bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of feeding complete feed block containing rumen protected protein, non‐protein nitrogen and rumen protected fat on improving body condition and carcass traits of cull ewes
Authors: Bhatt R. S. , Sahoo A.
Published: January 2017

Nutrient utilization, body condition and carcass traits of cull ewes were studied in three dietary regimens based on complete feed block (CFB) feeding to control (C) with rumen protected protein (RPP), CU [RPP + urea (6 g/kg)] and CUF [RPP + urea + rumen protected fat (RPF; 40 g/kg)]. The RPP component (g/kg) in C had 1% formaldehyde‐treated soy flakes 50, mustard cake 50 and sesame cake 30. The mustard and sesame cakes were replaced with urea on equivalent N basis in CU and CUF. The ewes were offered ad libitum CFB composed (g/kg) of concentrate 650, roughage 300 and molasses 50. The digestibility of OM and EE was higher (p < 0.05) in CUF than in CU and C, while that of NDF and ADF was lower (p < 0.05). The CP digestibility was higher in both CU and CUF. Utilization of N and Ca was higher (p < 0.05) in CUF compared with C and CU. Urinary purine derivatives analysis and microbial N synthesis were similar in all the groups. Blood glucose concentration improved at 90 day compared with 0 day. Ruminal attributes showed a higher (p < 0.05) pH, total N, TCA precipitable N, entodiniomorphs and total ciliate population in CU and CUF than in the control. The CUF had higher (p < 0.01) DM, digestible OM and ME intake, which resulted in higher (p < 0.05) weight gain and better feed efficiency. Ewes in all the groups showed an improvement in carcass traits at 90 day. The pre‐slaughter weight was higher (p < 0.05) and dissected and KOH bone content was lower in CUF. Thus, feeding of CFB with urea as a cheaper N source and RPF to enrich with energy supported the improved performance as evidenced from higher nutrient input, ‘utilization and efficiency with enhanced carcass traits’ for better marketability and returns from cull ewes.
Effects of feeding frequency on meat quality traits and Longissimus muscle proteome in finishing pigs
Authors: Liu J. B. , Cai X. , Xiong H. , Zhang H. F.
Published: January 2017

Sixty‐four barrows with an initial body weight of 59.8 ± 2.1 kg were allocated to one of the two feeding frequency regimes (had free access to diet and fed two meals per day). Pigs had free access (FA) to feed were fed on an ad libitum basis during the 8‐week experimental period. Pigs fed twice daily (M2) were allowed to consume their meals in 2 h. Pigs fed twice daily had lower average daily feed intake (p < 0.01) and average daily gain (p < 0.1), but a greater G:F (p < 0.05) than FA pigs. Lower perirenal fat deposition, hot carcass weight, intramuscular fat content (p < 0.05) and dressing percentage (p < 0.1) were found in M2 pigs compared with FA pigs. Activities of citrate synthase, β‐hydroxylacyl‐CoA dehydrogenase and lactate dehydrogenase were greater in the Longissimus muscle (LM) of M2 pigs compared with FA pigs (p < 0.05). Proteomic analysis revealed that expression abundances of proteins involved in glucose metabolism, energy production and lipid utilization were upregulated, but expression levels of proteins participating in protein and amino acid metabolism, stress response and redox homeostasis were downregulated in the LM of M2 pigs than those in FA pigs (p < 0.05). In conclusion, the less meal frequency impairs growth rate, has marginal effects on carcass and meat quality traits and affects expression abundances of proteins in the LM of finishing pigs.
Do occupational exposures to vinyl chloride cause hepatocellular carcinoma and cirrhosis?
Authors: Lotti Marcello
Published: January 2017

Controversy exists about the association between occupational exposures to vinyl chloride and hepatocellular carcinoma and cirrhosis. Two large multicentre mortality cohort studies, one American and another European, reported higher mortality for primary cancer of liver and biliary tract. However, the American study was not able to rule out misclassification, because based on death certificates and under the heading primary liver cancers, some angiosarcomas, the typical neoplasia associated with vinyl chloride, may have been included. The American study does not report on cirrhosis mortality. The European study also reports higher mortality of primary liver cancer, but contrary to the American study in a further analysis based on 10 verified cases of hepatocellular carcinoma, an exposure‐response trend with duration of employment and with cumulative exposure to vinyl chloride was detected. A smaller cohort belonging to this multicentre cohort confirmed these results. Meta‐analyses based on the two large cohorts concluded for a small excess of primary liver cancer, although misclassification could not be ruled out. Excess risk of cirrhosis was reported in the European cohort, in a subcohort and in a cross‐sectional study. However, a meta‐analysis did not confirm this excess. Several critical appraisals of the literature reached antithetical conclusions about hepatocellular carcinoma, cirrhosis and occupational exposures to vinyl chloride. For both hepatocellular carcinoma and cirrhosis, a study suggests an additive and multiplicative effect of vinyl chloride exposure with viral hepatitis and alcohol consumption respectively. Pathology reports seem to indicate a possible development of hepatocellular carcinoma but not of cirrhosis after high exposures to vinyl chloride.
Progress in the Study of Bioluminescent Earthworms
Authors: Rodionova Natalja S. , Rota Emilia , Tsarkova Aleksandra S. , Petushkov Valentin N.
Published: January 2017

