936 research outputs found
The Violent Youth of Bright and Massive Cluster Galaxies and their Maturation over 7 Billion Years
In this study we investigate the formation and evolution mechanisms of the
brightest cluster galaxies (BCGs) over cosmic time. At high redshift
(), we selected BCGs and most massive cluster galaxies (MMCGs) from
the Cl1604 supercluster and compared them to low-redshift ()
counterparts drawn from the MCXC meta-catalog, supplemented by SDSS imaging and
spectroscopy. We observed striking differences in the morphological, color,
spectral, and stellar mass properties of the BCGs/MMCGs in the two samples.
High-redshift BCGs/MMCGs were, in many cases, star-forming, late-type galaxies,
with blue broadband colors, properties largely absent amongst the low-redshift
BCGs/MMCGs. The stellar mass of BCGs was found to increase by an average factor
of from to . Through this and other
comparisons we conclude that a combination of major merging (mainly wet or
mixed) and \emph{in situ} star formation are the main mechanisms which build
stellar mass in BCGs/MMCGs. The stellar mass growth of the BCGs/MMCGs also
appears to grow in lockstep with both the stellar baryonic and total mass of
the cluster. Additionally, BCGs/MMCGs were found to grow in size, on average, a
factor of , while their average S\'ersic index increased by 0.45
from to , also supporting a scenario involving major
merging, though some adiabatic expansion is required. These observational
results are compared to both models and simulations to further explore the
implications on processes which shape and evolve BCGs/MMCGs over the past
7 Gyr.Comment: Accepted for publication in MNRA
Intelligent Playful Environments for Animals
© Owner/Author 2015. This is the author's version of the work. It is posted here for your personal use. Not for redistribution. The definitive Version of Record was published in Interacción '15 Proceedings of the XVI International Conference on Human Computer Interaction, http://dx.doi.org/10.1145/2829875.2829879We are evolving towards an interconnected and ubiquitous world, where digital devices and interfaces progressively adapt themselves to fit our needs and ease our daily activities. Although we coexist with plenty of animal species, such as our pets, we are approaching the evolution of technology in a strictly human-centric manner. A new field in Computer Science, called Animal-Computer Interaction (ACI), aims at filling this technological gap by developing systems and interfaces specifically designed for animals. Supporting animals' natural behavior and habits with suitable technology could improve both humans and animals' wellbeing. As a consequence, this doctoral research aims to explore, design and develop animal-centered intelligent systems that focus on enhancing one of the most natural animal behaviors: play. Therefore, the main goal of this research is to expand ACI with the ability of automatically manage and adapt animals play activity in order to improve their wellbeing.Work supported by MINECO (TIN2010-20488 and TIN2014-60077-R), UPV (UPV-FE-2014-24), MECD (FPU13/03831) and GVA (APOSTD/2013/013).Pons Tomás, P.; Jaén MartÃnez, FJ.; Catalá Bolós, A. (2015). Intelligent Playful Environments for Animals. ACM. https://doi.org/10.1145/2829875.2829879SHu, F., Silver, D., and Trude, A. LonelyDog@Home. 2007 IEEE/WIC/ACM International Conferences on Web Intelligence and Intelligent Agent Technology - Workshops, IEEE (2007), 333--337.Huizinga, J.Homo ludens. Wolters-Noordhoff, Groningen, The Nederlands, 1985.Mancini, C. Animal-computer interaction: a manifesto. Magazine interactions 18, 4 (2011), 69--73.Mancini, C. Animal-computer interaction (ACI): changing perspective on HCI, participation and sustainability. CHI '13 Extended Abstracts on Human Factors in Computing Systems, ACM Press (2013), 2227--2236.Matsuzawa, T. The Ai project: historical and ecological contexts. Animal cognition 6, 4 (2003), 199--211.Pons, P., Jaen, J., and Catala, A. Animal Ludens: Building Intelligent Playful Environments for Animals. 11th Conference on Advances in Computer Entertainment - Workshop on Animal Human Computer Interaction, (2014).Pons, P., Jaen, J., and Catala, A. Envisioning Future Playful Interactive Environments for Animals. In A. Nijholt, ed., More Playful User Interfaces. Springer, 2015.Robinson, C., Mancini, C., van der Linden, J., Guest, C., and Harris, R. Empowering assistance dogs: an alarm interface for canine use. Intelligent Systems for Animal Welfare, (2014).Rumbaugh, D.M., Gill, T. V., Brown, J. V., et al. A computer-controlled language training system for investigating the language skills of young apes. Behavior Research Methods & Instrumentation 5, 5 (1973), 385--392.Westerlaken, M. and Gualeni, S. Felino: The Philosophical Practice of Making an Interspecies Videogame. The Philosophy of Computer Games Conference, (2014), 1--12.Wingrave, C.A., Rose, J., Langston, T., and LaViola, J.J.J. Early explorations of CAT: canine amusement and training. CHI '10 Extended Abstracts on Human Factors in Computing Systems, (2010), 2661--2669.SpeakDolphin. http://www.speakdolphin.com
Alfalfa Varieties for South Dakota
Alfalfa varieties for South Dakota discusses varietal selection, persistence, winter hardiness, drought tolerance, disease and insect resistance, and use of alfalfa. Also included are definitions of terminology related to alfalfa crops
