Deep 10 and 18 micron Imaging of the HR 4796A Circumstellar Disk: Transient Dust Particles & Tentative Evidence for a Brightness Asymmetry

We present new 10.8 and 18.2 micron images of HR 4796A, a young A0V star that was recently discovered to have a spectacular, nearly edge-on, circumstellar disk prominent at ~20 microns (Jayawardhana et al. 1998; Koerner et al. 1998). These new images, obtained with OSCIR at Keck II, show that the disk's size at 10 microns is comparable to its size at 18 microns. Therefore, the 18 micron-emitting dust may also emit some, or all, of the 10 micron radiation. Using these multi-wavelength images, we determine a "characteristic" diameter of 2-3 microns for the mid-infrared-emitting dust particles if they are spherical and composed of astronomical silicates. Particles this small are expected to be blown out of the system by radiation pressure in a few hundred years, and therefore these particles are unlikely to be primordial. Dynamical modeling of the disk (Wyatt et al. 2000) indicates that the disk surface density is relatively sharply peaked near 70 AU, which agrees with the mean annular radius deduced by Schneider et al. (1999) from their NICMOS images. We present evidence (~1.8 sigma significance) for a brightness asymmetry that may result from the presence of the hole and the gravitational perturbation of the disk particle orbits by the low-mass stellar companion or a planet. This "pericenter glow," which must still be confirmed, results from a very small (a few AU) shift of the disk's center of symmetry relative to the central star HR 4796A; one side of the inner boundary of the annulus is shifted towards HR 4796A, thereby becoming warmer and more infrared-emitting. The possible detection of pericenter glow implies that the detection of even complex dynamical effects of planets on disks is within reach.Comment: 18 pages. 9 GIF images. Total size ~800 kB. High resolution images available upon request. Accepted for publication in the Astrophysical Journal (scheduled for January 10, 2000

Statins and Exercise Training Response in Heart Failure Patients: Insights From HF-ACTION.

OBJECTIVES: The aim of this study was to assess for a treatment interaction between statin use and exercise training (ET) response. BACKGROUND: Recent data suggest that statins may attenuate ET response, but limited data exist in patients with heart failure (HF). METHODS: HF-ACTION (Heart Failure: A Controlled Trial Investigating Outcomes of Exercise Training) was a randomized trial of 2,331 patients with chronic HF with ejection fraction ≤35% who were randomized to usual care with or without ET. We evaluated whether there was a treatment interaction between statins and ET response for the change in quality of life and aerobic capacity (peak oxygen consumption and 6-min walk distance) from baseline to 3 months. We also assessed for a treatment interaction among atorvastatin, simvastatin, and pravastatin and change in these endpoints with ET. Multiple linear regression analyses were performed for each endpoint, adjusting for baseline covariates. RESULTS: Of 2,331 patients in the HF-ACTION trial, 1,353 (58%) were prescribed statins at baseline. Patients treated with statins were more likely to be older men with ischemic HF etiology but had similar use of renin angiotensin system blockers and beta-blockers. There was no evidence of a treatment interaction between statin use and ET on changes in quality of life or exercise capacity, nor was there evidence of differential association between statin type and ET response for these endpoints (all p values \u3e0.05). CONCLUSIONS: In a large chronic HF cohort, there was no evidence of a treatment interaction between statin use and short-term change in aerobic capacity and quality of life with ET. These findings contrast with recent reports of an attenuation in ET response with statins in a different population, highlighting the need for future prospective studies. (Exercise Training Program to Improve Clinical Outcomes in Individuals With Congestive Heart Failure; NCT00047437)

Breast implant-associated anaplastic large cell lymphoma: a review

El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado.Breast implant-associated anaplastic large cell lymphoma is a newly recognized provisional entity in the 2017 revision of the World Health Organization Classification of Tumors of Hematopoietic and Lymphoid Tissues. It is an uncommon, slow growing T-cell lymphoma with morphology and immunophenotype similar to anaplastic lymphoma kinase-negative anaplastic large cell lymphoma. However, the presentation and treatment are unique. Breast implant-associated anaplastic large cell lymphoma often presents as a unilateral effusion confined to the capsule of a textured-surface breast implant, a median time of 9 years after the initial implants have been placed. Although it follows an indolent clinical course, breast implant-associated anaplastic large cell lymphoma has the potential to form a mass, to invade locally through the capsule into breast parenchyma or soft tissue and/or to spread to regional lymph nodes. In most cases, an explantation with a complete capsulectomy removing all disease, without chemotherapy is considered to be curative and confers an excellent event free and overall survival. Here we provide a comprehensive review of breast implant-associated anaplastic large cell lymphoma, including history, epidemiology, clinical features, imaging and pathology findings, pathologic handling, pathogenic mechanisms, model for progression, therapy and outcomes as well as an analysis of causality between breast implants and anaplastic large cell lymphoma.Revisión por pare

Dust Morphology and Composition in FU Orionis Systems

FU Orionis stars are a small group of pre–main-sequence stars known for large-amplitude optical variability. These objects also exhibit multiwavelength phenomena suggestive of active accretion from a circumstellar disk. We present high spatial resolution mid-IR imaging and spectroscopy, submillimeter photometry, and 3–4 μm photometry of four FU Ori–class objects, RNO 1B and C, Z CMa, and Par 21, and one object classified as a pre–FU Ori star, V380 Ori. We resolve multiple IR sources and extended emission in the RNO 1B/C system, and we discuss in detail their association with disk activity and the source of the Infrared Astronomical Satellite far-IR and radio maser emission in this field. We derive dust temperatures and masses for all sources and discuss how dust composition and morphology is related to the evolutionary stage of these objects

Pesquisa participativa em melhoramento de mandioca: uma experiência no Semi-Árido do Nordeste do Brasil.

