4,436 research outputs found
Fitting Neutrino Physics with a U(1)_R Lepton Number
We study neutrino physics in the context of a supersymmetric model where a
continuous R-symmetry is identified with the total Lepton Number and one
sneutrino can thus play the role of the down type Higgs. We show that
R-breaking effects communicated to the visible sector by Anomaly Mediation can
reproduce neutrino masses and mixing solely via radiative contributions,
without requiring any additional degree of freedom. In particular, a relatively
large reactor angle (as recently observed by the Daya Bay collaboration) can be
accommodated in ample regions of the parameter space. On the contrary, if the
R-breaking is communicated to the visible sector by gravitational effects at
the Planck scale, additional particles are necessary to accommodate neutrino
data.Comment: 19 pages, 3 figures; v2: references added, constraints updated,
overall conclusions unchange
Channel Capacities for Different Antenna Arrays with Various Transmitting Angles in Tunnels
[[abstract]]This paper focuses on the research of channel capacity of multiple-input multipleoutput
(MIMO) system with different transmitting angles in straight and curvy tunnels.Araytracing
technique is developed to calculate channel frequency responses for tunnels, and the
channel frequency response is further used to calculate corresponding channel capacity. The
channel capacities are calculated based on the realistic environment. The channel capacities
of MIMO long term evolution system using spatial and polar antenna arrays by different
transmitting angles are computed. Numerical results show that, The channel capacity for
transmitting angle at 15◦ is largest compared to the other angles in the tunnels. Moreover,
the channel capacity of polar array is better than that of spatial array both in the straight and
curvy tunnels. Besides, the channel capacity for the tunnels with traffic is larger than that
without traffic. Finally, it isworth noting that in these cases the presentwork provides not only
comparative information but also quantitative information on the performance reduction.[[notice]]補正完畢[[incitationindex]]SC
High-pressure tuning of valence and magnetic interactions in Eu0.5Yb0.5Ga4
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Pressure-induced changes in valence and magnetic ordering are observed in a Eu0.5Yb0.5Ga4 compound by means of element selective x-ray absorption spectroscopy at Eu and Yb L-3 edges. Concomitant Eu and Yb valence transitions towards a 3+ state, together with an antiferromagnetic to ferromagnetic transition, are observed with applied pressures up to 30 GPa. With the support of density functional theory calculations, we argue that hybridization between (Eu/Yb)-5d and Ga orbitals regulates the valence and magnetic exchange interactions in this system.8524Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)US Department of Energy, Office of Science, Office of Basic Energy Sciences [DE-AC-02- 06CH11357]Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)US Department of Energy, Office of Science, Office of Basic Energy Sciences [DE-AC-02- 06CH11357
An Event-driven SOA-based Platform for Energy-efficiency Applications in Buildings
The topic of optimization of building operation is attracting significant interest in the community: monitoring of
relevant Key Performance Indicators can help enhance state awareness and understanding; fault detection and
identification can help identify irregular and ineffective operational modes; and, advanced control design
techniques can yield effective/optimized operation with regards to energy performance and thermal comfort.
Despite significant effort on development of algorithmic and methodological approaches to address these
problems, the inherent complexity associated with practical demonstrations, has precluded testing and
implementation of such approaches in realistic contexts. Within this paper, an event-driven Service-Oriented
Architecture platform, is developed to address this gap and help facilitate the provision of advanced energyefficiency
and energy-management services in buildings. The use of the Industry Foundation Classes provides a
standardized data-model for describing the building and its components, while the use of Model View definitions
is employed to define the exchange requirements for proper software component interoperability. Data collection
and homogenization from the building is addressed through an abstraction layer, capable of hiding many of the
intricacies and providing a clean interface for the development of building services. An exemplary application of
the proposed architecture in a real office building in Greece is presented
Ensuring that the Sentinel-3A altimeter provides climate-quality data
Sentinel-3A, launched in February 2016, is part of ESA's long-term commitment to climate monitoring from space. Its suite of instruments for measuring surface topography includes a Microwave Radiometer (MWR) and SRAL, the first delay-Doppler instrument to provide global coverage. SRAL promises fine spatial resolution and reduced noise levels that should together lead to improved performance over all Earth surfaces. The Sentinel-3 Mission Performance Centre (S3MPC) has been developing the methodology to evaluate the accuracy of retrievals, monitor any changes and develop solutions to known problems.
The S3MPC monitors internal temperatures, path delays and the shape of the generated pulses to assess the instruments
health. The MWR records over known reference surfaces are compared with those from other spaceborne instruments.
Over the ocean the SRAL's return pulses are analysed to give range to the sea surface, wave height and signal strength (which can be interpreted as wind speed). The metocean data are regularly contrasted with records from in situ measurements and the output from meteorological models, which rapidly highlights the effects of any changes in processing.
Range information is used to give surface elevation, which is assessed in three ways. First, flights over a dedicated radar transponder provide an estimate of path delay to within ~10 mm (r.m.s.). Second, measurements are compared to GPS- levelled surfaces near Corsica and over Lake Issyk-kul. Third, there are consistency checks between ascending and descending passes and with other missions. Further waveform analysis techniques are being developed to improve the retrieval of information over sea-ice, land-ice and inland waters
Neutrino masses from new generations
We reconsider the possibility that Majorana masses for the three known
neutrinos are generated radiatively by the presence of a fourth generation and
one right-handed neutrino with Yukawa couplings and a Majorana mass term. We
find that the observed light neutrino mass hierarchy is not compatible with low
energy universality bounds in this minimal scenario, but all present data can
be accommodated with five generations and two right-handed neutrinos. Within
this framework, we explore the parameter space regions which are currently
allowed and could lead to observable effects in neutrinoless double beta decay,
conversion in nuclei and experiments. We
also discuss the detection prospects at LHC.Comment: 28 pages, 4 figures. Version to be published. Some typos corrected.
