1,813 research outputs found
Fermion masses and mixings and muon anomaly in a 3-3-1 model with family symmetry
We propose a predictive model based on the gauge symmetry, which is supplemented by the family symmetry and
several auxiliary cyclic symmetries whose spontaneous breaking produces the
observed SM fermion mass and mixing pattern. The masses of the light active
neutrinos are produced by an inverse seesaw mechanism mediated by three right
handed Majorana neutrinos. To the best of our knowledge the model corresponds
to the first implementation of the family symmetry in a theory with three right handed Majorana neutrinos and
inverse seesaw mechanism. Our proposed model successfully accommodates the
experimental values of the SM fermion mass and mixing parameters, the muon
anomalous magnetic moment as well as the Higgs diphoton decay rate constraints.
The consistency of our model with the muon anomalous magnetic moment requires
electrically charged scalar masses at the sub TeV scale.Comment: 17 page
Sustainable use of groundwater in Spain
El espectacular desarrollo que en las últimas décadas ha experimentado la utilización de las aguas subterráneas ha sido llevado a cabo principalmente por particulares, con escasa participación del sector público. Este desarrollo ha dado lugar a importantes beneficios socioeconómicos, pero su escasa planificación ha ocasionado en algunos casos problemas significativos. El artículo repasa los beneficios e impactos negativos producidos por el uso intensivo de las aguas subterráneas. Esta valoración contribuye a analizar la sostenibilidad futura del uso del recurso. También se plantean algunas áreas en las que es necesario avanzar para reducir los impactos producidos y garantizar el uso sostenible de las aguas subterráneas y de los recursos hídricos en general, como son la gestión colectiva de los acuíferos, y la educación, información y participación adecuada de los usuarios en su sentido más amplio.The spectacular development of groundwater resources that has taken place over the past few decades, has been primarily driven by private interests, with little involvement of the public sector. This development has resulted in important socio-economic benefits, but has
generally been unplanned, thus resulting in some cases in significant problems. This article reviews the benefits and negative impacts of intensive groundwater use. This evaluation is important in order to analyse the future sustainability of groundwater development. It also
discusses some areas in which some progress is necessary in order to limit the negative impacts and ensure the sustainability of groundwater use in particular, and of water resources in general. Some of these areas are: the collective management of aquifers; and the education,
information and effective participation of all stakeholders.Depto. de Geodinámica, Estratigrafía y PaleontologíaFac. de Ciencias GeológicasTRUEFundación Marcelino Botínpu
Public participation and transparency in water management
Public participation is considered broadly to have a positive impact on the quality of governance. Transparency is the first step in the public participation ladder since it implies that people have access to the necessary information to make informed contributions to decision-making. This chapter gives an overview of the main
challenges for the Spanish water sector in terms of public participation in the water planning process of the Water Framework Directive (WFD), and presents results of an
assessment of the information transparency of the Spanish water authorities. Although the WFD has contributed to improving the situation, in Spain the tradition of public accessibility to data and public participation in water management decisions is still rather poor. In addition to making all relevant information publicly available, the
most compelling challenge is possibly ensuring its reliability and consistency. Another key issue is making the information accessible to different target audiences by adapting it to their level of interest and technical capacit
Analysis of genome expression of rhizobium etli in free living and plant-associated symbiotic state
Comunicaciones a congreso
Gaia Early Data Release 3:Modelling and calibration of Gaia's point and line spread functions
Context: The unprecedented astrometric precision of the Gaia mission relies
on accurate estimates of the locations of sources in the Gaia data stream. This
is ultimately performed by point spread function (PSF) fitting, which in turn
requires an accurate reconstruction of the PSF. Gaia Early Data Release 3
(EDR3) will, for the first time, use a PSF calibration that models several of
the strongest dependences, leading to signficantly reduced systematic errors.
Aims: We describe the PSF model and calibration pipeline implemented for Gaia
EDR3, including an analysis of the calibration results over the 34 months of
data. We include a discussion of the limitations of the current pipeline and
directions for future releases. This will be of use both to users of Gaia data
and as a reference for other precision astrometry missions. Methods: We develop
models of the 1D line spread function (LSF) and 2D PSF profiles based on a
linear combination of basis components. We fit the models to selected primary
sources in independent time ranges, using simple parameterisations for the
colour and other dependences. Variation in time is smoothed by merging the
independent calibrations in a square root information filter, with resets at
certain mission events that induce a discontinuous change in the PSF. Results:
The PSF calibration shows strong time and colour dependences that accurately
reproduce the varying state of the Gaia astrometric instrument. Analysis of the
residuals reveals both the performance and the limitations of the current
models and calibration pipeline, and indicates the directions for future
development. Conclusions: The PSF modelling and calibration carried out for
Gaia EDR3 represents a major step forwards in the data processing and will lead
to reduced systematic errors in the core mission data products. Further
significant improvements are expected in the future data releases.Comment: Accepted by A&A for inclusion in Gaia EDR3 special issu
The unusual protoplanetary disk around the T Tauri star ET Cha
We present new continuum and line observations, along with modelling, of the
