bluuebunny/crossref_metadata_2025 huggingface dataset:
Knee ultrasound from research to real practice: a systematic literature review of adult knee ultrasound assessment feasibility studies.
Authors: Peltea Alexandra , Berghea Florian , Gudu Tania , Ionescu Ruxandra
Published: December 2016

Objective: To identify and analyse existing data regarding knee ultrasound (US) feasibility in clinical practice. Material and methods: A systematic literature review was performed using the terms: (“knee”) AND (“ultrasound” OR “ultrasonography”) AND (“feasibility” OR “pilot” OR “proof of concept”). Feasibility studies regarding knee US or US aided maneuver involving knee joint, published during 2005-2015, were selected and evaluated against a complex framework constructed around mandatory key areas for feasibility studies: acceptability, demand, implementation, practicality, adaptation, integration and expansion. Results: One hundred and fifty-nine publications were identified, of which 9 were included in the final analysis: 6 dealt with the development and implementation of novel US scores, while the rest focused on implementing MSUS in clinical practice, evaluating the usefulness of articular cartilage US assessment and the feasibility of sonography for intra-articular knee injections, respectively. Six studies quantified feasibility as time spent for the evaluation, with only two addressing areassuch as acceptability, implementation and practicality, although none of these systematically assessed all feasibility domains. Conclusion: Knee US feasibility is still poorly addressed; the time required for US assessment is the main area addressed. This information gap should be properly addressed in future works, in order to ensure the right place for this technique.
Takotsubo Cardiomyopathy presenting as ST-elevation myocardial infarction: wide triggering spectrum and specific echocardiographical pattern in a consecutive case series report.
Authors: Homorodean Călin , Ober Mihai C. , Olinic Maria , Homorodean Romana , Hassoune Abdesamad , Tătaru Dan , Spînu Mihai , Olinic Dan M.
Published: December 2016

We report a series of six consecutive cases of Takotsubo Cardiomyopathy (TCM) presenting as ST-elevation acute myocardial infarction and consequently addressed to the emergency coronary angiography, inside a time-frame of one year (2015). This series underlines the wide possible triggering spectrum and clinical severity of TCM and recognizes echocardiography as an essential imaging technique in the diagnosis due to its widespread availability and feasibility in the acute care setting.
Complete atrioventricular septal defect in the era of prenatal diagnosis
Authors: Mureşan Daniel , Mărginean Claudiu , Zaharie Gabriela , Stamatian Florin
Published: December 2016

Complete atrioventricular septal defect (CAVSD) is a fetal cardiac malformation (5% of all cardiac malformations) that can be detected prenatally with a reserved prognosis. The diagnosis can be suspected early at the end of the first trimester using the transabdominal or transvaginal ultrasound approach. Generally, the diagnostic can be established during the mid-trimester scan at 19-24 weeks of gestation. The percentage of antenatal diagnostic of CAVSD is between 57-92%. This review aims to analyze the anatomical principles and the ultrasound techniques that can improve the prenatal diagnosis of CAVSD. We have also analyzed the structural and genetic anomalies frequently associated with CAVSD.
Penile masses: Shear Wave Elastography correlated with Magnetic Resonance Imagining. A two cases report.
Authors: Alis Deniz Can , Ustabasioglu Fethi Emre , Samancı Cesur , Boz Sinan Murat , Sirolu Sabri , Kantarcı Fatih
Published: December 2016

Definitive diagnosis of penile masses usually depends on clinical symptoms and patient history but in some challenging cases the help of radiologic diagnostic tools is required. Although ultrasound is an effective tool for detecting penile masses, unlike magnetic resonance imagining, it is not able to differentiate benign and malignant pathologies. Shear wave elastography (SWE) is a novel method, which has the ability to differentiate malignant and benign tissues by giving quantitative information about tissue elasticity. In this paper we present two cases with penile masses to demonstrate the potential use of SWE in the differential diagnosis of penile masses.
How to get ductus venosus flow velocity waveforms between 11 and 14 weeks: Candle Flame and Falling Drop Signs
Authors: Gürses Cemil
Published: December 2016

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Contrast-enhanced ultrasonography is useful for evaluating the intraplaque neovascularization in aortic complex plaque of ischemic stroke patients
Authors: Kouchi Maiko , Mizuma Atsushi , Netsu Shizuka , Ishihara Mai , Nagata Eiichiro , Takizawa Shunya
Published: December 2016

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Fabrication of nanopower generators using thin atomic layer deposited films
Authors: Given Robert Parker , Wenger Kyle S. , Wheeler Virginia D. , Utter Brian C. , Scarel Giovanna
Published: December 2016

