Aims
The objective of our study was to compare the microbiota diversity between two different age groups of Western European women.
Methods and Results
Skin‐swab samples were collected directly on ...the forehead of 34 healthy Western European women: 17 younger (21‐31 years old) and 17 older individuals (54‐69 years old). Bacterial communities were evaluated using the 16S rRNA gene sequencing. Data revealed a higher alpha diversity on the skin of older individuals compared with younger ones. Overall microbiota structure was different between the two age groups, as demonstrated by beta diversity analysis, which also highlighted a high interpersonal variation within older individuals. Furthermore, taxonomic composition analysis showed both an increase in Proteobacteria and a decrease in Actinobacteria on the older skin. At the genus level, older skin exhibited a significant increase in Corynebacterium and a decrease in Propionibacterium relative abundance.
Conclusions
Our study revealed a shift in the distribution of skin microbiota during chronological aging in Western European women.
Significance and Impact of Study
Altogether these results could become the basis to develop new approaches aiming to rebalance the skin microbiota, which is modified during the aging process.
Cockroaches Bell, William J; Roth, Louis M; Nalepa, Christine A ...
2007, 2007-07-27
eBook
The cockroach is truly an evolutionary wonder. This definitive volume provides a complete overview of suborder Blattaria, highlighting the diversity of these amazing insects in their natural ...environments. Beginning with a foreword by E. O. Wilson, the book explores the fascinating natural history and behavior of cockroaches, describing their various colors, sizes, and shapes, as well as how they move on land, in water, and through the air. In addition to habitat use, diet, reproduction, and behavior, Cockroaches covers aspects of cockroach biology, such as the relationship between cockroaches and microbes, termites as social cockroaches, and the ecological impact of the suborder.
With over 100 illustrations, an expanded glossary, and an invaluable set of references, this work is destined to become the classic book on the Blattaria. Students and research entomologists can mine each chapter for new ideas, new perspectives, and new directions for future study.
The sirtuins (SIRT 1-7) comprise a family of NAD⁺-dependent protein-modifying enzymes with activities in lysine deacetylation, adenosinediphospho(ADP)-ribosylation, and/or deacylation. These enzymes ...are involved in the cell's stress response systems and in regulating gene expression, DNA damage repair, metabolism and survival. Sirtuins have complex roles in both promoting and/or suppressing tumorigenesis. This review presents recent research progress concerning sirtuins and cancer. On one hand, functional loss of sirtuin genes, particularly SIRT1, involved in maintaining genome integrity and DNA repair will promote tumorigenesis because of genomic instability upon their loss. On the other hand, cancer cells tend to require sirtuins for these same processes to allow them to survive, proliferate, repair the otherwise catastrophic genomic events and evolve. The bifurcated roles of SIRT1, and perhaps several other sirtuins, in cancer may be in part a result of the nature of the genes that are involved in the cell's genome maintenance systems. The in-depth understanding of sirtuin functions may have significant implication in designing precise modulation of selective sirtuin members to aid cancer prevention or treatment under defined conditions.
We utilise multi-epoch MUSE spectroscopy to study binary stars in the core of the Galactic globular cluster NGC 3201. Our sample consists of 3553 stars with 54 883 spectra in total comprising 3200 ...main-sequence stars up to 4 magnitudes below the turn-off. Each star in our sample has between 3 and 63 (with a median of 14) reliable radial velocity measurements within five years of observations. We introduce a statistical method to determine the probability of a star showing radial velocity variations based on the whole inhomogeneous radial velocity sample. Using HST photometry and an advanced dynamical MOCCA simulation of this specific cluster we overcome observational biases that previous spectroscopic studies had to deal with. This allows us to infer a binary frequency in the MUSE field of view and enables us to deduce the underlying true binary frequency of (6.75 ± 0.72)% in NGC 3201. The comparison of the MUSE observations with the MOCCA simulation suggests a large portion of primordial binaries. We can also confirm a radial increase in the binary fraction towards the cluster centre due to mass segregation. We discovered that in the core of NGC 3201 at least (57.5 ± 7.9)% of blue straggler stars are in a binary system. For the first time in a study of globular clusters, we were able to fit Keplerian orbits to a significant sample of 95 binaries. We present the binary system properties of eleven blue straggler stars and the connection to SX Phoenicis-type stars. We show evidence that two blue straggler formation scenarios, the mass transfer in binary (or triple) star systems and the coalescence due to binary-binary interactions, are present in our data. We also describe the binary and spectroscopic properties of four sub-subgiant (or red straggler) stars. Furthermore, we discovered two new black hole candidates with minimum masses (M sin i) of (7.68 ± 0.50) M⊙, (4.4 ± 2.8) M⊙, and refine the minimum mass estimate on the already published black hole to (4.53 ± 0.21) M⊙. These black holes are consistent with an extensive black hole subsystem hosted by NGC 3201.
The processing of raw data from modern astronomical instruments is often carried out nowadays using dedicated software, known as pipelines, largely run in automated operation. In this paper we ...describe the data reduction pipeline of the Multi Unit Spectroscopic Explorer (MUSE) integral field spectrograph operated at the ESO Paranal Observatory. This spectrograph is a complex machine: it records data of 1152 separate spatial elements on detectors in its 24 integral field units. Efficiently handling such data requires sophisticated software with a high degree of automation and parallelization. We describe the algorithms of all processing steps that operate on calibrations and science data in detail, and explain how the raw science data is transformed into calibrated datacubes. We finally check the quality of selected procedures and output data products, and demonstrate that the pipeline provides datacubes ready for scientific analysis.
