200 research outputs found
MeerKAT HI line observations of the nearby interacting galaxy pair NGC 1512/1510
We present MeerKAT HI line observations of the nearby interacting galaxy pair
NGC 1512/1510. The MeerKAT data yield high-fidelity image sets characterised by
an excellent combination of high angular resolution (~20") and and sensitivity
(~0.08 Msun/pc^2), thereby offering the most detailed view of this well-studied
system's neutral atomic hydrogen content, especially the HI co-located with the
optical components of the galaxies. The stellar bulge and bar of NGC 1512 are
located within a central HI depression where surface densities fall below 1
Msun/pc^2, while the galaxy's starburst ring coincides with a well-defined HI
annulus delimited by a surface density of 3 Msun/pc^2. In stark contrast, the
star-bursting companion, NGC 1510, has its young stellar population precisely
matched to the highest HI over-densities we measure (~12.5 Msun/pc^2). The
improved quality of the MeerKAT data warrants the first detailed measurements
of the lengths and masses of the system's tidally-induced HI arms. We measure
the longest of the two prominent HI arms to extend over ~27 kpc and to contain
more than 30% of the system's total HI mass. We quantitatively explore the
spatial correlation between HI and far-ultraviolet flux over a large range of
HI mass surface densities spanning the outer disk. The results indicate the
system's HI content to play an important role in setting the pre-conditions
required for wide-spread, high-mass star formation. This work serves as a
demonstration of the remarkable efficiency and accuracy with which MeerKAT can
image nearby systems in HI line emission.Comment: 12 pages, 11 figures. Submitted only to arXi
Factors shaping species richness and biodiversity of riverine macroinvertebrate assemblages at the local and regional scale
The biodiversity and species richness of benthic macroinvertebrate assemblages are under the strong pressure of environmental variables compounded with geographical and historical processes. Numerous studies that have investigated biodiversity and assemblage stability have shown the importance of choosing proper methodologies and paradigms. Consequently, the use of diversity measures and the partitioning of biodiversity at different spatial and temporal scales are of particular significance. Within habitats, only those species whose preferences remain within a tolerable range of the variability of abiotic factors are able to survive. The structure of biocoenosis at the local scale is determined mainly by current velocity/discharge, granulometry of the inorganic bottom substrate, quantity and quality of particulate organic matter, as well as water quality variables. Dispersion plays a key role in shaping regional diversity gradients, which supports the permanent inflow of individuals and their exchange between riverine basins. However, dispersion is also one of the basic aspects of the saturation/non-saturation of local communities with species from the regional species pool; a respective concept tries to determine how, why and to what degree local species richness is dependent on regional species richness
The role of septal perforators and "myocardial bridging effect" in atherosclerotic plaque distribution in the coronary artery disease
The distribution of atherosclerotic plaque burden in the human coronary arteries is not uniform. Plaques are located mostly in the left anterior descending artery (LAD), then in the right coronary artery (RCA), circumflex branch (LCx) and the left main coronary artery (LM) in a decreasing order of frequency. In the LAD and LCx, plaques tend to cluster within the proximal segment, while in the RCA their distribution is more uniform. Several factors have been involved in this phenomenon, particularly flow patterns in the left and right coronary artery. Nevertheless, it does not explain the difference in lesion frequency between the LAD and the LCx as these are both parts of the left coronary artery. Branching points are considered to be the risk points of atherosclerosis. In the LCx, the number of side branches is lower than in the LAD or RCA and there are no septal perforators with intramuscular courses like in the proximal third of the LAD and the posterior descending artery (PDA). We hypothesized that septal branches generate disturbed flow in the LAD and PDA in a similar fashion to the myocardial bridge (myocardial bridging effect). This coronary architecture determines the non-uniform plaque distribution in coronary arteries and LAD predisposition to plaque formation
BaWO4:Ce Single Crystals Codoped with Na Ions
Single crystals of BaWO4, BaWO4:0.5at.%Ce; BaWO4:1at.%Ce; BaWO4:0.5at.%Ce,1at.%Na; and BaWO4:1at.%Ce,2at.%Na were grown from an inductively heated iridium crucible by the Czochralski method on a Malvern MSR4 puller. They were investigated using Electron Paramagnetic Resonance (EPR) spectroscopy at helium temperatures. One isolated center of high (D2d or S4) symmetry was found and two or more other centers of lower symmetry were identified, depending on crystal doping. From the fitting using the EPR-NMR program, the following parameters of g-matrix for the high symmetry center were found: gx = 1.505, gy = 1.505, and gz = 2.731. The linewidth vs. temperature revealed an increasing exponential tendency with increasing temperature. It showed one phonon at the lower temperatures and a Raman + Orbach effect at the higher temperatures. Radioluminescence and pulse height spectra showed rather poor scintillation properties, without any contribution from cerium emission
The self-care of diabetics : the role of a nurse
