2,234 research outputs found
Near-infrared colors of minor planets recovered from VISTA - VHS survey (MOVIS)
The Sloan Digital Sky Survey (SDSS) and Wide-field Infrared Survey Explorer
(WISE) provide information about the surface composition of about 100,000 minor
planets. The resulting visible colors and albedos enabled us to group them in
several major classes, which are a simplified view of the diversity shown by
the few existing spectra. We performed a serendipitous search in VISTA-VHS
observations using a pipeline developed to retrieve and process the data that
corresponds to solar system objects (SSo). The colors and the magnitudes of the
minor planets observed by the VISTA survey are compiled into three catalogs
that are available online: the detections catalog (MOVIS-D), the magnitudes
catalog (MOVIS-M), and the colors catalog (MOVIS-C). They were built using the
third data release of the survey (VISTA VHS-DR3). A total of 39,947 objects
were detected, including 52 NEAs, 325 Mars Crossers, 515 Hungaria asteroids,
38,428 main-belt asteroids, 146 Cybele asteroids, 147 Hilda asteroids, 270
Trojans, 13 comets, 12 Kuiper Belt objects and Neptune with its four
satellites. The colors found for asteroids with known spectral properties
reveal well-defined patterns corresponding to different mineralogies. The
distributions of MOVIS-C data in color-color plots shows clusters identified
with different taxonomic types. All the diagrams that use (Y-J) color separate
the spectral classes more effectively than the (J-H) and (H-Ks) plots used
until now: even for large color errors (<0.1), the plots (Y-J) vs (Y-Ks) and
(Y-J) vs (J-Ks) provide the separation between S-complex and C-complex. The end
members A, D, R, and V-types occupy well-defined regions.Comment: 19 pages, 16 figure
Dynamics of Quintessence Models of Dark Energy with Exponential Coupling to the Dark Matter
We explore quintessence models of dark energy which exhibit non-minimal
coupling between the dark matter and the dark energy components of the cosmic
fluid. The kind of coupling chosen is inspired in scalar-tensor theories of
gravity. We impose a suitable dynamics of the expansion allowing to derive
exact Friedmann-Robertson-Walker solutions once the coupling function is given
as input. Self-interaction potentials of single and double exponential types
emerge as result of our choice of the coupling function. The stability and
existence of the solutions is discussed in some detail. Although, in general,
models with appropriated interaction between the components of the cosmic
mixture are useful to handle the coincidence problem, in the present study the
coincidence can not be evaded due to the choice of the solution generating
ansatz.Comment: 10 pages, 7 figure
Orbit-based deformation procedure for two-field models
We present a method for generating new deformed solutions starting from
systems of two real scalar fields for which defect solutions and orbits are
known. The procedure generalizes the approach introduced in a previous work
[Phys. Rev. D 66, 101701(R) (2002)], in which it is shown how to construct new
models altogether with its defect solutions, in terms of the original model and
solutions. As an illustration, we work out an explicit example in detail.Comment: 15 pages, 14 figures; version to appear in PR
First Successful Capture and Satellite Tracking of a West Indian Manatee (Trichechus manatus) in Panama: Feasibility of Capture and Telemetry Techniques
It is currently unknown how important the Central American countries south of Belize are as a link between manatee populations in the north (Belize and Mexico) and populations in South America. Therefore, apart from knowing where manatees are found, it is important to understand how manatees are using these habitats and if they are moving between countries or distinct population centers. Here we report the results of a multi-national and multiinstitutional collaboration resulting in the first successful capture and satellite tracking of a West Indian manatee in southern Central America
Cysteine-proteases and cystatins from barley: molecular and functional characterization in housekeeping and defense processes
