bluuebunny/crossref_metadata_2025 huggingface dataset:
Fatigue Properties of Cellulosic-Fiber Mat Reinforced Thermosetting Plastic Composites
Authors: Xiao Bing , Hojo Toshihiko , Hamada Hiroyuki , Yang Yuqiu
Published: February 2016

Natural fiber composite materials are expected as capable materials which may replace the conventional and synthetic materials for the practical applications where manufacture requires less weight and energy conservation. In this study, three kinds of cellulosic-fiber mats including kenaf, bamboo and jute mats were used to fabricate composites by hand lay-up and compression molding methods. As the basic investigation, low cycle fatigue tests were carried out to analyze the material’s fatigue properties by using different bending or tensile loads. Moreover, the scanning electron microscope observation (SEM) on the fracture surfaces has been carried out respectively to investigate the degradation under cycle loads and discuss the possibility of kenaf/bamboo/jute composites achieving hypothetical outstanding mechanical properties in engineering uses.
Development of a Synergistic Damage Mechanics-Based Model for Predicting Multiaxial Effects in Progressive Failure of Composite Structures
Authors: Montesano John , Singh Chandra Veer
Published: February 2016

A major benefit of advanced fiber-reinforced polymer composites is that they can be tailored and optimized to suit a particular structural application by orienting the reinforcing fibers along multiple directions. For practical load-bearing structural components manufactured from multidirectional laminates, predicting their mechanical behaviour is quite complex. This is specifically the case for progressive failure analysis of these materials when subjected to quasi-static or fatigue loading since local cracks will initiate and evolve in multiple directions simultaneously. The difficulty of the problem increases further when these laminates are subjected to complex multiaxial stress states. This is due to the fact that the multidirectional crack state will be subjected to additional crack driving stress components, which will ultimately alter the crack evolution characteristics. A synergistic damage mechanics (SDM) methodology has recently been developed to address these issues in progressive damage analyses of composite laminates containing multiple damage modes and subjected to uniaxial loading [1]. By combining micromechanics and continuum damage mechanics, the SDM methodology provides a rigorous and practical tool for accurate prediction of progressive damage behaviour in composite structures. This is essential for accurately predicting the integrity and durability of practical structures, which will lead to safer and more efficient designs.
Environmental Degradation Behavior of Kenaf Fiber Mat Composite
Authors: Liao Mengyuan , Hojo Toshihiko , Xian Guijun , Yang Yuqiu , Hamada Hiroyuki
Published: February 2016

Nowadays “eco-design” is becoming a philosophy to guide next generation of materials and products as global environmental issue produced by fossil fuels and resource overusing. With an industrial increasing interest in sustainable, eco-efficient and green material’s application, natural fiber in polymer composite is guided to develop rapidly. As well know that, natural fibers possess advantages over synthetic or manmade fibers due to its abundance, biodegradability, CO2 neutrality, excellent price/performance ratio and comparable specific strength properties. However, outdoor applications of natural fiber composite are still constrained and raising concerns in terms of their durability, including UV resistance, moisture resistance and extreme temperature withstand and dimensional stability. Continuing with previous research on kenaf non-woven reinforced unsaturated polyester composites three months degradation performance, in order to get a good knowledge of its degradation process/cycle in complicated outdoor environments, longer degradation periods up to 6 months and 12 months in this paper were added for further investigation and comparison. Initially, three sets of kenaf fiber mat composite samples were located in extreme cold temperature (Harbin), mild sea climate Kyoto (Japan), subtropical marine monsoon climate Shanghai (China) and tropical monsoon climate Zaria (Nigeria) respectively from the same starting time until predetermined ageing periods, afterwards weight change and mechanical behavior in terms of tensile, flexural, impact and fracture toughness were measured instrumentally for ageing effect discussion and comparison. As expected, the aged specimens in those different positions all showed the dropped mechanical properties with increasing ageing periods. Furthermore, the trend of degradation in various mechanical parameters was established, which demonstrated weight loss made more serious effect on aged sample’s mechanical properties’ reduction than water absorption behavior. In a word, dropped mechanical properties of the degraded composites accompanied with weight change behavior were clarified, in which degradation phenomenon of embrittled the matrix polymer, deteriorated reinforced fiber and interfacial properties were detected.
Wind dependence of ambient noise in a biologically rich coastal area
Authors: Mathias Delphine , Gervaise Cédric , Di Iorio Lucia
Published: February 2016

The wind dependence of acoustic spectrum between 100 Hz and 16 kHz is investigated for coastal biologically rich areas. The analysis of 5 months of continuous measurements run in a 10 m deep shallow water environment off Brittany (France) showed that wind dependence of spectral levels is subject to masking by biological sounds. When dealing with raw data, the wind dependence of spectral levels was not significant for frequencies where biological sounds were present (2 to 10 kHz). An algorithm developed by Kinda, Simard, Gervaise, Mars, and Fortier [J. Acoust. Soc. Am. 134(1), 77–87 (2013)] was used to automatically filter out the loud distinctive biological contribution and estimated the ambient noise spectrum. The wind dependence of ambient noise spectrum was always significant after application of this filter. A mixture model for ambient noise spectrum which accounts for the richness of the soundscape is proposed. This model revealed that wind dependence holds once the wind speed was strong enough to produce sounds higher in amplitude than the biological chorus (9 kn at 3 kHz, 11 kn at 8 kHz). For these higher wind speeds, a logarithmic affine law was adequate and its estimated parameters were compatible with previous studies (average slope 27.1 dB per decade of wind speed increase).
Clofazimine Inhibits the Growth of Babesia and Theileria Parasites
In Vitro
and
In Vivo
Authors: Tuvshintulga Bumduuren , AbouLaila Mahmoud , Davaasuren Batdorj , Ishiyama Aki , Sivakumar Thillaiampalam , Yokoyama Naoaki , Iwatsuki Masato , Otoguro Kazuhiko , Ōmura Satoshi , Igarashi Ikuo
Published: February 2016