Chorzy na cukrzycę powinni stać się samowystarczalni w zakresie kontroli stężenia glukozy we krwi oraz wstrzyknięć insuliny do tkanki podskórnej. Posiadanie tych umiejętności nie uzależnia ich od innych osób. Stawiają się w komfortowej sytuacji, jaką jest zdolność do samoopieki. Wychodząc naprzeciw tej tezie autorzy omawiają korzystanie ze strzykawki do wstrzyknięć insuliny, charakteryzują obsługę automatycznych wstrzykiwaczy ( PEN-ów). Przedstawiają także nowoczesne rozwiązania techniczne stosowane w leczeniu chorych na cukrzycę insulinozależną.Diabetics should become self-sufficient as far as controlling their glucose level and injecting insulin to the subcutaneous tissue are concerned. Having these skill makes them independent from the help of others. It puts them in a convenient position of being capable of self-care. With the intention of exploring this matter, the authors discuss using the syringe to inject insulin and characterize the use of automatic injectors (pens). They also present modern technological solutions used for treating the insulin-dependent diabetics
Roughness of a subglacial conduit under Hansbreen, Svalbard
K.M., J.G., X.L. and Y.C. were supported by the National Science Foundation (NSF) under Grant No. #1503928. Thefieldwork team (K.M., J.G., M.C.) were supported by the Norwegian Arctic Research Council and Svalbard Science Forum, RiS #6106. K.M. was also supported by the National Aeronautics and Space Administration (NASA)Headquarters under the NASA Earth and Space Science Fellowship Program – Grant NNX10AN83H, the University of California, Santa Cruz, and the Woods Hole Oceanographic Institution Ocean and Climate Change Institute post-graduate fellowship. Portions of this work were conducted while J.G. was supported by the NSF EAR Postdoctoral Fellowship (#0946767). S.T. was funded by NASA grant NNX11AH61G.Hydraulic roughness exerts an important but poorly understood control on water pressure in subglacial conduits. Where relative roughness values are 5%. Here we report the first quantitative assessment of roughness heights and hydraulic diameters in a subglacial conduit. We measured roughness heights in a 125 m long section of a subglacial conduit using structure-from-motion to produce a digital surface model, and hand-measurements of the b-axis of rocks. We found roughness heights from 0.07 to 0.22 m and cross-sectional areas of 1-2 m2, resulting in relative roughness of 3-12% and >5% for most locations. A simple geometric model of varying conduit diameter shows that when the conduit is small relative roughness is >30% and has large variability. Our results suggest that parameterizations of conduit hydraulic roughness in subglacial hydrological models will remain challenging until hydraulic diameters exceed roughness heights by a factor of 20, or the conduit radius is >1 m for the roughness elements observed here.Publisher PDFPeer reviewe
Educating diabetics
Cukrzyca podobnie jak wiele innych chorób jest nieuleczalna. Diabetycy, aby mogli skutecznie kontrolować i panować nad chorobą muszą znać jej tajniki. Dogłębne poznanie choroby pozwoli na przewidywanie reakcji, z jakimi można się spotkać. Nieodzownym elementem w leczeniu cukrzycy typu 1 oprócz insulinoterapii jest sposób żywienia. I właśnie zasadom żywienia w cukrzycy poświęcony jest niniejszy artykuł.Like many other illnesses, diabetes is incurable. In order to have the illness under control in a proper manner, diabetics must know all the details related to it. An in-depth knowledge on the disease allows them to anticipate possible reactions. Apart from insulin therapy, an essential element of the treatment of type 1diabetes is a proper diet. This article is devoted precisely to the way diabetics should select their food
The monitoring of glycaemia concentration
Jedną z najważniejszych rzeczy jakiej muszą nauczyć się diabetycy to kontrola glikemii. Autorzy w artykule omawiają zasady funkcjonowania i posługiwania się glukometrem. Szczegółowiej charakteryzują także urządzenia do pobierania krwi kapilarnej, oraz urządzenia alternatywne służące temu procederowi. Podkreślają także znaczenie oznaczeń stężenie hemoglobiny glikowanej u diabetyków.One of the most crucial things diabetics have to learn is controlling the glycaemia concentration. In this paper, the description of functions and operation of a glucometer is offered. Devices used to draw capillary blood and their substitutes are characterised in greater detail. Moreover, the significance of glycated haemoglobin measures for diabetics
Dipole relaxation process and giant dielectric permittivity in Eu3+- doped CdMoO4 single crystal
Single crystal of Eu3+-doped cadmium molybdate (Cd0.9268 M 0.0244Eu0.0488MoO4, where M denotes
cationic vacancies) has been successfully grown by the Czochralski method in air and under 1 MPa. X-ray
diffraction analysis indicates that as-grown single crystal exhibits tetragonal scheelite-type structure
(a = b = 5.16188(14) A; c = 11.2080(5) A; space group I41/a). Eu3+ ions do not show long-range order and
they are randomly distributed in CdMoO4 framework substituting Cd2+ ones. UVevis diffuse reflectance
measurements revealed very close optical band gap (Eg) values, i.e. ~1.74 eV along [100] and [001]
crystallographic directions that are twice smaller than Eg of microcrystalline pure CdMoO4 as well as
powder Eu3+-doped single crystal. Magnetic and electrical studies of Eu3+-doped cadmium molybdate
single crystal showed a paramagnetic and n-type semiconducting behaviour with the metal-insulator
transition above 350 K along both crystallographic directions. Dielectric results analysis using the
Cole-Cole fit function revealed that the dipole relaxation process has different time scale depending on
the crystallographic direction and exhibits Arrhenius temperature dependence for both studied directions.
This fact is accompanied by the colossal dielectric permittivity with er > 8 • 103. The above results
are considered in the framework of narrow europium multiplets of energy comparable to thermal energy
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