symmetric parametric integrable Hamiltonian systems, presenting a bifurcation analysis of the different flows. It includes the "elliptic core" model in 1-D nonlinear oscillators, recently proposed in the literature. We make use of the energy-momentum mapping, which will give us the fundamental fibration of the four-dimensional phase space. Special attention is given to the singular values of the energy-momentum mapping connected with rectilinear and circular orbits. They are related to the saddle-center and pitchfork scenarios with the associated homoclinic and heteroclinic trajectories. We also study how the geometry of the phase space evolves during the transition from the one-dimensional to the two-dimensional model. Within an elliptic function approach, the solutions are given using Legendre elliptic integrals of the first and third kind and the corresponding Jacobi elliptic functions.
REDUNDANT MORPHOLOGICAL WAVELET AND LOCAL PATTERN SPECTRUM
Authors: YAMAGUCHI TOMONARI , FUJIO MITSUHIKO , INOUE KATSUHIRO
Published: July 2013

Time-frequency analysis methods such as wavelet analysis are applied to investigate characteristic from non-stationary signals. In this study, we proposed redundant morphological wavelet analysis that was a kind of nonlinear discrete wavelet and redundant wavelet. This method analyzes a transition of shape information from signals in detail since this method keeps property of shift invariance though information of decomposition includes redundancy. Local pattern spectrum which corresponds to nonlinear short time Fourier transform is derived from this nonlinear wavelet. The characteristics of these methods were confirmed by applying to simulation data and actual data.
PERFECT-TRANSLATION-INVARIANT CUSTOMIZABLE COMPLEX DISCRETE WAVELET TRANSFORM
Authors: TODA HIROSHI , ZHANG ZHONG , IMAMURA TAKASHI
Published: July 2013

The theorems, giving the condition of perfect translation invariance for discrete wavelet transforms, have already been proven. Based on these theorems, the dual-tree complex discrete wavelet transform, the 2-dimensional discrete wavelet transform, the complex wavelet packet transform, the variable-density complex discrete wavelet transform and the real-valued discrete wavelet transform, having perfect translation invariance, were proposed. However, their customizability of wavelets in the frequency domain is limited. In this paper, also based on these theorems, a new type of complex discrete wavelet transform is proposed, which achieves perfect translation invariance with high degree of customizability of wavelets in the frequency domain.
COMPUTATIONAL CONTOUR OF MIXED MODE CRACK-TIP PLASTIC ZONE FOR ALUMINUM ALLOY 2024T351
Authors: DO TIEN DUNG , LEROY RENE , JOLY DAMIEN
Published: July 2013

The studies on mixed mode crack-tip plastic zones are one of the fundamental importance in describing the process of failure and in evaluation of the material life. The approach is also applied to predict crack initiation under mixed mode loading. The objective of this work is to study the contour of mixed mode crack-tip plastic zones, the minimum plastic zone radius (MPZR) and the direction of initial crack for aluminum alloy 2024T351 in Compact tension specimen by using Matlab software. This paper computed the shape, size of plastic zone at crack-tip and the minimum plastic zone radius with reference to the loading angle and stress intensity factor in linear elastic fracture mechanics regime for plane strain condition according to Von Mises yield criteria, the study is conducted for various loading angle. We found that the mixed mode loading (β = 60°) can lead to material fracture earlier than any mode loading.
Comparison of magnetic, electrical and ground penetrating radar surveys to detect buried forensic objects in semi-urban and domestic patio environments
Authors: Hansen J. D. , Pringle J. K.
Published: July 2013

Near-surface geophysical techniques should be routinely utilized by law enforcement agencies to locate shallowly buried forensic objects, saving human and other resources. However, there has been little published research on optimum geophysical detection method(s) and configurations beyond metal detectors. This paper details multi-technique geophysical surveys to detect simulated unmarked illegal weapons, explosive devices and arms caches that were shallowly buried within a semi-urban environment test site. A concrete patio was then overlaid to represent a common household garden environment before re-surveying. Results showed that the easily utilized magnetic susceptibility probe was optimal for target detection in both semi-urban and patio environments, while basic metal detector surveys had a lower target detection rate in the patio scenario with some targets remaining undetected. High-frequency (900 MHz) ground penetrating radar antennae were optimum for target detection in the semi-urban environment, while 450 and 900 MHz frequencies had similar detection rates in the patio scenario. Resistivity surveys at 0.25 m probe and sampling spacing were good for target detection in the semi-urban environment. 2D profiles were sufficient for target detection, but resistivity datasets required site de-trending to resolve targets in map view. Forensic geophysical techniques are rapidly evolving to assist search investigators to detect hitherto difficult-to-locate buried forensic targets.
On collocations and topic models
Authors: Lau Jey Han , Baldwin Timothy , Newman David
Published: July 2013