The present study evaluated the growth-inhibitory effects of clofazimine, currently used for treating leprosy, against
Babesia bovis
,
B. bigemina
,
B. caballi
, and
Theileria equi
in
in vitro
culture and against
Babesia microti
in mice. The 50% inhibitory concentrations (IC
50
s) of clofazimine against the
in vitro
growth of
B. bovis
,
B. bigemina
,
B. caballi
, and
T. equi
were 4.5, 3, 4.3, and 0.29 μM, respectively. In mice infected with
B. microti
, treatment with 20 mg/kg of body weight of clofazimine administered orally resulted in a significantly lower peak parasitemia (5.3%) than that in the control group (45.9%), which was comparable to the subcutaneous administration of 25 mg/kg diminazene aceturate, the most widely used treatment for animal piroplasmosis. Although slight anemia was observed in both clofazimine- and diminazene aceturate-treated infected mice, the level and duration of anemia were lower and shorter, respectively, than those in untreated infected mice. Using blood transfusions and PCR, we also examined whether clofazimine completely killed
B. microti
. On day 40 postinfection, when blood analysis was performed, parasites were not found in blood smears; however, the DNA of
B. microti
was detected in the blood of clofazimine-treated animals and in several tissues of clofazimine- and diminazene aceturate-treated mice by PCR. The growth of parasites was observed in mice after blood transfusions from clofazimine-treated mice. In conclusion, clofazimine showed excellent inhibitory effects against
Babesia
and
Theileria in vitro
and
in vivo
, and further study on clofazimine is required for the future development of a novel chemotherapy with high efficacy and safety against animal piroplasmosis and, possibly, human babesiosis.
Longitudinal Analysis of the Effect of Inflammation on Voriconazole Trough Concentrations
Authors: Encalada Ventura M. A. , van Wanrooy M. J. P. , Span L. F. R. , Rodgers M. G. G. , van den Heuvel E. R. , Uges D. R. A. , van der Werf T. S. , Kosterink J. G. W. , Alffenaar J. W. C.
Published: February 2016

Voriconazole (VCZ) exhibits great inter- and intrapatient variability. The latter variation cannot exclusively be explained by concomitant medications, liver disease or dysfunction, and genetic polymorphisms in cytochrome P450 2C19 (CYP2C19). We hypothesized that inflammatory response in patients under VCZ medication might also influence this fluctuation in concentrations. In this study, we explored the association between inflammation, reflected by the C-reactive protein (CRP) concentration, and VCZ trough concentrations over time. A retrospective analysis of data was performed for patients with more than one steady-state VCZ trough concentration and a CRP concentration measured on the same day. A longitudinal analysis was used for series of observations obtained from many study participants over time. The approach involved inclusion of random effects and autocorrelation in linear models to reflect within-person cross-time correlation. A total of 50 patients were eligible for the study, resulting in 139 observations (paired VCZ and CRP concentrations) for the analysis, ranging from 2 to 6 observations per study participant. Inflammation, marked by the CRP concentration, had a significant association with VCZ trough concentrations (
P
< 0.001). Covariates such as age and interacting comedication ([es]omeprazole), also showed a significant correlation between VCZ and CRP concentrations (
P
< 0.05). The intrapatient variation of trough concentrations of VCZ was 1.401 (confidence interval [CI], 0.881 to 2.567), and the interpatient variation was 1.756 (CI, 0.934 to 4.440). The autocorrelation between VCZ trough concentrations at two sequential time points was calculated at 0.71 (CI, 0.51 to 0.92). The inflammatory response appears to play a significant role in the largely unpredictable pharmacokinetics of VCZ, especially in patients with high inflammatory response, as reflected by high CRP concentrations.
Network Analysis of Sequence-Function Relationships and Exploration of Sequence Space of TEM β-Lactamases
Authors: Zeil Catharina , Widmann Michael , Fademrecht Silvia , Vogel Constantin , Pleiss Jürgen
Published: February 2016

