bluuebunny/crossref_metadata_2025 huggingface dataset:
Gene fusions with lacZ by duplication insertion in the radioresistant bacterium Deinococcus radiodurans
Authors: Lennon E , Minton K W
Published: November 2016

Deinococcus radiodurans is the most-studied species of a eubacterial family characterized by extreme resistance to DNA damage. We have focused on developing molecular biological techniques to investigate the genetics of this organism. We report construction of lacZ gene fusions by a method involving both in vitro splicing and the natural transformation of D. radiodurans. Numerous fusion strains were identified by expression of beta-galactosidase. Among these fusion strains, several were inducible by exposure to the DNA-damaging agent mitomycin C, and four of the inducible fusion constructs were cloned in Escherichia coli. Hybridization studies indicate that one of the damage-inducible genes contains a sequence reiterated throughout the D. radiodurans chromosome. Survival measurements show that two of the fusion strains have increased sensitivity to mitomycin C, suggesting that the fusions within these strains inactivate repair functions.
Morganella morganii urease: purification, characterization, and isolation of gene sequences
Authors: Hu L T , Nicholson E B , Jones B D , Lynch M J , Mobley H L
Published: November 2016

Morganella morganii, a very common cause of catheter-associated bacteriuria, was previously classified with the genus Proteus on the basis of urease production. M. morganii constitutively synthesizes a urease distinct from that of other uropathogens. The enzyme, purified 175-fold by passage through DEAE-Sepharose, phenyl-Sepharose, Mono-Q, and Superose 6 chromatography resins, was found to have a native molecular size of 590 kilodaltons and was composed of three distinct subunits with apparent molecular sizes of 63, 15, and 6 kilodaltons, respectively. Amino-terminal analysis of the subunit polypeptides revealed a high degree of conservation of amino acid sequence between jack bean and Proteus mirabilis ureases. Km for urea equalled 0.8 mM. Antiserum prepared against purified enzyme inhibited activity by 43% at a 1:2 dilution after 1 h of incubation. All urease activity was immunoprecipitated from cytosol by a 1:16 dilution. Antiserum did not precipitate ureases of other species except for one Providencia rettgeri strain but did recognize the large subunits of ureases of Providencia and Proteus species on Western blots (immunoblots). Thirteen urease-positive cosmid clones of Morganella chromosomal DNA shared a 3.5-kilobase (kb) BamHI fragment. Urease gene sequences were localized to a 7.1-kb EcoRI-SalI fragment. Tn5 mutagenesis revealed that between 3.3 and 6.6 kb of DNA were necessary for enzyme activity. A Morganella urease DNA probe did not hybridize with gene sequences of other species tested. Morganella urease antiserum recognized identical subunit polypeptides on Western blots of cytosol from the wild-type strain and Escherichia coli bearing the recombinant clone which corresponded to those seen in denatured urease. Although the wild-type strain and recombinant clone produced equal amounts of urease protein, the clone produced less than 1% of the enzyme activity of the wild-type strain.
Genetic and physiological characterization of the purine salvage pathway in the archaebacterium Methanobacterium thermoautotrophicum Marburg
Authors: Worrell V E , Nagle D P
Published: November 2016

The enzymes involved in the purine interconversion pathway of wild-type and purine analog-resistant strains of Methanobacterium thermoautotrophicum Marburg were assayed by radiometric and spectrophotometric methods. Wild-type cells incorporated labeled adenine, guanine, and hypoxanthine, whereas mutant strains varied in their ability to incorporate these bases. Adenine, guanine, hypoxanthine, and xanthine were activated by phosphoribosyltransferase activities present in wild-type cell extracts. Some mutant strains simultaneously lost the ability to convert both guanine and hypoxanthine to the respective nucleotide, suggesting that the same enzyme activates both bases. Adenosine, guanosine, and inosine phosphorylase activities were detected for the conversion of base to nucleoside. Adenine deaminase activity was detected at low levels. Guanine deaminase activity was not detected. Nucleoside kinase activities for the conversion of adenosine, guanosine, and inosine to the respective nucleotides were detected by a new assay. The nucleotide-interconverting enzymes AMP deaminase, succinyl-AMP synthetase, succinyl-AMP lyase, IMP dehydrogenase, and GMP synthetase were present in extracts; GMP reductase was not detected. The results indicate that this autotrophic methanogen has a complex system for the utilization of exogenous purines.
Nucleotide sequences and mutational analysis of the structural genes for nitrogenase 2 of Azotobacter vinelandii
Authors: Joerger R D , Loveless T M , Pau R N , Mitchenall L A , Simon B H , Bishop P E
Published: November 2016