We investigate the impact of preextracting and tokenizing bigram collocations on topic models. Using extensive experiments on four different corpora, we show that incorporating bigram collocations in the document representation creates more parsimonious models and improves topic coherence. We point out some problems in interpreting test likelihood and test perplexity to compare model fit, and suggest an alternate measure that penalizes model complexity. We show how the Akaike information criterion is a more appropriate measure, which suggests that using a modest number (up to 1000) of top-ranked bigrams is the optimal topic modelling configuration. Using these 1000 bigrams also results in improved topic quality over unigram tokenization. Further increases in topic quality can be achieved by using up to 10,000 bigrams, but this is at the cost of a more complex model. We also show that multiword (bigram and longer) named entities give consistent results, indicating that they should be represented as single tokens. This is the first work to explicitly study the effect of
n
-gram tokenization on LDA topic models, and the first work to make empirical recommendations to topic modelling practitioners, challenging the standard practice of unigram-based tokenization.
Semantic interpretation of noun compounds using verbal and other paraphrases
Authors: Nakov Preslav I. , Hearst Marti A.
Published: July 2013

We study the problem of semantic interpretation of noun compounds such as
bee honey
,
malaria mosquito
,
apple cake
, and
stem cell
. In particular, we explore the potential of using predicates that make explicit the hidden relation that holds between the nouns that form the noun compound. For example,
mosquito that carries malaria
is a paraphrase of the compound
malaria mosquito
in which the verb explicitly states the semantic relation between the two nouns. We study the utility of using such paraphrasing verbs, with associated weights, to build a representation of the semantics of a noun compound, for example,
malaria mosquito
can be represented as follows:
carry
(23),
spread
(16),
cause
(12),
transmit
(9), and so on. We also explore the potential of using multiple paraphrasing verbs as features for predicting abstract semantic relations such as CAUSE, and we demonstrate that using explicit paraphrases can help improve statistical machine translation.
Elder Chinese Martial Art Practitioners Have Higher Radial Bone Strength, Hand-Grip Strength, and Better Standing Balance Control
Authors: Fong Shirley S. M. , Guo X. , Cheung Alice P. M. , Jo Alex T. L. , Lui Gary K. W. , Mo Dennis K. C. , Ng Shamay S. M. , Tsang William W. N.
Published: July 2013

This study explored the feasibility of using Ving Tsun (VT) martial art as a fall-prevention exercise for male seniors. We compared the radial bone strength, hand-grip strength, and standing balance control of senior VT practitioners and nonpractitioners under various sensory environments. Sixteen male VT practitioners (mean age ± SD: years) and 17 sex- and age-matched control adults (mean age ± SD: years) participated in the study. The bone strength of the distal radius, hand-grip strength, and standing balance control were assessed using an ultrasound bone sonometer, a Jamar dynamometer, and sensory organization test (SOT) on the NeuroCom Balance Master, respectively. A multivariate analysis of variance (MANOVA) was used to compare the outcome variables between the two groups. Results revealed that VT practitioners had significantly higher radial bone strength (-score) on the dominant side (), hand-grip strength (dominant side, ; nondominant side, ), and standing balance control (SOT composite equilibrium score, ) than the control participants. Male elder VT practitioners had higher radial bone strength, hand-grip strength, and better standing balance control than nonpractitioners. Our findings shed light on the use of VT exercise to prevent falls and fall-related fractures of the distal radius in male elders.
The Impact of FLT3 Mutations on the Development of Acute Myeloid Leukemias
Authors: Testa Ugo , Pelosi Elvira
Published: July 2013

The development of the genetic studies on acute myeloid leukemias (AMLs) has led to the identification of some recurrent genetic abnormalities. Their discovery was of fundamental importance not only for a better understanding of the molecular pathogenesis of AMLs, but also for the identification of new therapeutic targets. In this context, it is essential to identify AML-associated “driver” mutations, which have a causative role in leukemogenesis. Evidences accumulated during the last years indicate that activating internal tandem duplication mutations in FLT3 (FLT3-ITD), detected in about 20% of AMLs, represents driver mutations and valid therapeutic targets in AMLs. Furthermore, the screening of FLT3-ITD mutations has also considerably helped to improve the identification of more accurate prognostic criteria and of the therapeutic selection of patients.
Insights Gained from P. falciparum Cultivation in Modified Media
Authors: Desai Sanjay A.
Published: July 2013