The Lactamase Engineering Database (
www.LacED.uni-stuttgart.de
) was developed to facilitate the classification and analysis of TEM β-lactamases. The current version contains 474 TEM variants. Two hundred fifty-nine variants form a large scale-free network of highly connected point mutants. The network was divided into three subnetworks which were enriched by single phenotypes: one network with predominantly 2be and two networks with 2br phenotypes. Fifteen positions were found to be highly variable, contributing to the majority of the observed variants. Since it is expected that a considerable fraction of the theoretical sequence space is functional, the currently sequenced 474 variants represent only the tip of the iceberg of functional TEM β-lactamase variants which form a huge natural reservoir of highly interconnected variants. Almost 50% of the variants are part of a quartet. Thus, two single mutations that result in functional enzymes can be combined into a functional protein. Most of these quartets consist of the same phenotype, or the mutations are additive with respect to the phenotype. By predicting quartets from triplets, 3,916 unknown variants were constructed. Eighty-seven variants complement multiple quartets and therefore have a high probability of being functional. The construction of a TEM β-lactamase network and subsequent analyses by clustering and quartet prediction are valuable tools to gain new insights into the viable sequence space of TEM β-lactamases and to predict their phenotype. The highly connected sequence space of TEM β-lactamases is ideally suited to network analysis and demonstrates the strengths of network analysis over tree reconstruction methods.
Serological Conservation of Parasite-Infected Erythrocytes Predicts Plasmodium falciparum Erythrocyte Membrane Protein 1 Gene Expression but Not Severity of Childhood Malaria
Authors: Warimwe George M. , Abdi Abdirahman I. , Muthui Michelle , Fegan Gregory , Musyoki Jennifer N. , Marsh Kevin , Bull Peter C.
Published: February 2016

Plasmodium falciparum
erythrocyte membrane protein 1 (PfEMP1), expressed on
P. falciparum-
infected erythrocytes, is a major family of clonally variant targets of naturally acquired immunity to malaria. Previous studies have demonstrated that in areas where malaria is endemic, antibodies to infected erythrocytes from children with severe malaria tend to be more seroprevalent than antibodies to infected erythrocytes from children with nonsevere malaria. These data have led to a working hypothesis that PfEMP1 variants associated with parasite virulence are relatively conserved in structure. However, the longevity of such serologically conserved variants in the parasite population is unknown. Here, using infected erythrocytes from recently sampled clinical
P. falciparum
samples, we measured serological conservation using pools of antibodies in sera that had been sampled 10 to 12 years earlier. The serological conservation of infected erythrocytes strongly correlated with the expression of specific PfEMP1 subsets previously found to be associated with severe malaria. However, we found no association between serological conservation
per se
and disease severity within these data. This contrasts with the simple hypothesis that
P. falciparum
isolates with a serologically conserved group of PfEMP1 variants cause severe malaria. The data are instead consistent with periodic turnover of the immunodominant epitopes of PfEMP1 associated with severe malaria.
The Yersiniabactin-Associated ATP Binding Cassette Proteins YbtP and YbtQ Enhance Escherichia coli Fitness during High-Titer Cystitis
Authors: Koh Eun-Ik , Hung Chia S. , Henderson Jeffrey P.
Published: February 2016

The
Yersinia
high-pathogenicity island (HPI) is common to multiple virulence strategies used by
Escherichia coli
strains associated with urinary tract infection (UTI). Among the genes in this island are
ybtP
and
ybtQ
, encoding distinctive ATP binding cassette (ABC) proteins associated with iron(III)-yersiniabactin import in
Yersinia pestis
. In this study, we compared the impact of
ybtPQ
on a model
E. coli
cystitis strain during
in vitro
culture and experimental murine infections. A
ybtPQ
-null mutant exhibited no growth defect under standard culture conditions, consistent with nonessentiality in this background. A growth defect phenotype was observed and genetically complemented
in vitro
during iron(III)-yersiniabactin-dependent growth. Following inoculation into the bladders of C3H/HEN and C3H/HeOuJ mice, this strain exhibited a profound, 10
6
-fold competitive infection defect in the subgroup of mice that progressed to high-titer bladder infections. These results identify a virulence role for YbtPQ in the highly inflammatory microenvironment characteristic of high-titer cystitis. The profound competitive defect may relate to the apparent selection of
Yersinia
HPI-positive
E. coli
in uncomplicated clinical UTIs.
Susceptibility to Ticks and Lyme Disease Spirochetes Is Not Affected in Mice Coinfected with Nematodes
Authors: Maaz Denny , Rausch Sebastian , Richter Dania , Krücken Jürgen , Kühl Anja A. , Demeler Janina , Blümke Julia , Matuschka Franz-Rainer , von Samson-Himmelstjerna Georg , Hartmann Susanne
Published: February 2016

Small rodents serve as reservoir hosts for tick-borne pathogens, such as the spirochetes causing Lyme disease. Whether natural coinfections with other macroparasites alter the success of tick feeding, antitick immunity, and the host's reservoir competence for tick-borne pathogens remains to be determined. In a parasitological survey of wild mice in Berlin, Germany, approximately 40% ofIxodes ricinus-infested animals simultaneously harbored a nematode of the genusHeligmosomoides. We therefore aimed to analyze the immunological impact of the nematode/tick coinfection as well as its effect on the tick-borne pathogenBorrelia afzelii. Hosts experimentally coinfected withHeligmosomoides polygyrusand larval/nymphalI. ricinusticks developed substantially stronger systemic type 2 T helper cell (Th2) responses, on the basis of the levels of GATA-3 and interleukin-13 expression, than mice infected with a single pathogen. During repeated larval infestations, however, anti-tick Th2 reactivity and an observed partial immunity to tick feeding were unaffected by concurrent nematode infections. Importantly, the strong systemic Th2 immune response in coinfected mice did not affect susceptibility to tick-borneB. afzelii. An observed trend for decreased local and systemic Th1 reactivity againstB. afzeliiin coinfected mice did not result in a higher spirochete burden, nor did it facilitate bacterial dissemination or induce signs of immunopathology. Hence, this study indicates that strong systemic Th2 responses in nematode/tick-coinfected house mice do not affect the success of tick feeding and the control of the causative agent of Lyme disease.
Contributions of Sinorhizobium meliloti Transcriptional Regulator DksA to Bacterial Growth and Efficient Symbiosis with Medicago sativa
Authors: Wippel Kathrin , Long Sharon R.
Published: February 2016