Animals sense the environment through pathways that link sensory organs to the brain. In the visual system, these feedforward pathways define the classical feedforward receptive field (ffRF), the ...area in space in which visual stimuli excite a neuron
. The visual system also uses visual context-the visual scene surrounding a stimulus-to predict the content of the stimulus
, and accordingly, neurons have been identified that are excited by stimuli outside their ffRF
. However, the mechanisms that generate excitation to stimuli outside the ffRF are unclear. Here we show that feedback projections onto excitatory neurons in the mouse primary visual cortex generate a second receptive field that is driven by stimuli outside the ffRF. The stimulation of this feedback receptive field (fbRF) elicits responses that are slower and are delayed in comparison with those resulting from the stimulation of the ffRF. These responses are preferentially reduced by anaesthesia and by silencing higher visual areas. Feedback inputs from higher visual areas have scattered receptive fields relative to their putative targets in the primary visual cortex, which enables the generation of the fbRF. Neurons with fbRFs are located in cortical layers that receive strong feedback projections and are absent in the main input layer, which is consistent with a laminar processing hierarchy. The observation that large, uniform stimuli-which cover both the fbRF and the ffRF-suppress these responses indicates that the fbRF and the ffRF are mutually antagonistic. Whereas somatostatin-expressing inhibitory neurons are driven by these large stimuli, inhibitory neurons that express parvalbumin and vasoactive intestinal peptide have mutually antagonistic fbRF and ffRF, similar to excitatory neurons. Feedback projections may therefore enable neurons to use context to estimate information that is missing from the ffRF and to report differences in stimulus features across visual space, regardless of whether excitation occurs inside or outside the ffRF. By complementing the ffRF, the fbRF that we identify here could contribute to predictive processing.
Context. Starbursts are galaxies undergoing massive episodes of star formation. The combined effect of stellar winds from hot stars and supernova explosions creates a high-temperature cavity in the ...nuclear region of these objects. The very hot gas expands adiabatically and escapes from the galaxy creating a superwind which sweeps matter from the galactic disk. The superwind region in the halo is filled with a multi-phase gas with hot, warm, cool, and relativistic components. Aims. The shocks associated with the superwind of starbursts and the turbulent gas region of the bubble inflated by them might accelerate cosmic rays up to high energies. In this work we calculate the cosmic ray production associated with the superwind using parameters that correspond to the nearby southern starburst galaxy NGC 253, which has been suggested as a potential accelerator of ultra-high-energy cosmic rays. Methods. We evaluate the efficiency of both diffusive shock acceleration (DSA) and stochastic diffusive acceleration (SDA) in the superwind of NGC 253. We estimate the distribution of both hadrons and leptons and calculate the corresponding spectral energy distributions of photons. The electromagnetic radiation can help to discriminate between the different scenarios analyzed. Results. We find that the strong mass load of the superwind, recently determined through ALMA observations, strongly attenuates the efficiency of DSA in NGC 253, whereas SDA is constrained by the age of the starburst. Conclusions. We conclude that NGC 253 and similar starbursts can only accelerate iron nuclei beyond ~1018 eV under very special conditions. If the central region of the galaxy harbors a starved supermassive black hole of ~106 M⊙, as suggested by some recent observations, a contribution in the range 1018−1019 eV can be present for accretion rates ṁ ~ 10−3 in Eddington units. Shock energies of the order of 100 EeV might only be possible if very strong magnetic field amplification occurs close to the superwind.
Abstract
As part of our massive spectroscopic survey of 25 Galactic globular clusters with MUSE, we performed multiple epoch observations of NGC 3201 with the aim of constraining the binary fraction. ...In this cluster, we found one curious star at the main-sequence turn-off with radial velocity variations of the order of 100 km s− 1, indicating the membership to a binary system with an unseen component since no other variations appear in the spectra. Using an adapted variant of the generalized Lomb–Scargle periodogram, we could calculate the orbital parameters and found the companion to be a detached stellar-mass black hole with a minimum mass of 4.36 ± 0.41 M⊙. The result is an important constraint for binary and black hole evolution models in globular clusters as well as in the context of gravitational wave sources.
Hough-based tracking of non-rigid objects Godec, M.; Roth, P.M.; Bischof, H.
Computer vision and image understanding,
10/2013, Letnik:
117, Številka:
10
Journal Article
Recenzirano
► We track previously unknown non-rigid objects by learning their appearance. ► A rough segmentation avoids the bounding-box restriction of previous approaches. ► The rough segmentation increases the ...robustness of the online learning algorithm. ► We demonstrate the approach for various challenging scenarios. ► We compare to recent state-of-the-art approaches.
Online learning has shown to be successful in tracking-by-detection of previously unknown objects. However, most approaches are limited to a bounding-box representation with fixed aspect ratio and cannot handle highly non-rigid and articulated objects. Moreover, they provide only a limited foreground/background separation, which in turn, increases the amount of noise introduced during online self-training. To overcome the limitations of a rigid bounding box, we present a novel tracking-by-detection approach based on the generalized Hough-transform. We extend the idea of Hough Forests to the online domain and couple the voting-based detection and back-projection with a rough GrabCut segmentation. Because of the increased granularity of the object description the amount of noisy training samples during online learning is reduced significantly which prevents drifting of the tracker. To show the benefits of our approach, we demonstrate it for a variety of previously unknown objects even under heavy non-rigid transformations, partial occlusions, scale changes, and rotations. Moreover, we compare our tracker to state-of-the-art methods (bounding-box-based as well as part-based) and show robust and accurate tracking results on various challenging sequences.
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