Even though bioluminescent oligochaetes rarely catch people's eyes due to their secretive lifestyle, glowing earthworms sighting reports have come from different areas on all continents except Antarctica. A major breakthrough in the research of earthworm bioluminescence occurred in the 1960s with the studies of the North American Diplocardia longa. Comparative studies conducted on 13 earthworm species belonging to six genera showed that N‐isovaleryl‐3‐aminopropanal (Diplocardia luciferin) is the common substrate for bioluminescence in all examined species, while luciferases appeared to be responsible for the color of bioluminescence. The second momentous change in the situation has occurred with the discovery in Siberia (Russia) of two unknown luminous enchytraeids. The two bioluminescent systems belong to different types, have different spectral characteristics and localization, and different temperature and pH optima. They are unique, and this fact is confirmed by the negative results of all possible cross‐reactions. The bioluminescent system of Henlea sp. comprises four essential components: luciferase, luciferin, oxygen and calcium ion. For Friderica heliota, the luminescent reaction requires five components: luciferase, luciferin, ATP, magnesium ion and oxygen. Along with luciferin, more than a dozen analogues were isolated from worm biomass. These novel peptide‐like natural compounds represent an unprecedented chemistry found in terrestrial organisms.
Changes in Time Spent Outdoors During the Daytime in Rural Populations in Four Geographically Distinct Regions in China: A Retrospective Study
Authors: Gao Qian , Wang Fang , Hu Liwen , Yu Jiaming , Liu Rong , Wang Yang , Liu Yang
Published: January 2017

Changes in time‐activity patterns may influence personal exposure to various environmental factors and affect individual health. However, few studies have investigated the changes in patterns of time spent outdoors. To investigate the trends in outdoor activity in recent decades in China, a retrospective questionnaire was used to examine the amount and pattern of time spent outdoors during the day by 2076 subjects in four geographically distinct rural regions of China. Rural Chinese people spent less time outdoors than they used to because of the economic development, increase in education and changes in working conditions that occurred over time. Outdoor time was the shortest during the school stage of life (Sanya: 3.24–3.61; Shaoxing: 3.35–3.68; Lhasa: 4.37–4.54; Xiuyan: 2.94–3.26 h per day). Subjects in wealthy regions spent less time outdoors during their working stage of life. In the four regions in this study, the average daily times spent outdoors were 3–13% lower for subjects aged 40–59 years and 20–38% lower for those under 40 years compared to subjects aged 60 years and over. Certain health‐related issues, such as vitamin D deficiency, will become more prominent in China if this trend continues.
Challenges Faced by Pre-service Science Teachers during the Teaching and Learning Process in Turkey
Authors: Takaoğlu Zeynep Başkan
Published: January 2017

Pre-service teachers’ first experiences and ideas prior to application affect their teaching activities. For this reason, it is aimed to determine transferring the experiences and ideas of prospective science teachers before lesson activities and its development with lesson activities. The study was carried out with 29 third year prospective teachers who attended the course named Laboratory Application II and undergraduate students at the Department of Science Education at Karadeniz Technical University during 2012-2013 spring semesters. The study was conducted by case study design. Thirty-minute lesson activities were carried out by them. Reflective writings constituted by candidates, lesson observations and plans were used as data collecting tools. They were examined through inductive thematic analyze. When compared before and during lesson activities process, it was determined that pre-service teachers’ perception, ideas or application had changed at some concepts. This case might be a proof of development of pre service teachers’ professional skills doing practice.
Evaluation of Measurement Uncertainties for Pneumatic Multihole Probes Using a Monte Carlo Method
Authors: Hölle Magnus , Bartsch Christian , Jeschke Peter
Published: January 2017

The subject of this paper is a statistical method for the evaluation of the uncertainties for pneumatic multihole probe measurements. The method can be applied to different types of evaluation algorithms and is suitable for steady flow-field measurements in compressible flows. The evaluation of uncertainties is performed by a Monte Carlo method (MCM). Each calibration and measurement input quantity are randomly varied on the basis of its corresponding probability density function (PDF) and propagated through the deterministic parameter evaluation algorithm. Other than linear Taylor series based uncertainty evaluation methods, the MCM features several advantages: it does not suffer from lower-order expansion errors and can therefore reproduce nonlinearity effects. Furthermore, different types of PDFs can be assumed for the input quantities, and the corresponding coverage intervals can be calculated for any coverage probability. To demonstrate the uncertainty evaluation, a calibration and subsequent measurements in the wake of an airfoil with a five-hole probe are performed. The MCM is applied to different parameter evaluation algorithms. It is found that the MCM cannot be applied to polynomial curve fits, if the differences between the calibration data and the polynomial curve fits are of the same order of magnitude compared to the calibration uncertainty. Since this method has not yet been used for the evaluation of measurement uncertainties for pneumatic multihole probes, the aim of this paper is to present a highly accurate and easy-to-implement uncertainty evaluation method.
Investigation of Cycle-to-Cycle Variation of In-Cylinder Engine Swirl Flow Fields Using Quadruple Proper Orthogonal Decomposition
Authors: Ge Penghui , Hung David L. S.
Published: January 2017