The stringent response, mediated by the (p)ppGpp synthetase RelA and the RNA polymerase-binding protein DksA, is triggered by limiting nutrient conditions. For some bacteria, it is involved in regulation of virulence. We investigated the role of two DksA-like proteins from the Gram-negative nitrogen-fixing symbiont
Sinorhizobium meliloti
in free-living culture and in interaction with its host plant
Medicago sativa
. The two paralogs, encoded by the genes
SMc00469
and
SMc00049
, differ in the constitution of two major domains required for function in canonical DksA: the DXXDXA motif at the tip of a coiled-coil domain and a zinc finger domain. Using mutant analyses of single, double, and triple deletions for
SMc00469
(designated
dksA
),
SMc00049
, and
relA
, we found that the Δ
dksA
mutant but not the Δ
SMc00049
mutant showed impaired growth on minimal medium, reduced nodulation on the host plant, and lower nitrogen fixation activity in early nodules, while its
nod
gene expression was normal. The Δ
relA
mutant showed severe pleiotropic phenotypes under all conditions tested. Only
S. meliloti
dksA
complemented the metabolic defects of an
Escherichia coli dksA
mutant. Modifications of the DXXDXA motif in SMc00049 failed to establish DksA function. Our results imply a role for transcriptional regulator DksA in the
S. meliloti-M. sativa
symbiosis.

IMPORTANCE
The stringent response is a bacterial transcription regulation process triggered upon nutritional stress.
Sinorhizobium meliloti
, a soil bacterium establishing agriculturally important root nodule symbioses with legume plants, undergoes constant molecular adjustment during host interaction. Analyzing the components of the stringent response in this alphaproteobacterium helps understand molecular control regarding the development of plant interaction. Using mutant analyses, we describe how the lack of DksA influences symbiosis with
Medicago sativa
and show that a second paralogous
S. meliloti
protein cannot substitute for this missing function. This work contributes to the field by showing the similarities and differences of
S. meliloti
DksA-like proteins to orthologs from other species, adding information to the diversity of the stringent response regulatory system.
Formate Metabolism in Shewanella oneidensis Generates Proton Motive Force and Prevents Growth without an Electron Acceptor
Authors: Kane Aunica L. , Brutinel Evan D. , Joo Heena , Maysonet Rebecca , VanDrisse Chelsey M. , Kotloski Nicholas J. , Gralnick Jeffrey A.
Published: February 2016

Shewanella oneidensisstrain MR-1 is a facultative anaerobe that thrives in redox-stratified environments due to its ability to utilize a wide array of terminal electron acceptors. Conversely, the electron donors utilized byS. oneidensisare more limited and include products of primary fermentation such as lactate, pyruvate, formate, and hydrogen. Lactate, pyruvate, and hydrogen metabolisms inS. oneidensishave been described previously, but little is known about the role of formate oxidation in the ecophysiology of these bacteria. Formate is produced byS. oneidensisthrough pyruvate formate lyase during anaerobic growth on carbon sources that enter metabolism at or above the level of pyruvate, and the genome contains three gene clusters predicted to encode three complete formate dehydrogenase complexes. To determine the contribution of each complex to formate metabolism, strains lacking one, two, or all three annotated formate dehydrogenase gene clusters were generated and examined for growth rates and yields on a variety of carbon sources. Here, we report that formate oxidation contributes to both the growth rate and yield ofS. oneidensisthrough the generation of proton motive force. Exogenous formate also greatly accelerated growth onN-acetylglucosamine, a carbon source normally utilized very slowly byS. oneidensisunder anaerobic conditions. Surprisingly, deletion of all three formate dehydrogenase gene clusters enabled growth ofS. oneidensisusing pyruvate in the absence of a terminal electron acceptor, a mode of growth never before observed in these bacteria. Our results demonstrate that formate oxidation is a fundamental strategy under anaerobic conditions for energy conservation inS. oneidensis.

IMPORTANCEShewanellaspecies have garnered interest in biotechnology applications for their ability to respire extracellular terminal electron acceptors, such as insoluble iron oxides and electrodes. While much effort has gone into studying the proteins for extracellular electron transport, how electrons generated through the oxidation of organic carbon sources enter this pathway remains understudied. Here, we quantify the role of formate oxidation in the anaerobic physiology ofShewanella oneidensis. Formate oxidation contributes to both the growth rate and yield on a variety of carbon sources through the generation of proton motive force. Advances in our understanding of the anaerobic metabolism ofS. oneidensisare important for our ability to utilize and engineer this organism for applications in bioenergy, biocatalysis, and bioremediation.
Mycobacterium tuberculosis Transcription Machinery: Ready To Respond to Host Attacks
Authors: Flentie Kelly , Garner Ashley L. , Stallings Christina L.
Published: February 2016