The nucleotide sequence (6,559 base pairs) of the genomic region containing the structural genes for nitrogenase 2 (V nitrogenase) from Azotobacter vinelandii was determined. The open reading frames present in this region are organized into two transcriptional units. One contains vnfH (encoding dinitrogenase reductase 2) and a ferredoxinlike open reading frame (Fd). The second one includes vnfD (encoding the alpha subunit of dinitrogenase 2), vnfG (encoding a product similar to the delta subunit of dinitrogenase 2 from A. chroococcum), and vnfK (encoding the beta subunit of dinitrogenase 2). The 5'-flanking regions of vnfH and vnfD contain sequences similar to ntrA-dependent promoters. This gene arrangement allows independent expression of vnfH-Fd and vnfDGK. Mutant strains (CA80 and CA11.80) carrying an insertion in vnfH are still able to synthesize the alpha and beta subunits of dinitrogenase 2 when grown in N-free, Mo-deficient, V-containing medium. A strain (RP1.11) carrying a deletion-plus-insertion mutation in the vnfDGK region produced only dinitrogenase reductase 2.
Cloning and expression of daunorubicin biosynthesis genes from Streptomyces peucetius and S. peucetius subsp. caesius
Authors: Otten S L , Stutzman-Engwall K J , Hutchinson C R
Published: November 2016

Genes for the biosynthesis of daunorubicin (daunomycin) and doxorubicin (adriamycin), important antitumor drugs, were cloned from Streptomyces peucetius (the daunorubicin producer) and S. peucetius subsp. caesius (the doxorubicin producer) by use of the actI/tcmIa and actIII polyketide synthase gene probes. Restriction mapping and Southern analysis of the DNA cloned in a cosmid vector established that the DNA represented three nonoverlapping regions of the S. peucetius subsp. caesius genome. These three regions plus an additional one that hybridized to the same probes are present in the S. peucetius genome, as reported previously (K. J. Stutzman-Engwall and C. R. Hutchinson, Proc. Natl. Acad. Sci. USA 86:3135-3139, 1989). Functional analysis of representative clones from some of these regions in S. lividans, S. peucetius ATCC 29050, S. peucetius subsp. caesius ATCC 27952, and two of its blocked mutants (strains H6101 and H6125) showed that many of the antibiotic production genes reside in the region of DNA represented by the group IV clones. This conclusion is based on the production of epsilon-rhodomycinone, a key intermediate of the daunorubicin pathway, in certain S. lividans transformants and on the apparent complementation of mutations that block daunorubicin biosynthesis in strains H6101 and H6125. Some of the transformants of strains 29050, 27952, and H6125 exhibited substantial overproduction of epsilon-rhodomycinone and daunorubicin.
Transduction in the archaebacterium Methanobacterium thermoautotrophicum Marburg
Authors: Meile L , Abendschein P , Leisinger T
Published: November 2016

The virulent bacteriophage psi M1 of Methanobacterium thermoautotrophicum Marburg mediated transduction of a resistance marker and of three biosynthesis markers. Transductants were observed at frequencies of 6 x 10(-4) to 5 x 10(-6)/PFU.
Activation of expression of the Escherichia coli cir gene by an iron-independent regulatory mechanism involving cyclic AMP-cyclic AMP receptor protein complex
Authors: Griggs D W , Kafka K , Nau C D , Konisky J
Published: November 2016

Synthesis of the colicin I receptor protein, encoded by the cir gene, was determined to be sensitive to control by the catabolite repression regulatory system. Under both high- and low-iron conditions for growth, mutants unable to produce cyclic AMP (cAMP) (cya) or functional cAMP receptor protein (crp) exhibited decreased membrane levels of the receptor relative to those of the wild-type strain. Exogenous addition of cAMP to the cya mutant restored maximal expression. cAMP-dependent changes in steady-state levels of cir mRNA suggested that the effect is mediated by control of transcript synthesis or stability. Potential mechanisms for regulation were examined by deletion and sequence analysis.
The Bacillus subtilis sigma D-dependent operon encoding the flagellar proteins FliD, FliS, and FliT
Authors: Chen L , Helmann J D
Published: November 2016

During a genetic screen to identify metalloregulated loci in Bacillus subtilis, we isolated a Tn917-lacZ insertion in the second gene of an operon downstream of the flagellin (hag) gene. Sequence analysis indicates that this gene encodes a homolog of the enteric flagellar filament cap protein FliD. The fliD gene is followed by homologs of the fliS and fliT genes. Transcription of the fliD-lacZ fusion is sigma D dependent, with peak expression at the end of logarithmic-phase growth. Like other sigma D-dependent genes, expression of fliD-lacZ is greatly reduced by mutations in genes essential for assembly and function of the basal body and hook complex (class II functions). These results suggest that B. subtilis flagellar genes are organized in a hierarchy of gene expression similar to that found in enteric bacteria with hag and fliD as class III genes. Expression from the fliD operon promoter, but not the hag promoter, is repressed by iron, which suggests that the target of metalloregulation is the promoter rather than the sigma D protein.
Characterization of a region of plasmid pBL1 of Brevibacterium lactofermentum involved in replication via the rolling circle model
Authors: Fernandez-Gonzalez C , Cadenas R F , Noirot-Gros M F , Martin J F , Gil J A
Published: November 2016

The minimal region for autonomous replication of pBL1, a 4.5-kb cryptic plasmid of Brevibacterium lactofermentum ATCC 13869 that has been used to construct a variety of corynebacterium vectors, was shown to be contained on a 1.8-kb HindII-SphI DNA fragment. This region contains two open reading frames (ORFs) (ORF1 and ORF5) which are essential for pBL1 replication in B. lactofermentum. Accumulation of single-strand intermediates in some of the constructions indicates that plasmid pBL1 replicates via the rolling circle replication model; its plus strand and minus strand were identified by hybridization with two synthetic oligonucleotide probes complementary to each pBL1 strand. ORF1 seems to encode the Rep protein and showed partial homology with sequences for Rep proteins from Streptomyces plasmids which replicate via rolling circle replication such as pIJ101, pSB24, and pJV1.
Gonococcal transferrin-binding protein 2 facilitates but is not essential for transferrin utilization
Authors: Anderson J E , Sparling P F , Cornelissen C N
Published: November 2016