Infrared (IR) power generation is emerging as a useful method to harvest IR light and transform it into usable energy available day and night. Here, the authors continue the effort to fabricate thin thermoelectric TiO2/TiN nanolaminate films via atomic layer deposition (ALD) and, specifically, focus on the effects of film sheet resistance Rs on the voltage produced by nanopower generator devices with these films as their active elements. By changing the number and the thickness of the TiO2/TiN nanolaminate, the authors control the sheet resistance Rs over 3 orders of magnitude. The authors observe that the voltage produced by nanopower generator devices increases with Rs and exhibits two roughly linear regimes. In the first regime, when Rs < 1 kΩ/◻, the nanopower generator produces a voltage which slowly increases with increasing Rs with a slope of approximately 0.6 × 10−7 mV (◻/Ω). The second regime appears in films with Rs > 1 kΩ/◻, where the slope characterizing the increase of voltage with sheet resistance Rs is approximately 7.5 × 10−7 mV (◻/Ω). The existence of these two regimes is consistent with the hypothesis that the nanopower generator device works as an electric circuit in which the produced voltage is proportional to R, where R is resistance. Although models can be developed to explain the mechanisms of voltage and temperature production when the nanopower generator devices are illuminated by the IR light, it is not entirely clear with the data available so far what explains the observed values of voltage, and what the effects of errors might be on them. Further investigations will be focusing on these issues. Nevertheless, the observed trends between produced voltage and sheet resistance are interesting. These studies pave the way to improving the performance of nanopower generator devices by increasing the Rs of the active materials in the form of thin films fabricated via ALD.
Acoustics from a rectangular supersonic nozzle exhausting over a flat surface
Authors: Mora Pablo , Baier Florian , Kailasanath K. , Gutmark Ephraim J.
Published: December 2016

A jet exhausting over a plate at different distances away from the nozzle was investigated to simulate jets exhausting over airframe surfaces and the jet-ground interaction during take-off and landing operations. A supersonic rectangular nozzle of 2:1 aspect ratio and 1.5 design Mach number was tested with and without the plate. Far-field acoustics from the cold and heated jets at over-expanded, design, and under-expanded conditions were measured at the reflected, sideline, and shielded azimuthal directions. When the plate starts at the nozzle exit, the “scrubbing” and “scattering” noise from the surface-jet interaction was observed at the low-end frequencies of the reflected and shielded measurements and increased as the plate approached the jet. In the sideline, the plate attached to the nozzle exit diminished the broadband shock-associated noise while the shadowgraph results showed a connection to weakening of the shock-cell structures. In the cold jet, screech was mitigated with the plate attached at the nozzle exit. When the plate was moved away from the nozzle, screech tones were intensified at the under-expanded condition. Crackle levels were significantly intensified in the sideline within a range of plate positions. Noise levels in the shielded region were considerably lower due to the shielding effect.
Etiology of Neuromuscular Fatigue After Repeated Sprints Depends on Exercise Modality
Authors: Tomazin Katja , Morin Jean-Benoit , Millet Guillaume Y.
Published: December 2016

Purpose:

To compare neuromuscular fatigue induced by repeated-sprint running vs cycling.

Methods:

Eleven active male participants performed 2 repeated-maximal-sprint protocols (5×6 s, 24-s rest periods, 4 sets, 3 min between sets), 1 in running (treadmill) and 1 in cycling (cycle ergometer). Neuromuscular function, evaluated before (PRE); 30 s after the first (S1), the second (S2), and the last set (LAST); and 5 min after the last set (POST5) determined the knee-extensor maximal voluntary torque (MVC); voluntary activation (VA); single-twitch (Tw), high- (Db100), and low- (Db10) frequency torque; and maximal muscle compound action potential (M-wave) amplitude and duration of vastus lateralis.

Results:

Peak power output decreased from 14.6 ± 2.2 to 12.4 ± 2.5 W/kg in cycling (P < .01) and from 21.4 ± 2.6 to 15.2 ± 2.6 W/kg in running (P < .001). MVC declined significantly from S1 in running but only from LAST in cycling. VA decreased after S2 (~–7%, P < .05) and LAST (~–9%, P < .01) set in repeated-sprint running and did not change in cycling. Tw, Db100, and Db10/Db100 decreased to a similar extent in both protocols (all P < .001 post-LAST). Both protocols induced a similar level of peripheral fatigue (ie, low-frequency peripheral fatigue, no changes in M-wave characteristics), while underlying mechanisms probably differed. Central fatigue was found only after running.

Conclusion:

Findings about neuromuscular fatigue resulting from RS cycling cannot be transferred to RS running.
Predictive Indicators of Overuse Injuries in Adolescent Endurance Athletes
Authors: Martínez-Silván Daniel , Díaz-Ocejo Jaime , Murray Andrew
Published: December 2016

Purpose:

To analyze the influence of training exposure and the utility of self-report questionnaires on predicting overuse injuries in adolescent endurance athletes.

Methods:

Five adolescent male endurance athletes (15.7 ± 1.4 y) from a full-time sports academy answered 2 questionnaires (Recovery Cue; RC-q and Oslo Sports Trauma Research questionnaire; OSTRC-q) on a weekly basis for 1 season (37 wk) to detect signs of overtraining and underrecovery (RC-q) and early symptoms of lower-limb injuries (OSTRC-q). All overuse injuries were retrospectively analyzed to detect which variations in the questionnaires in the weeks preceding injury were best associated. Overuse incidence rates were calculated based on training exposure.

Results:

Lower-limb overuse injuries accounted for 73% of total injuries. The incidence rate for overuse training-related injuries was 10 injuries/1000 h. Strong correlations were observed between individual running exposure and overuse injury incidence (r2 = .66), number of overuse injuries (r2 = .69), and days lost (r2 = .66). A change of 20% or more in the RC-q score in the preceding week was associated with 67% of the lower-limb overuse injuries. Musculoskeletal symptoms were only detected in advance by the OSTRC-q in 27% of the episodes.