Regulating responses to stress is critical for all bacteria, whether they are environmental, commensal, or pathogenic species. For pathogenic bacteria, successful colonization and survival in the host are dependent on adaptation to diverse conditions imposed by the host tissue architecture and the immune response. Once the bacterium senses a hostile environment, it must enact a change in physiology that contributes to the organism's survival strategy. Inappropriate responses have consequences; hence, the execution of the appropriate response is essential for survival of the bacterium in its niche. Stress responses are most often regulated at the level of gene expression and, more specifically, transcription. This minireview focuses on mechanisms of regulating transcription initiation that are required by
Mycobacterium tuberculosis
to respond to the arsenal of defenses imposed by the host during infection. In particular, we highlight how certain features of
M. tuberculosis
physiology allow this pathogen to respond swiftly and effectively to host defenses. By enacting highly integrated and coordinated gene expression changes in response to stress,
M. tuberculosis
is prepared for battle against the host defense and able to persist within the human population.
Functional Dissection of the CroRS Two-Component System Required for Resistance to Cell Wall Stressors in Enterococcus faecalis
Authors: Kellogg Stephanie L. , Kristich Christopher J.
Published: February 2016

Bacteria use two-component signal transduction systems (TCSs) to sense and respond to environmental changes via a conserved phosphorelay between a sensor histidine kinase and its cognate response regulator. The opportunistic pathogen
Enterococcus faecalis
utilizes a TCS comprised of the histidine kinase CroS and the response regulator CroR to mediate resistance to cell wall stresses such as cephalosporin antibiotics, but the molecular details by which CroRS promotes cephalosporin resistance have not been elucidated. Here, we analyzed mutants of
E. faecalis
carrying substitutions in CroR and CroS to demonstrate that phosphorylated CroR drives resistance to cephalosporins, and that CroS exhibits kinase and phosphatase activities to control the level of CroR phosphorylation
in vivo
. Deletion of
croS
in various lineages of
E. faecalis
revealed a CroS-independent mechanism for CroR phosphorylation and led to the identification of a noncognate histidine kinase capable of influencing CroR (encoded by
OG1RF_12162
; here called
cisS
). Further analysis of this TCS network revealed that both systems respond to cell wall stress.

IMPORTANCE
TCSs allow bacteria to sense and respond to many different environmental conditions. The opportunistic pathogen
Enterococcus faecalis
utilizes the CroRS TCS to mediate resistance to cell wall stresses, including clinically relevant antibiotics such as cephalosporins and glycopeptides. In this study, we use genetic and biochemical means to investigate the relationship between CroRS signaling and cephalosporin resistance in
E. faecalis
cells. Through this, we uncovered a signaling network formed between the CroRS TCS and a previously uncharacterized TCS that also responds to cell wall stress. This study provides mechanistic insights into CroRS signaling and cephalosporin resistance in
E. faecalis
.
Bacterial Cysteine-Inducible Cysteine Resistance Systems
Authors: Takumi Kazuhiro , Nonaka Gen
Published: February 2016

Cysteine donates sulfur to macromolecules and occurs naturally in many proteins. Because low concentrations of cysteine are cytotoxic, its intracellular concentration is stringently controlled. In bacteria, cysteine biosynthesis is regulated by feedback inhibition of the activities of serine acetyltransferase (SAT) and 3-phosphoglycerate dehydrogenase (3-PGDH) and is also regulated at the transcriptional level by inducing the cysteine regulon using the master regulator CysB. Here, we describe two novel cysteine-inducible systems that regulate the cysteine resistance of
Pantoea ananatis
, a member of the family
Enterobacteriaceae
that shows great potential for producing substances useful for biotechnological, medical, and industrial purposes. One locus, designated
ccdA
(formerly PAJ_0331), encodes a novel cysteine-inducible cysteine desulfhydrase (CD) that degrades cysteine, and its expression is controlled by the transcriptional regulator encoded by
ccdR
(formerly PAJ_0332 or
ybaO
), located just upstream of
ccdA
. The other locus, designated
cefA
(formerly PAJ_3026), encodes a novel cysteine-inducible cysteine efflux pump that is controlled by the transcriptional regulator
cefR
(formerly PAJ_3027), located just upstream of
cefA
. To our knowledge, this is the first example where the expression of CD and an efflux pump is regulated in response to cysteine and is directly involved in imparting resistance to excess levels of cysteine. We propose that
ccdA
and
cefA
function as safety valves that maintain homeostasis when the intra- or extracellular cysteine concentration fluctuates. Our findings contribute important insights into optimizing the production of cysteine and related biomaterials by
P. ananatis
.

IMPORTANCE
Because of its toxicity, the bacterial intracellular cysteine level is stringently regulated at biosynthesis. This work describes the identification and characterization of two novel cysteine-inducible systems that regulate, through degradation and efflux, the cysteine resistance of
Pantoea ananatis
, a member of the family
Enterobacteriaceae
that shows great potential for producing substances useful for industrial purposes. We propose that this novel mechanism for sensing and regulating cysteine levels is a safety valve enabling adaptation to sudden changes in intra- or extracellular cysteine levels in bacteria. Our findings provide important insights into optimizing the production of cysteine and related biomaterials by
P. ananatis
and also a deep understanding of sulfur/cysteine metabolism and regulation in this plant pathogen and related bacteria.
Fit to WHO weight standard of European infants over time
Authors: Levin Daniel , Marryat Louise , Cole Tim J , McColl John , Harjunmaa Ulla , Ashorn Per , Wright Charlotte
Published: February 2016

Objectives

The 2006 WHO growth charts were created to provide an international standard for optimal growth, based on healthy, breastfed populations, but it has been suggested that Northern European children fit them poorly. This study uses infant weight data spanning 50 years to determine how well-nourished preschool children from different eras fit the WHO standard, and discuss the implications of deviations.

