206 research outputs found
On the Radio Polarization Signature of Efficient and Inefficient Particle Acceleration in Supernova Remnant SN 1006
We present a radio polarization study of SN 1006, based on combined VLA and
ATCA observations at 20 cm that resulted in sensitive images with an angular
resolution of 10 arcsec. The fractional polarization in the two bright radio
and X-ray lobes of the SNR is measured to be 0.17, while in the southeastern
sector, where the radio and non-thermal X-ray emission are much weaker, the
polarization fraction reaches a value of 0.6 +- 0.2, close to the theoretical
limit of 0.7. We interpret this result as evidence of a disordered, turbulent
magnetic field in the lobes, where particle acceleration is believed to be
efficient, and a highly ordered field in the southeast, where the acceleration
efficiency has been shown to be very low. Utilizing the frequency coverage of
our observations, an average rotation measure of ~12 rad/m2 is determined from
the combined data set, which is then used to obtain the intrinsic direction of
the magnetic field vectors. While the orientation of magnetic field vectors
across the SNR shell appear radial, a large fraction of the magnetic vectors
lie parallel to the Galactic Plane. Along the highly polarized southeastern
rim, the field is aligned tangent to the shock, and therefore also nearly
parallel to the Galactic Plane. These results strongly suggest that the ambient
field surrounding SN 1006 is aligned with this direction (i.e., from northeast
to southwest) and that the bright lobes are due to a polar cap geometry. Our
study establishes that the most efficient particle acceleration and generation
of magnetic turbulence in SN 1006 is attained for shocks in which the magnetic
field direction and shock normal are quasi-parallel, while inefficient
acceleration and little to no generation of magnetic turbulence obtains for the
quasi-perpendicular case.Comment: Accepted for publication in Astronomical Journa
BIM MEDIATES IMATINIB-INDUCED APOPTOSIS OF GASTROINTESTINAL STROMAL TUMORS: TRANSLATIONAL IMPLICATIONS
Gastrointestinal stromal tumors (GISTs) are oncogene-addicted cancers driven by activating mutations in the genes encoding receptor tyrosine kinases KIT and PDGFR-α. Imatinib mesylate, a specific inhibitor of KIT and PDGFR-α signaling, delays progression of GIST, but is incapable of achieving cure. Thus, most patients who initially respond to imatinib therapy eventually experience tumor progression, and have limited therapeutic options thereafter. To address imatinib-resistance and tumor progression, these studies sought to understand the molecular mechanisms that regulate apoptosis in GIST, and evaluate combination therapies that kill GISTs cells via complementary, but independent, mechanisms. BIM (Bcl-2 interacting mediator of apoptosis), a pro-apoptotic member of the Bcl-2 family, effects apoptosis in oncogene-addicted malignancies treated with targeted therapies, and was recently shown to mediate imatinib-induced apoptosis in GIST. This dissertation examined the molecular mechanism of BIM upregulation and its cytotoxic effect in GIST cells harboring clinically-representative KIT mutations. Additionally, imatinib-induced alterations in BIM and pro-survival Bcl-2 proteins were studied in specimens from patients with GIST, and correlated to apoptosis, FDG-PET response, and survival. Further, the intrinsic pathway of apoptosis was targeted therapeutically in GIST cells with the Bcl-2 inhibitor ABT-737. These studies show that BIM is upregulated in GIST cells and patient tumors after imatinib exposure, and correlates with induction of apoptosis, response by FDG-PET, and disease-free survival. These studies contribute to the mechanistic understanding of imatinib-induced apoptosis in clinically-relevant models of GIST, and may facilitate prediction of resistance and disease progression in patients. Further, combining inhibition of KIT and Bcl-2 induces apoptosis synergistically and overcomes imatinib-resistance in GIST cells. Given that imatinib-resistance and GIST progression may reflect inadequate BIM-mediated inhibition of pro-survival Bcl-2 proteins, the preclinical evidence presented here suggests that direct engagement of apoptosis may be an effective approach to enhance the cytotoxicity of imatinib and overcome resistance
A partial classification of simple regular representations of bimodules type over
In this paper, we use Galois descent techniques to find suitable
representatives of the regular simple representations of the species of type
over , where is a positive integer and
is the field of Laurent series over the
complexes. These regular representations are essential for the definition of
canonical algebras. Our work is inspired by the work done for species of type
on in ``A model for the canonical algebras of bimodules type (1, 4)
over truncated polynomial rings''. We presents all the regular simple