Improved figures 3 and
Ciliated Epithelial Cell Differentiation at Air-Liquid Interface Using Commercially Available Culture Media
The human nasal epithelium contains basal stem/progenitor cells that produce differentiated multiciliated and mucosecretory progeny. Basal epithelial cells can be expanded in cell culture and instructed to differentiate at an air-liquid interface using transwell membranes and differentiation media. For basal cell expansion, we have used 3T3-J2 co-culture in epithelial culture medium containing EGF, insulin, and a RHO-associated protein kinase (ROCK) inhibitor, Y-27632 (3T3 + Y). Here we describe our protocols for ciliated differentiation of these cultures at air-liquid interface and compare four commercially available differentiation media, across nine donor cell cultures (six healthy, two patients with chronic obstructive pulmonary disease (COPD), and one with primary ciliary dyskinesia (PCD)). Bright-field and immunofluorescence imaging suggested broad similarity between differentiation protocols. Subtle differences were seen in transepithelial electrical resistance (TEER), ciliary beat frequency, mucus production, and the extent to which basal cells are retained in differentiated cultures. Overall, the specific differentiation medium used in our air-liquid interface culture protocol was not a major determinant of ciliation, and our data suggest that the differentiation potential of basal cells at the outset is a more critical factor in air-liquid interface culture outcome. Detailed information on the constituents of the differentiation media was only available from one of the four manufacturers, a factor that may have profound implications in the interpretation of some research studies
The Roles of the S3MPC: Monitoring, Validation and Evolution of Sentinel-3 Altimetry Observations
The Sentinel-3 Mission Performance Centre (S3MPC) is tasked by the European Space Agency (ESA) to monitor the health of the Copernicus Sentinel-3 satellites and ensure a high data quality to the users. This paper deals exclusively with the effort devoted to the altimeter and microwave radiometer, both components of the Surface Topography Mission (STM). The altimeters on Sentinel-3A and -3B are the first to operate in delay-Doppler or SAR mode over all Earth surfaces, which enables better spatial resolution of the signal in the along-track direction and improved noise reduction through multi-looking, whilst the radiometer is a two-channel nadir-viewing system. There are regular routine assessments of the instruments through investigation of telemetered housekeeping data, calibrations over selected sites and comparisons of geophysical retrievals with models, in situ data and other satellite systems. These are performed both to monitor the daily production, assessing the uncertainties and errors on the estimates, and also to characterize the long-term performance for climate science applications. This is critical because an undetected drift in performance could be misconstrued as a climate variation. As the data are used by the Copernicus Services (e.g., CMEMS, Global Land Monitoring Services) and by the research community over open ocean, coastal waters, sea ice, land ice, rivers and lakes, the validation activities encompass all these domains, with regular reports openly available. The S3MPC is also in charge of preparing improvements to the processing, and of the development and tuning of algorithms to improve their accuracy. This paper is thus the first refereed publication to bring together the analysis of SAR altimetry across all these different domains to highlight the benefits and existing challenges
Impaired Inhibitory Control in Recreational Cocaine Users
Chronic use of cocaine is associated with impairment in response inhibition but it is an open question whether and to which degree findings from chronic users generalize to the upcoming type of recreational users. This study compared the ability to inhibit and execute behavioral responses in adult recreational users and in a cocaine-free-matched sample controlled for age, race, gender distribution, level of intelligence, and alcohol consumption. Response inhibition and response execution were measured by a stop-signal paradigm. Results show that users and non users are comparable in terms of response execution but users need significantly more time to inhibit responses to stop-signals than non users. Interestingly, the magnitude of the inhibitory deficit was positively correlated with the individuals lifetime cocaine exposure suggesting that the magnitude of the impairment is proportional to the degree of cocaine consumed
The role of the helper lipid on the DNA transfection efficiency of lipopolyplex formulations.
Multifunctional, lipopolyplex formulations comprising a mixture of cationic liposomes and cationic, receptor-targeting peptides have potential use in gene therapy applications. Lipopolyplex formulations described here are typically far more efficient transfection agents than binary lipoplex or polyplex formulations. It has been shown previously that the peptide component mediates both DNA packaging and targeting of the nanoparticle while in this report we investigate the contribution of the lipid component. We hypothesised that the lipid components synergise with the peptides in the transfection process by promoting endosomal escape after lipid bilayer fusion. Lipopolyplexes were prepared with cationic liposomes comprising DOTAP with either neutral lipid DOPE or DOPC. DOPE promotes fusogenic, inverted hexagonal lipid structures while DOPC promotes more stable laminar structures. Lipopolyplexes containing DOPE showed substantially higher transfection efficiency than those formulated with DOPC, both in vitro and in vivo. DOPE-containing lipopolyplexes showed rapid endosomal trafficking and nuclear accumulation of DNA while DOPC-containing formulations remained within the late endo-lysosomal compartments. These findings are consistent with previous finding for the role of DOPE in lipoplexes and support the hypothesis regarding the function of the lipid components in lipopolyplexes. These findings will help to inform future lipopolyplex design, strategies and clinical development processes
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