38 research outputs found
Making maps of cosmic microwave background polarization for B-mode studies: The POLARBEAR example
Analysis of cosmic microwave background (CMB) datasets typically requires some filtering of the raw time-ordered data. For instance, in the context of ground-based observations, filtering is frequently used to minimize the impact of low frequency noise, atmospheric contributions and/or scan synchronous signals on the resulting maps. In this work we have explicitly constructed a general filtering operator, which can unambiguously remove any set of unwanted modes in the data, and then amend the map-making procedure in order to incorporate and correct for it. We show that such an approach is mathematically equivalent to the solution of a problem in which the sky signal and unwanted modes are estimated simultaneously and the latter are marginalized over. We investigated the conditions under which this amended map-making procedure can render an unbiased estimate of the sky signal in realistic circumstances. We then discuss the potential implications of these observations on the choice of map-making and power spectrum estimation approaches in the context of B-mode polarization studies. Specifically, we have studied the effects of time-domain filtering on the noise correlation structure in the map domain, as well as impact it may haveon the performance of the popular pseudo-spectrum estimators. We conclude that although maps produced by the proposed estimators arguably provide the most faithful representation of the sky possible given the data, they may not straightforwardly lead to the best constraints on the power spectra of the underlying sky signal and special care may need to be taken to ensure this is the case. By contrast, simplified map-makers which do not explicitly correct for time-domain filtering, but leave it to subsequent steps in the data analysis, may perform equally well and be easier and faster to implement. We focused on polarization-sensitive measurements targeting the B-mode component of the CMB signal and apply the proposed methods to realistic simulations based on characteristics of an actual CMB polarization experiment, POLARBEAR. Our analysis and conclusions are however more generally applicable. \ua9 ESO, 2017
High-resolution CT phenotypes in pulmonary sarcoidosis: a multinational Delphi consensus study
One view of sarcoidosis is that the term covers many different diseases. However, no classification framework exists for the future exploration of pathogenetic pathways, genetic or trigger predilections, patterns of lung function impairment, or treatment separations, or for the development of diagnostic algorithms or relevant outcome measures. We aimed to establish agreement on high-resolution CT (HRCT) phenotypic separations in sarcoidosis to anchor future CT research through a multinational two-round Delphi consensus process. Delphi participants included members of the Fleischner Society and the World Association of Sarcoidosis and other Granulomatous Disorders, as well as members' nominees. 146 individuals (98 chest physicians, 48 thoracic radiologists) from 28 countries took part, 144 of whom completed both Delphi rounds. After rating of 35 Delphi statements on a five-point Likert scale, consensus was achieved for 22 (63%) statements. There was 97% agreement on the existence of distinct HRCT phenotypes, with seven HRCT phenotypes that were categorised by participants as non-fibrotic or likely to be fibrotic. The international consensus reached in this Delphi exercise justifies the formulation of a CT classification as a basis for the possible definition of separate diseases. Further refinement of phenotypes with rapidly achievable CT studies is now needed to underpin the development of a formal classification of sarcoidosis
El cultivo de garbanzo (Cicer arietinum L.) en Argentina
El Programa Transferencia de Resultados de Investigación y
Comunicación Pública de la Ciencia (PROTRI), de la Secretaría de
Ciencia y Tecnología del Gobierno de la Provincia de Córdoba,
financió la realización del libro El cultivo de garbanzo en Argentina
con el objeto de promover la transferencia de resultados,
experiencias o saberes entre las áreas del sector social y productivo
para una mejor calidad de vida.
Para la ejecución de esta obra han sido convocados técnicos e
investigadores de las Ciencias Agropecuarias, Biológicas y
Económicas, quienes en una forma clara y sencilla, aunque no menos
consistente, ponen a disposición del lector sus experiencias
adquiridas a lo largo de varios años de trabajo.
El desarrollo de los diferentes temas se realiza a través de
dieciséis Capítulos que abarcan desde la domesticación de Cicer y su
llegada a la Argentina (Capítulo 1), pasando por el estudio
morfológico de las diferentes partes de la planta en relación a los
cultivares locales (Capítulo 2), además del manejo del suelo y sus
nutrientes, en cuanto a requerimientos edáficos en los sistemas
productivos (Capítulo 3). También se contempla el análisis de la
influencia de los diversos factores ambientales para la determinación
de zonas productivas (Capítulo 4). En el Capítulo 5 se hace referencia
a la ecofisiología del cultivo, sus requerimientos en las diferentes
etapas fenológicas, y cuándo y cómo se expresan en los cultivares.
