545 research outputs found
Bilinear R-parity Violation and Small Neutrino Masses: a Self-consistent Framework
We study extensions of supersymmetric models without R-parity which include
an anomalous U(1)_H horizontal symmetry. Bilinear R-parity violating terms
induce a neutrino mass at tree level of approximately eV
where is the U(1)_H breaking parameter and is an
integer number that depends on the horizontal charges of the leptons. For
a unique self-consistent model arises in which i) all the
superpotential trilinear R-parity violating couplings are forbidden by
holomorphy; ii) the tree level neutrino mass falls in the range suggested by
the atmospheric neutrino problem; iii) radiative contributions to neutrino
masses are strongly suppressed resulting in a squared solar mass difference of
few 10^{-8} eV^2 which only allows for the LOW (or quasi-vacuum) solution to
the solar neutrino problem; iv) the neutrino mixing angles are not suppressed
by powers of and can naturally be large.Comment: Latex, 15 pages including 1 figure, some typos correcte
Pilot-tone assisted 16-QAM photonic wireless bridge operating at 250 GHz
A photonic wireless bridge operating at a carrier frequency of 250 GHz is
proposed and demonstrated. To mitigate the phase noise of the free-running
lasers present in such a link, the tone-assisted carrier recovery is used.
Compared to the blind phase noise compensation (PNC) algorithm, this technique
exhibited penalties of 0.15 dB and 0.46 dB when used with aggregated Lorentzian
linewidths of 28 kHz and 359 kHz, respectively, and 20 GBd 16-quadrature
amplitude modulation (QAM) signals. The wireless bridge is also demonstrated in
a wavelength division multiplexing (WDM) scenario, where 5 optical channels are
generated and sent to the Tx remote antenna unit (RAU). In this configuration,
the full band from 224 GHz to 294 GHz is used. Finally, a 50 Gbit/s
transmission is achieved with the proposed wireless bridge in single channel
configuration. The wireless transmission distance is limited to 10 cm due to
the low power emitted by the uni-travelling carrier photodiode used in the
experiments. However, link budget calculations based on state-of-the-art THz
technology show that distances >1000 m can be achieved with this approach.Comment: 13 pages, in Journal of Lightwave Technolog
Los juegos grupales en la dimensión corporal de los niños de Jardín.
Describir la incidencia de los juegos grupales en el desarrollo de la dimensión corporal de los niños de 4 a 5 años del grado Jardín del Centro Educativo Pajarillos.El presente trabajo de investigación describe la incidencia de los juegos grupales en el desarrollo de la dimensión corporal de los niños de 4 a 5 años del grado Jardín del Centro Educativo Pajarillos; en el que se escogió trabajar el enfoque mixto con el propósito de dar solidez a la investigación por medio de la triangulación de la información recopiladaen la teoría y en la práctica, logrando una perspectiva más amplia y profunda del fenómeno y corroborando lo encontrado con las distintas técnicas e instrumentos implementados (Observación participante, aplicación de test, aplicación de la escala abreviada del desarrollo, la encuesta),de este modo, el diseño de investigación que se estima como el más pertinente para este proyecto es el cuasiexperimental, porque permite tomar dos grupos de observación, uno experimental y otro de control.Loanterior favoreció a la recolección de los siguientes resultados:los niños presentabandificultades al momento de realizar las habilidades básicas motrices; pero después de aplicar los juegos grupales comoestrategia metodológica para estimular el desarrollo de la dimensión corporalse evidenciaron avances significativos; porlo que concluimos que los juegos grupales inciden en el desarrollo de la dimensión corporal y que requieren de un acompañamientointencionado por parte de un docente idóneo; para alcanzar un logro óptimo
Controlled release microspheres loaded with BMP7 suppress primary tumors from human glioblastoma