Design

Four longitudinal datasets from the UK and one from Finland were used comprising over 8000 children born between1959 and 2003. Weights from birth to 2 years were converted to age–sex-adjusted Z scores using the WHO standard and summarised using Generalized Additive Models for Location, Scale and Shape.

Results

Weights showed a variable fit to the WHO standard. Mean weights for all cohorts were above the WHO median at birth, but dipped by up to 0.5 SD to a nadir at 8 weeks before rising again. Birth weights increased in successive cohorts and the initial dip became slightly shallower. By age 1 year, cohorts were up to 0.75 SD above the WHO median, but there was no consistent pattern by era.

Conclusions

The WHO standard shows an acceptable, but variable fit for Northern European infants. While birth weights increased over time, there was, unexpectedly, no consistent variation by cohort beyond this initial period. Discrepancies in weight from the standard may reflect differences in measurement protocol and trends in infant feeding practice.
Capillary haemangioma on the palate: a diagnostic conundrum
Authors: Singh Pooja , Parihar Anuj Singh , Siddique Sana Noor , Khare Pooja
Published: February 2016

Haemangiomas are benign tumours of blood vessel origin and are classified as capillary, cavernous or central. They appear as flat or raised reddish-blue lesions and are generally solitary, affecting women in younger age groups. The tumour may be slowly progressive, involving extensive portions of the superficial and deep blood vessels, and affect function, depending on location. They are common in the head and neck region but rarely in the oral cavity. Oral lesions generally appear on the lips, buccal mucosa and tongue, but rarely on the palate. As the lesion can be confused with pyogenic granuloma, histopathological examination is important for a final diagnosis. The case presented here signifies a rare location of a capillary haemangioma on the palate in a middle aged man. The lesion was diagnosed by histopathology after surgical excision.
Sports injuries and illnesses during the 2015 Winter European Youth Olympic Festival
Authors: Ruedl G , Schnitzer M , Kirschner W , Spiegel R , Platzgummer H , Kopp M , Burtscher M , Pocecco E
Published: February 2016

Background

The prevention of injury and illness remains an important issue among young elite athletes. Systematic surveillance of injuries and illnesses during multi-sport events might provide a valuable basis to develop preventive measures, focusing especially on adequate information for youth athletes.

Aim

To analyse the frequencies and characteristics of injuries and illnesses during the 2015 Winter European Youth Olympic Festival (W-EYOF).

Methods

All National Olympic Committees were asked to report daily the occurrence or non-occurrence of newly sustained injuries and illnesses on a standardised reporting form.

Results

Among the 899 registered athletes (37% female) with a mean age of 17.1±0.8 years, a total of 38 injuries and 34 illnesses during the 5 competition days of the W-EYOF were reported, resulting in an incidence of 42.3 injuries and 37.8 illnesses per 1000 athletes, respectively. Injury frequency was highest in snowboard cross (11%), Nordic combined (9%), alpine skiing (6%), and ice hockey (6%), taking into account the respective number of registered athletes. In snowboard cross, females showed a significant higher injury frequency compared to males (22% vs 4%, p=0.033). The lower back (16%), the pelvis (13%), the knee (11%), and the face (11%) were the most common injury locations. About 58% of injuries occurred in competition and about 42% in training. In total, 42% of injuries resulted in an absence of training or competition. The prevalence of illness was highest in figure skating (10%) and Nordic combined (9%), and the respiratory system was affected most often (53%).

Conclusions

Four per cent of the athletes suffered from an injury and 4% from illnesses during the 2015 W-EYOF, which is about twofold lower compared to the first Winter Youth Olympic Games in 2012.
Using kernel density estimation to understand the influence of neighbourhood destinations on BMI
Authors: King Tania L , Bentley Rebecca J , Thornton Lukar E , Kavanagh Anne M
Published: February 2016

Objectives

Little is known about how the distribution of destinations in the local neighbourhood is related to body mass index (BMI). Kernel density estimation (KDE) is a spatial analysis technique that accounts for the location of features relative to each other. Using KDE, this study investigated whether individuals living near destinations (shops and service facilities) that are more intensely distributed rather than dispersed, have lower BMIs.

Study design and setting

A cross-sectional study of 2349 residents of 50 urban areas in metropolitan Melbourne, Australia.

Methods

Destinations were geocoded, and kernel density estimates of destination intensity were created using kernels of 400, 800 and 1200 m. Using multilevel linear regression, the association between destination intensity (classified in quintiles Q1(least)–Q5(most)) and BMI was estimated in models that adjusted for the following confounders: age, sex, country of birth, education, dominant household occupation, household type, disability/injury and area disadvantage. Separate models included a physical activity variable.

Results

For kernels of 800 and 1200 m, there was an inverse relationship between BMI and more intensely distributed destinations (compared to areas with least destination intensity). Effects were significant at 1200 m: Q4, β −0.86, 95% CI −1.58 to −0.13, p=0.022; Q5, β −1.03 95% CI −1.65 to −0.41, p=0.001. Inclusion of physical activity in the models attenuated effects, although effects remained marginally significant for Q5 at 1200 m: β −0.77 95% CI −1.52, −0.02, p=0.045.

