727 research outputs found
Flavor constraints in a Bosonic Technicolor model
Flavor constraints in a bosonic Technicolor model are considered. We
illustrate different sources for their origin, and emphasize in particular the
role played by the vector states present in the Technicolor model. This feature
is the essential difference in comparison to an analogous model with two
fundamental Higgs scalar doublets.Comment: 16 pages, 13 figure
Whole genome sequence analysis of antimicrobial resistance genes, multilocus sequence types and plasmid sequences in ESBL/AmpC Escherichia coli isolated from broiler caecum and meat
Plasmid-encoded extended-spectrum β-lactamase and AmpC gene-carrying Escherichia coli (ESBL/AmpC E. coli) is an increasing cause of human infections worldwide. Increasing carbapenem and colistin resistance further complicate treatment of these infections. The aim of this study was to assess the occurrence of ESBL/AmpC E. coli in different broiler flocks and farms, as well as in broiler meat, in a country with no antimicrobial usage in broiler production. An additional goal was to assess the genetic characteristics of ESBL/AmpC E. coli isolates by using whole genome sequencing (WGS). Altogether 520 caecal swabs and 85 vacuum-packed broiler meat samples were investigated at the slaughterhouse level. WGS of the bacterial isolates revealed acquired antimicrobial resistance (AMR) genes, multilocus sequence types (MLST) and plasmid sequences. ESBL/AmpC E. coli was identified in 92 (18%) of the caecum and 27 (32%) of the meat samples. ESBL/AmpC E. coli-carrying birds derived from six (33%) out of 18 farms. Of the two blaESBL/AmpC genes detected by PCR, blaCMY-2 (96%) was predominant over blaCTX-M-1 (4%). Furthermore, WGS revealed an additional AMR gene sul2. Carbapenemase, colistin, and other AMR genes were not detected from the isolates of either the caecal or meat samples. Altogether seven MLSTs (ST101, ST117, ST212, ST351, ST373, ST1594 and an unknown ST) and a variety of different plasmid sequences (IncB/O/K/Z, IncI1, IncFII, IncII, IncFIB, IncFIC, IncX1 and an additional set of Col-plasmids) were detected. This is the first study on genomic epidemiology of ESBL/AmpC E. coli on broiler farms and flocks with no antimicrobial usage, by using WGS analysis. Results show that ESBL/AmpC E. coli occurrence is common both in the caecum and in the packaged meat. However, compared to other European countries, the occurrence is low and the presence of AMR genes other than blaCMY-2 and blaCTX-M-1 is rare. More studies are needed to understand the ESBL/AmpC E. coli occurrence in broiler production to prevent the meat from contamination during slaughter and processing, thereby also preventing zoonotic transmission of ESBL/AmpC E. coli. Additionally, more studies are needed to understand the ecology and fitness cost of Enterobacteriaceae plasmids in animal production in order to prevent their acquisition of plasmid-encoded antimicrobial resistance genes such as carbapenem and colistin resistance genes, as this would pose a great hazard to food safety.Peer reviewe
Vacancy cluster growth and thermal recovery in hydrogen-irradiated tungsten
The thermal evolution of vacancies and vacancy clusters in tungsten (W) has been studied. W (100) single crystals were irradiated with 200 keV hydrogen (H) ions to a low damage level (5.8 x 10(-3) dpa) at 290 K and then annealed at temperatures in the range of 500-1800 K. The resulting defects were characterized by positron annihilation lifetime spectroscopy (PALS) and positron annihilation Doppler broadening spectroscopy (DBS). Annealing at 700 K resulted in the formation of clusters containing 10-15 vacancies, while at 800 K and higher temperatures clusters containing about 20 vacancies or more were formed. Reduction of the defect concentration likely accompanied by further coarsening of the clusters started at 1300 K and ended at 1800 K with the complete defect recovery. The determined cluster sizes at 700 K and 800 K were larger than the estimated minimum cluster sizes that are thermally stable at these temperatures, indicating that the migration and ensuing coalescence of small clusters plays an important role in cluster growth. (C) 2020 Max-Planck-Institut fur Plasmaphysik. Published by Elsevier B.V. All rights reserved.Peer reviewe
Searching for massless dark photons at the lhc via higgs production
Massless dark photons are predicted in hidden-sector models with an unbroken dark U(1) gauge symmetry. A particular class of these models, aiming to solve both the Yukawa-hierarchy and the dark-matter problems of the standard model, manifests natural Higgs nondecoupling properties for the dark photon. As a consequence, we show that the Higgs-boson production at colliders followed by the Higgs decay into a photon and a dark photon provides a very promising dark-photon production mechanism. This decay gives rise to an unconventional Higgs signature characterized by a resonating gamma-plus-missing-momentum system with a monochromatic photon. We discuss the sensitivity of the LHC to the corresponding signal for a Higgs boson produced in both gluon-fusion and vector-boson-fusion channels. © Copyright owned by the author(s).Peer reviewe
Triboson interpretations of the ATLAS diboson excess
The ATLAS excess in fat jet pair production is kinematically compatible with
the decay of a heavy resonance into two gauge bosons plus an extra particle.