It has been observed that the swirl characteristics of in-cylinder air flow in a spark ignition direct injection (SIDI) engine affect the fuel spray dispersion and flame propagation speed, impacting the fuel mixture formation and combustion process under high swirl conditions. In addition, the cycle-to-cycle variations (CCVs) of swirl flow often degrade the air–fuel mixing and combustion quality in the cylinder. In this study, the 2D flow structure along a swirl plane at 30 mm below the injector tip was recorded using high-speed particle image velocimetry (PIV) in a four-valve optical SIDI engine under high swirl condition. Quadruple proper orthogonal decomposition (POD) was used to investigate the cycle-to-cycle variations of 200 consecutive cycles. The flow fields were analyzed by dividing the swirl plane into four zones along the measured swirl plane according to the positions of intake and exhaust valves in the cylinder head. Experimental results revealed that the coefficient of variation (COV) of the quadruple POD mode coefficients could be used to estimate the cycle-to-cycle variations at a specific crank angle. The dominant structure was represented by the first POD mode in which its kinetic energy could be correlated with the motions of the intake valves. Moreover, higher order flow variations were closely related to the flow stability at different zones. In summary, quadruple POD provides another meaningful way to understand the intake swirl impact on the cycle-to-cycle variations of the in-cylinder flow characteristics in SIDI engine.
The Comparison of Viscous Force Approximations of Smoothed Particle Hydrodynamics in Poiseuille Flow Simulation
Authors: Liu Zhengang , Liu Zhenxia
Published: January 2017

Poiseuille flows at two Reynolds numbers (Re) 2.5 × 10−2 and 5.0 are simulated by two different smoothed particle hydrodynamics (SPH) schemes on regular and irregular initial particles' distributions. In the first scheme, the viscous stress is calculated directly by the basic SPH particle approximation, while in the second scheme, the viscous stress is calculated by the combination of SPH particle approximation and finite difference method (FDM). The main aims of this paper are (a) investigating the influences of two different schemes on simulations and reducing the numerical instability in simulating Poiseuille flows discovered by other researchers and (b) investigating whether the similar instability exists in other cases and comparing results with the two viscous stress approximations. For Re = 2.5 × 10−2, the simulation with the first scheme becomes instable after the flow approaches to steady-state. However, this instability could be reduced by the second scheme. For Re = 5.0, no instability for two schemes is found.
Aerodynamics and Vortex Flowfield of a Slender Delta Wing With Apex Flap and Tip Flap
Authors: Lee T. , Ko L. S.
Published: January 2017

The effect of apex flap and tip flap, deflected both independently and jointly, on the vortex flow and lift generation of a 65 deg-sweep delta wing was investigated experimentally. The drooped apex flap produced a higher lift at medium-to-high angle of attack regime and also a delayed stall. The anhedral (introduced by the downward tip flap) generally promoted lift increment, whereas dihedral had the opposite effect. Meanwhile, the joint apex and tip flap deflection gave a delayed leading-edge vortex (LEV) breakdown and an enhanced lift. The LEVs were generally drawn closer to the wing upper surface, while being pushed further away from the wing centerline by the application of apex flap and tip flap. The flap also modified the vorticity distribution in the LEV; the bursting behavior was, however, not affected. Dye-injection flow visualization and particle image velocimetry (PIV) measurements of the vortex flow were also discussed.
Open Loop and Closed Loop Performance of Solid Oxide Fuel Cell Turbine Hybrid Systems During Fuel Composition Changes
Authors: Harun Nor Farida , Tucker David , Adams Thomas A.
Published: January 2017

The dynamic behavior of a solid oxide fuel cell gas turbine hybrid system (SOFC/GT) from both open and closed loop transients in response to sudden changes in fuel composition was experimentally investigated. A pilot-scale (200–700 kW) hybrid facility available at the U.S. Department of Energy, National Energy Technology Laboratory was used to perform the experiments using a combination of numerical models and actual equipment. In the open loop configuration, the turbine speed was driven by the thermal effluent fed into the gas turbine system, where the thermal effluent was determined by the feedforward fuel cell control system. However, in the closed loop configuration, a load-based speed control system was used to maintain the turbine speed constant at 40,500 rpm by adjusting the load on the turbine, in addition to the implementation of the fuel cell system control. The open loop transient response showed that the impacts of fuel composition changes on key process variables, such as fuel cell thermal effluent, turbine speed, and cathode feed stream conditions, in the SOFC/GT systems were propagated over the course of the test, except for the cathode inlet temperature. The trajectories of the aforementioned variables are discussed in this paper to better understand the resulting mitigation/propagation behaviors. This will help lead to the development of novel control strategies to mitigate the negative impacts experienced during fuel composition transients of SOFC/GT systems.
Molecular ligand modulation of palladium nanocatalysts for highly efficient and robust heterogeneous oxidation of cyclohexenone to phenol
Authors: Xue Teng , Lin Zhaoyang , Chiu Chin-Yi , Li Yongjia , Ruan Lingyan , Wang Gongming , Zhao Zipeng , Lee Chain , Duan Xiangfeng , Huang Yu
Published: January 2017

Molecular ligand modulation of Pd nanoparticle catalysts achieves exceptional activity and stability.
The mechanics and design of a lightweight three-dimensional graphene assembly
Authors: Qin Zhao , Jung Gang Seob , Kang Min Jeong , Buehler Markus J.
Published: January 2017