representations on the -crown quiver, and from these, we establish a partial
classification of regular simple representations of bimodules type .Comment: 26 pages, comments welcom
Decreasing Turnover Rate and Increasing Productivity at Daiwa Massage Chairs
Daiwa Massage Chairs by U.S Jaclean is a Japanese owned company that specializes in massage chairs, health, and wellness items. The company has 13 branches in the United States and has accrued approximately 200 employees within the last 40 years. After the COVID-19 pandemic, the company experienced a fluctuation of employees and was unable to retain them. The company has faced major backlash from employees that feel as though they lack training and a system to operate efficiently. The purpose of this project is to set the framework for decreasing the employee turnover rate and increasing productivity by implementing continuous improvement solutions. These solutions include the implementation of a training development plan, systematic checklists, documentation maintenance, emphasis on safety equipment, research on Department of Transportation (DOT), and optimizing the company equipment. Within the training development plan, continuous improvement tools were included like Standard Operating Procedures (SOPs), mistake-proof techniques, instructional videos, quizzes, and 5s improvement plans. Overall, the implementation of these strategies not only resolves immediate issues but also fosters a culture of continuous improvement and long-term competitiveness in the market
On the Radio Polarization Signature of Efficient and Inefficient Particle Acceleration in Supernova Remnant SN 1006
Radio polarization observations provide essential information on the degree of order and orientation of magnetic fields, which themselves play a key role in the particle acceleration processes that take place in supernova remnants (SNRs). Here we present a radio polarization study of SN 1006, based on combined Very Large Array and Australia Telescope Compact Array observations at 20 cm that resulted in sensitive images with an angular resolution of 10 arcsec. The fractional polarization in the two bright radio and X-ray lobes of the SNR is measured to be 0.17, while in the southeastern sector, where the radio and non-thermal X-ray emission are much weaker, the polarization fraction reaches a value of 0.6 ± 0.2, close to the theoretical limit of 0.7. We interpret this result as evidence of a disordered, turbulent magnetic field in the lobes, where particle acceleration is believed to be efficient, and a highly ordered field in the southeast, where the acceleration efficiency has been shown to be very low. Utilizing the frequency coverage of our observations, an average rotation measure of ~12 rad m-2 is determined from the combined data set, which is then used to obtain the intrinsic direction of the magnetic field vectors. While the orientation of magnetic field vectors across the SNR shell appear to be radial, a large fraction of the magnetic vectors lie parallel to the Galactic plane. Along the highly polarized southeastern rim, the field is aligned tangent to the shock, and therefore also nearly parallel to the Galactic plane. These results strongly suggest that the ambient field surrounding SN 1006 is aligned with this direction (i.e., from northeast to southwest) and that the bright lobes are due to a polar cap geometry. Our study establishes that the most efficient particle acceleration and generation of magnetic turbulence in SN 1006 is attained for shocks in which the magnetic field direction and shock normal are quasi-parallel, while inefficient acceleration and little to no generation of magnetic turbulence are obtained for the quasi-perpendicular case.Fil: Reynoso, Estela Marta. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Hughes, John P.. Rutgers University; Estados UnidosFil: Moffett, David A.. Furman University; Estados Unido
Análisis de las normas sectoriales de telecomunicaciones y protección al consumidor, a la luz del nacimiento de un nuevo soporte publicitario
El señor Rojas presentó una denuncia contra Entel Perú S.A., alegando la representatividad
de toda la ciudadanía, por infracción al deber de idoneidad, toda vez que la empresa
reproducía el anuncio “Eres Entel, eres cine” antes de establecer la conexión de una llamada,
obligando a los usuarios de telefonía a recibir publicidad no requerida. Indecopi decidió
encauzar la imputación por métodos comerciales agresivos o engañosos, declarando
infundada la denuncia en primera instancia e improcedente el extremo referido a la supuesta
afectación de derechos de los usuarios. En segunda instancia, resolvió declarar improcedente
la denuncia en el extremo relacionado a que la locución podría afectar a los usuarios,
indicando que Osiptel es el organismo competente para analizar dicha conducta, finalmente
confirmó que el denunciante no contaba con legitimidad para accionar la defensa de los
intereses de los consumidores.