This hypothesis would explain the absence of such a large excess in the
analogous CMS analysis of fat dijet final states, as well as the negative
results of diboson resonance searches in the semi-leptonic decay modes. If the
extra particle is the Higgs boson, this hypothesis might also explain
-statistical fluctuations aside- why the CMS search for WH resonances in the
semi-leptonic channel finds some excess while in the fully hadronic one it does
not have a significant deviation.Comment: LaTeX 17 pages. v2: Enlarged discussion to address CMS WH excess. v3:
Added discussion of diboson helicities. Final version to appear in JHE
Trends in the incidence, rate and treatment of miscarriage-nationwide register-study in Finland, 1998-2016
STUDY QUESTION: What changes have occurred in the incidence of miscarriage, its treatment options, and the profile of the women having miscarriages in Finland between 1998 and 2016? SUMMARY ANSWER: The annual incidence of registry-identified miscarriage has declined significantly between 1998 and 2016, and non-surgical management has become the dominant treatment. WHAT IS KNOWN ALREADY: Miscarriage occurs in 8-15% of clinically recognized pregnancies and in similar to 30% of all pregnancies. Increasing maternal age is associated with an increasing risk of miscarriage. The treatment of miscarriage has evolved significantly in recent years: previously, surgical evacuation of the uterus was the standard of care, but nowadays medical and expectant management are increasingly used. STUDY DESIGN, SIZE, DURATION: We conducted a nationwide retrospective cohort study of 128381 women that had experienced a miscarriage that was managed in public healthcare between 1998 and 2016 in Finland. PARTICIPANTS/MATERIALS, SETTING, METHODS: We used the National Hospital Discharge Registry for the data. Women aged 15-49 years that had experienced their first miscarriage during the follow-up period and had miscarriage-related diagnoses during their admission to public hospital were included in the study. Miscarriages were defined by the 10(th) Revision of the International Statistical Classification of Diseases and related Medical Problems (ICD-10) diagnostic codes O02*, O03* and O08*. Women with ectopic, molar and continuing pregnancies and induced abortions were excluded. Treatment was divided into surgical and non-surgical treatment using the surgical procedure codes. MAIN RESULTS AND THE ROLE OF CHANCE: The annual incidence of registry-identified miscarriage has declined from 6.8/1000 15-49-year-old women in 1998 to 5.0/1000 in 2016 (P <0.001). Also, the incidence rate of registry-identified miscarriage (i.e. the proportion of miscarriages of registry-identified pregnancies [i.e. deliveries, induced abortions, and miscarriages]) has declined from 112/1000 15-49-year-old pregnant women in 1998 to 83/1000 in 2016 (P <0.001). The largest decrease in this proportion occurred among women over 40 years of age, among whom 26.5% of registry-identified pregnancies in 1998 ended in miscarriage compared to that of 16.4% in 2016. The proportion of missed abortion has increased (30.3 to 38.8%, P <0.001) whereas that of blighted ovum has decreased (25.4 to 12.8%, P <0.001). The proportion of registry-identified miscarriages seen among nulliparous women has increased from 43.7 to 49.6% (P <0.001). Mean age at the time of miscarriage remained at 31 years throughout the study. Altogether, 29% of all miscarriages were treated surgically and 71% underwent medical or expectant management. The proportion of surgical management has decreased from 38.0 to 1.6% for spontaneous abortion, from 60.7 to 9.4% for blighted ovum and 70.9 to 11.2% for missed abortion between 1998 and 2016. LIMITATIONS, REASONS FOR CAUTION: This study includes only women with registry-identified pregnancies, i.e. women who were treated in public hospitals. However, the number of women treated elsewhere is presumed to be small. Neither can this study estimate the number of women having spontaneous miscarriage with no hospital contact. WIDER IMPLICATIONS OF THE FINDINGS: Both the annual incidence and incidence rate of miscarriage of all registry-identified pregnancies has decreased, and non-surgical management has become the standard of care. These findings are of value when planning allocation of healthcare resources and at individual level considering fertility and miscarriage questions. We speculate that improving ultrasound diagnostics explains the increasing proportion of missed abortion relative to other types of miscarriage. More investigation is needed to examine potential risk factors, complications and morbidity associated with miscarriages.Peer reviewe
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