Conclusions

This study conducted within urban Melbourne, Australia, found that participants living in areas of greater destination intensity within 1200 m of home had lower BMIs. Effects were partly explained by physical activity. The results suggest that increasing the intensity of destination distribution could reduce BMI levels by encouraging higher levels of physical activity.
SCALS: a fourth-generation study of assisted living technologies in their organisational, social, political and policy context
Authors: Greenhalgh Trisha , Shaw Sara , Wherton Joe , Hughes Gemma , Lynch Jenni , A'Court Christine , Hinder Sue , Fahy Nick , Byrne Emma , Finlayson Alexander , Sorell Tom , Procter Rob , Stones Rob
Published: February 2016

Introduction

Research to date into assisted living technologies broadly consists of 3 generations: technical design, experimental trials and qualitative studies of the patient experience. We describe a fourth-generation paradigm: studies of assisted living technologies in their organisational, social, political and policy context. Fourth-generation studies are necessarily organic and emergent; they view technology as part of a dynamic, networked and potentially unstable system. They use co-design methods to generate and stabilise local solutions, taking account of context.

Methods and analysis

SCALS (Studies in Co-creating Assisted Living Solutions) consists (currently) of 5 organisational case studies, each an English health or social care organisation striving to introduce technology-supported services to support independent living in people with health and/or social care needs. Treating these cases as complex systems, we seek to explore interdependencies, emergence and conflict. We employ a co-design approach informed by the principles of action research to help participating organisations establish, refine and evaluate their service. To that end, we are conducting in-depth ethnographic studies of people's experience of assisted living technologies (micro level), embedded in evolving organisational case studies that use interviews, ethnography and document analysis (meso level), and exploring the wider national and international context for assisted living technologies and policy (macro level). Data will be analysed using a sociotechnical framework developed from structuration theory.

Ethics and dissemination

Research ethics approval for the first 4 case studies has been granted. An important outcome will be lessons learned from individual co-design case studies. We will document the studies’ credibility and rigour, and assess the transferability of findings to other settings while also recognising unique aspects of the contexts in which they were generated. Academic outputs will include a cross-case analysis and progress in theory and method of fourth-generation assisted living technology research. We will produce practical guidance for organisations, policymakers, designers and service users.
HIV counselling and testing practices for children seen in an urban emergency department of a tertiary referral hospital in Dar es Salaam, Tanzania: a retrospective cross-sectional study
Authors: Sawe Hendry R , Mfinanga Juma A , Ringo Faith H , Mwafongo Victor , Reynolds Teri A , Runyon Michael S
Published: February 2016

Objectives

To describe the HIV counselling and testing practices for children presenting to an emergency department (ED) in a low-income country.

Setting

The ED of a large east African national referral hospital.

Participants

This retrospective review of all paediatric (<18 years old) ED visits in 2012 enrolled patients who had an HIV test ordered and excluded those without testing. Files were available for 5540/5774 (96%) eligible patients and 1632 (30%) were tested for HIV, median age 1.3 years (IQR 9 months to 4 years), 58% <18 months old and 61% male.

Primary and secondary outcome measures

The primary outcome measure was documentation of pretest and post-test counselling, or deferral of counselling, for children tested for HIV in the ED. Secondary measures included the overall rate of HIV testing, rate of counselling documented in the inpatient record when deferred in the ED, rate of counselling documented when testing was initiated by the inpatient service, rate of counselling documented by test result (positive vs negative) and the rate of referral to follow-up HIV care among patients testing positive.

Results

Of 418 patients tested in the ED, counselling, or deferral of counselling, was documented for 70 (17%). When deferred to the ward, subsequent counselling was documented for 15/42 (36%). Counselling was documented in 33% of patients testing positive versus 1.1% patients testing negative (OR 43 (95% CI 23 to 83). Of 199 patients who tested positive and survived to hospital discharge, 76 (38%) were referred for follow-up at the HIV clinic on discharge.

Conclusions

Physicians documented the provision, or deferral, of counselling for <20% of children tested for HIV in the ED. Counselling was much more likely to be documented when the test result was positive. Less than 40% of those testing positive were referred for follow-up care.
Impact of conflict on medical education: a cross-sectional survey of students and institutions in Iraq
Authors: Barnett-Vanes Ashton , Hassounah Sondus , Shawki Marwan , Ismail Omar Abdulkadir , Fung Chi , Kedia Tara , Rawaf Salman , Majeed Azeem
Published: February 2016

Objective

This study surveyed all Iraqi medical schools and a cross-section of Iraqi medical students regarding their institutional and student experiences of medical education amidst ongoing conflict. The objective was to better understand the current resources and challenges facing medical schools, and the impacts of conflict on the training landscape and student experience, to provide evidence for further research and policy development.

Setting

Deans of all Iraqi medical schools registered in the World Directory of Medical Schools were invited to participate in a survey electronically. Medical students from three Iraqi medical schools were invited to participate in a survey electronically.

Outcomes

Primary: Student enrolment and graduation statistics; human resources of medical schools; dean perspectives on impact of conflict. Secondary: Medical student perspectives on quality of teaching, welfare and future career intentions.