Conclusion:

Training exposure (especially running exposure) was shown to be related to overuse injuries, suggesting that monitoring training load is a key factor for injury prevention. Worsening scores in the RC-q (but not the OSTRC) may be an indicator of overuse injury in adolescent endurance runners when used longitudinally.
Effects of Training Load and Leg Dominance on Achilles and Patellar Tendon Structure
Authors: Esmaeili Alireza , Stewart Andrew M. , Hopkins William G. , Elias George P. , Aughey Robert J.
Published: December 2016

Purpose:

Detrimental changes in tendon structure increase the risk of tendinopathies. The aim of this study was to investigate the influence of individual internal and external training loads and leg dominance on changes in the Achilles and patellar tendon structure.

Methods:

The internal structure of the Achilles and patellar tendons of both limbs of 26 elite Australian footballers was assessed using ultrasound tissue characterization at the beginning and the end of an 18-wk preseason. Linear-regression analysis was used to estimate the effects of training load on changes in the proportion of aligned and intact tendon bundles for each side. Standardization and magnitude-based inferences were used to interpret the findings.

Results:

Possibly to very likely small increases in the proportion of aligned and intact tendon bundles occurred in the dominant Achilles (initial value 81.1%; change, ±90% confidence limits 1.6%, ±1.0%), nondominant Achilles (80.8%; 0.9%, ±1.0%), dominant patellar (75.8%; 1.5%, ±1.5%), and nondominant patellar (76.8%; 2.7%, ±1.4%) tendons. Measures of training load had inconsistent effects on changes in tendon structure; eg, there were possibly to likely small positive effects on the structure of the nondominant Achilles tendon, likely small negative effects on the dominant Achilles tendon, and predominantly no clear effects on the patellar tendons.

Conclusion:

The small and inconsistent effects of training load are indicative of the role of recovery between tendon-overloading (training) sessions and the multivariate nature of the tendon response to load, with leg dominance a possible influencing factor.
The Influence of Changes in Acute Training Load on Daily Sensitivity of Morning-Measured Fatigue Variables in Elite Soccer Players
Authors: Thorpe Robin T. , Strudwick Anthony J. , Buchheit Martin , Atkinson Greg , Drust Barry , Gregson Warren
Published: December 2016

Purpose:

To determine the sensitivity of a range of potential fatigue measures to daily training load accumulated over the previous 2, 3, and 4 d during a short in-season competitive period in elite senior soccer players (N = 10).

Methods:

Total highspeed-running distance, perceived ratings of wellness (fatigue, muscle soreness, sleep quality), countermovement-jump height (CMJ), submaximal heart rate (HRex), postexercise heart-rate recovery (HRR), and heart-rate variability (HRV: Ln rMSSD) were analyzed during an in-season competitive period (17 d). General linear models were used to evaluate the influence of 2-, 3-, and 4-d total high-speed-running-distance accumulation on fatigue measures.

Results:

Fluctuations in perceived ratings of fatigue were correlated with fluctuations in total high-speed-running-distance accumulation covered on the previous 2 d (r = –.31; small), 3 d (r = –.42; moderate), and 4 d (r = –.28; small) (P < .05). Changes in HRex (r = .28; small; P = .02) were correlated with changes in 4-d total high-speed-running-distance accumulation only. Correlations between variability in muscle soreness, sleep quality, CMJ, HRR%, and HRV and total high-speed-running distance were negligible and not statistically significant for all accumulation training loads.

Conclusions:

Perceived ratings of fatigue and HRex were sensitive to fluctuations in acute total high-speed-running-distance accumulation, although sensitivity was not systematically influenced by the number of previous days over which the training load was accumulated. The present findings indicate that the sensitivity of morning-measured fatigue variables to changes in training load is generally not improved when compared with training loads beyond the previous day’s training.
Coefficient of Friction at the Fingertips in Type II Diabetics Compared to Healthy Adults
Authors: Thames Beatriz H. , Gorniak Stacey L.
Published: December 2016

Clinical observations suggest that type II diabetes patients are more susceptible to skin changes, which may be associated with reduced coefficient of friction at the fingertips. Reduced coefficient of friction may explain recent reports of fine motor dysfunction in diabetic patients. Coefficient of friction was evaluated using slip force evaluation in a cross-sectional cohort of diabetic patients and age- and sex-matched healthy controls. Covariates of tactile sensation, disease duration, glycated hemoglobin, and clinical diagnosis of peripheral neuropathy were also assessed. A significant decrease in fingertip coefficient of friction in the diabetic group was found as compared to controls. Health state covariates did not alter the strength of between-group differences in statistical analyses. This finding of between-group differences for fingertip frictional properties suggests that causative factors of reported manual motor dysfunction lie in both the distal and proximal portions of the nervous system.
Draft Genome Sequence of Aeromonas caviae CH129, a Marine-Derived Bacterium Isolated from the Coast of São Paulo State, Brazil
Authors: Cardozo Flávio Augusto , Alfonso Vargas Nadia Catalina , Zimpel Cristina Kraemer , Pessoa Adalberto , Rivera Irma Nelly Gutierrez
Published: December 2016

We report here the draft genome sequence of
Aeromonas caviae
CH129, a marine-derived bacterium isolated from the coast of São Paulo state, Brazil. Genomic analysis revealed genes encoding enzymes involved in binding, transport, and chitin metabolism and different virulence-associated factors.
Genetic characterization of frameshift suppressors with new decoding properties
Authors: Hughes D , Thompson S , O'Connor M , Tuohy T , Nichols B P , Atkins J F
Published: December 2016