Plant cysteine-proteases (CysProt) represent a well-characterized type of proteolytic enzymes that fulfill tightly regulated physiological functions (senescence and seed germination among others) and defense roles. This article is focused on the group of papain-proteases C1A (family C1, clan CA) and their inhibitors, phytocystatins (PhyCys). In particular, the protease–inhibitor interaction and their mutual participation in specific pathways throughout the plant's life are reviewed. C1A CysProt and PhyCys have been molecularly characterized, and comparative sequence analyses have identified consensus functional motifs. A correlation can be established between the number of identified CysProt and PhyCys in angiosperms. Thus, evolutionary forces may have determined a control role of cystatins on both endogenous and pest-exogenous proteases in these species. Tagging the proteases and inhibitors with fluorescence proteins revealed common patterns of subcellular localization in the endoplasmic reticulum–Golgi network in transiently transformed onion epidermal cells. Further in vivo interactions were demonstrated by bimolecular fluorescent complementation, suggesting their participation in the same physiological processes
Effects of resistance training program on muscle mass and muscle strength and the relationship with cognition in Older Women
The aim of this study was to study the effects of a resistance training programme on Maximal Dynamic Strength (MDS) and muscle morphology of the upper limbs (UL) and lower limbs (LL), as well as to analyse their association with cognition, in a population of older women. The study had a duration of 24 months and a total of 93 Chilean older women participated. The participants were divided into two groups: The Physical Activity Group (PAG, n = 45, age (X ± SD) 77.93 ± 3.54 years), and the Sedentary Group (SG, n = 48, age (X ± SD) 77.71 ± 3.41 years). The PAG carried out a muscle strength training routine twice per week. The following variables were evaluated: Muscle function through maximal dynamic strength (1RM), muscle morphology through arm and calf circumference (AC and CC, respectively), and cognition (Mini Mental State Examination: MMSE). The results show that the SG recorded significant decreases (percent changes; p < 0.05) in the analysed variables: MMSE (-3.5%), MDS in UL (-3.3%), MDS in LL (-4.1%), AC (-4.5%), CC (-4.1%), and BMI (-3.1%). However, the PAG improved significantly in all the analysed variables except in BMI: MMSE (3.9%), MDS in UL (3.6%), MDS in LL (3.5%), AC (1.8%), and CC (2.5%). Moreover, there was a significant association (p < 0.05) between the changes in the muscle strength variables and the changes in cognition level. Therefore, it can be concluded that a two-year muscle strength training programme (load intensity between 30-55% 1RM) in older women improves Maximal Dynamic Strength in UL and LL, as well as muscle mass in arms and calves. Furthermore, it can be asserted that the changes in muscle strength levels could predict the changes in the levels of cognition in older women. © 2021 by the authors. Licensee MDPI, Basel, Switzerland
Early Science with the Large Millimeter Telescope: an energy-driven wind revealed by massive molecular and fast X-ray outflows in the Seyfert Galaxy IRAS 17020+4544
We report on the coexistence of powerful gas outflows observed in millimeter
and X-ray data of the Radio-Loud Narrow Line Seyfert 1 Galaxy IRAS 17020+4544.
Thanks to the large collecting power of the Large Millimeter Telescope, a
prominent line arising from the 12CO(1-0) transition was revealed in recent
observations of this source. The complex profile is composed by a narrow
double-peak line and a broad wing. While the double-peak structure may be
arising in a disk of molecular material, the broad wing is interpreted as the
signature of a massive outflow of molecular gas with an approximate bulk
velocity of -660 km/s. This molecular wind is likely associated to a
multi-component X-ray Ultra-Fast Outflow with velocities reaching up to ~0.1c
and column densities in the range 10^{21-23.9} cm^-2 that was reported in the
source prior to the LMT observations. The momentum load estimated in the two
gas phases indicates that within the observational uncertainties the outflow is
consistent with being propagating through the galaxy and sweeping up the gas
while conserving its energy. This scenario, which has been often postulated as
a viable mechanism of how AGN feedback takes place, has so far been observed
only in ULIRGs sources. IRAS 17020+4544 with bolometric and infrared luminosity
respectively of 5X10^{44} erg/s and 1.05X10^{11} L_sun appears to be an example
of AGN feedback in a NLSy1 Galaxy (a low power AGN). New proprietary
multi-wavelength data recently obtained on this source will allow us to
corroborate the proposed hypothesis.Comment: Accepted for publication on ApJ Letters, 9 pages, 4 figure
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