In vitro cultivation of Plasmodium falciparum, the agent of severe human malaria, has enabled advances in basic research and accelerated the development of new therapies. Since the introduction of in vitro parasite culture nearly 40 years ago, most workers have used a medium consisting of RPMI 1640 medium supplemented with lipids and hypoxanthine. While these standardized conditions yield robust parasite growth and facilitate comparison of results from different studies, they may also lead to implicit assumptions that limit future advances. Here, I review recent studies that used modified culture conditions to challenge these assumptions and explore parasite physiology. The findings are relevant to understanding in vivo parasite phenotypes and the prioritization of antimalarial targets.
Use ofMetarhizium anisopliaeChitinase Genes for Genotyping and Virulence Characterization
Authors: Niassy Saliou , Subramanian Sevgan , Ekesi Sunday , Bargul Joel L. , Villinger Jandouwe , Maniania Nguya K.
Published: July 2013

Virulence is the primary factor used for selection of entomopathogenic fungi (EPF) for development as biopesticides. To understand the genetic mechanisms underlying differences in virulence of fungal isolates on various arthropod pests, we compared the chitinase genes,chi2andchi4, of 8 isolates ofMetarhizium anisopliae. The clustering of the isolates showed various groups depending on their virulence. However, the analysis of their chitinase DNA sequenceschi2andchi4did not reveal major divergences. Although their protein translates have been implicated in fungal virulence, the predicted protein structure ofchi2was identical for all isolates. Despite the critical role of chitin digestion in fungal infection, we conclude thatchi2andchi4genes cannot serve as molecular markers to characterize observed variations in virulence amongM. anisopliaeisolates as previously suggested. Nevertheless, processes controlling the efficient upregulation of chitinase expression might be responsible for different virulence characteristics. Further studies using comparative “in vitro” chitin digestion techniques would be more appropriate to compare the quality and the quantity of chitinase production between fungal isolates.
Effect of Intermittent Low-Frequency Electrical Stimulation on the Rat Gastrocnemius Muscle
Authors: Tsutaki Arata , Ogasawara Riki , Kobayashi Koji , Lee Kihyuk , Kouzaki Karina , Nakazato Koichi
Published: July 2013

Low-frequency neuromuscular electrical stimulation (NMES) has been used as an endurance exercise model. This study aimed to test whether low-frequency NMES increases the phosphorylation of anabolic signaling molecules and induces skeletal muscle hypertrophy, as seen with high-frequency NMES. Using Sprague-Dawley rats, 1 bout of exercise (with dissection done immediately (Post0) and 3 h (Post3) after exercise) and another 6 sessions of training were performed. All experimental groups consisted of high- and low-frequency stimulation (HFS: 100 Hz; LFS: 10 Hz). Periodic acid-Schiff (PAS) staining was conducted to investigate type II fiber activation, and western blot analysis (WB) was conducted to examine whether NMES leads to anabolic intracellular signaling. At first, we examined the acute effect of exercise. PAS staining revealed that glycogen depletion occurred in both type I and type II fibers. WB results demonstrated that p70S6K phosphorylation was significantly increased by HFS, but there was no significant difference with LFS. In contrast, ERK 1/2 phosphorylation was increased by LFS at Post0. In the 6-session training, the wet weight and myofibrillar protein were significantly increased by both HFS and LFS. In conclusion, LFS has a similar anabolic effect for skeletal muscle hypertrophy as HFS, but the mediating signaling pathway might differ.
Resveratrol Prevents Dendritic Cell Maturation in Response to Advanced Glycation End Products
Authors: Buttari Brigitta , Profumo Elisabetta , Facchiano Francesco , Ozturk Elif Inci , Segoni Luca , Saso Luciano , Riganò Rachele
Published: July 2013