Alfalfa Varieties for South Dakota
Alfalfa varieties for South Dakota discusses varietal selection, persistence, winter hardiness, drought tolerance, disease and insect resistance, and use of alfalfa. Also included are definitions of terminology related to alfalfa crops
Alfalfa Varieties for South Dakota
Alfalfa varieties for South Dakota discusses varietal selection, persistence, winter hardiness, drought tolerance, disease and insect resistance, and use of alfalfa. Also included are definitions of terminology related to alfalfa crops
Alfalfa Management
Guide to alfalfa management discusses alfalfa-grass mixtures, stand establishment, harvesting and grazing management, fertilization, insect, weed, and disease control, and using alfalfa as a soil-building crop
Alfalfa Management on Dryland
Alfalfa management on dryland discusses alfalfa-grass mixtures, stand establishment, harvesting and grazing management, fertilization, insect, weed, and disease control, and using alfalfa as a soil-building crop
Emotional engagements predict and enhance social cognition in young chimpanzees
Social cognition in infancy is evident in coordinated triadic engagements, that is, infants attending jointly with social partners and objects. Current evolutionary theories of primate social cognition tend to highlight species differences in cognition based on human-unique cooperative motives. We consider a developmental model in which engagement experiences produce differential outcomes. We conducted a 10-year-long study in which two groups of laboratory-raised chimpanzee infants were given quantifiably different engagement experiences. Joint attention, cooperativeness, affect, and different levels of cognition were measured in 5- to 12-month-old chimpanzees, and compared to outcomes derived from a normative human database. We found that joint attention skills significantly improved across development for all infants, but by 12 months, the humans significantly surpassed the chimpanzees. We found that cooperativeness was stable in the humans, but by 12 months, the chimpanzee group given enriched engagement experiences significantly surpassed the humans. Past engagement experiences and concurrent affect were significant unique predictors of both joint attention and cooperativeness in 5- to 12-month-old chimpanzees. When engagement experiences and concurrent affect were statistically controlled, joint attention and cooperation were not associated. We explain differential social cognition outcomes in terms of the significant influences of previous engagement experiences and affect, in addition to cognition. Our study highlights developmental processes that underpin the emergence of social cognition in support of evolutionary continuity
The Properties of Radio Galaxies and the Effect of Environment in Large Scale Structures at
In this study we investigate 89 radio galaxies that are
spectroscopically-confirmed to be members of five large scale structures in the
redshift range of . Based on a two-stage classification
scheme, the radio galaxies are classified into three sub-classes: active
galactic nucleus (AGN), hybrid, and star-forming galaxy (SFG). We study the
properties of the three radio sub-classes and their global and local
environmental preferences. We find AGN hosts are the most massive population
and exhibit quiescence in their star-formation activity. The SFG population has
a comparable stellar mass to those hosting a radio AGN but are unequivocally
powered by star formation. Hybrids, though selected as an intermediate
population in our classification scheme, were found in almost all analyses to
be a unique type of radio galaxies rather than a mixture of AGN and SFGs. They
are dominated by a high-excitation radio galaxy (HERG) population. We discuss
environmental effects and scenarios for each sub-class. AGN tend to be
preferentially located in locally dense environments and in the cores of
clusters/groups, with these preferences persisting when comparing to galaxies
of similar colour and stellar mass, suggesting that their activity may be
ignited in the cluster/group virialized core regions. Conversely, SFGs exhibit
a strong preference for intermediate-density global environments, suggesting
that dusty starbursting activity in LSSs is largely driven by galaxy-galaxy
interactions and merging.Comment: 28 pages, 10 figures, accepted to MNRA
Construction of a bacterial autoinducer detection system in mammalian cells
Quorum sensing (QS) is a cell density-dependent signaling system used by bacteria to coordinate gene expression within a population. QS systems in Gram negative bacteria consist of transcription factors of the LuxR family and their acyl homoserine lactone (AHL) ligands. We describe here a method for examining QS signaling systems in mammalian cells that uses engineered LuxR-type proteins from the opportunistic pathogen, Pseudomonas aeruginosa, which can function as AHL-dependent transcription factors. The engineered proteins respond to their cognate ligands and display sequence specific DNA binding properties. This system has several potential biotechnological and biological applications. It may be used to characterize any LuxR-type protein, screen animal and plant cell extracts or exudates for compounds that mimic or interfere with AHL signaling or to screen different cell types for AHL inactivating activities
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