faint (6-8) Myr old T Tauri star ET Cha belonging to the eta Chamaeleontis
cluster. We have acquired HERSCHEL/PACS photometric fluxes at 70 mic and 160
mic, as well as a detection of the [OI] 63 mic fine-structure line in emission,
and derived upper limits for some other far-IR OI, CII, CO and o-H2O lines. The
HERSCHEL data is complemented by new ANDICAM B-K photometry, new HST/COS and
HST/STIS UV-observations, a non-detection of CO J=3-2 with APEX, re-analysis of
a UCLES high-resolution optical spectrum showing forbidden emission lines like
[OI] 6300A, [SII] 6731A and 6716A, and [NII] 6583A, and a compilation of
existing broad-band photometric data. We used the thermo-chemical disk code
ProDiMo and the Monte-Carlo radiative transfer code MCFOST to model the
protoplanetary disk around ET Cha. Based on these models we can determine the
disk dust mass Mdust = (2.E-8 - 5.E-8) Msun, whereas the total disk gas mass is
found to be only little constrained, Mgas = (5.E-5 - 3.E-3) Msun. In the
models, the disk extends from 0.022 AU (just outside of the co-rotation radius)
to only about 10 AU. Larger disks are found to be inconsistent with the CO
J=3-2 non-detection. The low velocity component of the [OI] 6300A emission line
is consistent with being emitted from the inner disk. The model can also
reproduce the line flux of H2 v=1-0 S(1) at 2.122 mic. An additional
high-velocity component of the [OI] 6300A emission line, however, points to the
existence of an additional jet/outflow of low velocity (40 - 65) km/s with mass
loss rate ~1.E-9 Msun/yr. In relation to our low estimations of the disk mass,
such a mass loss rate suggests a disk lifetime of only ~(0.05 - 3) Myr,
substantially shorter than the cluster age. The evolutionary state of this
unusual protoplanetary disk is discussed.Comment: accepted by Astronomy & Astrophysics (18 pages, 11 figures and 7
tables). Additional 9-page appendix with 6 figures, 3 tables and 37 equation
Permafrost conditions in the Mediterranean region since the Last Glaciation.
Cold-climate geomorphological processes today in the Mediterranean region are only distributed in the highest mountain environments. However, climate condition prevailing during the Late Pleistocene and Holocene have conditioned significant spatio-temporal variations of the glacial and periglacial domain in these mountains, including permafrost. In this communication we examine permafrost condition in the Mediterranean region taking into account five periods: Last Glaciation, deglaciation, Holocene, Little Ice Age (LIA) and present-day. The distribution of currently inactive permafrost-derived landforms and sedimentary records indicates that the permafrost elevation during the Last Glaciation was ca. 1000 m lower than present. Permafrost was also widespread in non-glaciated slopes above the snowline forming rock glaciers and block streams, as well as in relatively flat summit areas where meter-sized stone circles developed. As in most areas of the Northern Hemisphere, the deglaciation in the Mediterranean region started ca. 19-20 ka. The exposed terrain by retreating glaciers was affected by paraglacial dynamics and intense periglacial processes, mostly associated with permafrost condition. Many rock glaciers, protalus lobes and block streams formed in these recently deglaciated environments, becoming gradually inactive as temperatures rose during the Bølling-Allerød. Following the Younger Dryas glacial advance, the last massive deglaciation in Mediterranean mountains took place during the Early Holocene together with a progressive shift of the periglacial belt to higher elevations. It is unlikely that widespread permafrost have existed in Mediterranean mountains during the Holocene, except in the highest massifs exceeding 2500-3000 m. The colder climate prevailing during the LIA favoured a minor glacial advance and the spatial expansion of permafrost, with the development of new protalus lobes and rock glaciers in the highest massifs. Finally, the warming started during the second half of the 19th century has led to glacial retreat and/or complete melting, increased paraglacial activity, migration of periglacial processes to the highest lands and degradation of alpine permafrost along with geoecological changes
Predicting Survival after Allogeneic Hematopoietic Cell Transplantation in Myelofibrosis : Performance of the Myelofibrosis Transplant Scoring System (MTSS) and Development of a New Prognostic Model
Accurate prognostic tools are crucial to assess the risk/benefit ratio of allogeneic hematopoietic cell transplantation (allo-HCT) in patients with myelofibrosis (MF). We aimed to evaluate the performance of the Myelofibrosis Transplant Scoring System (MTSS) and identify risk factors for survival in a multicenter series of 197 patients with MF undergoing allo-HCT. After a median follow-up of 3.1 years, 47% of patients had died, and the estimated 5-year survival rate was 51%. Projected 5-year risk of nonrelapse mortality and relapse incidence was 30% and 20%, respectively. Factors independently associated with increased mortality were a hematopoietic cell transplantation-specific comorbidity index (HCT-CI) ≥3 and receiving a graft from an HLA-mismatched unrelated donor or cord blood, whereas post-transplant cyclophosphamide (PT-Cy) was associated with improved survival. Donor type was the only parameter included in the MTSS model with independent prognostic value for survival. According to the MTSS, 3-year survival was 62%, 66%, 37%, and 17% for low-, intermediate-, high-, and very high-risk groups, respectively. By pooling together the low- and intermediate-risk groups, as well as the high- and very high-risk groups, we pinpointed 2 categories: standard risk and high risk (25% of the series). Three-year survival was 62% in standard-risk and 25% in high-risk categories (P <.001). We derived a risk score based on the 3 independent risk factors for survival in our series (donor type, HCT-CI, and PT-Cy). The corresponding 5-year survival for the low-, intermediate-, and high-risk categories was 79%, 55%, and 32%, respectively (P <.001). In conclusion, the MTSS model failed to clearly delineate 4 prognostic groups in our series but may still be useful to identify a subset of patients with poor outcome. We provide a simple prognostic scoring system for risk/benefit considerations before transplantation in patients with MF
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