Findings

Of 24 medical schools listed in the World Directory of Medical Schools, 15 replied to an initial email sent to confirm their contact details, and 8 medical schools responded to our survey, giving a response rate from contactable medical schools of 53% and overall of 33%. Five (63%) medical schools reported medical student educational attainment being impaired or significantly impaired; 4 (50%) felt the quality of training medical schools could offer had been impaired or significantly impaired due to conflict. A total of 197 medical students responded, 62% of whom felt their safety had been threatened due to violent insecurity. The majority (56%) of medical students intended to leave Iraq after graduating.

Conclusions

Medical schools are facing challenges in staff recruitment and adequate resource provision; the majority believe quality of training has suffered as a result. Medical students are experiencing added psychological stress and lower quality of teaching; the majority intend to leave Iraq after graduation.
Inpatient detection of cardiac-inherited disease: the impact of improving family history taking
Authors: Waddell-Smith Kathryn E , Donoghue Tom , Oates Stephanie , Graham Amanda , Crawford Jackie , Stiles Martin K , Aitken Andrew , Skinner Jonathan R
Published: February 2016

Objectives

‘Idiopathic’ cardiac conditions such as dilated cardiomyopathy (DCM) and resuscitated sudden cardiac death (RSCD) may be familial. We suspected that inpatient cardiology services fail to recognise this. Our objective was to compare diagnostic value of family histories recorded by inpatient cardiology teams with a multigenerational family tree obtained by specially trained allied professionals.

Methods

2 experienced cardiology nurses working in 2 tertiary adult cardiac units were trained in cardiac-inherited diseases and family history (FHx) taking, and established as regional coordinators for a National Cardiac Inherited Disease Registry. Over 6 months they sought ‘idiopathic’ cardiology inpatients with conditions with a possible familial basis, reviewed the FHx in the clinical records and pursued a minimum 3-generation family tree for syncope, young sudden death and cardiac disease (full FHx).

Results

37 patients (22 males) were selected: mean age 51 years (range 15–79). Admission presentations included (idiopathic) RSCD (14), dyspnoea or heart failure (11), ventricular tachycardia (2), other (10). 3 patients had already volunteered their familial diagnosis to the admitting team. FHx was incompletely elicited in 17 (46%) and absent in 20 (54%). 29 patients (78%) provided a full FHx to the coordinator; 12 of which (41%) were strongly consistent with a diagnosis of a cardiac-inherited disease (DCM 7, hypertrophic cardiomyopathy 3, long QT 1, left ventricular non-compaction 1). Overall, a familial diagnostic rate rose from 3/37(8%) to 12/37 (32%).

Conclusions

Adult cardiology inpatient teams are poor at recording FHx and need to be reminded of its powerful diagnostic value.
On partitions of G-spaces and G-lattices
Authors: Banakh Taras , Ravsky Oleksandr , Slobodianiuk Sergiy
Published: February 2016

Given a [Formula: see text]-space [Formula: see text] and a non-trivial [Formula: see text]-invariant ideal [Formula: see text] of subsets of [Formula: see text], we prove that for every partition [Formula: see text] of [Formula: see text] into [Formula: see text] pieces there is a piece [Formula: see text] of the partition and a finite set [Formula: see text] of cardinality [Formula: see text] such that [Formula: see text] where [Formula: see text] is the difference set of the set [Formula: see text]. Also we investigate the growth of the sequence [Formula: see text] and show that [Formula: see text] where [Formula: see text] is the Lambert [Formula: see text]-function, defined implicitly as [Formula: see text]. This shows that [Formula: see text] grows faster than that any exponent [Formula: see text] but slower than the sequence [Formula: see text] of factorials.
A Geometry Calibration Technique for Hydrophone Array with Sources in Near Field
Authors: Zou Nan , Wang Yan , Fu Jin , Liang Guolong
Published: February 2016

A new algorithm involving flank array geometry calibration under strong multipath conditions is proposed to address the problem of installation errors and the shell deformation. The derived linear mapping relationship between geometric error of sensors and signal eigenvector reduces the calculating difficulty in near calibration mode. By regarding the reflection as coherent visual sources in known position, the compensation strategy of strong multipath matching is put forward. Cramer–Rao bound (CRB) analysis for the calibration mode is employed. Numerical simulations and lake trials verify the efficiency of the proposed algorithm and illustrate the performance improvement under strong multipath conditions.
Methodology for the Design of the Geometry of a Cavity and Its Absorption Coefficients as Random Design Variables Under Vibroacoustic Criteria
Authors: Troian Renata , Shimoyama Koji , Gillot Frédéric , Besset Sébastien
Published: February 2016

Reducing the noise level in the acoustic cavities is the important problem when treating inflight conditions of commercial planes or boats. Shape optimization of the acoustic cavity that will take into account the geometrical and material uncertainties, arising during the manufacturing process, is presented in this paper. The noise level is controlled by minimizing the energy density in the cavity, obtained through an energy method called Simplified Energy Method. Such formulation is based on our previous published work where transformation function mapping 3D cavity surface on a 2D domain was proposed. The optimization process directly relies on this function and thus avoids remeshing of the geometry. Robust optimization is performed using the nondominated sorting genetic algorithm (NSGA-II) together with the Kriging surrogate model. Influence of geometrical and material characteristics on the optimal solution is identified.