The Cone of Mueller Matrices

In the study of polarized light, there are two basic notions: the Stokes vectors and the matrices which preserve them, called Mueller matrices. The set of Stokes vectors forms a cone: the Future Light Cone. In this work we will see that the Mueller matrices also form a cone in the vector space of real matrices of size 4X4, called the Mueller Cone. We obtain some properties of the Mueller cone, which in turn will be translated into properties of the Stokes vectors. As an application we will give a computational program to calibrate polarimeters by means of the eigenvectors of Mueller matrices (ECM). We include computational programs to 1. Deduce if a matrix is a Mueller matrix, 2. Give an approximation of a matrix by a Mueller matrix, 3. An approximation of a Mueller matrix by Mueller invertibles, 4. An approximation of a Mueller matrix by a Stokes-cone-primitive Mueller matrix, see (4.7) and 5. An Eigenvalue Calibration Method. All these programs and implementations can be found in https://github.com/IvanLopezR22/cone-of-mueller-matrices/tree/masterComment: 20 pages, 1 figure and computer program

The Early Data Release of the Dark Energy Spectroscopic Instrument

\ua9 2024. The Author(s). Published by the American Astronomical Society. The Dark Energy Spectroscopic Instrument (DESI) completed its 5 month Survey Validation in 2021 May. Spectra of stellar and extragalactic targets from Survey Validation constitute the first major data sample from the DESI survey. This paper describes the public release of those spectra, the catalogs of derived properties, and the intermediate data products. In total, the public release includes good-quality spectral information from 466,447 objects targeted as part of the Milky Way Survey, 428,758 as part of the Bright Galaxy Survey, 227,318 as part of the Luminous Red Galaxy sample, 437,664 as part of the Emission Line Galaxy sample, and 76,079 as part of the Quasar sample. In addition, the release includes spectral information from 137,148 objects that expand the scope beyond the primary samples as part of a series of secondary programs. Here, we describe the spectral data, data quality, data products, Large-Scale Structure science catalogs, access to the data, and references that provide relevant background to using these spectra

A global research priority agenda to advance public health responses to fatty liver disease

Background & aims An estimated 38% of adults worldwide have non-alcoholic fatty liver disease (NAFLD). From individual impacts to widespread public health and economic consequences, the implications of this disease are profound. This study aimed to develop an aligned, prioritised fatty liver disease research agenda for the global health community. Methods Nine co-chairs drafted initial research priorities, subsequently reviewed by 40 core authors and debated during a three-day in-person meeting. Following a Delphi methodology, over two rounds, a large panel (R1 n = 344, R2 n = 288) reviewed the priorities, via Qualtrics XM, indicating agreement using a four-point Likert-scale and providing written feedback. The core group revised the draft priorities between rounds. In R2, panellists also ranked the priorities within six domains: epidemiology, models of care, treatment and care, education and awareness, patient and community perspectives, and leadership and public health policy. Results The consensus-built fatty liver disease research agenda encompasses 28 priorities. The mean percentage of ‘agree’ responses increased from 78.3 in R1 to 81.1 in R2. Five priorities received unanimous combined agreement (‘agree’ + ‘somewhat agree’); the remaining 23 priorities had >90% combined agreement. While all but one of the priorities exhibited at least a super-majority of agreement (>66.7% ‘agree’), 13 priorities had 90% combined agreement. Conclusions Adopting this multidisciplinary consensus-built research priorities agenda can deliver a step-change in addressing fatty liver disease, mitigating against its individual and societal harms and proactively altering its natural history through prevention, identification, treatment, and care. This agenda should catalyse the global health community’s efforts to advance and accelerate responses to this widespread and fast-growing public health threat. Impact and implications An estimated 38% of adults and 13% of children and adolescents worldwide have fatty liver disease, making it the most prevalent liver disease in history. Despite substantial scientific progress in the past three decades, the burden continues to grow, with an urgent need to advance understanding of how to prevent, manage, and treat the disease. Through a global consensus process, a multidisciplinary group agreed on 28 research priorities covering a broad range of themes, from disease burden, treatment, and health system responses to awareness and policy. The findings have relevance for clinical and non-clinical researchers as well as funders working on fatty liver disease and non-communicable diseases more broadly, setting out a prioritised, ranked research agenda for turning the tide on this fast-growing public health threat