Glioblastoma tumor initiating cells are believed to be the main drivers behind tumor recurrence, and therefore therapies that specifically manage this population are of great medical interest. In a previous work, we synthesized controlled release microspheres optimized for intracranial delivery of BMP7, and showed that these devices are able to stop the in vitro growth of a glioma cell line. Towards the translational development of this technology, we now explore these microspheres in further detail and characterize the mechanism of action and the in vivo therapeutic potential using tumor models relevant for the clinical setting: human primary glioblastoma cell lines. Our results show that BMP7 can stop the proliferation and block the self-renewal capacity of those primary cell lines that express the receptor BMPR1B. BMP7 was encapsulated in poly (lactic-co-glycolic acid) microspheres in the form of a complex with heparin and Tetronic, and the formulation provided effective release for several weeks, a process controlled by carrier degradation. Data from xenografts confirmed reduced and delayed tumor formation for animals treated with BMP7-loaded microspheres. This effect was coincident with the activation of the canonical BMP signaling pathway. Importantly, tumors treated with BMP7-loaded microspheres also showed downregulation of several markers that may be related to a malignant stem cell-like phenotype: CD133(+), Olig2, and GFAPδ. We also observed that tumors treated with BMP7-loaded microspheres showed enhanced expression of cell cycle inhibitors and reduced expression of the proliferation marker PCNA. In summary, BMP7-loaded controlled release microspheres are able to inhibit GBM growth and reduce malignancy markers. We envisage that this kind of selective therapy for tumor initiating cells could have a synergistic effect in combination with conventional cytoreductive therapy (chemo-, radiotherapy) or with immunotherapy.This study was supported by grants from: Ministerio de Economía y Competitividad, Fondo de Investigación Sanitaria (PI12/101 to HM; PI12/00775 to PSG; PS09/1786 to MGF and PI13/01258 to AHL), Comunidad de Madrid (S2010/BMD-2336 to HM), Xunta de Galicia (EM2013/042 to MGF), Fundación BBVA (2014-PO010 to MGF) and Ministerio de Economía y Competitividad, Red Temática de Investigación Cooperativa en Cáncer (RD12/0036/0027 to PSG and AHL).
PGG was recipient of a “Sara Borell” postdoctoral fellowship, and MdF of a “Miguel Servet” contract from Ministerio de Economía y CompetitividadS
Baryon Triality and Neutrino Masses from an Anomalous Flavor U(1)
We construct a concise U(1)_X Froggatt-Nielsen model in which baryon
triality, a discrete gauge Z_3 symmetry, arises from U(1)_X breaking. The
proton is thus stable, however, R-parity is violated. With the proper choice of
U(1)_X charges we can obtain neutrino masses and mixings consistent with an
explanation of the atmospheric and solar neutrino anomalies in terms of
neutrino oscillations, with no right-handed neutrinos required. The only mass
scale apart from M_grav is m_3/2 ~ m_soft.Comment: matches published version, typos corrected, references added, 54
pages, 3 figures, 5 table
Capturing the Severity and Impairment Associated With Depression: The Overall Depression Severity and Impairment Scale (ODSIS) Validation in a Spanish Clinical Sample
Background: The Overall Depression Severity and Impairment Scale (ODSIS) is a self-report scale designed to evaluate the severity and functional impairment associated with depression.
Objective: This study evaluated the psychometric properties of the online version of the ODSIS in Spanish outpatients with depression and anxiety disorders.
Method: Patients with a main diagnosis of a depressive (n = 283) or anxiety disorder (n = 191) and a mean age of 38.15 (SD = 12.06) were evaluated with a clinical diagnostic interview and measures assessing depression, anxiety, positive and negative affect, and quality of life. Factorial structure, internal consistency, convergent, and discriminant validity and cutoff scores were analyzed.
Results: Consistent with previous validations of the instrument, Confirmatory Factor Analysis showed a unidimensional factor structure. Furthermore, the results obtained supported the internal consistency and construct validity of the ODSIS scores. A score of 5 was found to meet the criteria used in this study for the optimal cutoff score.
