1,434 research outputs found
Directional emission from asymmetric resonant cavities
Asymmetric resonant cavities (ARCs) with highly non-circular but convex
cross-sections are predicted theoretically to have high-Q whispering gallery
modes with very anisotropic emission. We develop a ray dynamics model for the
emission pattern and present numerical and experimental confirmation of the
theory.Comment: 7 pages LaTeX, 3 postscript figure
Steady-state energy balance in animal models of obesity and weight loss
Supported by European Union Seventh Framework Programme (FP7/2007-2013, n°266408 (Full4Health)), the Joint Programme of the Medical Faculty of Norwegian University of Science and Technology (NTNU) and St. Olav’s University Hospital, the Liaison Committee between the Central Norway Regional Health Authority and NTNU.Peer reviewedPostprin
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Seasonal dynamics of bacterial meningitis: a time-series analysis
Background Bacterial meningitis, which is caused mainly by Neisseria meningitidis, Haemophilus infl uenzae, and
Streptococcus pneumoniae, infl icts a substantial burden of disease worldwide. Yet, the temporal dynamics of this
disease are poorly characterised and many questions remain about the ecology of the disease. We aimed to
comprehensively assess seasonal trends in bacterial meningitis on a global scale.
Methods We developed the fi rst bacterial meningitis global database by compiling monthly incidence data as reported
by country-level surveillance systems. Using country-level wavelet analysis, we identifi ed whether a 12 month periodic
component (annual seasonality) was detected in time-series that had at least 5 years of data with at least 40 cases
reported per year. We estimated the mean timing of disease activity by computing the centre of gravity of the
distribution of cases and investigated whether synchrony exists between the three pathogens responsible for most
cases of bacterial meningitis.
Findings We used country-level data from 66 countries, including from 47 countries outside the meningitis belt in
sub-Saharan Africa. A persistent seasonality was detected in 49 (96%) of the 51 time-series from 38 countries eligible
for inclusion in the wavelet analyses. The mean timing of disease activity had a latitudinal trend, with bacterial
meningitis seasons peaking during the winter months in countries in both the northern and southern hemispheres.
The three pathogens shared similar seasonality, but time-shifts diff ered slightly by country.
Interpretation Our fi ndings provide key insight into the seasonal dynamics of bacterial meningitis and add to
knowledge about the global epidemiology of meningitis and the host, environment, and pathogen characteristics
driving these patterns. Comprehensive understanding of global seasonal trends in meningitis could be used to design
more eff ective prevention and control strategies
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Display of a Maize cDNA library on baculovirus infected insect cells
<p>Abstract</p> <p>Background</p> <p>Maize is a good model system for cereal crop genetics and development because of its rich genetic heritage and well-characterized morphology. The sequencing of its genome is well advanced, and new technologies for efficient proteomic analysis are needed. Baculovirus expression systems have been used for the last twenty years to express in insect cells a wide variety of eukaryotic proteins that require complex folding or extensive posttranslational modification. More recently, baculovirus display technologies based on the expression of foreign sequences on the surface of <it>Autographa californica </it>(AcMNPV) have been developed. We investigated the potential of a display methodology for a cDNA library of maize young seedlings.</p> <p>Results</p> <p>We constructed a full-length cDNA library of young maize etiolated seedlings in the transfer vector pAcTMVSVG. The library contained a total of 2.5 × 10<sup>5 </sup>independent clones. Expression of two known maize proteins, calreticulin and auxin binding protein (ABP1), was shown by western blot analysis of protein extracts from insect cells infected with the cDNA library. Display of the two proteins in infected insect cells was shown by selective biopanning using magnetic cell sorting and demonstrated proof of concept that the baculovirus maize cDNA display library could be used to identify and isolate proteins.</p> <p>Conclusion</p> <p>The maize cDNA library constructed in this study relies on the novel technology of baculovirus display and is unique in currently published cDNA libraries.</p> <p>Produced to demonstrate proof of principle, it opens the way for the development of a eukaryotic <it>in vivo </it>display tool which would be ideally suited for rapid screening of the maize proteome for binding partners, such as proteins involved in hormone regulation or defence.</p