Suppressor mutants that cause ribosomes to shift reading frame at specific and new sequences are described. Suppressors for trpE91, the only known suppressible -1 frameshift mutant, have been isolated in Escherichia coli and in Salmonella typhimurium. E. coli hopR acts on trpE91 within the 9-base-pair sequence GGA GUG UGA, is dominant, and is located at min 52 on the chromosome. Its Salmonella homolog maps at an equivalent position and arises as a rarer class in that organism as compared with E. coli. The Salmonella suppressor, hopE, believed to be in a duplicate copy of the same gene, maps at min 17. The +1 suppressor, sufT, acts at the nonmonotonous sequence CCGU, is dominant, and maps at min 59 on the Salmonella chromosome.
Purification and properties of glutathione transferase from Issatchenkia orientalis
Authors: Tamaki H , Kumagai H , Tochikura T
Published: December 2016

Glutathione transferase (GST) (EC 2.5.1.18) was purified from a cell extract of Issatchenkia orientalis, and two GST isoenzymes were isolated. They had molecular weights of 37,500 and 40,000 and were designated GST Y-1 and GST Y-2, respectively. GST Y-1 and GST Y-2 gave single bands with molecular weights of 22,000 and 23,500, respectively, on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. GST Y-1 and GST Y-2 were immunologically distinguished from each other. GST Y-1 showed specific activity 10.4-times and 6.0-times higher when 1-chloro-2,4-dinitrobenzene and o-dinitrobenzene were used as substrates, respectively, than GST Y-2. GST activity was not detected for either isoenzyme when other substrates such as bromosulfophthalein and trans-4-phenyl-3-buten-2-one were used. GST Y-1 and GST Y-2 had Km values of 0.51 and 0.75 mM for glutathione, respectively, and of 0.16 and 4.01 mM for 1-chloro-2,4-dinitrobenzene. GST Y-1 was significantly inhibited by Cibacron blue 3G-A, and GST Y-2 was significantly inhibited by bromosulfophthalein.
Effect of mutations in the cyclic AMP receptor protein-binding site on araBAD and araC expression
Authors: Stoltzfus L , Wilcox G
Published: December 2016

Maximum expression of the adjacent but divergently transcribed araBAD operon and araC gene requires the presence of cyclic AMP (cAMP) and the cAMP receptor protein (CRP). DNase I protection studies have previously revealed a high-affinity CRP-binding site in the ara regulatory region. Deletion mutations introduced into this site resulted in reduced expression of araBAD and araC. However, other experiments have demonstrated that spacing changes in the ara regulatory region may have multiple effects due to disruption of a DNA loop. Thus, the deletions could have destroyed the CRP-binding site, the ability to form a loop, or both. In the present study, substitution mutations were introduced into the CRP site in order to avoid creating spacing changes. We found that a 3-base-pair substitution resulted in a 30% reduction in araBAD expression, whereas a 6-base-pair substitution resulted in an 80% reduction. Both of these substitution mutations reduced araC expression threefold. We conclude that CRP bound to this site regulates expression in both directions. We found that a spacing change in the CRP site does not alter araBAD expression any more than does a substitution mutation.
Translation and processing of Bacillus amyloliquefaciens extracellular RNase
Authors: Paddon C J , Vasantha N , Hartley R W
Published: December 2016

Bacillus amyloliquefaciens extracellular RNase has been previously cloned and expressed in Bacillus subtilis. Site-specific mutagenesis experiments have identified codon -39 as the start site of translation. We have determined the primary signal peptide cleavage site of preprobarnase and propose a pathway for the conversion of probarnase to mature barnase.
Nucleotide sequence and transcriptional analysis of the Streptomyces griseus gene (afsA) responsible for A-factor biosynthesis
Authors: Horinouchi S , Suzuki H , Nishiyama M , Beppu T
Published: December 2016

The nucleotide sequence of the Streptomyces griseus afsA gene, possibly encoding a key enzyme for A-factor (2-isocapryloyl-3R-hydroxymethyl-gamma-butyrolactone) biosynthesis, was determined. The translational initiation codon was identified by introducing out-of-frame mutations at appropriate positions by oligonucleotide-directed mutagenesis. The afsA gene was thus found to code for a protein of 301 amino acid residues and 32.6 kilodaltons whose codon usage pattern was in agreement with the general tendency of Streptomyces genes with an extremely high guanine-plus-cytosine content. High-resolution S1 nuclease mapping indicated that the transcriptional start point was the A residue, the first position of the ATG translational initiation codon.
Evolutionary trees for the genus Bordetella
Authors: Altschul S F
Published: December 2016

Recent data on enzyme electrophoretic mobility and DNA sequences for pertussis toxin allow the construction of evolutionary trees for various strains belonging to the genus Bordetella. In contrast to previous analyses, these data can be seen to support the separate clustering of Bordetella pertussis strains, in agreement with the traditional classification based on other phenotypic characteristics. An earlier argument placing the divergence of B. pertussis and B. parapertussis before 1912 does not follow from the evolutionary trees proposed here, which also have different implications for several other claims concerning the evolution of these strains.
Construction of an ordered cosmid collection of the Escherichia coli K-12 W3110 chromosome
Authors: Tabata S , Higashitani A , Takanami M , Akiyama K , Kohara Y , Nishimura Y , Nishimura A , Yasuda S , Hirota Y
Published: December 2016