Conclusion: The results obtained in this study show that the Spanish version of the ODSIS delivered online is an adequate tool to assess the depression-related severity and impairment in a brief and easy fashion
Standard and non-standard neutrino properties
I review the interpretation of solar and atmospheric neutrino data in terms
neutrino oscillations and describe some ways to account for the required
neutrino masses and mixing angles from first principles, both within top-down
and bottom-up approaches. I also discuss non-oscillation phenomena such as
nu-less double beta which may probe the absolute scale of neutrino mass, and
also reveal its Majorana nature. I note that leptonic CP violation induced by
``Majorana'' phases drop from oscillations but play a role in the leptogenesis
scenario for the baryon asymmetry of the Universe. Direct tests of leptonic CP
violation in oscillation experiments, such as neutrino factories, will be a
tough challenge, due to the hierarchical neutrino mass splittings and the
smallness of theta13 indicated by reactors. The large solar mixing angle
theta12 offers a way to probe otherwise inaccessible features of supernova
physics. Finally, I note that in low-scale models of neutrino mass, one may
probe all mixing angles, including the atmospheric theta23, at high energy
accelerator experiments such as the LHC or NLC. A neat example is supersymmetry
with bilinear breaking of R parity, where the LSP decay branching ratios are
directly correlated to the neutrino mixing angles. I also discuss
non-oscillation solutions to the solar neutrino problem in terms of spin-flavor
precession and non-standard neutrino interactions, which will be crucially
tested at KamLAND.Comment: Invited talk at the XXth Internat. Conf. on Neutrino Physics and
Astrophysics (Neutrino 2002), Munich, Germany, May 25-30, 2002. 12 pages, 18
figs, includes espcrc2.st
The antiviral and virucidal activities of voacangine and structural analogs extracted from Tabernaemontana cymosa depend on the Dengue virus strain
Currently, no specific licensed antiviral exists for treating the illness caused by dengue virus (DENV). Therefore, the search for compounds of natural origin with antiviral activity is an important area of research. In the present study, three compounds were isolated and identified from seeds of Tabernaemontana cymosa plants. The in vitro antiviral effect of those compounds and voacangine against different DENV strains was assessed using different experimental approaches: compounds added before the infection (Pre), at the same time with the virus (Trans), after the infection (Post) or compounds present in all moments of the experiment (Pre-Trans-Post, Combined treatment). In silico studies (docking and molecular dynamics) were also performed to explain the possible antiviral mechanisms. The identified compounds were three structural analogs of voacangine (voacangine-7-hydroxyindolenine, rupicoline and 3-oxo-voacangine). In the Pre-treatment, only voacangine-7-hydroxyindolenine and rupicoline inhibited the infection caused by the DENV-2/NG strain (16.4% and 29.6% infection, respectively). In the Trans-treatment approach, voacangine, voacangine-7-hydroxyindolenine and rupicoline inhibited the infection in both DENV-2/NG (11.2%, 80.4% and 75.7% infection, respectively) and DENV-2/16681 infection models (73.7%, 74.0% and 75.3% infection, respectively). The latter strain was also inhibited by 3-oxo-voacangine (82.8% infection). Moreover, voacangine (most effective virucidal agent) was also effective against one strain of DENV-1 (DENV-1/WestPac/74) and against the third strain of DENV-2 (DENV-2/S16803) (48.5% and 32.4% infection, respectively). Conversely, no inhibition was observed in the post-treatment approach. The last approach (combined) showed that voacangine, voacangine-7-hydroxyindolenine and rupicoline inhibited over 90% of infections (3.5%, 6.9% and 3.5% infection, respectively) of both strains (DENV-2/NG and DENV-2/16681). The free energy of binding obtained with an in silico approach was favorable for the E protein and compounds, which ranged between −5.1 and −6.3 kcal/mol. Finally, the complex formed between DENV-2 E protein and the best virucidal compound was stable for 50 ns. Our results show that the antiviral effect of indole alkaloids derived from T. cymose depends on the serotype and the virus strain.https://scienti.colciencias.gov.co/cvlac/visualizador/generarCurriculoCv.do?cod_rh=0000213748https://scholar.google.es/citations?user=flSrsSIAAAAJ&hl=eshttps://scienti.minciencias.gov.co/gruplac/jsp/visualiza/visualizagr.jsp?nro=00000000000695https://orcid.org/0000-0002-9429-005
Anomaly Mediated Supersymmetry Breaking without R-Parity
We analyze the low energy features of a supersymmetric standard model where
the anomaly--induced contributions to the soft parameters are dominant in a
scenario with bilinear --parity violation. This class of models leads to
mixings between the standard model particles and supersymmetric ones which
change the low energy phenomenology and searches for supersymmetry. In
addition, --parity violation interactions give rise to small neutrino masses
which we show to be consistent with the present observations.Comment: 38 pages, 15 figures. For higher resolution figures go to
http://www.fma.if.usp.br/~magro/figures
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