Fine-Scale Community Structure Analysis of ANME in Nyegga Sediments with High and Low Methane Flux
To obtain knowledge on how regional variations in methane seepage rates influence the stratification, abundance, and diversity of anaerobic methanotrophs (ANME), we analyzed the vertical microbial stratification in a gravity core from a methane micro-seeping area at Nyegga by using 454-pyrosequencing of 16S rRNA gene tagged amplicons and quantitative PCR. These data were compared with previously obtained data from the more active G11 pockmark, characterized by higher methane flux. A down core stratification and high relative abundance of ANME were observed in both cores, with transition from an ANME-2a/b dominated community in low-sulfide and low methane horizons to ANME-1 dominance in horizons near the sulfate-methane transition zone. The stratification was over a wider spatial region and at greater depth in the core with lower methane flux, and the total 16S rRNA copy numbers were two orders of magnitude lower than in the sediments at G11 pockmark. A fine-scale view into the ANME communities at each location was achieved through operational taxonomical units (OTU) clustering of ANME-affiliated sequences. The majority of ANME-1 sequences from both sampling sites clustered within one OTU, while ANME-2a/b sequences were represented in unique OTUs. We suggest that free-living ANME-1 is the most abundant taxon in Nyegga cold seeps, and also the main consumer of methane. The observation of specific ANME-2a/b OTUs at each location could reflect that organisms within this clade are adapted to different geochemical settings, perhaps due to differences in methane affinity. Given that the ANME-2a/b population could be sustained in less active seepage areas, this subgroup could be potential seed populations in newly developed methane-enriched environments
Photoinduced ultrafast transition of the local correlated structure in chalcogenide phase-change materials
Revealing the bonding and time-evolving atomic dynamics in functional
materials with complex lattice structures can update the fundamental knowledge
on rich physics therein, and also help to manipulate the material properties as
desired. As the most prototypical chalcogenide phase change material, Ge2Sb2Te5
has been widely used in optical data storage and non-volatile electric memory
due to the fast switching speed and the low energy consumption. However, the
basic understanding of the structural dynamics on the atomic scale is still not
clear. Using femtosecond electron diffraction, structure factor calculation and
TDDFT-MD simulation, we reveal the photoinduced ultrafast transition of the
local correlated structure in the averaged rock-salt phase of Ge2Sb2Te5. The
randomly oriented Peierls distortion among unit cells in the averaged rock-salt
phase of Ge2Sb2Te5 is termed as local correlated structures. The ultrafast
suppression of the local Peierls distortions in individual unit cell gives rise
to a local structure change from the rhombohedral to the cubic geometry within
~ 0.3 ps. In addition, the impact of the carrier relaxation and the large
amount of vacancies to the ultrafast structural response is quantified and
discussed. Our work provides new microscopic insights into contributions of the
local correlated structure to the transient structural and optical responses in
phase change materials. Moreover, we stress the significance of femtosecond
electron diffraction in revealing the local correlated structure in the subunit
cell and the link between the local correlated structure and physical
properties in functional materials with complex microstructures
Complex sublinear burrows in the deep sea may be constructed by amphipods
Trails, burrows, and other “life traces” in sediment provide important evidence for understanding ecology—both of the maker and of other users—and behavioral information often lacking in inaccessible ecosystems, such as the deep sea or those that are already extinct. Here, we report novel sublinear rows of openings in the abyssal plains of the North Pacific, and the first plausible hypothesis for a maker of these constructions. Enigmatic serial burrows have now been recorded in the Pacific and Atlantic deep sea. Based on image and specimen evidence, we propose that these Bering Sea excavations represent amphipod burrows, while the maker of the previously known Mid-Atlantic Ridge constructions remains undetermined. We propose that maerid amphipods could create the Pacific burrows by eating–digging horizontally below the surface along a nutrient-rich layer in the sediment, making the serial openings above them as they go, for conveniently removing excavated sediment as the excavation progresses. These striking structures contribute to local biodiversity, and their maker could be considered a deep-sea ecosystem engineer.publishedVersio