Pathogenic Neisseria species have been shown to scavenge iron from transferrin (Tf), although the mechanism is not yet fully understood. Two iron-repressible proteins that exhibit Tf-binding activity have been identified. This work describes the cloning and sequencing of tbpB, a 2.1-kb gene in N. gonorrhoeae that encodes Tbp2, an 85-kDa iron-repressible lipoprotein. Transcriptional interruption of tbpB had a strong polar effect on tbpA, the structural gene for Tbp1 that is located immediately downstream from tbpB. Such tbpB mutants did not express either Tbp2 or Tbp1, did not bind Tf to whole cells, did not grow on Tf plates, and did not take up iron from Tf. A mutant in which most of tbpB was deleted, presumably leaving tbpA under transcriptional control of the tbpB promoter, was constructed. This mutant did not express Tbp2 but expressed wild-type levels of Tbp1 and possessed the phenotype of reduced binding of Tf, decreased iron uptake from Tf, but normal growth on Tf plates. Mutants expressing Tbp2 and not Tbp1 bound less Tf, did not grow on Tf plates, and did not take up iron from Tf. These results suggest that tbpB and tbpA are polycistronic. Tbp2 apparently facilitates binding of Tf but is not essential for acquisition of iron from Tf under these in vitro conditions.
Evidence that coupling sequences play a frequency-determining role in conjugative transposition of Tn916 in Enterococcus faecalis
Authors: Jaworski D D , Clewell D B
Published: November 2016

The conjugative transposon Tn916 (encodes resistance to tetracycline), originally identified in Enterococcus faecalis, moves by an excision-insertion process in which the rate-limiting step is believed to be excision. Individual transposon-containing strains exhibit characteristic mating frequencies which range over several orders of magnitude; the basis of this phenomenon is addressed in the present study. We were able to generate independent single-copy insertions in identical target locations and with similar orientations within a plasmid hemolysin determinant (cylA); however, transposition from this site occurred at very different frequencies (10(-8) to 10(-4) per donor) depending on the individual isolate. DNA sequencing analyses showed that the coupling (junction) sequences differed between isolates and thus appeared to be responsible for differences in excision frequencies. Other experiments showed that inducible transcription into either end of the transposon had no significant effect on transfer.
Characterization of IS905, a new multicopy insertion sequence identified in lactococci
Authors: Dodd H M , Horn N , Gasson M J
Published: November 2016

IS905 is a multicopy insertion sequence identified in Lactococcus lactis. It is 1313 bp long, bounded by 28-bp imperfect inverted repeats, and encodes a putative transposase of 391 amino acids. One end of IS905 contains sequences that are potentially promoter active. It displays sequence homology to the IS256 class of elements.
Disseminated cryptococcosis in an immunocompetent child
Authors: Saeed Noora , Ansari Hena A , Khan Nazoora , Aijaz Mohsin
Published: November 2016

Cryptococcusis a ubiquitous fungus and is known for causing meningitis and cutaneous infections in immunocompromised individuals. Disseminated cryptococcal infection is very rare and almost always found to occur in immunocompromised individuals especially in persons infected with HIV. This is particularly attributed to its capsulated spores. But there are few reported cases in which it has been found to cause disseminated infections even in immunocompetent individuals. We report a similar case of disseminated cryptococcal infection in an immunocompetent host. Early detection and treatment of disseminated cryptococcosis is essential to reduce morbidity and for better outcome.
Acquired haemophilia A: an unusual postoperative complication
Authors: Arora Sumant , Goyal Gaurav , Sarmad Rehan , Wool Kenneth J
Published: November 2016

An African-American man aged 65 years with multiple malignancies in remission was admitted for small bowel obstruction. He was treated with laparotomy following failure of conservative management. Postoperatively, he developed intra-abdominal bleed, which persisted, despite surgical haematoma evacuation. Further haematological workup revealed isolated prolongation of activated partial thromboplastin time (aPTT) with reduced factor VIII (FVIII) activity and raised FVIII inhibitor titre. Assuming acquired haemophilia A (AHA), FVIII inhibitor bypassing activity and corticosteroids were started with subsequent resolution of the bleeding from the surgical site. The patient remained free of bleeding episodes at 3-month follow-up and the aPTT normalised. This case report highlights the association of surgery with AHA and summarises the treatments with underlying mechanisms.
Lost information during the handover of critically injured trauma patients: a mixed-methods study
Authors: Zakrison Tanya Liv , Rosenbloom Brittany , McFarlan Amanda , Jovicic Aleksandra , Soklaridis Sophie , Allen Casey , Schulman Carl , Namias Nicholas , Rizoli Sandro
Published: November 2016

Background

Clinical information may be lost during the transfer of critically injured trauma patients from the emergency department (ED) to the intensive care unit (ICU). The aim of this study was to investigate the causes and frequency of information discrepancies with handover and to explore solutions to improving information transfer.