A cosmid library of the Escherichia coli K-12 W3110 chromosome was constructed in which clones were assigned to locations on the chromosome map by hybridization and genetic marker complementation tests. Approximately 70% of the genome was represented by this library. The identified clones can be maintained in the homologous system and would facilitate genetic studies of E. coli.
Buoyant density, growth rate, and the cell cycle in Streptococcus faecium
Authors: Glaser D , Higgins M
Published: December 2016

The buoyant density in rapidly growing Streptococcus faecium 9790 cells varies over the cell cycle, in contrast to the density in Escherichia coli. Buoyant density in S. faecium was measured by using Percoll (Pharmacia Fine Chemicals, Piscataway, N.J.) density gradients. We found that the mean and coefficient of variation of the population density increased with growth rate; and within a population, the mean cell volume, which was measured electronically, increased with density. These results were compared with electron microscopic measurements of the size distributions of cell wall growth sites within each fraction of the density gradient. As the density increased within a population, the frequency of large cells increased and the frequency of newly initiated cell wall growth sites increased. These effects were more marked as the growth rate increased. Next, these data were regrouped by cell size by using the size of the central growth site as an index of cell cycle stage. Each frequency value was weighted by the proportion of the population represented by that density fraction. Then, the average buoyant density was calculated for each value of cell size. In all cell populations, the density decreased and then increased as the central site enlarged. Peripheral growth sites were initiated as density reached a maximum. At faster growth rates, density increased more steeply, and new peripheral growth sites opened up at a higher frequency. We suggest that the rate at which density increases during the cell cycle correlates with the initiation of new cell wall growth sites.
Sulfide induction of synthesis of a periplasmic protein in the cyanobacterium Oscillatoria limnetica
Authors: Arieli B , Binder B , Shahak Y , Padan E
Published: December 2016

Two proteins which may play a role in the induction of anoxygenic photosynthesis in Oscillatoria limnetica have been demonstrated by comparing the pattern of labeling during pulses of [35S]methionine of cells incubated under inducing conditions [anaerobic conditions plus 3-(3,4-dichlorophenyl)-1,1-dimethylurea, light, and sulfide) with that of cells incubated under noninducing conditions (without sulfide). The major inducible protein has an apparent molecular mass of 11.5 kilodaltons and is associated with a less strongly labeled 12.5-kilodalton protein. The synthesis of both proteins commences within the first 30 min of induction and continues throughout the 2-h induction period. Since these proteins are not synthesized in the presence of dithionite without sulfide, low redox potential alone is insufficient as an inducer of these proteins. Lysozyme treatment and/or osmotic shock of intact cells results in the release of the sulfide-induced proteins. Our data thus indicate that these proteins are located in the periplasmic space of the cells.
DNA bending near the replication origin of IncFII plasmid NR1
Authors: Dong X N , Rouillard K P , Womble D D , Rownd R H
Published: December 2016

The DNA replication origin of plasmid NR1 is located approximately 190 base pairs downstream from the 3' end of the repA1 gene, which encodes the essential initiation protein for replication of the plasmid. Restriction endonuclease fragments that contain the NR1 replication origin and its flanking sequences at circularly permuted positions were obtained by digesting oligomers of ori-containing DNA fragments with sets of enzymes that each cut only once in every ori fragment. Polyacrylamide gel electrophoresis of these permuted restriction fragments showed anomalous mobilities, indicating the presence of a DNA bending locus. Through analysis of the relative mobility plots of these permuted fragments, we found one or two possible DNA bending sites located in the intervening region between the repA1 gene and the replication origin of NR1. It seems possible that DNA bending in this region might help to orient the replication origin alongside the repA1 gene, which could contribute to the cis-acting character of the RepA1 initiation protein.
Nucleotide sequence of a cluster of Escherichia coli enterobactin biosynthesis genes: identification of entA and purification of its product 2,3-dihydro-2,3-dihydroxybenzoate dehydrogenase
Authors: Liu J , Duncan K , Walsh C T
Published: December 2016

The nucleotide sequence of a region of the Escherichia coli chromosome encoding part of a cluster of genes involved in the biosynthesis of the iron chelator enterobactin has been determined. Four closely linked open reading frames, corresponding to the coding regions of entE (carboxy-terminal 144 amino acids), entB (32,554 daltons), entA (26,249 daltons), and an unidentified gene (P15) encoding a 14,970-dalton protein, were found. The lack of intergenic sequences and promoterlike elements suggests that these genes form part of the same transcription unit. We report the purification to homogeneity of the entA product, 2,3-dihydro-2,3-dihydroxybenzoate dehydrogenase. It is an octamer of native molecular weight 210,000; the amino-terminal amino acid sequence confirmed the entA coding region. No isochorismate synthase activity was associated with this polypeptide. This finding leads to the conclusion that the recent suggestion (M. S. Nahlik, T. P. Fleming, and M. A. McIntosh, J. Bacteriol. 169:4163-4170, 1987) that 2,3-dihydro-2,3-dihydroxybenzoate dehydrogenase and isochorismate synthase activities reside on a single 26,000-dalton bifunctional enzyme is incorrect, even though the entA and entC mutations map to the same genetic locus.
Gliding motility in Myxococcus xanthus: mgl locus, RNA, and predicted protein products
Authors: Stephens K , Hartzell P , Kaiser D
Published: December 2016