The mechanics of a lightweight three-dimensional graphene assembly, quantified by computational simulation and 3D printing, are discussed.
Tumor location determines tissue-specific recruitment of tumor-associated macrophages and antibody-dependent immunotherapy response
Authors: Lehmann Birgit , Biburger Markus , Brückner Christin , Ipsen-Escobedo Andrea , Gordan Sina , Lehmann Christian , Voehringer David , Winkler Thomas , Schaft Niels , Dudziak Diana , Sirbu Horia , Weber Georg F. , Nimmerjahn Falk
Published: January 2017

Tissue environment determines which immune effector cells contribute to tumor rejection by therapeutic antibodies.
Biofilm Composition and Threshold Concentration for Growth of Legionella pneumophila on Surfaces Exposed to Flowing Warm Tap Water without Disinfectant
Authors: van der Kooij Dick , Bakker Geo L. , Italiaander Ronald , Veenendaal Harm R. , Wullings Bart A.
Published: January 2017

Legionella pneumophila
in potable water installations poses a potential health risk, but quantitative information about its replication in biofilms in relation to water quality is scarce. Therefore, biofilm formation on the surfaces of glass and chlorinated polyvinyl chloride (CPVC) in contact with tap water at 34 to 39°C was investigated under controlled hydraulic conditions in a model system inoculated with biofilm-grown
L. pneumophila
. The biofilm on glass (average steady-state concentration, 23 ± 9 pg ATP cm
−2
) exposed to treated aerobic groundwater (0.3 mg C liter
−1
; 1 μg assimilable organic carbon [AOC] liter
−1
) did not support growth of the organism, which also disappeared from the biofilm on CPVC (49 ± 9 pg ATP cm
−2
) after initial growth.
L. pneumophila
attained a level of 4.3 log CFU cm
−2
in the biofilms on glass (1,055 ± 225 pg ATP cm
−2
) and CPVC (2,755 ± 460 pg ATP cm
−2
) exposed to treated anaerobic groundwater (7.9 mg C liter
−1
; 10 μg AOC liter
−1
). An elevated biofilm concentration and growth of
L. pneumophila
were also observed with tap water from the laboratory. The
Betaproteobacteria Piscinibacter
and
Methyloversatilis
and amoeba-resisting
Alphaproteobacteria
predominated in the clones and isolates retrieved from the biofilms. In the biofilms, the
Legionella
colony count correlated significantly with the total cell count (TCC), heterotrophic plate count, ATP concentration, and presence of
Vermamoeba vermiformis
. This amoeba was rarely detected at biofilm concentrations of <100 pg ATP cm
−2
. A threshold concentration of approximately 50 pg ATP cm
−2
(TCC = 1 × 10
6
to 2 × 10
6
cells cm
−2
) was derived for growth of
L. pneumophila
in biofilms.

IMPORTANCE
Legionella pneumophila
is the etiologic agent in more than 10,000 cases of Legionnaires' disease that are reported annually worldwide and in most of the drinking water-associated disease outbreaks reported in the United States. The organism proliferates in biofilms on surfaces exposed to warm water in engineered freshwater installations. An investigation with a test system supplied with different types of warm drinking water without disinfectant under controlled hydraulic conditions showed that treated aerobic groundwater (0.3 mg liter
−1
of organic carbon) induced a low biofilm concentration that supported no or very limited growth of
L. pneumophila
. Elevated biofilm concentrations and
L. pneumophila
colony counts were observed on surfaces exposed to two types of extensively treated groundwater, containing 1.8 and 7.9 mg C liter
−1
and complying with the microbial water quality criteria during distribution. Control measures in warm tap water installations are therefore essential for preventing growth of
L. pneumophila
.
Diverse Bacteria Affiliated with the Genera Microvirga, Phyllobacterium, and Bradyrhizobium Nodulate Lupinus micranthus Growing in Soils of Northern Tunisia
Authors: Msaddak Abdelhakim , Durán David , Rejili Mokhtar , Mars Mohamed , Ruiz-Argüeso Tomás , Imperial Juan , Palacios José , Rey Luis
Published: January 2017

The genetic diversity of bacterial populations nodulating
Lupinus micranthus
in five geographical sites from northern Tunisia was examined. Phylogenetic analyses of 50 isolates based on partial sequences of
recA
and
gyrB
grouped strains into seven clusters, five of which belong to the genus
Bradyrhizobium
(28 isolates), one to
Phyllobacterium
(2 isolates), and one, remarkably, to
Microvirga
(20 isolates). The largest
Bradyrhizobium
cluster (17 isolates) grouped with the
B. lupini
species, and the other five clusters were close to different recently defined
Bradyrhizobium
species. Isolates close to
Microvirga
were obtained from nodules of plants from four of the five sites sampled. We carried out an in-depth phylogenetic study with representatives of the seven clusters using sequences from housekeeping genes (
rrs
,
recA
,
glnII
,
gyrB
, and
dnaK
) and obtained consistent results. A phylogeny based on the sequence of the symbiotic gene
nodC
identified four groups, three formed by
Bradyrhizobium
isolates and one by the
Microvirga
and
Phyllobacterium
isolates. Symbiotic behaviors of the representative strains were tested, and some congruence between symbiovars and symbiotic performance was observed. These data indicate a remarkable diversity of
L. micranthus
root nodule symbionts in northern Tunisia, including strains from the
Bradyrhizobiaceae
,
Methylobacteriaceae
, and
Phyllobacteriaceae
families, in contrast with those of the rhizobial populations nodulating lupines in the Old World, including
L. micranthus
from other Mediterranean areas, which are nodulated mostly by
Bradyrhizobium
strains.

