100 research outputs found
Multiple Homes and Parallel Civil Societies: Refugee Diasporas and Transnationalism (Reprinted from Volume 23.1)
Lung Nodule Detection in Screening Computed Tomography
A computer-aided detection (CAD) system for the identification of pulmonary
nodules in low-dose multi-detector helical Computed Tomography (CT) images with
1.25 mm slice thickness is presented. The basic modules of our lung-CAD system,
a dot-enhancement filter for nodule candidate selection and a neural classifier
for false-positive finding reduction, are described. The results obtained on
the collected database of lung CT scans are discussed.Comment: 3 pages, 4 figures; Proceedings of the IEEE NNS and MIC Conference,
Oct. 29 - Nov. 4, 2006, San Diego, Californi
GPCALMA: A Tool For Mammography With A GRID-Connected Distributed Database
The GPCALMA (Grid Platform for Computer Assisted Library for MAmmography)
collaboration involves several departments of physics, INFN sections, and
italian hospitals. The aim of this collaboration is developing a tool that can
help radiologists in early detection of breast cancer. GPCALMA has built a
large distributed database of digitised mammographic images (about 5500 images
corresponding to 1650 patients) and developed a CAD (Computer Aided Detection)
software which is integrated in a station that can also be used for acquire new
images, as archive and to perform statistical analysis. The images are
completely described: pathological ones have a consistent characterization with
radiologist's diagnosis and histological data, non pathological ones correspond
to patients with a follow up at least three years. The distributed database is
realized throught the connection of all the hospitals and research centers in
GRID tecnology. In each hospital local patients digital images are stored in
the local database. Using GRID connection, GPCALMA will allow each node to work
on distributed database data as well as local database data. Using its database
the GPCALMA tools perform several analysis. A texture analysis, i.e. an
automated classification on adipose, dense or glandular texture, can be
provided by the system. GPCALMA software also allows classification of
pathological features, in particular massive lesions analysis and
microcalcification clusters analysis. The performance of the GPCALMA system
will be presented in terms of the ROC (Receiver Operating Characteristic)
curves. The results of GPCALMA system as "second reader" will also be
presented.Comment: 6 pages, Proceedings of the Seventh Mexican Symposium on Medical
Physics 2003, Vol. 682/1, pp. 67-72, Mexico City, Mexic
Observation of the thermal Casimir force
Quantum theory predicts the existence of the Casimir force between
macroscopic bodies, due to the zero-point energy of electromagnetic field modes
around them. This quantum fluctuation-induced force has been experimentally
observed for metallic and semiconducting bodies, although the measurements to
date have been unable to clearly settle the question of the correct
low-frequency form of the dielectric constant dispersion (the Drude model or
the plasma model) to be used for calculating the Casimir forces. At finite
temperature a thermal Casimir force, due to thermal, rather than quantum,
fluctuations of the electromagnetic field, has been theoretically predicted
long ago. Here we report the experimental observation of the thermal Casimir
force between two gold plates. We measured the attractive force between a flat
and a spherical plate for separations between 0.7 m and 7 m. An
electrostatic force caused by potential patches on the plates' surfaces is
included in the analysis. The experimental results are in excellent agreement
(reduced of 1.04) with the Casimir force calculated using the Drude
model, including the T=300 K thermal force, which dominates over the quantum
fluctuation-induced force at separations greater than 3 m. The plasma
model result is excluded in the measured separation range.Comment: 6 page
GPCALMA: a Grid-based tool for Mammographic Screening
The next generation of High Energy Physics (HEP) experiments requires a GRID
approach to a distributed computing system and the associated data management:
the key concept is the Virtual Organisation (VO), a group of distributed users
with a common goal and the will to share their resources. A similar approach is
being applied to a group of Hospitals which joined the GPCALMA project (Grid
Platform for Computer Assisted Library for MAmmography), which will allow
common screening programs for early diagnosis of breast and, in the future,
lung cancer. HEP techniques come into play in writing the application code,
which makes use of neural networks for the image analysis and proved to be
useful in improving the radiologists' performances in the diagnosis. GRID
technologies allow remote image analysis and interactive online diagnosis, with
a potential for a relevant reduction of the delays presently associated to
screening programs. A prototype of the system, based on AliEn GRID Services, is
already available, with a central Server running common services and several
clients connecting to it. Mammograms can be acquired in any location; the
related information required to select and access them at any time is stored in
a common service called Data Catalogue, which can be queried by any client. The
result of a query can be used as input for analysis algorithms, which are
executed on nodes that are in general remote to the user (but always local to
the input images) thanks to the PROOF facility. The selected approach avoids
data transfers for all the images with a negative diagnosis (about 95% of the
sample) and allows an almost real time diagnosis for the 5% of images with high
cancer probability.Comment: 9 pages, 4 figures; Proceedings of the HealthGrid Workshop 2004,
January 29-30, Clermont-Ferrand, Franc
Social Control in Transnational Families: Somali Women and Dignity in Johannesburg
Transnational mobility often separates families and distances individuals from the kinship and social structures by which they organized their lives prior to migration. Myriad forms of insecurity have been the impetus for Somali movement into the diaspora, with people fleeing the realities of conflict that have marked Somalia for decades while physically dividing families as individuals settle in different countries around the world. Mobility has altered the dynamics of households, families, and communities post-migration, reshaping social constructions as individuals move on without the familial support that sustained them in Somalia. While outcomes of these hardships are variable and often uneven in different settlement spaces, migration can offer new opportunities for people to pursue avenues from which they were previously excluded, such as by assuming roles and responsibilities their relatives once filled. These changes precipitate shifting identities and are challenging for women who find themselves self-reliant in the diaspora, particularly in the absence of (supportive) husbands and close kin.Drawing on ethnographic research in Johannesburg’s Somali community, this chapter explores the assumption that migration provides an opening for women to challenge subordinating gender norms. Settlement often grants women greater freedom to make choices in their lives, such as in employment and personal relationships, and yet they remain constrained by networks that limit their autonomy. Even with transnational migration and protracted separation, women are family representatives who must uphold cultural notions of respectability despite realities that position them as guardians and family providers. Women remain under the watchful eye of their extended families through expansive networks and the ease of modern communication, which facilitate a new form of social control as women’s behavior is carefully monitored and reported to relatives afar. These actualities raise questions about the degree to which transnational movement is a liberating force for women or rather a reconfiguration of social control. I argue that despite women’s changing position in their households and families, they remain limited by social control within their extended families and communities
Radionuclide imaging of bone marrow disorders
Noninvasive imaging techniques have been used in the past for visualization the functional activity of the bone marrow compartment. Imaging with radiolabelled compounds may allow different bone marrow disorders to be distinguished. These imaging techniques, almost all of which use radionuclide-labelled tracers, such as 99mTc-nanocolloid, 99mTc-sulphur colloid, 111In-chloride, and radiolabelled white blood cells, have been used in nuclear medicine for several decades. With these techniques three separate compartments can be recognized including the reticuloendothelial system, the erythroid compartment and the myeloid compartment. Recent developments in research and the clinical use of PET tracers have made possible the analysis of additional properties such as cellular metabolism and proliferative activity, using 18F-FDG and 18F-FLT. These tracers may lead to better quantification and targeting of different cell systems in the bone marrow. In this review the imaging of different bone marrow targets with radionuclides including PET tracers in various bone marrow diseases are discussed
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