Mutants of Myxococcus xanthus that had lost the ability to glide were examined to elucidate the mechanism of gliding motility. Nonmotile mutants resulting from a single mutational step were all defective at the same locus, mgl, which implied an important role for the mgl product(s) in gliding. Deletion experiments, transposon insertion mutagenesis, and genetic rescue of mgl mutants mapped the locus to a 1.6-kilobase segment of Myxococcus DNA. Two species of RNA that hybridized with mgl DNA were found both during vegetative growth and during the starvation-induced development of fruiting bodies, which also requires cell movement. The two RNA species, of 1.5 and 1.3 kilobases, had the same 5' to 3' orientation and overlapped extensively. The DNA sequences of mgl+ and of seven mgl mutants were determined. Each mutant differed from mgl+ by a single-base-pair change in the sequence. Two adjacent open reading frames were found in the sequence hybridizing to both species of mgl RNA. Six of the single-base-pair changes, each of which would result in a single-amino-acid change, and an insertion-produced mgl mutation were located in the downstream open reading frame. This open reading frame (of 195 amino acids) is therefore an mgl gene, called mglA. The function of the upstream open reading frame is not known with certainty, although it does contain one of the mgl mutant sites and could be a second mgl gene.
Ornithine cyclodeaminase from octopine Ti plasmid Ach5: identification, DNA sequence, enzyme properties, and comparison with gene and enzyme from nopaline Ti plasmid C58
Authors: Schindler U , Sans N , Schröder J
Published: December 2016

Octopine and nopaline are two arginine-derived opines synthesized in plant cells transformed with octopine or nopaline plasmids. Utilization in Agrobacterium tumefaciens is mediated by Ti plasmid regions called occ or noc (octopine or nopaline catabolism), and recent experiments showed that noc in pTiC58 codes for a pathway from nopaline to L-proline. The last enzyme is ornithine cyclodeaminase (OCD), an unusual protein converting L-ornithine directly into L-proline. We investigated whether octopine plasmid pTiAch5 also harbors a gene for OCD. The results revealed an ocd gene which is induced by octopine and maps in the occ region. DNA sequence analysis and comparison with the gene from pTiC58 showed that the two genes are related (69% homology in DNA and deduced amino acid sequence), and antiserum against OCD(C58) also reacted with OCD(Ach5). The enzyme activity was characterized, and a comparison with OCD(C58) showed that the properties are similar, but not identical. Differences were detected in the regulation of enzyme activity by L-arginine and L-proline and in the response to varying ratios of NAD+/NADH. It is proposed that this reflects different mechanisms for integration of opine catabolism into general metabolism.
A second global regulator gene (arcB) mediating repression of enzymes in aerobic pathways of Escherichia coli
Authors: Iuchi S , Cameron D C , Lin E C
Published: December 2016

In Escherichia coli anaerobic growth lowers the basal or induced levels of numerous enzymes associated with aerobic metabolism. Mutations in arcA (dye) at min 0 relieve this pleiotropic anaerobic repression and render the cell sensitive to the redox dye toluidine blue. In this study we identified a second pleiotropic control gene, arcB, at min 69.5. Mutations, including a deletion, in this gene also relieved the anaerobic repression and caused sensitivity to toluidine blue. Mutations in arcA or arcB did not significantly change the catabolite repression of the target phi(sdh-lacZ) operon, in which lacZ is fused to a structural gene for succinate dehydrogenase, nor did the mutations strikingly influence the pattern of excretion products during glucose fermentation. The presence of arcA+ in a multicopy plasmid restored anaerobic repression in arcB mutants, as indicated by the expression of phi(sdh-lacZ). The arcB product might be a sensor protein for the redox or energy state of the arc regulatory system.
Involvement of multiple genetic determinants in high-level methicillin resistance in Staphylococcus aureus
Authors: Murakami K , Tomasz A
Published: December 2016

A methicillin-susceptible, novobiocin-resistant strain of Staphylococcus aureus (RN2677; methicillin MIC, 0.8 micrograms/ml) was transformed with DNA prepared from highly and homogeneously methicillin-resistant S. aureus strains (methicillin MIC, greater than or equal to 400 micrograms/ml) or from heterogeneous strains in which the majority of cells had a low level of resistance (methicillin MIC, 6.3 micrograms/ml). All methicillin-resistant transformants showed low and heterogeneous resistance (methicillin MIC, 3.1 micrograms/ml) irrespective of the resistance level of DNA donors. All transformants examined produced normal amounts of the low-affinity penicillin-binding protein (PBP) 2a, and methicillin resistance and the capacity to produce PBP 2a showed the same degree of genetic linkage to the novobiocin resistance marker with both homogeneous and heterogeneous DNA donors. Next, we isolated a methicillin-susceptible mutant from a highly and homogeneously resistant strain which had a Tn551 insertion near or within the PBP 2a gene and thus did not produce PBP 2a. With this mutant used as the recipient, genetic transformation of the methicillin resistance gene was repeated with DNA isolated either from highly and homogeneously resistant strains or from heterogeneous (low-resistance) strains. All transformants obtained expressed high and homogeneous resistance and produced PBP 2a irrespective of the resistance level of the DNA donors. Our findings suggest that (i) the methicillin resistance locus is identical to the structural gene for PBP 2a, (ii) although the ability to produce PBP 2a is essential for resistance, the MICs for the majority of cells are not related to the cellular concentration of PBP 2a, and (iii) high MICs and homogeneous expression of resistance require the products of other distinct genetic elements as well.
Cloning and heterologous expression in Streptomyces lividans of Streptomyces rimosus genes involved in oxytetracycline biosynthesis
Authors: Binnie C , Warren M , Butler M J
Published: December 2016