IMPORTANCE
Lupinus micranthus
is a legume broadly distributed in the Mediterranean region and plays an important role in soil fertility and vegetation coverage by fixing nitrogen and solubilizing phosphate in semiarid areas. Direct sowing to extend the distribution of this indigenous legume can contribute to the prevention of soil erosion in pre-Saharan lands of Tunisia. However, rhizobial populations associated with
L. micranthus
are poorly understood. In this context, the diversity of endosymbionts of this legume was investigated. Most
Lupinus
species are nodulated by
Bradyrhizobium
strains. This work showed that about half of the isolates from northern Tunisian soils were in fact
Bradyrhizobium
symbionts, but the other half were found unexpectedly to be bacteria within the genera
Microvirga
and
Phyllobacterium
. These unusual endosymbionts may have a great ecological relevance. Inoculation with the appropriate selected symbiotic bacterial partners will increase
L. micranthus
survival with consequent advantages for the environment in semiarid areas of Tunisia.
Large-Scale Transposition Mutagenesis of Streptomyces coelicolor Identifies Hundreds of Genes Influencing Antibiotic Biosynthesis
Authors: Xu Zhong , Wang Yemin , Chater Keith F. , Ou Hong-Yu , Xu H. Howard , Deng Zixin , Tao Meifeng
Published: January 2017

Gram-positive
Streptomyces
bacteria produce thousands of bioactive secondary metabolites, including antibiotics. To systematically investigate genes affecting secondary metabolism, we developed a hyperactive transposase-based Tn
5
transposition system and employed it to mutagenize the model species
Streptomyces coelicolor
, leading to the identification of 51,443 transposition insertions. These insertions were distributed randomly along the chromosome except for some preferred regions associated with relatively low GC content in the chromosomal core. The base composition of the insertion site and its flanking sequences compiled from the 51,443 insertions implied a 19-bp expanded target site surrounding the insertion site, with a slight nucleic acid base preference in some positions, suggesting a relative randomness of Tn
5
transposition targeting in the high-GC
Streptomyces
genome. From the mutagenesis library, 724 mutants involving 365 genes had altered levels of production of the tripyrrole antibiotic undecylprodigiosin (RED), including 17 genes in the RED biosynthetic gene cluster. Genetic complementation revealed that most of the insertions (more than two-thirds) were responsible for the changed antibiotic production. Genes associated with branched-chain amino acid biosynthesis, DNA metabolism, and protein modification affected RED production, and genes involved in signaling, stress, and transcriptional regulation were overrepresented. Some insertions caused dramatic changes in RED production, identifying future targets for strain improvement.

IMPORTANCE
High-GC Gram-positive streptomycetes and related actinomycetes have provided more than 100 clinical drugs used as antibiotics, immunosuppressants, and antitumor drugs. Their genomes harbor biosynthetic genes for many more unknown compounds with potential as future drugs. Here we developed a useful genome-wide mutagenesis tool based on the transposon Tn
5
for the study of secondary metabolism and its regulation. Using
Streptomyces coelicolor
as a model strain, we found that chromosomal insertion was relatively random, except at some hot spots, though there was evidence of a slightly preferred 19-bp target site. We then used prodiginine production as a model to systematically survey genes affecting antibiotic biosynthesis, providing a global view of antibiotic regulation. The analysis revealed 348 genes that modulate antibiotic production, among which more than half act to reduce production. These might be valuable targets in future investigations of regulatory mechanisms, for strain improvement, and for the activation of silent biosynthetic gene clusters.
Increasing Growth Yield and Decreasing Acetylation in Escherichia coli by Optimizing the Carbon-to-Magnesium Ratio in Peptide-Based Media
Authors: Christensen David G. , Orr James S. , Rao Christopher V. , Wolfe Alan J.
Published: January 2017

Complex media are routinely used to cultivate diverse bacteria. However, this complexity can obscure the factors that govern cell growth. While studying protein acetylation in buffered tryptone broth supplemented with glucose (TB7-glucose), we observed that
Escherichia coli
did not fully consume glucose prior to stationary phase. However, when we supplemented this medium with magnesium, the glucose was completely consumed during exponential growth, with concomitant increases in cell number and biomass but reduced cell size. Similar results were observed with other sugars and other peptide-based media, including lysogeny broth. Magnesium also limited cell growth for
Vibrio fischeri
and
Bacillus subtilis
in TB7-glucose. Finally, magnesium supplementation reduced protein acetylation. Based on these results, we conclude that growth in peptide-based media is magnesium limited. We further conclude that magnesium supplementation can be used to tune protein acetylation without genetic manipulation. These results have the potential to reduce potentially deleterious acetylated isoforms of recombinant proteins without negatively affecting cell growth.

