479 research outputs found
CHILES: HI morphology and galaxy environment at z=0.12 and z=0.17
We present a study of 16 HI-detected galaxies found in 178 hours of
observations from Epoch 1 of the COSMOS HI Large Extragalactic Survey (CHILES).
We focus on two redshift ranges between 0.108 <= z <= 0.127 and 0.162 <= z <=
0.183 which are among the worst affected by radio frequency interference (RFI).
While this represents only 10% of the total frequency coverage and 18% of the
total expected time on source compared to what will be the full CHILES survey,
we demonstrate that our data reduction pipeline recovers high quality data even
in regions severely impacted by RFI. We report on our in-depth testing of an
automated spectral line source finder to produce HI total intensity maps which
we present side-by-side with significance maps to evaluate the reliability of
the morphology recovered by the source finder. We recommend that this become a
common place manner of presenting data from upcoming HI surveys of resolved
objects. We use the COSMOS 20k group catalogue, and we extract filamentary
structure using the topological DisPerSE algorithm to evaluate the \hi\
morphology in the context of both local and large-scale environments and we
discuss the shortcomings of both methods. Many of the detections show disturbed
HI morphologies suggesting they have undergone a recent interaction which is
not evident from deep optical imaging alone. Overall, the sample showcases the
broad range of ways in which galaxies interact with their environment. This is
a first look at the population of galaxies and their local and large-scale
environments observed in HI by CHILES at redshifts beyond the z=0.1 Universe.Comment: 23 pages, 12 figures, 1 interactive 3D figure, accepted to MNRA
Sequential decoupling of negative-energy states in Douglas-Kroll-Hess theory
Here, we review the historical development, current status, and prospects of
Douglas--Kroll--Hess theory as a quantum chemical relativistic electrons-only
theory.Comment: 15 page
Antimicrobial resistance of Campylobacter isolates from small scale and backyard chicken in Kenya
Background Thermophilic Campylobacter species are a major cause of bacterial
foodborne diarrhoea in humans worldwide. Poultry and their products are the
predominant source for human campylobacteriosis. Resistance of Campylobacter
to antibiotics is increasing worldwide, but little is known about the
antibiotic resistance in Campylobacter isolated from chicken in Kenya. In this
study, 35 suspected Campylobacter strains isolated from faeces and cloacal
swabs of chicken were tested for their susceptibility to seven antibiotics
using a broth microdilution assay and molecular biological investigations.
Results Overall, DNA of thermophilic Campylobacter was identified in 53
samples by PCR (34 C. jejuni, 18 C. coli and one mix of both species) but only
35 Campylobacter isolates (31 C. jejuni and 4 C. coli) could be re-cultivated
after transportation to Germany. Isolates were tested for their susceptibility
to antibiotics using a broth microdilution assay. Additionally, molecular
biological detection of antibiotic resistance genes was carried out. C. jejuni
isolates showed a high rate of resistance to nalidixic acid, tetracycline and
ciprofloxacin of 77.4, 71.0 and 71.0 %, respectively. Low resistance (25.8 %)
was detected for gentamicin and chloramphenicol. Multidrug resistance in C.
jejuni could be detected in 19 (61.3 %) isolates. Resistance pattern of C.
coli isolates was comparable. Resistance to ciprofloxacin was confirmed by
MAMA–PCR and PCR–RFLP in all phenotypically resistant isolates. The tet(O)
gene was detected only in 54.5 % of tetracycline resistant C. jejuni isolates.
The tet(A) gene, which is also responsible for tetracycline resistance, was
found in 90.3 % of C. jejuni and in all C. coli isolates. Thirteen
phenotypically erythromycin-resistant isolates could not be characterised by
using PCR–RFLP and MAMA–PCR. Conclusions To the best of our knowledge, this
study is the first report about resistance to antibiotics in thermophilic
Campylobacter originating from chicken in Kenya. Campylobacter spp. show a
high level of resistance to ciprofloxacin, nalidixic acid and tetracycline but
also a remarkable one to chloramphenicol and gentamicin and they are multidrug
resistant. Resistance to antibiotics is a global public health concern. In
Kenya, resistance surveillance needs further attention in the future. Efforts
to establish at least a National Laboratory with facilities for performing
phenotypic and genotypic characterization of thermophilic Campylobacter is
highly recommended
CHILES VI:HI and H alpha observations for z <0.1 galaxies; probing HI spin alignment with filaments in the cosmic web
We present neutral hydrogen (HI) and ionized hydrogen (H)
observations of ten galaxies out to a redshift of 0.1. The HI observations are
from the first epoch (178 hours) of the COSMOS HI Large Extragalactic Survey
(CHILES). Our sample is HI biased and consists of ten late-type galaxies with
HI masses that range from M to
M. We find that although the majority of galaxies show irregularities
in the morphology and kinematics, they generally follow the scaling relations
found in larger samples. We find that the HI and H velocities reach
the flat part of the rotation curve. We identify the large-scale structure in
the nearby CHILES volume using DisPerSE with the spectroscopic catalog from
SDSS. We explore the gaseous properties of the galaxies as a function of
location in the cosmic web. We also compare the angular momentum vector (spin)
of the galaxies to the orientation of the nearest cosmic web filament. Our
results show that galaxy spins tend to be aligned with cosmic web filaments and
show a hint of a transition mass associated with the spin angle alignment.Comment: 24 pages, 25 figures, 6 tables, accepted for publication in MNRA
