13 research outputs found
Coffee, Society, and Power in Latin America, edited by William Roseberry, Lowell Gudmundson, and Mario Samper Kutschbach; Baltimore: The Johns Hopkins University Press, 1995
Coffee, Society, and Power in Latin America, edited by William Roseberry, Lowell Gudmundson, and Mario Samper Kutschbach; Baltimore: The Johns Hopkins University Press, 1995. 304 pp. Reviewed by Deborah Sick, Research Associate, Department of Anthropology, McGill University
An ultrasound based platform for image-guided radiotherapy in canine bladder cancer patients
Background and purpose: Ultrasound (US) is a non-invasive, non-radiographic imaging technique with high spatial and temporal resolution that can be used for localizing soft-tissue structures and tumors in real-time during radiotherapy (RT) (inter- and intra-fraction). A comprehensive approach incorporating an in-house 3D-US system within RT is presented. This system is easier to adopt into existing treatment protocols than current US based systems, with the aim of providing millimeter intra-fraction alignment errors and sensitivity to track intra-fraction bladder movement.
Materials and methods: An in-house integrated US manipulator and platform was designed to relate the computed tomographic (CT) scanner, 3D-US and linear accelerator coordinate systems. An agar-based phantom with measured speed of sound and densities consistent with tissues surrounding the bladder was rotated (0-45°) and translated (up to 55 mm) relative to the US and CT coordinate systems to validate this device. After acquiring and integrating CT and US images into the treatment planning system, US-to-US and US-to-CT images were co-registered to re-align the phantom relative to the linear accelerator.
Results: Statistical errors from US-to-US registrations for various patient orientations ranged from 0.1 to 1.7 mm for x, y, and z translation components, and 0.0-1.1° for rotational components. Statistical errors from US-to-CT registrations were 0.3-1.2 mm for the x, y and z translational components and 0.1-2.5° for the rotational components.
Conclusions: An ultrasound-based platform was designed, constructed and tested on a CT/US tissue-equivalent phantom to track bladder displacement with a statistical uncertainty to correct and track inter- and intra-fractional displacements of the bladder during radiation treatments
LSST: from Science Drivers to Reference Design and Anticipated Data Products
(Abridged) We describe here the most ambitious survey currently planned in
the optical, the Large Synoptic Survey Telescope (LSST). A vast array of
science will be enabled by a single wide-deep-fast sky survey, and LSST will
have unique survey capability in the faint time domain. The LSST design is
driven by four main science themes: probing dark energy and dark matter, taking
an inventory of the Solar System, exploring the transient optical sky, and
mapping the Milky Way. LSST will be a wide-field ground-based system sited at
Cerro Pach\'{o}n in northern Chile. The telescope will have an 8.4 m (6.5 m
effective) primary mirror, a 9.6 deg field of view, and a 3.2 Gigapixel
camera. The standard observing sequence will consist of pairs of 15-second
exposures in a given field, with two such visits in each pointing in a given
night. With these repeats, the LSST system is capable of imaging about 10,000
square degrees of sky in a single filter in three nights. The typical 5
point-source depth in a single visit in will be (AB). The
project is in the construction phase and will begin regular survey operations
by 2022. The survey area will be contained within 30,000 deg with
, and will be imaged multiple times in six bands, ,
covering the wavelength range 320--1050 nm. About 90\% of the observing time
will be devoted to a deep-wide-fast survey mode which will uniformly observe a
18,000 deg region about 800 times (summed over all six bands) during the
anticipated 10 years of operations, and yield a coadded map to . The
remaining 10\% of the observing time will be allocated to projects such as a
Very Deep and Fast time domain survey. The goal is to make LSST data products,
including a relational database of about 32 trillion observations of 40 billion
objects, available to the public and scientists around the world.Comment: 57 pages, 32 color figures, version with high-resolution figures
available from https://www.lsst.org/overvie
RPE Minga
Versión en inglés disponible en la Biblioteca Digital del IDRC: Managing environmental processes across boundaries : a review of the literature on institutions and resource managemen
RPE Minga
Spanish version available in IDRC Digital Library: Gestión de procesos ambientales a través de fronteras : una revisión de literatura sobre instituciones y gestión de recursos naturale
Coffee, cooperatives and small-farmer decision making in Costa Rica.
Coffee production in Costa Rica has brought prosperity to many small farmers, but conflicts of interest with the companies which process and market coffee are still a problem. In addition, producers and processors are plagued by the periodic market cycles of agricultural commodities. Various agencies have promoted cooperatives to help small farmers deal with these problems, but they often fail due to poor management and lack of participation.This thesis, a multi-layered study of coffee production, processing, and marketing, examines how household producers manage the constraints and opportunities posed by the international market, the Costa Rican state, and the coffee tree itself. A comparative analysis between cooperative and private coffee processors; between two rural communities; and among households in these communities provides the ethnographic context in which the effectiveness of cooperatives as mediating institutions between producers and the world market is analyzed
Community-Based Conservation and Development: Lessons Learned from the 2004 Equator Prize
Occurrence of hybrids between Momotus momota and Baryphthengus ruficapillus (Momotidae) in central Brazil
The Post-Acute Phase of SARS-CoV-2 Infection in Two Macaque Species Is Associated with Signs of Ongoing Virus Replication and Pathology in Pulmonary and Extrapulmonary Tissues
The post-acute phase of SARS-CoV-2 infection was investigated in rhesus (Macaca mulatta) and cynomolgus macaques (Macaca fascicularis). During the acute phase of infection, SARS-CoV-2 was shed via the nose and throat, and viral RNA was occasionally detected in feces. This phase coincided with a transient change in systemic immune activation. Even after the alleged resolution of the infection, computed tomography (CT) and positron emission tomography (PET)-CT revealed pulmonary lesions and activated tracheobronchial lymph nodes in all animals. Post-mortem histological examination of the lung tissue revealed mostly marginal or resolving minimal lesions that were indicative of SARS-CoV-2 infection. Evidence for SARS-CoV-2-induced histopathology was also found in extrapulmonary tissue samples, such as conjunctiva, cervical, and mesenteric lymph nodes. However, 5â6 weeks after SARS-CoV-2 exposure, upon necropsy, viral RNA was still detectable in a wide range of tissue samples in 50% of the macaques and included amongst others the heart, the respiratory tract and surrounding lymph nodes, salivary gland, and conjunctiva. Subgenomic messenger RNA was detected in the lungs and tracheobronchial lymph nodes, indicative of ongoing virus replication during the post-acute phase. These results could be relevant for understanding the long-term consequences of COVID-19 in humans