The anhydrotetracycline (ATC) oxygenase enzyme which carries out the conversion of ATC to dehydrotetracycline was purified and the N-terminal amino acid sequence was determined. The sequence displays a significant similarity to that of the p-hydroxybenzoate hydroxylase from Pseudomonas fluorescens. This is consistent with the activity of the oxygenase, i.e., addition of a hydroxyl moiety to an aromatic ring structure. Oligonucleotide probes were designed and used to clone the corresponding fragment of chromosomal DNA from Streptomyces rimosus. This DNA fragment was used to screen a cosmid library, allowing the isolation of flanking DNA sequences. Surprisingly, the gene was located within the previously cloned cluster of genes involved in the synthesis of the biosynthetic intermediate ATC and not as had been expected (P. M. Rhodes, N. Winskill, E. J. Friend, and M. Warren, J. Gen. Microbiol. 124:329-338, 1981) at a separate locus on the other side of the chromosome. Subcloning of an appropriate DNA fragment from one of the cosmid clones onto pIJ916 produced Streptomyces lividans transformants which synthesized oxytetracycline.
Biosynthesis of linkage units for teichoic acids in gram-positive bacteria: distribution of related enzymes and their specificities for UDP-sugars and lipid-linked intermediates
Authors: Yokoyama K , Mizuguchi H , Araki Y , Kaya S , Ito E
Published: December 2016

The distribution and substrate specificities of enzymes involved in the formation of linkage units which contain N-acetylglucosamine (GlcNAc) and N-acetylmannosamine (ManNAc) or glucose and join teichoic acid chains to peptidoglycan were studied among membrane systems obtained from the following two groups of gram-positive bacteria: group A, including Bacillus subtilis, Bacillus licheniformis, Bacillus pumilus, Staphylococcus aureus, and Lactobacillus plantarum; group B, Bacillus coagulans. All the membrane preparations tested catalyzed the synthesis of N-acetylglucosaminyl pyrophosphorylpolyprenol (GlcNAc-PP-polyprenol). The enzymes transferring glycosyl residues to GlcNAc-PP-polyprenol were specific to either UDP-ManNAc (group A strains) or UDP-glucose (group B strains). In the synthesis of the disaccharide-bound lipids, GlcNAc-PP-dolichol could substitute for GlcNAc-PP-undecaprenol. ManNAc-GlcNAc-PP-undecaprenol, ManNAc-GlcNAc-PP-dolichol, Glc-GlcNAc-PP-undecaprenol, Glc-GlcNAc-PP-dolichol, and GlcNAc-GlcNAc-PP-undecaprenol were more or less efficiently converted to glycerol phosphate-containing lipid intermediates and polymers in the membrane systems of B. subtilis W23 and B. coagulans AHU 1366. However, GlcNAc-GlcNAc-PP-dolichol could not serve as an intermediate in either of these membrane systems. Further studies on the exchangeability of ManNAc-GlcNAc-PP-undecaprenol and Glc-GlcNAc-PP-undecaprenol revealed that in the membrane systems of S. aureus strains and other B. coagulans strains both disaccharide-inked lipids served almost equally as intermediates in the synthesis of polymers. In the membrane systems of other B. subtilis strains as well as B. licheniformis and B. pumilus strains, however, the replacement of ManNAc-GlcNAc-PP-undecaprenol by Glc-GlcNAc-PP-undecaprenol led to a great accumulation of (glycerol phosphate)-Glc-GlcNAc-PP-undecaprenol accompanied by a decrease in the formation of polymers.
Insertion proQ220::Tn5 alters regulation of proline porter II, a transporter of proline and glycine betaine in Escherichia coli
Authors: Milner J L , Wood J M
Published: December 2016

Mutation pro-220::Tn5, which increases the resistance of Escherichia coli to 3,4-dehydroproline (M. E. Stalmach, S. Grothe, and J. M. Wood, J. Bacteriol. 156:481-486, 1983), is not linked to putP, proP, or proU. It was located at 40.4 min on the E. coli chromosomal linkage map, by conjugational and transductional mapping, and is now denoted proQ220::Tn5. Proline porter II was not detectable when proQ220::Tn5 proP+ bacteria were cultivated under optimal conditions or with nutritional stress (amino acid limitation). Toxic proline analog sensitivity and proline porter II activity were partially restored to proQ220::Tn5 proP+ bacteria, but not to a proQ220::Tn5 proP219 strain, by a hyperosmotic shift and by growth under osmotic stress. Elevated expression of a proP::lacZ gene fusion, for bacteria grown under osmotic stress, was not influenced by the proQ220::Tn5 insertion. We propose that the proQ locus encodes a positive regulatory element which elevates proline porter II activity.
Adult ileocolic intussusception caused by Burkitt lymphoma
Authors: Bernardi Daniele , Asti Emanuele , Bonavina Luigi
Published: December 2016

Ileocolic intussusception due to Burkitt lymphoma is extremely rare in adults. A man aged 17 years presented with a history of recurrent abdominal pain over the past 3 weeks. The abdomen was distended with diffuse tenderness, and bowel sounds were present. Abdominal ultrasound and CT scans showed evidence of small bowel obstruction with marked wall thickening in the ileocecal region and ‘target’ signs suggestive for intussusception. At laparoscopy, a mass involving the caecum and the terminal ileum was found, along with multiple locoregional nodes, which was highly suggestive of malignancy. A typical en bloc right colectomy with intracorporeal ileocolic anastomosis was performed. Histopathological examination showed a high-grade B-cell Burkitt lymphoma that was confirmed by immunohistochemistry. The patient was subsequently treated with adjuvant combination chemotherapy and is alive and disease-free at the 3-year follow-up.
Multi-year impacts of permafrost disturbance and thermal perturbation on High Arctic stream chemistry
Authors: Lamhonwah Daniel , Lafrenière M. J. , Lamoureux S. F. , Wolfe B. B.
Published: December 2016