Advanced glycation end products (AGEs), generated through nonenzymatic glycosylation of proteins, lipids, and nucleic acids, accumulate in the body by age thus being considered as biomarkers of senescence. Senescence is characterized by a breakdown of immunological self-tolerance, resulting in increased reactivity to self-antigens. Previous findings suggest that AGE and its receptor RAGE may be involved in the pathogenesis of autoimmune reactions through dendritic cell (DC) activation. The aim of this study was to investigate whether resveratrol, a polyphenolic antioxidant compound with tolerogenic effects on DCs, was able to counteract the mechanisms triggered by AGE/RAGE interaction on DCs. By immunochemical and cytofluorimetric assays, we demonstrated thatin vitropretreatment of human monocyte-derived DCs with resveratrol prevents DC activation in response to glucose-treated albumin (AGE-albumin). We found that resveratrol exerts an inhibitory effect on DC surface maturation marker and RAGE up-regulation in response to AGE-albumin. It also inhibited proinflammatory cytokine expression, allostimulatory ability upregulation, mitogen-activated protein (MAP) kinases, and NF-κB activation in AGE-albumin-stimulated DCs. We suggest that resveratrol, by dismantling AGE/RAGE signaling on DCs may prevent or reduce increased reactivity to self-molecules in aging.
An Eigenvalue-Eigenvector Method for Solving a System of Fractional Differential Equations with Uncertainty
Authors: Shahriyar M. R. Balooch , Ismail F. , Aghabeigi S. , Ahmadian A. , Salahshour S.
Published: July 2013

A new method is proposed for solving systems of fuzzy fractional differential equations (SFFDEs) with fuzzy initial conditions involving fuzzy Caputo differentiability. For this purpose, three cases are introduced based on the eigenvalue-eigenvector approach; then it is shown that the solution of system of fuzzy fractional differential equations is vector of fuzzy-valued functions. Then the method is validated by solving several examples.
PLD Grown Polycrystalline Tungsten Disulphide (WS2) Films
Authors: Alfihed Salman , Hossain Mohammad , Alharbi Abdulaziz , Alyamani Ahmed , Alharbi Fahhad H.
Published: July 2013

Polycrystalline WS2 films were grown by pulsed laser deposition (PLD) system at relatively low temperature. The main objective of this study is to optimize the growth conditions for polycrystalline WS2 films at relatively low temperature to use them for photovoltaics (PVs). Different growth conditions and substrates are used and examined systematically. It is found out that films grown on strontium titanate SrTiO3 (STO) substrate have the best structural properties when compared to other substrates examined in this work. X-ray diffraction and optical characterizations of these films reveal crystallographic growth and very promising optical properties for PVs. Furthermore, it was observed that higher growth temperature (>300°C) has an unfavorable effect on the layers by creating some tungsten metallic droplets.
Immunity‐Based Optimal Estimation Approach for a New Real Time Group Elevator Dynamic Control Application for Energy and Time Saving
Authors: Baygin Mehmet , Karakose Mehmet
Published: July 2013

Nowadays, the increasing use of group elevator control systems owing to increasing building heights makes the development of high‐performance algorithms necessary in terms of time and energy saving. Although there are many studies in the literature about this topic, they are still not effective enough because they are not able to evaluate all features of system. In this paper, a new approach of immune system‐based optimal estimate is studied for dynamic control of group elevator systems. The method is mainly based on estimation of optimal way by optimizing all calls with genetic, immune system and DNA computing algorithms, and it is evaluated with a fuzzy system. The system has a dynamic feature in terms of the situation of calls and the option of the most appropriate algorithm, and it also adaptively works in terms of parameters such as the number of floors and cabins. This new approach which provides both time and energy saving was carried out in real time. The experimental results comparatively demonstrate the effects of method. With dynamic and adaptive control approach in this study carried out, a significant progress on group elevator control systems has been achieved in terms of time and energy efficiency according to traditional methods.
Stress and Temperature Sensitivity of Photonic Crystals Resonant Cavity
Authors: Li Yan , Zhao Xue , Li Xiao-li , Fu Hai-wei
Published: July 2013

The temperature and stress characteristic of photonic band gap structure resonant cavities with square and graphite lattice have been studied by finite‐difference time‐domain method. The results show that the resonant cavities, both square and graphite lattice, have more and more resonant frequency with the cavity enlarging. And the curves between the resonant frequency and stress have better linearity. When the cavity enlarges enough, the curve between resonant frequency and temperature will become sectionalized line from nonlinear curve. Especially, the temperature sensitivity will be descending as the cavity is enlarging. Nevertheless, once some structures are put in the center of the cavity, the temperature sensitivity will be rising fast for this kind of cavity. Obviously, this character is convenient for us to achieve the specification measurement for temperature and stress.