Vagal Blocking for Obesity Control : a Possible Mechanism-Of-Action
14 September 2016 Erratum to: Vagal Blocking for Obesity Control: a Possible Mechanism-Of-Action Helene Johannessen, David Revesz, Yosuke Kodama, Nikki Cassie, Karolina P Skibicka, Perry Barrett, Suzanne Dickson, Jens Holst, Jens Rehfeld, Geoffrey van der Plasse, Roger Adan, Bård Kulseng, Elinor Ben-Menachem, Chun-Mei Zhao, Duan Chen, 2016, 2016. Obesity surgery. In the original article on page 4 the figures are referred to as (Fig. 1b-d) and (Fig. 1e) in the text. The correct reference is (Fig. 1b-e) and (Fig. 1f), respectively. In the original article on page 5 the figures are referred to as (Fig. 3c) and (Fig. 3d) in the text. The correct reference is (Fig. 3c,d) and (Fig. 3e,f), respectively. Peer reviewedPostprin
Cosmic rays in the surroundings of SNR G35.6-0.4
HESS J1858+020 is a TeV gamma-ray source that was reported not to have any
clear cataloged counterpart at any wavelength. However, it has been recently
proposed that this source is indirectly associated with the radio source,
re-identified as a supernova remnant (SNR), G35.6-0.4. The latter is found to
be middle-aged ( kyr) and to have nearby molecular clouds (MCs). HESS
J1858+020 was proposed to be the result of the interaction of protons
accelerated in the SNR shell with target ions residing in the clouds. The Fermi
Large Area Telescope (LAT) First Source Catalog does not list any source
coincident with the position of HESS J1858+020, but some lie close. Here, we
analyse more than 2 years of data obtained with the Fermi-LAT for the region of
interest, and consider whether it is indeed possible that the closest LAT
source, 1FGL J1857.1+0212c, is related to HESS J1858+020. We conclude it is
not, and we impose upper limits on the GeV emission originating from HESS
J1858+020. Using a simplified 3D model for the cosmic-ray propagation out from
the shell of the SNR, we consider whether the interaction between SNR G35.6-0.4
and the MCs nearby could give rise to the TeV emission of HESS J1858+020
without producing a GeV counterpart. If so, the pair of SNR/TeV source with no
GeV detection would be reminiscent of other similarly-aged SNRs, such as some
of the TeV hotspots near W28, for which cosmic-ray diffusion may be used to
explain their multi-frequency phenomenology. However, for HESS J1858+020, we
found that although the phase space in principle allows for such GeV--TeV
non-correlation to appear, usual and/or observationally constrained values of
the parameters (e.g., diffusion coefficients and cloud-SNR likely distances)
would disfavor it.Comment: In press in MNRA
Effects on muscle tissue remodeling and lipid metabolism in muscle tissue from adult patients with polymyositis or dermatomyositis treated with immunosuppressive agents.
BACKGROUND: Polymyositis (PM) and dermatomyositis (DM) are autoimmune muscle diseases, conventionally treated with high doses of glucocorticoids in combination with immunosuppressive drugs. Treatment is often dissatisfying, with persisting muscle impairment. We aimed to investigate molecular mechanisms that might contribute to the persisting muscle impairment despite immunosuppressive treatment in adult patients with PM or DM using gene expression profiling of repeated muscle biopsies.
METHODS: Paired skeletal muscle biopsies from six newly diagnosed adult patients with DM or PM taken before and after conventional immunosuppressive treatment were examined by gene expression microarray analysis. Selected genes that displayed changes in expression were analyzed by Western blot. Muscle biopsy sections were evaluated for inflammation, T lymphocytes (CD3), macrophages (CD68), major histocompatibility complex (MHC) class I expression and fiber type composition.
RESULTS: After treatment, genes related to immune response and inflammation, including inflammasome pathways and interferon, were downregulated. This was confirmed at the protein level for AIM-2 and caspase-1 in the inflammasome pathway. Changes in genes involved in muscle tissue remodeling suggested a negative effect on muscle regeneration and growth. Gene markers for fast type II fibers were upregulated and fiber composition was switched towards type II fibers in response to treatment. The expression of genes involved in lipid metabolism was altered, suggesting a potential lipotoxic effect on muscles of the immunosuppressive treatment.
CONCLUSION: The anti-inflammatory effect of immunosuppressive treatment was combined with negative effects on genes involved in muscle tissue remodeling and lipid metabolism, suggesting a negative effect on recovery of muscle performance which may contribute to persisting muscle impairment in adult patients with DM and PM
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