Un tema de indudable importancia para las leguminosas en general, y
para el garbanzo en particular, es la simbiosis con las bacterias
fijadoras de nitrógeno y su influencia en la productividad, el cual se
desarrolla en el Capítulo 6.
La mejora genética en el país es abordada en el Capítulo 7,
donde se exponen sus inicios, desarrollo, disponibilidad de recursos,
bondades y potencial del germoplasma disponible.
A lo largo del ciclo biológico de la planta, el cultivo es visitado
por insectos e infectado por hongos. Identificarlos y conocer sus
ciclos biológicos y comportamientos es un aspecto importante para
seleccionar las medidas de manejo y control más adecuadas
(Capítulos 8 y 9).
Quizás pocos sepan que el volumen de semilla genética de un
cultivar, alcanza sólo unos pocos gramos (alrededor de 20). Para
llevar este pequeño volumen a toneladas, se requiere del trabajo y
tesón de investigadores, fitomejoradores y productores. Resultado de
ese esfuerzo es la difusión de los seis cultivares obtenidos en el país,
y se sigue trabajando para lograr nuevos materiales que se adapten a
las diversas áreas y sistemas de producción (Capítulo 10).
El desarrollo de los diferentes cultivares, que dan lugar a
diversas arquitecturas de plantas, sumado a la adopción de diversos
sistemas de producción, hace que el tema de la mecanización ocupe
un lugar importante. Maquinas pequeñas y grandes intervienen en las
etapas de siembra y de cosecha tratando de lograr la mayor
eficiencia posible y un producto de calidad (Capítulo 11).
Un cuello de botella para la expansión del cultivo es su
comercialización, tanto para consumo interno como externo. En el
Capítulo 12 se analizan los diferentes mercados y la necesidad de
lograr un producto rentable de alta calidad, para mercados muy
diversos.
En el Capítulo 13 se hace un recorrido por las diferentes
Provincias que actualmente producen garbanzo. Sus autores
comentan como se incorporó el cultivo a los sistemas productivos de
la región, sobre posibilidades y limitaciones, manejos y potencial de
rendimiento, entre otros aportes.
Los Capítulos 14 y 15 presentan dos temas de relevancia actual:
la composición química del grano y las posibilidades de brindar valor
agregado a éste, aspectos reforzados en la última década por el auge
de las tendencias que promueven un nuevo estilo de vida y una
alimentación sana, con alimentos naturales, bajos en grasa y con un
buen balance nutricional.
En el último Capítulo (16) se presentan experiencias de
investigación en las que se utilizó al garbanzo como materia prima o
como sustrato para diversas experimentaciones. La interacción
docente-investigador-alumno permitió que vieran la luz diversos
trabajos que, además de la formación de recursos humanos, brindan
una información útil y novedosa al incursionar en temas tales como
manejo de fechas de siembra, riego, alimento para pollos, cerdos y
abejas.
Estimado lector, tiene en sus manos un libro que es una
invitación a un viaje con dieciséis estaciones. En cada una de ellas
encontrará información sobre el cultivo del garbanzo en la Argentina.
Estos datos fueron obtenidos por docentes, investigadores,
productores, estudiantes que trabajaron y siguen trabajando para
aportar al conocimiento del cultivo en nuestro país, bajo la realidad
local y el contexto regional, ya que la mayoría de los trabajos y
publicaciones son de origen extranjero y la aplicación de muchas de
las tecnologías de manejo requieren una correcta adaptación y
validación. Esperamos que este libro, además de serle útil, pueda ser
disfrutado, sintiendo la pasión y el entusiasmo de cada uno de los
autores por brindar y compartir sus conocimientos y logros
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Post-transplant Inflammatory Bowel Disease Associated with Donor-Derived TIM-3 Deficiency.
