1,601 research outputs found
Extended Ultraviolet Disks and Ultraviolet-bright Disks in Low-mass E/S0 Galaxies
We have identified 15 extended ultraviolet (XUV) disks in a largely field sample of 38 E/S0 galaxies that have stellar masses primarily below ~4 × 10^(10) M_☉ and comparable numbers on the red and blue sequences. We use a new purely quantitative XUV-disk definition designed with reference to the "Type 1" XUV-disk definition found in the literature, requiring UV extension relative to a UV-defined star formation threshold radius. The 39% ± 9% XUV-disk frequency for these E/S0s is roughly twice the ~20% reported for late-type galaxies (although differences in XUV-disk criteria complicate the comparison), possibly indicating that XUV disks are preferentially associated with galaxies experiencing weak or inefficient star formation. Consistent with this interpretation, we find that the XUV disks in our sample do not correlate with enhanced outer-disk star formation as traced by blue optical outer-disk colors. However, UV-Bright (UV-B) disk galaxies with blue UV colors outside their optical 50% light radii do display enhanced optical outer-disk star formation as well as enhanced atomic gas content. UV-B disks occur in our E/S0s with a 42^(+9)_–8% frequency and need not coincide with XUV disks; thus their combined frequency is 61% ± 9%. For both XUV and UV-B disks, UV colors typically imply <1 Gyr ages, and most such disks extend beyond the optical R_(25) radius. XUV disks occur over the full sample mass range and on both the red and blue sequences, suggesting an association with galaxy interactions or another similarly general evolutionary process. In contrast, UV-B disks favor the blue sequence and may also prefer low masses, perhaps reflecting the onset of cold-mode gas accretion or another mass-dependent evolutionary process. Virtually all blue E/S0s in the gas-rich regime below stellar mass M_t ~ 5 × 10^9 M_☉ (the "gas-richness threshold mass") display UV-B disks, supporting the previously suggested association of this population with active disk growth
Reference signal generator for active power filters using MGP-FIR filter designed by evolutionary programming
This paper describes a high-performance reference signal generator for active power filters extracting the fundamental signal component from distorted current signals. In order to achieve high-quality output as well as computationally effective algorithm, the generator employs an adaptive and predictive MGP-FIR (Multiplicative General Parameter) bandpass filter designed by evolutionary programming. Detailed procedures of MGP-FIR filtering and evolutionary optimization are first discussed; theoretical conclusions are verified by illustrative simulation results.reviewe
At the Crossroads of Company and Insolvency Law
Company Law, Insolvency Law, Restructuring DirectiveThe article discusses one of the most fundamental aspects of corporate law, namely the interseÂction between company law and insolvency law, with specific regard to the recent EU Directive on Preventive Restructuring (EU 2019/1023, the ‘Restructuring Directive’ or ‘Directive’)2. It notes the forthcoming implementation of the Directive in the EU Member States. The key options for implementation of the Directive available to European legislators are introduced, including an option based on company law which, according to the recent LL.D.Âdissertation of the coÂauthor, would provide more tools for restructurings than are available under the frame works based on insolvency law. This would create efficient mechanisms in particular for the preventive restructuÂring of solvent companies, but also for the completion of a friendly takeover of a publiclyÂlisted company through a scheme of arrangement under company law. The scheme of arrangement mechanism has also been included in the recently published European Model Company Act.Non peer reviewe
Post-stroke enriched auditory environment induces structural connectome plasticity : secondary analysis from a randomized controlled trial
