1,005 research outputs found
Aharonov-Bohm effect for an exciton in a finite width nano-ring
We study the Aharonov-Bohm effect for an exciton on a nano-ring using a 2D attractive fermionic Hubbard model. We extend previous results obtained for a 1D ring in which only azimuthal motion is considered, to a more general case of 2D annular lattices. In general, we show that the
existence of the localization effect, increased by the nonlinearity, makes the phenomenon in the 2D system similar to the 1D case. However, the introduction of radial motion introduces extra frequencies, different from the original isolated frequency corresponding to the excitonic Aharonov-
Bohm oscillations. If the circumference of the system becomes large enough, the Aharonov-Bohm effect is suppressed
Fossil group origins: VIII RXJ075243.6+455653 a transitionary fossil group
It is thought that fossil systems are relics of structure formation in the
primitive Universe. They are galaxy aggregations that have assembled their mass
at high redshift with few or no subsequent accretion. Observationally these
systems are selected by large magnitude gaps between their 1st and 2nd ranked
galaxies. Nevertheless, there is still debate over whether or not this
observational criterium selects dynamically evolved ancient systems. We have
studied the properties of the nearby fossil group RXJ075243.6+455653 in order
to understand the mass assembly of this system. Deep spectroscopic observations
allow us to construct the galaxy luminosity function (LF) of RXJ075243.6+455653
down to M*+ 6. The analysis of the faint-end of the LF in groups and clusters
provides valuable information about the mass assembly of the system. In
addition, we have analyzed the nearby large-scale structure around this group.
We identified 26 group members within r200=0.9 Mpc. The LF of the group shows a
flat faint-end slope ( -1.08 +/- 0.33). This low density of dwarf galaxies is
confirmed by the low value of the dwarf-to-giant ratio (DGR = 0.99 +/- 0.49)
for this system. Both the lack of dwarf galaxies and the low luminosity of the
BGG suggests that RXJ075243.6+455653 still has to accrete mass from its nearby
environment. This mass accretion will be achieved because it is the dominant
structure of a rich environment formed by several groups of galaxies (15)
within 7 Mpc from the group center and with +/- 1000$ km/s. RXJ075243.6+455653
is a group of galaxies that has not yet completed the process of its mass
assembly. This new mass accretion will change the fossil state of the group.
This group is an example of a galaxy aggregation selected by a large magnitude
gap but still in the process of the accretion of its mass (Abridged).Comment: 9 pages, 9 figures, accepted in A&
Genomic Organization and Control of the Grb7 Gene Family
Grb7 and their related family members Grb10 and Grb14 are adaptor proteins, which participate in the functionality of multiple signal transduction pathways under the control of a variety of activated tyrosine kinase receptors and other tyrosine-phosphorylated proteins. They are involved in the modulation of important cellular and organismal functions such as cell migration, cell proliferation, apoptosis, gene expression, protein degradation, protein phosphorylation, angiogenesis, embryonic development and metabolic control. In this short review we shall describe the organization of the genes encoding the Grb7 protein family, their transcriptional products and the regulatory mechanisms implicated in the control of their expression. Finally, the alterations found in these genes and the mechanisms affecting their expression under pathological conditions such as cancer, diabetes and some congenital disorders will be highlighted
Review on Energy Efficiency using the Ecotect Simulation Software for Residential Building Sector
[EN] The building sectors are recognized as one of the essential contributors of global warming and
climate change because of their high energy use. The building sector is responsible for 40% of all
energy usage and 40% of the CO2 emissions in the developed countries. Researchers in the world
are working on energy management and conservation using simulation software to develop
strategies that lead to an overall reduction of energy consumption in the buildings. This review is
considered a modeling and simulation approach with a specific focus on residential building.
Modeling and simulation methods reviewed are presented categorically as per the strategic
approach adopted by the researchers. Simulation results available for residential building energy
are also introduced. This research has reviewed the capabilities and performances on Ecotect
simulation and modeling, including daylighting, solar radiation, thermal analysis, and shading for
energy management and conservation of residential building. Different modeling and simulation
approaches, from various building and climate, were reviewed and discussed. The analysis of
present work greatly help the researchers' decision-making and selection of software to perform
various simulations in energy management of residential buildings.Amani, N.; Sabamehr, A.; Palmero Iglesias, LM. (2022). Review on Energy Efficiency using the Ecotect Simulation Software for Residential Building Sector. International Journal of Energy and Environment (IJEE). 13(3):284-294. https://doi.org/10.5829/ijee.2022.13.03.0828429413
Fungal microbiota from rain water and pathogenicity of Fusarium species isolated from atmospheric dust and rainfall dust
In order to determine the presence of Fusarium spp. in atmospheric dust and rainfall dust, samples were collected during September 2007, and July, August, and October 2008. The results reveal the prevalence of airborne Fusarium species coming from the atmosphere of the South East coast of Spain. Five different Fusarium species were isolated from the settling dust: Fusarium oxysporum, F. solani, F. equiseti, F. dimerum, and F. proliferatum. Moreover, rainwater samples were obtained during significant rainfall events in January and February 2009. Using the dilution-plate method, 12 fungal genera were identified from these rainwater samples. Specific analyses of the rainwater revealed the presence of three species of Fusarium: F. oxysporum, F. proliferatum and F. equiseti. A total of 57 isolates of Fusarium spp. obtained from both rainwater and atmospheric rainfall dust sampling were inoculated onto melon (Cucumis melo L.) cv. Piñonet and tomato (Lycopersicon esculentum Mill.) cv. San Pedro. These species were chosen because they are the main herbaceous crops in Almeria province. The results presented in this work indicate strongly that spores or propagules of Fusarium are able to cross the continental barrier carried by winds from the Sahara (Africa) to crop or coastal lands in Europe. Results show differences in the pathogenicity of the isolates tested. Both hosts showed root rot when inoculated with different species of Fusarium, although fresh weight measurements did not bring any information about the pathogenicity. The findings presented above are strong indications that long-distance transmission of Fusarium propagules may occur. Diseases caused by species of Fusarium are common in these areas. They were in the past, and are still today, a problem for greenhouses crops in AlmerÃa, and many species have been listed as pathogens on agricultural crops in this region. Saharan air masses dominate the Mediterranean regions. The evidence of long distance dispersal of Fusarium spp. by atmospheric dust and rainwater together with their proved pathogenicity must be taken into account in epidemiological studies
Nuclear Components in the Bulges of Disk Galaxies
By combining surface brightness profiles from images taken in the HST/NICMOS
F160W and ground-based (GB) bands, we have obtained NIR profiles for a well
studied sample of inclined disk galaxies, spanning radial ranges from 20 pc to
a few kpc. We fit PSF-convolved Sersic-plus-exponential laws to the profiles,
and compare the results with the fits to the ground-based data alone. HST
profiles show light excesses over the best-fit Sersic law in the inner ~1
arcsec. This is often as a result of inner power-law cusps similar to the inner
profiles of intermediate-luminosity elliptical galaxies.Comment: 4 pages, 5 figures. Poster paper to "The Central kpc of Starbursts
and AGN: the La Palma connection'', Eds. J.H. Knapen, J.E. Beckman, I.
Shlosman and T.J. Mahoney, ASP conf. series, in press (2001
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