IMPORTANCE
Bacteria are often grown in complex media. These media are thought to provide the nutrients necessary to grow bacteria to high cell densities. In this work, we found that peptide-based media containing a sugar are magnesium limited for bacterial growth. In particular, magnesium supplementation is necessary for the bacteria to use the sugar for cell growth. Interestingly, in the absence of magnesium supplementation, the bacteria still consume the sugar. However, rather than use it for cell growth, the bacteria instead use the sugar to acetylate lysines on proteins. As lysine acetylation may alter the activity of proteins, this work demonstrates how lysine acetylation can be tuned through magnesium supplementation. These findings may be useful for recombinant protein production, when acetylated isoforms are to be avoided. They also demonstrate how to increase bacterial growth in complex media.
YMC-2011, a Temperate Phage of Streptococcus salivarius 57.I
Authors: Chou Wen-Chun , Huang Szu-Chuan , Chiu Cheng-Hsun , Chen Yi-Ywan M.
Published: January 2017

Streptococcus salivarius
is an abundant isolate of the oral cavity. The genome of
S. salivarius
57.I consists of a 2-Mb chromosome and a 40,758-bp circular molecule, designated YMC-2011. Annotation of YMC-2011 revealed 55 open reading frames, most of them associated with phage production, although plaque formation is not observed in
S. salivarius
57.I after lytic induction using mitomycin C. Results from Southern hybridization and quantitative real-time PCR confirmed that YMC-2011 exists extrachromosomally, with an estimated copy number of 3 to 4. Phage particles were isolated from the supernatant of mitomycin C-treated
S. salivarius
57.I cultures, and transmission electron microscopic examination indicated that YMC-2011 belongs to the
Siphoviridae
family. Phylogenetic analysis suggests that phage YMC-2011 and the
cos
-type phages of
Streptococcus thermophilus
originated from a common ancestor. An extended −10 element (p

L

) and a σ
70
-like promoter (p

R

) were mapped 5′ to Ssal_phage00013 (encoding a CI-like repressor) and Ssal_phage00014 (encoding a hypothetical protein), respectively, using 5′ rapid amplification of cDNA ends, indicating that YMC-2011 transcribes at least two mRNAs in opposite orientations. Studies using promoter-chloramphenicol acetyltransferase reporter gene fusions revealed that p

R

, but not p

L

, was sensitive to mitomycin C induction, suggesting that the switch from lysogenic growth to lytic growth was controlled mainly by the activity of these two promoters. In conclusion, a lysogenic state is maintained in
S. salivarius
57.I, presumably by the repression of genes encoding proteins for lytic growth.

IMPORTANCE
The movement of mobile genetic elements such as bacteriophages and the establishment of lysogens may have profound effects on the balance of microbial ecology where lysogenic bacteria reside. The discovery of phage YMC-2011 from
Streptococcus salivarius
57.I suggests that YMC-2011 and
Streptococcus thermophilus
-infecting phages share an ancestor. Although
S. salivarius
and
S. thermophilus
are close phylogenetically,
S. salivarius
is a natural inhabitant of the human mouth, whereas
S. thermophilus
is commonly found in the mammary mucosa of bovine species. Thus, the identification of YMC-2011 suggests that horizontal gene transfer via phage infection could take place between species from different ecological niches.
Open-source mobile digital platform for clinical trial data collection in low-resource settings
Authors: van Dam Joris , Omondi Onyango Kevin , Midamba Brian , Groosman Nele , Hooper Norman , Spector Jonathan , Pillai Goonaseelan (Colin) , Ogutu Bernhards
Published: January 2017

Background

Governments, universities and pan-African research networks are building durable infrastructure and capabilities for biomedical research in Africa. This offers the opportunity to adopt from the outset innovative approaches and technologies that would be challenging to retrofit into fully established research infrastructures such as those regularly found in high-income countries. In this context we piloted the use of a novel mobile digital health platform, designed specifically for low-resource environments, to support high-quality data collection in a clinical research study.

Objective

Our primary aim was to assess the feasibility of a using a mobile digital platform for clinical trial data collection in a low-resource setting. Secondarily, we sought to explore the potential benefits of such an approach.

Methods

The investigative site was a research institute in Nairobi, Kenya. We integrated an open-source platform for mobile data collection commonly used in the developing world with an open-source, standard platform for electronic data capture in clinical trials. The integration was developed using common data standards (Clinical Data Interchange Standards Consortium (CDISC) Operational Data Model), maximising the potential to extend the approach to other platforms. The system was deployed in a pharmacokinetic study involving healthy human volunteers.

Results

The electronic data collection platform successfully supported conduct of the study. Multidisciplinary users reported high levels of satisfaction with the mobile application and highlighted substantial advantages when compared with traditional paper record systems. The new system also demonstrated a potential for expediting data quality review.