Post-stroke neuroplasticity and cognitive recovery can be enhanced by multimodal stimulation via environmental enrichment. In this vein, recent studies have shown that enriched sound environment (i.e., listening to music) during the subacute post-stroke stage improves cognitive outcomes compared to standard care. The beneficial effects of post-stroke music listening are further pronounced when listening to music containing singing, which enhances language recovery coupled with structural and functional connectivity changes within the language network. However, outside the language network, virtually nothing is known about the effects of enriched sound environment on the structural connectome of the recovering post-stroke brain. Here, we report secondary outcomes from a single-blind randomized controlled trial (NCT01749709) in patients with ischaemic or haemorrhagic stroke (N = 38) who were randomly assigned to listen to vocal music, instrumental music, or audiobooks during the first 3 post-stroke months. Utilizing the longitudinal diffusion-weighted MRI data of the trial, the present study aimed to determine whether the music listening interventions induce changes on structural white matter connectome compared to the control audiobook intervention. Both vocal and instrumental music groups increased quantitative anisotropy longitudinally in multiple left dorsal and ventral tracts as well as in the corpus callosum, and also in the right hemisphere compared to the audiobook group. Audiobook group did not show increased structural connectivity changes compared to both vocal and instrumental music groups. This study shows that listening to music, either vocal or instrumental promotes wide-spread structural connectivity changes in the post-stroke brain, providing a fertile ground for functional restoration.Peer reviewe
Strongyloides stercoralis infection in a Finnish kennel
Background: Intestinal threadworm Strongyloides stercoralis is a parasite of dog, cat and primates
that occurs worldwide being most prevalent in tropical and subtropical countries. The adult
parasitic worm is about 2 mm long and slender. It possesses both parasitic and free-living lifecycles.
The parasitic worms are females. Strongyloides stercoralis infects the host via percutaneous, peroral
or transmammary transmission in addition to autoinfection. Clinical disease varies from inapparent
to severe enteritis and pneumonia. The diagnosis is based on demonstration of larvae in fresh
faeces, which is best made by Baermann technique.
Case presentation: Strongyloides stercoralis infection was diagnosed in autopsy in a 10-week-old
puppy born and raised in a Finnish kennel. Prior to its sudden death, the puppy had suffered from
gastrointestinal disturbance for three weeks. Subsequent sampling of the dogs in the kennel
revealed that three adult dogs in the kennel were also infected.
Conclusion: The present case shows that S. stercoralis can complete its life cycle and cause disease
in dogs also in Northern Europe. Infection can be maintained also in a temperate climate and may
become a chronic problem in a kennel environment. Infection may be underdiagnosed as Baermann
technique is not routinely performed in small animal practice
Long-Term Evolution of Massive Black Hole Binaries. III. Binary Evolution in Collisional Nuclei
[Abridged] In galactic nuclei with sufficiently short relaxation times,
binary supermassive black holes can evolve beyond their stalling radii via
continued interaction with stars. We study this "collisional" evolutionary
regime using both fully self-consistent N-body integrations and approximate
Fokker-Planck models. The N-body integrations employ particle numbers up to
0.26M and a direct-summation potential solver; close interactions involving the
binary are treated using a new implementation of the Mikkola-Aarseth chain
regularization algorithm. Even at these large values of N, two-body scattering
occurs at high enough rates in the simulations that they can not be simply
scaled to the large-N regime of real galaxies. The Fokker-Planck model is used
to bridge this gap; it includes, for the first time, binary-induced changes in
the stellar density and potential. The Fokker-Planck model is shown to
accurately reproduce the results of the N-body integrations, and is then
extended to the much larger N regime of real galaxies. Analytic expressions are
derived that accurately reproduce the time dependence of the binary semi-major
axis as predicted by the Fokker-Planck model. Gravitational wave coalescence is
shown to occur in <10 Gyr in nuclei with velocity dispersions below about 80
km/s. Formation of a core results from a competition between ejection of stars
by the binary and re-supply of depleted orbits via two-body scattering. Mass
deficits as large as ~4 times the binary mass are produced before coalescence.
After the two black holes coalesce, a Bahcall-Wolf cusp appears around the
single hole in one relaxation time, resulting in a nuclear density profile
consisting of a flat core with an inner, compact cluster, similar to what is
observed at the centers of low-luminosity spheroids.Comment: 21 page
- …