Supraestructure maxillectomy and orbital exenteration for treatment of basal cell carcinoma of inferior eyelid: Case report and review

Basal cell carcinoma (BCC) is the most frequent type of skin cancer in humans, with cumulative exposure to ultraviolet radiation as an important risk factor for development of illness such as severe solar burns during childhood or adolescence. BCC is mainly located on sun-exposed sites, head and neck being the areas of more incidences; although nose, eyelids and periorbitary tissue are unfavorable due to cosmetic results that BCC involves. Tumors can be classified as nodular, superficial, micronodular, morphea variety, infiltrating, pigmented, metatypic and fibroepithelioma of Pinkus. Several treatment options such as surgical and nonsurgical are available. The goal of treatment is complete excision of the tumor with preservation of surrounding structures in a way aesthetically acceptable. Mohs' micrographic surgery is the standard treatment for all nonmelanoma skin cancers. Orbital exenteration is also used for treatment of malignancies of ocular tissues, mainly squamous cell carcinoma, sebaceous cell carcinoma and BCC. The tissue beneath the surgical site can be left for second-intention granulation or covered with a cutaneous implant of partial thickness. The case of a 77-year-old patient is presented with BCC of inferior eyelid of 14 years' duration, formerly managed with radiotherapy; however, due to recurrent illness and invasion to the maxillary antrum, he needed supraestructure maxillectomy with left orbital exenteration

THE CONE OF THE MUELLER MATRICES

In the study of polarized light, there are two basic notions: the Stokes vectors and the matrices which preserve them, called Mueller matrices. The set of Stokes vectors forms a cone: the Future Light Cone. In this work we will see that the Mueller matrices also form a cone in the vector space of real matrices of size 4X4, called the Mueller Cone. We obtain some properties of the Mueller cone, which in turn will be translated into properties of the Stokes vectors. As an application we will give a computational program to calibrate polarimeters by means of the eigenvectors of Mueller matrices (ECM). We also include programs to see if a matrix is Mueller, to approximate a matrix by a Mueller matrix, to approximate it by an invertible Mueller matrix and by a Stokes-cone-primitive Mueller matrix

Combining Global Geopotential Models, Digital Elevation Models, and GNSS/Leveling for Precise Local Geoid Determination in Some Mexico Urban Areas: Case Study

This work shows improvements of geoid undulation values obtained from a high-resolution Global Geopotential Model (GGM), applied to local urban areas. The methodology employed made use of a Residual Terrain Model (RTM) to account for the topographic masses effect on the geoid. This effect was computed applying the spherical tesseroids approach for mass discretization. The required numerical integration was performed by 2-D integration with 1DFFT technique that combines DFT along parallels with direct numerical integration along meridians. In order to eliminate the GGM commission error, independent geoid undulations values obtained from a set of GNSS/leveling stations are employed. A corrector surface from the associated geoid undulation differences at the stations was generated through a polynomial regression model. The corrector surface, in addition to the GGM commission error, also absorbs the GNSS/leveling errors as well as datum inconsistencies and systematic errors of the data. The procedure was applied to five Mexican urban areas that have a geodetic network of GNSS/leveling points, which range from 166 to 811. Two GGM were evaluated: EGM2008 and XGM2019e_2159. EGM2008 was the model that showed relatively better agreement with the GNSS/leveling stations having differences with RMSE values in the range of 8–60 cm and standard deviations of 5–8 cm in four of the networks and 17 cm in one of them. The computed topographic masses contribution to the geoid were relatively small, having standard deviations on the range 1–24 mm. With respect to corrector surface estimations, they turned out to be fairly smooth yielding similar residuals values for two geoid models. This was also the case for the most recent Mexican gravity geoid GGM10. For the three geoid models, the second order polynomial regression model performed slightly better than the first order with differences up to 1 cm. These two models produced geoid correction residuals with a standard deviation in one test area of 14 cm while for the others it was of about 4–7 cm. However, the kriging method that was applied for comparison purposes produced slightly smaller values: 8 cm for one area and 4–6 cm for the others