Permafrost disturbances (such as active layer detachment (ALD) slides) and thermal perturbation (deep ground thaw from high soil temperatures) alter Arctic surface water chemistry. However, the potential multi-year impacts on water chemistry and the ultimate recovery time are not well understood. This study evaluates the impacts on surface waters and recovery following disturbance of a High Arctic catchment in 2007 from ALDs. We measured ion concentrations and stable isotopes in surface waters collected between 2006 and 2014 from paired catchments — one disturbed and the other not. The years 2007 and 2012 were exceptionally warm and represent unusual thermal perturbation for both catchments. Results indicate that the exposure and mobilization of soluble ions in near surface soil is a key control over dissolved ion concentrations and composition following ALDs. Runoff in the disturbed catchment shows increased total dissolved solute (TDS) concentrations and seasonal TDS fluxes and changes to the relative composition of individual ions in surface water. These impacts persisted for the 7 year study duration after disturbance and are consistent with the thawing of the solute-rich transient layer and upper permafrost. Thermal perturbation increased TDS concentrations and seasonal fluxes in runoff for up to 2 years, as ions released from ground thaw appear to be available for flushing in subsequent summers.
On displaceability of pre-Lagrangian toric fibers in contact toric manifolds
Authors: Marinković A. , Pabiniak M.
Published: December 2016

In this paper, we analyze displaceability of pre-Lagrangian toric fibers in contact toric manifolds. While every symplectic toric manifold contains at least one non-displaceable Lagrangian toric fiber and infinitely many displaceable ones, we show that this is not the case for contact toric manifolds. More precisely, we prove that for the contact toric manifolds [Formula: see text] and [Formula: see text] all pre-Lagrangian toric fibers are displaceable, and that for all contact toric manifolds for which the toric action is free, except possibly non-trivial [Formula: see text]-bundles over [Formula: see text], all pre-Lagrangian toric fibers are non-displaceable. Moreover, we also prove that if for a compact connected contact toric manifold all but finitely many pre-Lagrangian toric fibers are non-displaceable then the action is necessarily free. On the other hand, as we will discuss, displaceability of all pre-Lagrangian toric fibers seems to be related to the non-orderability of the underlying contact manifolds.
Upper Limb Motion Recognition Based on LLE-ELM Method of sEMG
Authors: Wu Qun , Shao Junkai , Wu Xuehua , Zhou Yongjian , Liu Fuping , Xiao Fu
Published: December 2016

The purpose of this paper is to develop an effective method to identify upper limb motions based on EMG signal for community rehabilitation. The method will be applicable to the control system in the rehabilitation equipment and provide objective data for quantitative assessment. The recognition goal sets of upper limb motion are constructed by decomposing assessment activities of activity of daily living scale (ADL). The recognition feature vector space is established by Variance (VAR), Mean Absolute Value (MAV), the fourth-order Autoregressive (the 4thAR), Zero Crossings (ZC’s), integral EMG (IEMG), and Root Mean Square (RMS), and various feature sets are extracted to get the best classification. Locally linear embedding (LLE) algorithm is used to reduce the computational complexity, and upper limb motions about shoulder, elbow and wrist are quickly classified through extreme leaving machine (ELM), which obtained the average accuracy of 98.14%, 98.61% and 94.77%, respectively. Furthermore, when ELM is compared with Back-propagation (BP) and Support vector machine (SVM), it has performed relatively better than BP and SVM. The results show that the validity of the mixed model for recognition is verified. In addition, the method can also provide a basis for recognition and assessment of the angle of upper limb joint in the next study.
Review: The Use of Equivalent Source Method in Computational Acoustics
Authors: Lee Seongkyu
Published: December 2016

This paper reviews the equivalent source method (ESM), an attractive alternative to the standard boundary element method (BEM). The ESM has been developed under different names: method of fundamental solutions, wave superposition method, equivalent source method, etc. However, regardless of the method name, the basic concept is very similar; that is to use auxiliary points called equivalent sources to reconstruct the acoustic pressure for radiation or scattering problems. The strength of the equivalent sources are then determined via various approaches such that the boundary conditions on the boundary surface are satisfied. This paper reviews several frequency-domain and time-domain ESMs. There are several distinct advantages in these types of methods: (1) the method is a meshless approach so that it is easy and simple to implement; (2) it does not have a numerical singularity problem that occurs in the BEM; (3) the number of equivalent sources can be fewer than the number of surface collocation points so that the matrix size is reduced and a fast computation is achieved for large problems. The main issue of the ESM is that there is no rule to find out the optimal number and position of equivalent sources. In addition, the ESM suffers from the numerical instability that is associated with the ill-conditioned matrix. Some guidelines have been suggested in terms of finding the number and position of the sources, and several numerical techniques have been developed to resolve the numerical instability. This paper reviews the common theories, numerical issues and challenges of the ESM, and it summarizes recent developments and applications of the ESM to aircraft noise.