Training in the practice of noninvasive brain stimulation: Recommendations from an IFCN committee
As the field of noninvasive brain stimulation (NIBS) expands, there is a growing need for comprehensive guidelines on training practitioners in the safe and effective administration of NIBS techniques in their various research and clinical applications. This article provides recommendations on the structure and content of this training. Three different types of practitioners are considered (Technicians, Clinicians, and Scientists), to attempt to cover the range of education and responsibilities of practitioners in NIBS from the laboratory to the clinic. Basic or core competencies and more advanced knowledge and skills are discussed, and recommendations offered regarding didactic and practical curricular components. We encourage individual licensing and governing bodies to implement these guidelines
Investigating Childhood Leukemia in Churchill County, Nevada
BACKGROUND: Sixteen children diagnosed with acute leukemia between 1997 and 2002 lived in Churchill County, Nevada, at the time of or before their illness. Considering the county population and statewide cancer rate, fewer than two cases would be expected. OBJECTIVES: In March 2001, the Centers for Disease Control and Prevention led federal, state, and local agencies in a cross-sectional, case-comparison study to determine if ongoing environmental exposures posed a health risk to residents and to compare levels of contaminants in environmental and biologic samples collected from participating families. METHODS: Surveys with more than 500 variables were administered to 205 people in 69 families. Blood, urine, and cheek cell samples were collected and analyzed for 139 chemicals, eight viral markers, and several genetic polymorphisms. Air, water, soil, and dust samples were collected from almost 80 homes to measure more than 200 chemicals. RESULTS: The scope of this cancer cluster investigation exceeded any previous study of pediatric leukemia. Nonetheless, no exposure consistent with leukemia risk was identified. Overall, tungsten and arsenic levels in urine and water samples were significantly higher than national comparison values; however, levels were similar among case and comparison groups. CONCLUSIONS: Although the cases in this cancer cluster may in fact have a common etiology, their small number and the length of time between diagnosis and our exposure assessment lessen the ability to find an association between leukemia and environmental exposures. Given the limitations of individual cancer cluster investigations, it may prove more efficient to pool laboratory and questionnaire data from similar leukemia clusters
Reconstruction of ancient microbial genomes from the human gut
Loss of gut microbial diversity1–6 in industrial populations is associated with chronic diseases7, underscoring the importance of studying our ancestral gut microbiome. However, relatively little is known about the composition of pre-industrial gut microbiomes. Here we performed a large-scale de novo assembly of microbial genomes from palaeofaeces. From eight authenticated human palaeofaeces samples (1,000–2,000 years old) with well-preserved DNA from southwestern USA and Mexico, we reconstructed 498 medium- and high-quality microbial genomes. Among the 181 genomes with the strongest evidence of being ancient and of human gut origin, 39% represent previously undescribed species-level genome bins. Tip dating suggests an approximate diversification timeline for the key human symbiont Methanobrevibacter smithii. In comparison to 789 present-day human gut microbiome samples from eight countries, the palaeofaeces samples are more similar to non-industrialized than industrialized human gut microbiomes. Functional profiling of the palaeofaeces samples reveals a markedly lower abundance of antibiotic-resistance and mucin-degrading genes, as well as enrichment of mobile genetic elements relative to industrial gut microbiomes. This study facilitates the discovery and characterization of previously undescribed gut microorganisms from ancient microbiomes and the investigation of the evolutionary history of the human gut microbiota through genome reconstruction from palaeofaeces.Ethics Overview of samples Reference-based taxonomic composition De novo genome reconstruction Methanobrevibacter smithii tip dating Functional genomic analysis Discussion Online content Method
Prevalence and risk factors for mesh erosion after laparoscopic-assisted sacrocolpopexy
The purpose of this study is to identify risk factors for mesh erosion in women undergoing minimally invasive sacrocolpopexy (MISC). We hypothesize that erosion is higher in subjects undergoing concomitant hysterectomy.
This is a retrospective cohort study of women who underwent MISC between November 2004 and January 2009. Demographics, operative techniques, and outcomes were abstracted from medical records. Multivariable regression identified odds of erosion.
Of 188 MISC procedures 19(10%) had erosions. Erosion was higher in those with total vaginal hysterectomy (TVH) compared to both post-hysterectomy (23% vs. 5%, p = 0.003) and supracervical hysterectomy (SCH) (23% vs. 5%, p = 0.109) groups. In multivariable regression, the odds of erosion for TVH was 5.67 (95% CI: 1.88–17.10) compared to post-hysterectomy. Smoking, the use of collagen-coated mesh, transvaginal dissection, and mesh attachment transvaginally were no longer significant in the multivariable regression model.
Based on this study, surgeons should consider supracervical hysterectomy over total vaginal hysterectomy as the procedure of choice in association with MISC unless removal of the cervix is otherwise indicated
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