Discussion and Conclusions

This pilot study demonstrated the feasibility of using a mobile digital platform for clinical research data collection in low-resource settings. Sustainable scientific capabilities and infrastructure are essential to attract and support clinical research studies. Since many research structures in Africa are being developed anew, stakeholders should consider implementing innovative technologies and approaches.
Basic life support education in secondary schools: a cross-sectional survey in London, UK
Authors: Salciccioli Justin D , Marshall Dominic C , Sykes Mark , Wood Alexander D , Joppa Stephanie A , Sinha Madhurima , Lim P Boon
Published: January 2017

Objectives

Basic life support (BLS) training in schools is associated with improved outcomes from cardiac arrest. International consensus statements have recommended universal BLS training for school-aged children. The current practice of BLS training in London schools is unknown. The aim of this study was to assess current practices of BLS training in London secondary schools.

Setting, population and outcomes

A prospective audit of BLS training in London secondary schools was conducted. Schools were contacted by email, and a subsequent telephone interview was conducted with staff familiar with local training practices. Response data were anonymised and captured electronically. Universal training was defined as any programme which delivers BLS training to all students in the school. Descriptive statistics were used to summarise the results.

Results

A total of 65 schools completed the survey covering an estimated student population of 65 396 across 19 of 32 London boroughs. There were 5 (8%) schools that provide universal training programmes for students and an additional 31 (48%) offering training as part of an extracurricular programme or chosen module. An automated external defibrillator (AED) was available in 18 (28%) schools, unavailable in 40 (61%) and 7 (11%) reported their AED provision as unknown. The most common reasons for not having a universal BLS training programme are the requirement for additional class time (28%) and that funding is unavailable for such a programme (28%). There were 5 students who died from sudden cardiac arrest over the period of the past 10 years.

Conclusions

BLS training rates in London secondary schools are low, and the majority of schools do not have an AED available in case of emergency. These data highlight an opportunity to improve BLS training and AEDs provision. Future studies should assess programmes which are cost-effective and do not require significant amounts of additional class time.
Comparison of self-perceived cardiovascular disease risk among smokers with Framingham and PROCAM scores: a cross-sectional analysis of baseline data from a randomised controlled trial
Authors: Desgraz Benoît , Collet Tinh-Hai , Rodondi Nicolas , Cornuz Jacques , Clair Carole
Published: January 2017

Objectives

Previous studies suggest that smokers have a misperception of their 10-year cardiovascular risk. We aimed to compare 10-year cardiovascular risk self-perception and calculated risk among smokers willing to quit and assess the determinants of a possible misperception.

Design

Cross-sectional secondary analysis of baseline data from a randomised controlled trial of smoking cessation.

Participants

514 participants, mean age 51.1 years, 46% women, 98% Caucasian. Eligible participants were regular smokers, aged between 40 and 70 years, with a consumption of at least 10 cigarettes per day for at least a year. None of them had experienced cardiovascular disease before. Exclusion criteria comprised a history of myocardial infarction, coronary heart disease, stroke, heart failure, peripheral vascular disease, carotid atherosclerosis or cardiac arrhythmia. Participants with renal or liver failure, psychiatric disorders, substance and alcohol abuse and with smoking cessation therapies were excluded.

Interventions

Participants were asked to estimate their 10-year cardiovascular risk using a 3-item scale corresponding to high-risk, moderate-risk and low-risk categories. We compared their risk perception with Framingham and Prospective Cardiovascular Munster Study (PROCAM) scores. We used multivariable-adjusted logistic regression models to determine characteristics of participants who underestimate their risk versus those who correctly estimate or overestimate it.

Results

Between 38% and 42% of smokers correctly perceived their 10-year cardiovascular risk, and 39–50% overestimated their 10-year cardiovascular risk while 12–19% underestimated it compared with their calculated 10-year cardiovascular risk depending on the score used. Underestimation of 10-year cardiovascular risk was associated with male gender (OR 8.16; CI 3.83 to 17.36), older age (OR 1.06; CI 1.02 to 1.09), and the presence of hyperlipidaemia (OR 2.71; CI 1.47 to 5.01) and diabetes mellitus (OR 13.93; CI 3.83 to 50.66).

Conclusions

Among smokers, misperception of their 10-year cardiovascular risk is common, with one-fifth underestimating it. These findings may help physicians target patients with such characteristics to help them change their health behaviour and adherence to risk-reduction therapy.

Trial registration number

NCT00548665; Post-results.
Development and validation of brief scales to measure emotional and behavioural problems among Chinese adolescents
Authors: Shen Minxue , Hu Ming , Sun Zhenqiu
Published: January 2017

Objectives

To develop and validate brief scales to measure common emotional and behavioural problems among adolescents in the examination-oriented education system and collectivistic culture of China.

Setting

Middle schools in Hunan province.

Participants

5442 middle school students aged 11–19 years were sampled. 4727 valid questionnaires were collected and used for validation of the scales. The final sample included 2408 boys and 2319 girls.

Primary and secondary outcome measures

The tools were assessed by the item response theory, classical test theory (reliability and construct validity) and differential item functioning.

Results

Four scales to measure anxiety, depression, study problem and sociality problem were established. Exploratory factor analysis showed that each scale had two solutions. Confirmatory factor analysis showed acceptable to good model fit for each scale. Internal consistency and test–retest reliability of all scales were above 0.7. Item response theory showed that all items had acceptable discrimination parameters and most items had appropriate difficulty parameters. 10 items demonstrated differential item functioning with respect to gender.