El presente informe, analiza si el denunciante cuenta o no con legitimidad para accionar la
protección de los intereses de los usuarios de telefonía. Asimismo, se cuestiona si la conducta
de la empresa configura un método comercial agresivo o engañoso, o nos encontramos ante
una vulneración al deber de idoneidad en la prestación del servicio público de
telecomunicaciones, observando además el actuar de la autoridad al momento de encauzar la
imputación formulada.Mr. Rojas filed a complaint against Entel Peru S.A., in representation of all citizens, for the
infringement of the duty of suitability, since the company reproduced the advertisement "You
are Entel, you are cinema" before establishing the connection during a call, forcing telephone
users to receive unrequired advertising. Indecopi decided to channel the accusation for
aggressive or deceptive commercial methods, and declared the complaint partially unfounded
and partially inadmissible (regarding the alleged infringement of the users’ rights). In the
second instance, Indecopi declared the complaint as inadmissible in the extreme related to the
fact that the locution could affect users; indicating that Osiptel is the competent entity to
analyze said conduct. Additionally, it confirmed that the complainant did not have legitimacy
to act for the defense of the interests of consumers.
This report analyzes whether the complainant has the legitimacy to act to protect the interests
of telephone users. Likewise, it is questioned whether the conduct of the company constitutes
an aggressive or deceptive commercial method, or if we are facing an infringement of the
duty of suitability in the provision of the public telecommunications service, also observing
the action of the authority at the time of channeling the imputation formulated
Mytillocactus (cactaecea) : botanical, agronomic, physichemical and chemical characteristics of fruits
Au Mexique, la production de fruits de Myrtillocactus est importante, pourtant ceux-ci sont souvent sous-utilisés. Bien qu'ils soient essentiellement exploités pour leur potentiel de colorants alimentaires, les fruits mériteraient davantage d'attention quant à leurs autres propriétés pour l'alimentation, mais les informations sur leur composition physico-chimique sont rares. Afin de disposer d'éléments de base pour le développement de la culture de Myrtillocactus, nous avons étudié les informations accessibles à ce jour. Description botanique. Quatre espèces de Myrtillocactus ont été identifiées et rapportées dans la littérature. Elles diffèrent par la forme, la couleur, et d'autres caractéristiques phénotypiques. Au Mexique, l'espèce prédominante est M. geometrizans, mais M. schenckii se développe également abondamment dans toutes les terres arides et semi-arides du pays. Les analyses cytologiques effectuées sur M. geometrizans ont montré que la plante était diploïde (2n = 22). Aspects agronomiques. Le genre Myrtillocactus appartient à la famille des cactacées. En raison de son métabolisme crassulacéen acide, la plante peut se développer dans les montagnes arides et semi-arides du Mexique. Les espèces de Myrtillocactus sont propagées asexuellement par explants ou par clonage. En conditions contrôlées, la micropropagation in vitro d'explants apicaux et basaux donne de hauts rendements. Pour la culture, une attention particulière doit être apportée aux températures hivernales minimales. Description des fruits et caractérisation biochimique. Le fruit comestible est globulaire, avec un diamètre atteignant 1,5 cm. La pulpe est colloïdale, sa couleur va du rougeoyant au rouge bleuâtre. La caractérisation chimique a principalement porté sur la composition en bétalaines, dont les composés prédominants sont la bétanine et les bétaxanthines. La teneur en bétalaines serait de 2,3 mg ·100 g -1 de pulpe. Le colorant semble être plus stable que celui des betteraves rouges. Consommation humaine et importance commerciale. Pendant la saison de production (juin à septembre), les fruits sont trouvés sur tous les marchés de leur lieu de production. Ils sont mangés frais ou transformés. La commercialisation du fruit est limitée principalement aux zones de production rurales dans certains états du Mexique. Conclusions. Notre synthèse a établi que les informations publiées sur Myrtillocactus étaient rares et incomplètes. La plante est sous utilisée, en dépit de ses propriétés alimentaires et de son potentiel commercial. Comme les espèces de Myrtillocactus s'adaptent facilement dans des conditions de grande sécheresse, elles mériteraient de faire l'objet de beaucoup plus de recherche (Résumé d'auteur
Morphological evidence for azimuthal variations of the cosmic ray ion acceleration at the blast wave of SN 1006