Methods

A mixed-methods research approach was used at our level I trauma centre. Information discrepancies between the ED and the ICU were measured using chart audits. Descriptive, parametric and non-parametric statistics were applied, as appropriate. Six focus groups of 46 ED and ICU nurses and nine individual interviews of trauma team leaders were conducted to explore solutions to improve information transfer using thematic analysis.

Results

Chart audits demonstrated that injuries were missed in 24% of patients. Clinical information discrepancies occurred in 48% of patients. Patients with these discrepancies were more likely to have unknown medical histories (p<0.001) requiring information rescue (p<0.005). Close to one in three patients with information rescue had a change in clinical management (p<0.01). Participants identified challenges according to their disciplines, with some overlap. Physicians, in contrast to nurses, were perceived as less aware of interdisciplinary stress and their role regarding variability in handover. Standardising handover, increasing non-technical physician training and understanding unit cultures were proposed as solutions, with nurses as drivers of a culture of safety.

Conclusion

Trauma patient information was lost during handover from the ED to the ICU for multiple reasons. An interprofessional approach was proposed to improve handover through cross-unit familiarisation and use of communication tools is proposed. Going beyond traditional geographical and temporal boundaries was deemed important for improving patient safety during the ED to ICU handover.
22nd Annual IHI Scientific Symposium on Improving the Quality and Value of Health Care
Authors: Parry Gareth
Published: November 2016

Background

Hosted by the Institute for Healthcare Improvement (IHI), the 22nd Annual Scientific Symposium on Improving the Quality and Value of Health Care takes place on Monday, December 5, 2016, in Orlando, Florida, USA. The Scientific Symposium aimed to attract high quality, scientific work, focused on the improvement of health and health care. The Symposium also aimed to foster dialog and share learning among participants. The day features keynote speakers, methods sessions, poster presentations and oral presentations. The 32 oral presentations were selected from 154 abstract submissions, through a process peer review process, that ensured each abstract was reviewed by four reviewers. For those authors that gave permission, the abstracts of the selected oral presentations are published in this supplement.

Acknowledgments

On behalf of the Institute for Healthcare Improvement, the hosts would like to thank the individuals whose contributions have made the 22nd Annual Scientific Symposium on Improving the Quality and Value of Health Care a success. Particular thanks are due to the abstract reviewers – Amrita Dasgupta, Anne Lambert-Kerzner, Anup Patel, Barry Appleton, Brant Oliver, David Williams, Don Goldmann, Edahrline Salas, Evie Alessandrini, Fiona Levy, Gareth Parry, Jane Roessner, Jon Finkelstein, Kedar Mate, Linson Naval, Lisa Cosimi, Lisa Rubenstien, Lloyd Provost, Mara Laderman, Marianne McPherson, Nana Twum-Danso, Natalie Henrich, Pierre Barker, Sandy Cohen, Sharon Muret-Wagstaff, A. J. Layon, Andrew Steele, Angela Green, Darren Klugman, David Mosen, Denise Remus, Ezequiel Garcia Elorrio, Jackie Valentine, Keith Mann, Mary Coleman, Omar Hasan, Rick McClead, Sandip Godambe, Thomas Bartman, Tina C. Foster, Uma Kotagal, and Wallace Crandall – without whose efforts we could not accomplish a Symposium of this quality. Thanks, as well, are due all those who were willing to submit their research for review. Last, but certainly not least, we thank our program committee members – Don Goldmann, Pierre Barker, Amy Reid, Beth McGlynn, John Finkelstein, Lisa Hirschhorn, Rohit Ramaswamy, Elizabeth McGlynn, Sabrina Selk, Rashad Massoud, Margee Louisias, Lloyd Provost, Laura Damschroder, Uma Kotagal, and Marianne McPherson – who provided valuable insight and guidance to make this year's Symposium as enriching as possible; and Amrita Dasgupta, Jason Reed and Linson Naval who have dedicated countless hours to the development of this year's program.
Opposed to the being of Henrietta: bioslavery, pop culture and the third life of HeLa cells
Authors: Moore Marlon Rachquel
Published: November 2016

Operating at the intersection of thanatopolitics and African-American cultural studies, this essay argues that the commercial sale of HeLa-themed art and other bioproducts perpetuates the bioslavery of HeLa cells, a circumstance created by legal and medical discourses tracing back to US racial slavery. Racial slavery normalised economic, social and legal inequities that the nation continues to struggle with and, the article posits, laid foundation for the dynamics that currently exist between Henrietta Lacks' genealogical family, the HeLa cell line, and the medical-pharmaceutical establishment. The author turns to fashion ethics discourse and trademark law as potential sites for reparations.
Endovascular stroke therapy may be safe in patients with elevated international normalized ratio
Authors: Mundiyanapurath Sibu , Tillmann Anne , Möhlenbruch Markus Alfred , Bendszus Martin , Ringleb Peter Arthur
Published: November 2016

Introduction

Endovascular therapy in acute ischemic stroke is safe and efficient. However, patients receiving oral anticoagulation were excluded in the larger trials.