Conclusions

Four brief scales were developed and validated among adolescents in middle schools of China. The scales have good psychometric properties with minor differential item functioning. They can be used in middle school settings, and will help school officials to assess the students’ emotional/behavioural problems.
Is having a family member with chronic health concerns bad for young people's health? Cross-sectional evidence from a national survey of young Australians
Authors: Moffat Anna K , Redmond Gerry
Published: January 2017

Objectives

Young people's perspectives on the association between having a family member with a chronic health concern (FHC) and their own health are under-researched. This study used young people's reports to assess the prevalence of FHCs and their association with negative health outcomes, with an aim of identifying potential inequalities between marginalised and non-marginalised young people. Family cohesion was examined as a moderating factor.

Design

Cross-sectional data from the Australian Child Wellbeing Project survey were used. Respondents were asked whether someone in their family experienced one or more FHCs (disability, mental illness or drug/alcohol addiction). In addition, their experience of different psychosomatic symptoms (headache, sleeplessness, irritability, etc), aspects of family relationships and social and economic characteristics (disability, materially disadvantaged and Indigenous) were documented.

Setting

Nationally representative Australian sample.

Participants

1531 students in school years 4 and 6 and 3846 students in year 8.

Results

A quarter of students reported having an FHC (years 4 and 6: 23.96% (95% CI 19.30% to 28.62%); year 8: 25.35% (95% CI 22.77% to 27.94%)). Significantly, more students with FHCs than those without reported experiencing 2 or more negative health symptoms at least weekly (OR=1.78; 95% CI 1.19 to 2.65; p<0.01). However, an independent relationship between FHCs and symptom load was only found in the case of FHC-drug/alcohol addiction. Marginalised students and students reporting low family cohesion had an increased prevalence of FHCs and notably higher symptom loads where FHCs were present. Level of family cohesion did not impact the relationship between FHCs and symptom load.

Conclusions

The burden of FHCs is inequitably distributed between marginalised and non-marginalised groups, and between young people experiencing different levels of family cohesion. More work is required regarding appropriate targets for community and family-level interventions to support young people in the context of FHCs.
Treatment targeted at underlying disease versus palliative care in terminally ill patients: a systematic review
Authors: Reljic Tea , Kumar Ambuj , Klocksieben Farina A , Djulbegovic Benjamin
Published: January 2017

Objective

To assess the efficacy of active treatment targeted at underlying disease (TTD)/potentially curative treatments versus palliative care (PC) in improving overall survival (OS) in terminally ill patients.

Design

We performed a systematic review and meta-analysis of randomised controlled trials (RCT). Methodological quality of included RCTs was assessed using the Cochrane risk of bias tool.

Data sources

Medline and Cochrane databases were searched, with no language restriction, from inception to 19 October 2016.

Eligibility criteria for selecting studies

Any RCT assessing the efficacy of any active TTD versus PC in adult patients with terminal illness with a prognosis of <6-month survival were eligible for inclusion.

Results

Initial search identified 8252 citations of which 10 RCTs (15 comparisons, 1549 patients) met inclusion criteria. All RCTs included patients with cancer. OS was reported in 7 RCTs (8 comparisons, 1158 patients). The pooled results showed no statistically significant difference in OS between TTD and PC (HR (95% CI) 0.85 (0.71 to 1.02)). The heterogeneity between pooled studies was high (I2=62.1%). Overall rates of adverse events were higher in the TTD arm.

Conclusions

Our systematic review of available RCTs in patients with terminal illness due to cancer shows that TTD compared with PC did not demonstrably impact OS and is associated with increased toxicity. The results provide assurance to physicians, patients and family that the patients' survival will not be compromised by referral to hospice with focus on PC.
Combining qualitative and quantitative operational research methods to inform quality improvement in pathways that span multiple settings
Authors: Crowe Sonya , Brown Katherine , Tregay Jenifer , Wray Jo , Knowles Rachel , Ridout Deborah A , Bull Catherine , Utley Martin
Published: January 2017

Background

Improving integration and continuity of care across sectors within resource constraints is a priority in many health systems. Qualitative operational research methods of problem structuring have been used to address quality improvement in services involving multiple sectors but not in combination with quantitative operational research methods that enable targeting of interventions according to patient risk. We aimed to combine these methods to augment and inform an improvement initiative concerning infants with congenital heart disease (CHD) whose complex care pathway spans multiple sectors.

Methods

Soft systems methodology was used to consider systematically changes to services from the perspectives of community, primary, secondary and tertiary care professionals and a patient group, incorporating relevant evidence. Classification and regression tree (CART) analysis of national audit datasets was conducted along with data visualisation designed to inform service improvement within the context of limited resources.

Results

A ‘Rich Picture’ was developed capturing the main features of services for infants with CHD pertinent to service improvement. This was used, along with a graphical summary of the CART analysis, to guide discussions about targeting interventions at specific patient risk groups. Agreement was reached across representatives of relevant health professions and patients on a coherent set of targeted recommendations for quality improvement. These fed into national decisions about service provision and commissioning.

Conclusions

When tackling complex problems in service provision across multiple settings, it is important to acknowledge and work with multiple perspectives systematically and to consider targeting service improvements in response to confined resources. Our research demonstrates that applying a combination of qualitative and quantitative operational research methods is one approach to doing so that warrants further consideration.