Combining Global Geopotential Models, Digital Elevation Models, and GNSS/Leveling for Precise Local Geoid Determination in Some Mexico Urban Areas: Case Study

This work shows improvements of geoid undulation values obtained from a high-resolution Global Geopotential Model (GGM), applied to local urban areas. The methodology employed made use of a Residual Terrain Model (RTM) to account for the topographic masses effect on the geoid. This effect was computed applying the spherical tesseroids approach for mass discretization. The required numerical integration was performed by 2-D integration with 1DFFT technique that combines DFT along parallels with direct numerical integration along meridians. In order to eliminate the GGM commission error, independent geoid undulations values obtained from a set of GNSS/leveling stations are employed. A corrector surface from the associated geoid undulation differences at the stations was generated through a polynomial regression model. The corrector surface, in addition to the GGM commission error, also absorbs the GNSS/leveling errors as well as datum inconsistencies and systematic errors of the data. The procedure was applied to five Mexican urban areas that have a geodetic network of GNSS/leveling points, which range from 166 to 811. Two GGM were evaluated: EGM2008 and XGM2019e_2159. EGM2008 was the model that showed relatively better agreement with the GNSS/leveling stations having differences with RMSE values in the range of 8–60 cm and standard deviations of 5–8 cm in four of the networks and 17 cm in one of them. The computed topographic masses contribution to the geoid were relatively small, having standard deviations on the range 1–24 mm. With respect to corrector surface estimations, they turned out to be fairly smooth yielding similar residuals values for two geoid models. This was also the case for the most recent Mexican gravity geoid GGM10. For the three geoid models, the second order polynomial regression model performed slightly better than the first order with differences up to 1 cm. These two models produced geoid correction residuals with a standard deviation in one test area of 14 cm while for the others it was of about 4–7 cm. However, the kriging method that was applied for comparison purposes produced slightly smaller values: 8 cm for one area and 4–6 cm for the others

Engendering reactivity at group 5-heteroatom multiple bonds via π-loading.

In this Perspective, we discuss the strategy of π-loading, i.e., coordination of two or more strongly π-donating ligands to a single metal center, as it applies to promoting reactivity at group 5 transition metal-imido groups. When multiple π-donor ligands compete to interact with the same symmetrically-available metal dπ orbitals, the energy of the imido-based frontier molecular orbitals increases, leading to amplified imido-based reactivity. This strategy is of particular relevance to group 5 metals, as mono(imido) complexes of these metals tend to be inert at the imido group. Electronic structure studies of group 5 bis(imido) complexes are presented, and examples of catalytically and stoichiometrically active group 5 bis(imido) and chalcogenido-imido complexes are reviewed. These examples are intended to encourage future work exploring π-loaded bis(imido) systems of the group 5 triad

Procedimiento para la elaboración y puesta en marcha de una revista financiera

El presente informe busca apoyar a profesionistas, emprendedores, e interesados en poner en el mercado un nuevo periódico y/o revista. Así como los procedimientos para la elaboración de los mismos, desde la creación hasta su lanzamiento, teniendo como contenido primordial la información financiera, al mismo tiempo que la revista sirva de medio de comunicación y que ayude para la promoción de diferentes contenidos. Puede darse el caso que numerosos inversionistas tienen interés per utilizar sus recursos monetarios en el desarrollo de nuevos negocios, es por ello que, en el presente informe se crea y desarrolla una nueva opción de negocios, esperando que el contenido de la información sea la mejor propuesta de inversión y una nueva propuesta de lectura