Objective

To analyze the safety of endovascular therapy in patients with acute ischemic stroke and elevated international normalized ratio (INR) values.

Methods

Retrospective database review of a tertiary care university hospital for patients with anterior circulation stroke treated with endovascular therapy. Patients with anticoagulation other than vitamin K antagonists were excluded. The primary safety endpoint was defined as symptomatic intracranial hemorrhage (sICH; ECASS II definition). The efficacy endpoint was the modified Rankin scale (mRS) score after 3 months, dichotomized into favorable outcome (mRS 0–2) and unfavorable outcome (mRS 3–6).

Results

435 patients were included. 90% were treated with stent retriever. 27 (6.2%) patients with an INR of 1.2–1.7 and 21 (4.8%) with an INR >1.7. 33 (7.6%) had sICH and 149 patients (34.3%) had a favorable outcome. Patients with an elevated INR did not have an increased risk for sICH or unfavorable outcome in multivariable analysis. The additional use of IV thrombolysis in patients with an INR of 1.2–1.7 did not increase the risk of sICH or unfavorable outcome. These results were replicated in a sensitivity analysis introducing an error of the INR of ±5%. They were also confirmed using other sICH definitions (Safe Implementation of Thrombolysis in Stroke (SITS), National Institute of neurological Disorders and Stroke (NINDS), Heidelberg bleeding classification).

Conclusions

Endovascular therapy in patients with an elevated INR is safe and efficient. Patients with an INR of 1.2–1.7 may be treated with combined IV thrombolysis and endovascular therapy.
Strategic planning in a forest supply chain: a multigoal and multiproduct approach
Authors: Broz Diego , Durand Guillermo , Rossit Daniel , Tohmé Fernando , Frutos Mariano
Published: November 2016

Supply chain management problems are widespread across all economic activities. We analyze here how to address these in the case of the forest industry, which in emerging economies such as Argentina is subject to high logistic costs and faces problems of biological and economic sustainability. In this work, we analyze a management model covering from the schedule of harvesting activities and the transportation of raw materials to the final transformation at several industrial plants. Since this involves more than one objective, single-criterion mathematical programming methods are not appropriate. Here, instead, we introduce an extended goal programming formulation of the problem, able to yield good solutions in a computationally efficient way. We consider four goals: the maximization of the net present value of the production, the minimization of interannual variations in harvests, the maximization of carbon capture in the form of forest biomass, and the minimization of variations in the mean annual distance covered in transportation to the industrial plants. We apply this theoretical model to derive solutions for an actual Argentinean company. We show that the model reaches the target levels of the different goals, except for carbon balance, which is negative in all of the scenarios under evaluation.
Variation in Zn, C, and N isotope ratios in three stream insects
Authors: Evans R. Douglas , Wang Wei , Evans Hayla E. , Georg R. Bastian
Published: November 2016

Total Zn concentrations and Zn isotope ratios were measured, using multicollector inductively coupled plasma (ICP)-mass spectrometry (MS), in three species of aquatic insects collected from a stream in Peterborough, Ontario, Canada. Total Zn levels averaged 193 ± 88 μg/g dry weight (dw) in water striders (Heteroptera: Gerridae, Aquarius remigis) and were significantly higher than the concentrations measured in stonefly nymphs (Plecoptera: Perlidae, Acroneuria abnormis) and caddisfly larvae (Trichoptera: Limnephilidae, Pycnopsyche guttifer), i.e., 136 ± 34 μg/g dw and 125 ± 26 μg/g dw, respectively. Average delta values for 66Zn/64Zn in the water striders were approximately 0.7‰ lighter (−1.2‰ ± 1.0‰) and were significantly different than those measured for stoneflies (−0.45‰ ± 0.62‰) and caddisflies (−0.51‰ ± 0.54‰). Nitrogen isotope ratios were significantly different ( P < 0.05) among the three species suggesting differences in trophic positioning. Similar to the Zn isotope ratios, δ 13C values for the water striders (−28.61‰ ± 0.98‰) were significantly different than those of the stoneflies and caddisflies, i.e., −30.75‰ ± 1.33‰ and −30.68‰ ± 1.01‰, respectively. The data suggest that the differences observed in Zn ratios relate to food source for these insects. Similar to their carbon sources, Zn in water striders appears to be primarily of terrestrial origin, and of aquatic origin for the other two species.
Fast timing for collider detectors
Authors: Tully Christopher G.
Published: November 2016

Advancements in fast timing particle detectors have opened up new possibilities to design [Formula: see text] collider detectors that fully reconstruct and separate event vertices and individual particles in the time domain. The applications of these techniques are considered for the physics at CEPC.
Doping effect on exciton binding energy in semiconductor quantum well
Authors: Li Yongkai , Yang Shuangbo
Published: November 2016