Using radio, X-ray and optical observations, we present evidence for
morphological changes due to efficient cosmic ray ion acceleration in the
structure of the southeastern region of the supernova remnant SN 1006. SN 1006
has an apparent bipolar morphology in both the radio and high-energy X-ray
synchrotron emission. In the optical, the shock front is clearly traced by a
filament of Balmer emission in the southeast. This optical emission enables us
to trace the location of the blast wave (BW) even in places where the
synchrotron emission from relativistic electrons is either absent or too weak
to detect. The contact discontinuity (CD) is traced using images in the
low-energy X-rays (oxygen band) which we argue reveals the distribution of
shocked ejecta. We interpret the azimuthal variations of the ratio of radii
between the BW and CD plus the X-ray and radio synchrotron emission at the BW
using CR-modified hydrodynamic models. We assumed different azimuthal profiles
for the injection rate of particles into the acceleration process, magnetic
field and level of turbulence. We found that the observations are consistent
with a model in which these parameters are all azimuthally varying, being
largest in the brightest regions.Comment: Accepted for publication in ApJ - 42 pages, 11 figure
Application of Ionic Liquids in Pot-in-Pot Reactions
Pot-in-pot reactions are designed such that two reaction media (solvents, catalysts and reagents) are isolated from each other by a polymeric membrane similar to matryoshka dolls (Russian nesting dolls). The first reaction is allowed to progress to completion before triggering the second reaction in which all necessary solvents, reactants, or catalysts are placed except for the starting reagent for the target reaction. With the appropriate trigger, in most cases unidirectional flux, the product of the first reaction is introduced to the second medium allowing a second transformation in the same glass reaction pot—albeit separated by a polymeric membrane. The basis of these reaction systems is the controlled selective flux of one reagent over the other components of the first reaction while maintaining steady-state catalyst concentration in the first “pot”. The use of ionic liquids as tools to control chemical potential across the polymeric membranes making the first pot is discussed based on standard diffusion models—Fickian and Payne’s models. Besides chemical potential, use of ionic liquids as delivery agent for a small amount of a solvent that slightly swells the polymeric membrane, hence increasing flux, is highlighted. This review highlights the critical role ionic liquids play in site-isolation of multiple catalyzed reactions in a standard pot-in-pot reaction
Navigating flood resilience: challenges, solutions, and lessons learnt from the Dominican Republic
© 2024 The authors. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisher’s website: https://doi.org/10.3390/w16030382Recent unprecedented events worldwide, such as floods in Dubai, recurring heavy rainfall in Santo Domingo, and abrupt temperature changes in the United Kingdom (UK), underscore the tangible impacts of climate change. In response to escalating threats from natural disasters, global communities prioritise resilience and effective disaster management systems. This paper addresses best practices for managing abnormal floods, laying the foundation for the next generation of preparedness and mitigation plans. Focusing on flood risk in Santo Domingo, the study employs the Community Disaster Resilience Framework, conducting a workshop with over 100 stakeholders from government, private, and academic sectors. The assessment spans physical, economic, environmental, and social aspects, revealing common challenges in infrastructure upkeep, public awareness, urban planning, drainage, and economic disparities. The paper proposes technological solutions like predictive maintenance and smart drainage systems, emphasising the potential for implementation. Recognising the importance of community involvement and preparedness, insights from the United Kingdom guide initial steps in strategy development. The conclusions advocate for collaborative efforts among government, academia, and society to navigate the complexities of disaster management and community resilience, ultimately proposing a framework to address these challenges. Further research is suggested in expanding online platforms for disaster risk reduction education in the Caribbean region.The Embassy of the Dominican Republic in the United Kingdom of Great Britain and Northern Ireland partially funded this research.Published onlin
- …