Acknowledgements: We thank the patient for his continuing support of this study. We thank the clinical staff for detailed and provident clinical care.Funder: University of BaselInflammatory bowel disease (IBD) occurring following allogeneic stem cell transplantation (aSCT) is a very rare condition. The underlying pathogenesis needs to be better defined. There is currently no systematic effort to exclude loss- or gain-of-function mutations in immune-related genes in stem cell donors. This is despite the fact that more than 100 inborn errors of immunity may cause or contribute to IBD. We have molecularly characterized a patient who developed fulminant inflammatory bowel disease following aSCT with stable 100% donor-derived hematopoiesis. A pathogenic c.A291G; p.I97M HAVCR2 mutation encoding the immune checkpoint protein TIM-3 was identified in the patient's blood-derived DNA, while being absent in DNA derived from the skin. TIM-3 expression was much decreased in the patient's serum, and in vitro-activated patient-derived T cells expressed reduced TIM-3 levels. In contrast, T cell-intrinsic CD25 expression and production of inflammatory cytokines were preserved. TIM-3 expression was barely detectable in the immune cells of the patient's intestinal mucosa, while being detected unambiguously in the inflamed and non-inflamed colon from unrelated individuals. In conclusion, we report the first case of acquired, "transplanted" insufficiency of the regulatory TIM-3 checkpoint linked to post-aSCT IBD
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Post-transplant Inflammatory Bowel Disease Associated with Donor-Derived TIM-3 Deficiency
Acknowledgements: We thank the patient for his continuing support of this study. We thank the clinical staff for detailed and provident clinical care.Funder: University of BaselInflammatory bowel disease (IBD) occurring following allogeneic stem cell transplantation (aSCT) is a very rare condition. The underlying pathogenesis needs to be better defined. There is currently no systematic effort to exclude loss- or gain-of-function mutations in immune-related genes in stem cell donors. This is despite the fact that more than 100 inborn errors of immunity may cause or contribute to IBD. We have molecularly characterized a patient who developed fulminant inflammatory bowel disease following aSCT with stable 100% donor-derived hematopoiesis. A pathogenic c.A291G; p.I97M HAVCR2 mutation encoding the immune checkpoint protein TIM-3 was identified in the patient’s blood-derived DNA, while being absent in DNA derived from the skin. TIM-3 expression was much decreased in the patient’s serum, and in vitro-activated patient-derived T cells expressed reduced TIM-3 levels. In contrast, T cell-intrinsic CD25 expression and production of inflammatory cytokines were preserved. TIM-3 expression was barely detectable in the immune cells of the patient’s intestinal mucosa, while being detected unambiguously in the inflamed and non-inflamed colon from unrelated individuals. In conclusion, we report the first case of acquired, “transplanted” insufficiency of the regulatory TIM-3 checkpoint linked to post-aSCT IBD
A Modified Reading the Mind in the Eyes Test Predicts Behavioral Variant Frontotemporal Dementia Better Than Executive Function Tests
The Simons Observatory: Gain, bandpass and polarization-angle calibration requirements for B-mode searches
We quantify the calibration requirements for systematic uncertainties for next-generation ground-based observatories targeting the large-angle B-mode polarization of the Cosmic Microwave Background, with a focus on the Simons Observatory (SO). We explore uncertainties on gain calibration, bandpass center frequencies, and polarization angles, including the frequency variation of the latter across the bandpass. We find that gain calibration and bandpass center frequencies must be known to percent levels or less to avoid biases on the tensor-to-scalar ratio r on the order of Δ r∼10-3, in line with previous findings. Polarization angles must be calibrated to the level of a few tenths of a degree, while their frequency variation between the edges of the band must be known to O(10) degrees. Given the tightness of these calibration requirements, we explore the level to which residual uncertainties on these systematics would affect the final constraints on r if included in the data model and marginalized over. We find that the additional parameter freedom does not degrade the final constraints on r significantly, broadening the error bar by O(10%) at most. We validate these results by reanalyzing the latest publicly available data from the collaboration within an extended parameter space covering both cosmological, foreground and systematic parameters. Finally, our results are discussed in light of the instrument design and calibration studies carried out within SO
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The Simons Observatory: gain, bandpass and polarization-angle calibration requirements for B-mode searches
We quantify the calibration requirements for systematic uncertainties for next-
generation ground-based observatories targeting the large-angle B-mode polarization of the
Cosmic Microwave Background, with a focus on the Simons Observatory (SO). We explore
uncertainties on gain calibration, bandpass center frequencies, and polarization angles, in-
cluding the frequency variation of the latter across the bandpass. We find that gain cali-
bration and bandpass center frequencies must be known to percent levels or less to avoid
biases on the tensor-to-scalar ratio r on the order of ∆r ∼ 10−3, in line with previous find-
ings. Polarization angles must be calibrated to the level of a few tenths of a degree, while
their frequency variation between the edges of the band must be known to O(10) degrees.