By solving the Schrödinger equation and Poisson’s equation self-consistently, we have calculated the electronic structure for Si-doped GaAs/Al[Formula: see text]Ga[Formula: see text]As quantum well system at [Formula: see text] K in the effective mass approximation. We obtain the self-consistent potentials, eigen-envelope functions and the subband energies for different doping concentrations and for different thicknesses of the doping layer. The binding energies of exciton in GaAs/Al[Formula: see text]Ga[Formula: see text]As quantum wells under different doping conditions are calculated by using a variational method. And the variation of the binding energy with the thickness of the doped layer and the doping concentration is analyzed. It is found that at a given doping concentration, with the increase of thickness of the doping layer, the self-consistent potential becomes wider and more shallow, the binding energy of exciton decreases. At a given thickness of the doping layer, with the increase of the doping concentration, the self-consistent potential becomes narrower and deeper, the binding energy of exciton increases.
Nanostructural and electrical properties of LA0.5SR0.5CoO3
Authors: Bahari A. , Ramzannezhad A. , Shajari D. , Najafi H.
Published: November 2016

A group of ABO3 perovskite-type oxides is currently under intensive studies for their potential as chemical sensing, ferroelectric memories, gas separation and computer devices. This group includes La[Formula: see text]Sr[Formula: see text]CoO3 (LSCO). In the present work, we have synthesized LSCO samples by using the sol–gel method and studied their nano structural and electrical properties with using the scanning electron microscopy (SEM), energy dispersive X-ray (EDX), Current density–voltage ([Formula: see text]–[Formula: see text]) and Fourier transform infrared spectroscopy (FTIR) techniques. We synthesized nanoparticles with diameters between 50 and 100 nm by calcination of the pulverized gel powders, and then studied its structure. The band gap characteristics of the La[Formula: see text]Sr[Formula: see text]CoO3 structure were also analyzed. The obtained results show that La[Formula: see text]Sr[Formula: see text]CoO3 with favorable carrier mobility ([Formula: see text] cm2v[Formula: see text]s[Formula: see text]) and dielectric constant (16) exhibits a variety of interesting physical properties which include ferroelectric, dielectric, pyroelectric and piezoelectric behavior.
Thermodynamic properties of rod-like chains: Entropic sampling simulations
Authors: Ferreira L. S. , Jorge L. N. , Caparica A. A. , Nascimento D. A. , Neto Minos A. , Sousa J. R.
Published: November 2016

In this work, we apply entropic sampling simulations to a three-state model which has exact solutions in the microcanonical and grand-canonical ensembles. We consider N chains placed on an unidimensional lattice, such that each site may assume one of the three states: empty (state 1), with a single molecule energetically null (state 2), and with a single molecule with energy [Formula: see text] (state 3). Each molecule, which we will treat here as dimers, consists of two monomers connected one to each other by a rod. The thermodynamic properties such as internal energy, densities of dimers and specific heat were obtained as functions of temperature, where the analytic results in the microcanonical and grand-canonical ensembles were successfully confirmed by the entropic sampling simulations.
Polarized-deuteron stripping reaction at intermediate energies
Authors: Kovalchuk Valery I.
Published: November 2016

A general analytical expressions for the cross-section and the polarization of nucleons arising in the inclusive deuteron stripping reaction have been derived in the diffraction approximation. The nucleon–nucleus phases were calculated in the framework of Glauber formalism and making use of the double-folding potential. The tabulated distributions of the target nucleus density and the realistic deuteron wave function with correct asymptotic at large nucleon–nucleon distances were used. The calculated angular dependences for the cross-sections and the analyzing powers of the [Formula: see text] reaction are compared with corresponding experimental data.
Commutative rings in which zero-components of essential primes are essential
Authors: Dube Themba
Published: November 2016

For a prime ideal [Formula: see text] of a commutative ring [Formula: see text] with identity, we denote (as usual) by [Formula: see text] its zero-component; that is, the set of members of [Formula: see text] that are annihilated by nonmembers of [Formula: see text]. We study rings in which [Formula: see text] is an essential ideal, whenever [Formula: see text] is an essential prime ideal. We characterize them in terms of the lattices (which are, in fact, complete Heyting algebras) of their radical ideals. We prove that the classical ring of quotients of any ring of this kind is itself of this kind. We show that direct products of rings of this kind are themselves of this kind. We observe that the ring of real-valued continuous functions on a Tychonoff space is of this kind precisely when the underlying set of the space is infinite. Replacing [Formula: see text] with the pure part of [Formula: see text], we obtain a formally stronger variant which is still characterizable in terms of the lattices of radical ideals.
Analysis of Interface Charge Densities for High-k Dielectric Materials based Metal Oxide Semiconductor Devices
Authors: Maity N. P. , Thakur R. R. , Maity Reshmi , Thapa R. K. , Baishya S.
Published: November 2016

In this paper, the interface charge densities ([Formula: see text]) are studied and analyzed for ultra thin dielectric metal oxide semiconductor (MOS) devices using different high-k dielectric materials such as Al2O3, ZrO2 and HfO2. The [Formula: see text] have been calculated by a new approach using conductance method and it indicates that by reducing the thickness of the oxide, the [Formula: see text] increases and similar increase is also found by replacing SiO2 with high-k. For the same oxide thickness, SiO2 has the lowest [Formula: see text] and found to be the order of 10[Formula: see text][Formula: see text]cm[Formula: see text][Formula: see text]eV[Formula: see text]. Linear increase in [Formula: see text] has been observed as the dielectric constant of the oxide increases. The [Formula: see text] is found to be in good agreement with published fabrication results at p-type doping level of [Formula: see text][Formula: see text]cm[Formula: see text]. Numerical calculations and solutions are performed by MATLAB and device simulation is done by ATLAS.
Intelligent FastSLAM: An Intelligent Factorized Solution to Simultaneous Localization and Mapping
Authors: Havangi Ramazan
Published: November 2016