Este trabalho teve por objetivos provar conjuntamente com agricultores, extensionistas e pesquisadores uma metodologia complementar, denominada de pesquisa participativa em melhoramento de mandioca, que aplicada a clones em etapas avançadas de avaliação, incremente a possibilidade de serem adotados pelos produtores, bem como estabelecer uma retroalimentação entre estes segmentos que permita identificar os principais critérios de seleção utilizados pelos produtores do semi-árido para a adoção de novas cultivares de mandioca. O trabalho foi desenvolvido em quatro locais do semi-árido dos Estados da Bahia (Itaberaba), Pernambuco (Petrolina e Araripina) e Ceara (Quixadá), em parceria com a EBDA,IPA e EPACE. Iniciou-se com um diagnostico, seguido do planejamento e implantação das provas participativas, avaliação e retro informação. Foram estabelecidas dezessete provas participativas, nos anos de 1993/94, com nove clones selecionados para as condições semi-áridas. Como resultados principais traçou-se o perfil de uma variedade ideal para o semi-árido, baseado nos critérios de seleção estabelecidos pelos produtores dessa região, formou-se um glossário sobre a terminologia agrícola local do produtor de mandioca e adaptou-se um livro de campo gerado no CIAT, as características consideradas importantes pelos produtores de mandioca do semi-árido.bitstream/item/81301/1/Pesquisa-Participativa-Wania-Fukuda-Documentos-73-1997.pd

Profile Of An Orthopedic Surgery Residency Applicant: What Factors Define A Successful Match?

The orthopedic match is highly competitive, and successful orthopedic applicants havehistorically had high Step 1 scores. Step 1 is Pass/Fail after January 26, 2022. Programs must change applicant assessment, and students must understand how to build asuccessful orthopedic application

Observations of Massive Star Forming Regions with Water Masers: Mid-Infrared Imaging

We present here a mid-infrared imaging survey of 26 sites of water maser emission. Observations were obtained at the InfraRed Telescope Facility 3-m telescope with the University of Florida mid-infrared imager/spectrometer OSCIR, and the JPL mid-infrared camera MIRLIN. The main purpose of the survey was to explore the relationship between water masers and the massive star formation process. It is generally believed that water masers predominantly trace outflows and embedded massive stellar objects, but may also exist in circumstellar disks around young stars. We investigate each of these possibilities in light of our mid-infrared imaging. We find that mid-infrared emission seems to be more closely associated with water and OH maser emission than cm radio continuum emission from UC HII regions. We also find from the sample of sources in our survey that, like groups of methanol masers, both water and OH masers have a proclivity for grouping into linear or elongated distributions. We conclude that the vast majority of linearly distributed masers are not tracing circumstellar disks, but outflows and shocks instead.Comment: 49 pages; 23 figures; To appear in February 2005 ApJS; To download a version with better quality figures, go to http://www.ctio.noao.edu/~debuizer

Taxa de recarga do aquífero em áreas de Latossolo Amarelo sem vegetação na Região Nordeste do Pará - Amazônia.

A recarga dos aquíferos é um processo hidrológico, no qual a água infiltra no solo através da zona insaturada até a zona saturada ou aquífero. Os fluxos de água podem ser modificados por qualquer alteração, como é o caso da ocupação de terras na Amazônia por cultivos agrícolas. O estudo foi realizado perto da cidade de Moju, Belém (PA) e tem como objetivo realizar uma simulação com o HYDRUS-1D para estimar a recarga da água subterrânea através da zona não saturada. Com a simulação de um cenário sem vegetação com dados de precipitação de um período de 715 dias, foi possível observar as taxas de recarga do aquífero. Os resultados permitiram observar as propriedades do perfil de solo, e a umidade do solo devido a dinâmica do fluxo de água e precipitação. A precipitação e recarga dos aquíferos mais elevados estão entre os meses de novembro a maio. Os fluxos de recarga variaram entre 30 e 46 mm/dia nos dias mais intensos de precipitação, enquanto na média anual não passam de 10 mm/dia

A biologist’s guide to planning and performing quantitative bioimaging experiments

Technological advancements in biology and microscopy have empowered a transition from bioimaging as an observational method to a quantitative one. However, as biologists are adopting quantitative bioimaging and these experiments become more complex, researchers need additional expertise to carry out this work in a rigorous and reproducible manner. This Essay provides a navigational guide for experimental biologists to aid understanding of quantitative bioimaging from sample preparation through to image acquisition, image analysis, and data interpretation. We discuss the interconnectedness of these steps, and for each, we provide general recommendations, key questions to consider, and links to high-quality open-access resources for further learning. This synthesis of information will empower biologists to plan and execute rigorous quantitative bioimaging experiments efficiently