Given the tightness of these calibration requirements, we explore the level to which residual
uncertainties on these systematics would affect the final constraints on r if included in the
data model and marginalized over. We find that the additional parameter freedom does
not degrade the final constraints on r significantly, broadening the error bar by O(10%) at
most. We validate these results by reanalyzing the latest publicly available data from the
BICEP2/Keck Array collaboration within an extended parameter space covering both cos-
mological, foreground and systematic parameters. Finally, our results are discussed in light
of the instrument design and calibration studies carried out within SO
Recommended from our members
The Simons Observatory: gain, bandpass and polarization-angle calibration requirements for B-mode searches
International audienceWe quantify the calibration requirements for systematic uncertainties for next-generation ground-based observatories targeting the large-angle B-mode polarization of the Cosmic Microwave Background, with a focus on the Simons Observatory (SO). We explore uncertainties on gain calibration, bandpass center frequencies, and polarization angles, including the frequency variation of the latter across the bandpass. We find that gain calibration and bandpass center frequencies must be known to percent levels or less to avoid biases on the tensor-to-scalar ratio r on the order of Δ r∼10-3, in line with previous findings. Polarization angles must be calibrated to the level of a few tenths of a degree, while their frequency variation between the edges of the band must be known to O(10) degrees. Given the tightness of these calibration requirements, we explore the level to which residual uncertainties on these systematics would affect the final constraints on r if included in the data model and marginalized over. We find that the additional parameter freedom does not degrade the final constraints on r significantly, broadening the error bar by O(10%) at most. We validate these results by reanalyzing the latest publicly available data from the collaboration within an extended parameter space covering both cosmological, foreground and systematic parameters. Finally, our results are discussed in light of the instrument design and calibration studies carried out within SO
Performance of a continuously rotating half-wave plate on the POLARBEAR telescope
A continuously rotating half-wave plate (CRHWP) is a promising tool to improve the sensitivity to large angular scales in cosmic microwave background (CMB) polarization measurements. With a CRHWP, single detectors can measure three of the Stokes parameters, I, Q and U, thereby avoiding the set of systematic errors that can be introduced by mismatches in the properties of orthogonal detector pairs. We focus on the implementation of CRHWPs in large aperture telescopes (i.e. the primary mirror is larger than the current maximum half-wave plate diameter of \ue2\u88\ubc0.5 m), where the CRHWP can be placed between the primary mirror and focal plane. In this configuration, one needs to address the intensity to polarization (I\ue2\u86\u92P) leakage of the optics, which becomes a source of 1/f noise and also causes differential gain systematics that arise from CMB temperature fluctuations. In this paper, we present the performance of a CRHWP installed in the \scshape Polarbear experiment, which employs a Gregorian telescope with a 2.5 m primary illumination pattern. The CRHWP is placed near the prime focus between the primary and secondary mirrors. We find that the I\ue2\u86\u92P leakage is larger than the expectation from the physical properties of our primary mirror, resulting in a 1/f knee of 100 mHz. The excess leakage could be due to imperfections in the detector system, i.e. detector non-linearity in the responsivity and time-constant. We demonstrate, however, that by subtracting the leakage correlated with the intensity signal, the 1/f noise knee frequency is reduced to 32 mHz (\ue2\u84\u93 \ue2\u88\ubc 39 for our scan strategy), which is very promising to probe the primordial B-mode signal. We also discuss methods for further noise subtraction in future projects where the precise temperature control of instrumental components and the leakage reduction will play a key role