FastSLAM is a well-known solution to the simultaneous localization and mapping (SLAM) problem. In FastSLAM, a nonparametric filter is used for the mobile robot pose (position and orientation) estimation, and a parametric filter is used for the feature location's estimation. The performance of the conventional FastSLAM degrades over time due to the particle depletion and unknown statistic noises. In this paper, intelligent FastSLAM (IFastSLAM) is proposed. In this approach, an evolutionary filter (EF) searches stochastically along with the state space for the best robot's pose estimation and an adaptive fuzzy unscented Kalman filter (AFUKF) is used for the feature location's estimation. In AFUKF, a fuzzy inference system (FIS) supervises the performance of the unscented Kalman filter with the aim of reducing the mismatch between the theoretical and actual covariance of the innovation sequences in order to get better consistency. We demonstrate the proposed algorithm with simulations and real-world experiments. The results show that the proposed method is effective, and its performance outperforms conventional FastSLAM.
APPROPRIABILITY PROFILES – DIFFERENT ACTORS, DIFFERENT OUTCOMES
Authors: HURMELINNA-LAUKKANEN PIA , VANHALA MIKA , OLANDER HEIDI
Published: November 2016

Compared to existing knowledge of innovation appropriability in general, or individual mechanisms contributing to value appropriation, little is known about the configurations of isolating appropriability mechanisms. Such configurations — appropriability profiles — may look quite different for different actors, and may generate quite different performance outcomes. We examine survey data from 167 firms and identify specific profiles among different actors: subtle, attained, and controlled appropriability. We further show that industry, presence in international markets, and firm goals for protection, for example, are important attributes of these profiles. The results also suggest that different profiles relate to different performance outcomes in the market, innovation, and alliance dimensions. These findings can help managers build appropriability profiles that genuinely match their characteristics and needs, thereby escaping the problems with under- or over-protection that can easily take place if, for example, only appropriation strategies building on individual mechanisms, such as patents, are followed.
Theoretical Modeling for Monitoring the Growth of Fusiform Abdominal Aortic Aneurysms Using Dielectric Elastomer Capacitive Sensors
Authors: Lü C. F. , Du Y. K.
Published: November 2016

To evaluate the rupture risk of abdominal aortic aneurysms, traditional medical imaging techniques, e.g., ultrasonography, CT scanning, or magnetic resonance imaging, form the regular clinic treatments for detecting the growth but can only provide the diameter of the aneurysm. This has been proved to be inadequate since a considerable portion of rupture has been missed by the critical rupture size that is established according to clinical statistics. We proposed to mount a dielectric elastomer capacitive sensor around an early-stage abdominal aneurysm and using the continuously varying capacitance for retrieving both the wall stress and morphology of the aneurysm in a real-time manner. A theoretical mechanics model based on the growth theory is developed to predict the correlation between the capacitance and the stress level as well as the geometrical parameters of the aneurysm. Numerical calculations agree well qualitatively with the clinical statistics of both rupture size and rupture stress of the aneurysm. The results suggest that the rupture risk of an aneurysm in a patient may be assessed more reliably by multiple indicators of stress and morphology during the growth process. A range of capacitance may also be recommended for elective repair based on the proposed theoretical model.
Stochastic equations for a self-regulating gene
Authors: Jansen Martin
Published: November 2016

Expression of cellular genes is regulated by binding of transcription factors to their promoter, either activating or inhibiting transcription of a gene. Particularly interesting is the case when the expressed protein regulates its own transcription. In this paper, the features of this self-regulating process are investigated. In the presented model here, the gene can be in two states. Either a protein is bound to its promoter or not. The steady state distributions of protein during and just before switching from one state to the next state are analyzed. Moreover, a powerful numerical method based on the corresponding master equation to compute the protein distribution in the steady state is presented and compared to an already-existing method. Additionally the special case of self-regulation, in which protein can only be produced, if one of these proteins is bound to the promoter region, is analyzed. Furthermore, a self-regulating gene is compared to a similar gene, which also has two states and produces the same amount of proteins but is not regulated by its protein-product.
Geothermal exploration in the Fell Sandstone Formation (Mississippian) beneath the city centre of Newcastle upon Tyne, UK: the Newcastle Science Central Deep Geothermal Borehole
Authors: Younger Paul L. , Manning David A. C. , Millward David , Busby Jonathan P. , Jones Charles R. C. , Gluyas Jonathan G.
Published: November 2016

The postulate that geothermal energy might be recoverable from strata laterally equivalent to the Fell Sandstone Formation (Carboniferous: Mississippian) beneath Newcastle upon Tyne has been examined by the drilling and testing of the 1821 m deep Newcastle Science Central Deep Geothermal Borehole. This proved 376.5 m of Fell Sandstone Formation below 1400 m, much of which resembled braided river deposits found at outcrop, although some lower portions were reddened and yielded grains of aeolian affinity. Downhole logging after attainment of thermal equilibrium proved a temperature of 73°C at 1740 m, and allowed estimation of heat flow at about 88 mW m
−2
. This relatively high value probably reflects deep convective transfer of heat over a distance of >8 km from the North Pennine Batholith, along the Ninety Fathom Fault. The Fell Sandstone traversed by the borehole proved to be of low hydraulic conductivity (
c
. 7 × 10
−5
 m d
−1
). The water that entered the well was highly saline, with a Na–(Ca)–Cl signature similar to other warm waters encountered in the region. It remains for future directional drilling to establish whether sufficient natural fracture permeability can be encountered, or wells stimulated, to support commercial heat production.
Landslide Research in China
Authors: Chen Zuyu , Meng Xingmin , Yin Yueping , Dijkstra Tom , Winter Mike , Wasowski Janusz
Published: November 2016

On 9 April 2000, a 91 Mm
3
rock avalanche occurred in Linzhi Prefecture, Tibet. The event was accompanied by a deafening noise, with the rock mass travelling from a maximum elevation of 5132 m and coming to a rest at an elevation of 2163 m. It formed a landslide dam in the Yigong Zangbo River of some 55 m height, impounding a reservoir of some 2 Gm
3
for a period of 62 days after which it emptied in less than 12 h. This event was a forewarning of a period of frequent geological disasters in China during the start of the 21st century. The ensuing Wenchuan earthquake (surface-wave magnitude M
s
8.0; May 2008), Zhouqu debris flow (August 2010) and Ludian earthquake (M
s
6.7; August 2014) led to the Chinese Government renewing its campaign against geological disasters and it has since invested heavily in scientific research to guide efforts to mitigate the impact of such natural disasters. This thematic set on Landslide Research in China was initiated to highlight this research. This paper provides a brief review of three of the featured subjects and accompanies the five papers published in the thematic set.
The first Russian monograph on the History of Geology by Grigory E. Shchurovsky, professor of Moscow University: on the 150th anniversary of the publication
Authors: Bessudnova Zoya A.
Published: November 2016

The first Russian monograph on the history of geology,
History of Geology of the Moscow Basin
, written by Grigory Efimovich Shchurovsky (1803–84), was published in 1866–67. Shchurovsky was Professor of Geology and Mineralogy at Moscow University, the head of the University's Mineralogical and Geological Cabinets (museums) and the first president of the Society of Amateurs of Natural History. He was the author of
The Ural Range in its Physiographic, Geological and Mineralogical Aspects
(1841) and of
Geological Tour across Altai, with Historical and Statistical Data on the Kolyvan-Voskresensky Factories
(1846), and of many others works on geology. He was one of the first popularizers of science and one of the first historians of geology in Russia. His scientific achievements are to this day remembered in Russia, but his work is not known abroad.
Genomic Selection in Dairy Cattle: The USDA Experience
Authors: Wiggans George R. , Cole John B. , Hubbard Suzanne M. , Sonstegard Tad S.
Published: November 2016

Genomic selection has revolutionized dairy cattle breeding. Since 2000, assays have been developed to genotype large numbers of single-nucleotide polymorphisms (SNPs) at relatively low cost. The first commercial SNP genotyping chip was released with a set of 54,001 SNPs in December 2007. Over 15,000 genotypes were used to determine which SNPs should be used in genomic evaluation of US dairy cattle. Official USDA genomic evaluations were first released in January 2009 for Holsteins and Jerseys, in August 2009 for Brown Swiss, in April 2013 for Ayrshires, and in April 2016 for Guernseys. Producers have accepted genomic evaluations as accurate indications of a bull's eventual daughter-based evaluation. The integration of DNA marker technology and genomics into the traditional evaluation system has doubled the rate of genetic progress for traits of economic importance, decreased generation interval, increased selection accuracy, reduced previous costs of progeny testing, and allowed identification of recessive lethals.
The Lymphatic System: Integral Roles in Immunity
Authors: Randolph Gwendalyn J. , Ivanov Stoyan , Zinselmeyer Bernd H. , Scallan Joshua P.
Published: November 2016

The lymphatic vasculature is not considered a formal part of the immune system, but it is critical to immunity. One of its major roles is in the coordination of the trafficking of antigen and immune cells. However, other roles in immunity are emerging. Lymphatic endothelial cells, for example, directly present antigen or express factors that greatly influence the local environment. We cover these topics herein and discuss how other properties of the lymphatic vasculature, such as mechanisms of lymphatic contraction (which immunologists traditionally do not take into account), are nonetheless integral in the immune system. Much is yet unknown, and this nascent subject is ripe for exploration. We argue that to consider the impact of lymphatic biology in any given immunological interaction is a key step toward integrating immunology with organ physiology and ultimately many complex pathologies.
Mechanisms and Medicines for Remyelination
Authors: Bothwell Mark
Published: November 2016

Demyelination of central nervous system axons, associated with traumatic injury and demyelinating diseases such as multiple sclerosis, causes impaired neural transmission and ultimately axon degeneration. Consequently, extensive research has focused on signaling systems that promote myelinating activity of oligodendrocytes or promote production of new oligodendrocytes from oligodendrocyte progenitor cells. Many receptor systems, notably including growth factor receptors and G protein–coupled receptors, control myelination. A number of recent clinical trials target these receptor signaling pathways.