178,115 research outputs found
An Adaptive Probailistic Approach to Goal-Level Imitation Learning
No full textImitation learning has been recognized as a promising technique to teach robots advanced skills. It is based on the idea that robots could learn new behaviors by observ- ing and imitating the behaviors of other skilled actors. We propose an adaptive probabilistic graphical model which copes with three core issues of any imitative behavior: observation, representation and reproduction of skills. Our model, Growing Hierarchical Dynamic Bayesian Network (GHDBN), is hierarchi- cal (i.e. able to characterize structured behaviors at different levels of abstraction), and growing (i.e. skills are learned or updated incrementally - and at each level of abstraction - every time a new observation sequence is available). A GHDBN, once trained, is able to recognize skills being observed and to reproduce them by exploiting the generative power of the model. The system has been successfully tested in simulation, and initial tests have been conducted on a NAO humanoid robot platform
Technetium-99m Sestamibi imaging in the detection of axillary lymph node involvement in patients with breast cancer.
No full textAnticancer Res. 1997 May-Jun;17(3B):1607-10.
Technetium-99m sestamibi imaging in the detection of axillary lymph node involvement in patients with breast cancer.
Schillaci O, Scopinaro F, Danieli R, Tavolaro R, Cannas P, Picardi V, Colella AC.
SourceDepartment of Experimental Medicine and Pathology, University La Sapienza, Rome, Italy.
Abstract
BACKGROUND: The status of the axillary lymph nodes is the most important prognostic factor in breast cancer, and the findings of axillary node dissection remain the gold standard for the patients staging and prognosis. The aim of this study was to evaluate the usefulness of Tc-99m sestamibi scintigraphy in the detection of axillary node involvement.
MATERIALS AND METHODS: Forty-nine patients (age range: 32-72 years) with breast cancer were studied. Dynamic images (1-20 minutes post-injection of the radiopharmaceutical) followed by multiple planar views and tomographic images were performed. Final diagnosis was achieved by histology after surgery.
RESULTS: Metastatic axillary lymph node involvement was present in 21 patients: sensitivity was 81% (17/21) for tomographic and 61.9% (13/21) for planar images; specificity was 92.9% (26/28) and 96.4% (27/28), respectively.
CONCLUSIONS: Tc-99m sestamibi imaging is a promising noninvasive method to detect axillary node metastases in patients with breast cancer, tomography appears more sensitive than planar views.
PMID:9179202[PubMed - indexed for MEDLINE
99mTc-sestamibi scintimammography in patients with suspicious breast lesions: comparison of SPET and planar images in the detection of primary tumours and axillary lymph node involvement.
No full textNucl Med Commun. 1997 Sep;18(9):839-45.
99Tcm-sestamibi scintimammography in patients with suspicious breast lesions: comparison of SPET and planar images in the detection of primary tumours and axillary lymph node involvement.
Schillaci O, Scopinaro F, Danieli R, Tavolaro R, Picardi V, Cannas P, Colella AC.
SourceDepartment of Experimental Medicine and Pathology, University La Sapienza, Rome, Italy.
Abstract
Planar scintimammography with 99Tcm-sestamibi (99Tcm-MIBI) has been shown to be useful in diagnosing breast carcinoma. The aim of this study was to compare single photon emission tomography (SPET) and planar imaging for scintimammography with 99Tcm-MIBI in the detection of primary breast cancer and axillary lymph node involvement. Sixty-three females with mammographically suspicious lesions and 12 controls were evaluated. Dynamic images were acquired commencing immediately after the injection of the radiopharmaceutical, followed by multiple planar images in the supine and prone positions plus SPET supine imaging. A final histopathological diagnosis was achieved after surgery. A total of 66 breast lesions were considered. No focal uptake of 99Tcm-MIBI was observed in the breasts or axillas of the controls. In the patients with breast cancer, the sensitivity was 92.9% (39/42) for SPET, 71.4% (30/42) for supine and 85.7% (36/42) for prone planar imaging, respectively; the specificity was 87.5% for SPET and 91.6% for the planar scans. Metastatic axillary lymph node involvement was seen in 19 patients: the sensitivity was 84.2% (16/19) for SPET and 63.2% (12/19) for planar images; the specificity was 91.3% and 95.7% respectively. Our results confirm the high diagnostic accuracy of 99Tcm scintimammography in the diagnosis of breast cancer, and suggest that SPET is more sensitive than planar images, especially in detecting axillary lymph node involvement.
PMID:9352550[PubMed - indexed for MEDLINE
Modeling soil organic carbon with Quantile Regression : dissecting predictors' effects on carbon stocks
No full textSoil organic carbon (SOC) estimation is crucial to manage natural and anthropic ecosystems. Many modeling procedures have been tested in the literature, however, most of them do not provide information on predictors' behavior at specific sub-domains of the SOC stock. Here, we implement Quantile Regression (QR) to spatially predict the SOC stock and gain insight on the role of predictors (topographic and remotely sensed) at varying SOC stock (0–30cm depth) in the agricultural areas of an extremely variable semi-arid region (Sicily, Italy, around 25,000km2). QR produces robust performances (maximum quantile loss = 0.49) and allows to recognize dominant effects among the predictors at varying quantiles. In particular, clay mostly contributes to maintain SOC stock at lower quantiles whereas rainfall and temperature influences are constantly positive and negative, respectively. This information, currently lacking, confirms that QR can discern predictor influences on SOC stock at specific SOC sub-domains. The QR map generated at the median shows a Mean Absolute Error of 17 t SOC ha-1 with respect to the data collected at sampling locations. Such MAE is lower than those of the Joint Research Centre at Global (18 t SOC ha-1) and at European (24 t SOC ha-1) scales and of the International Soil Reference and Information Centre (23 t SOC ha-1) while higher than the MAE reached in Schillaci et al. (2017b) (Geoderma, 2017, issue 286, page 35–45) using the same dataset (15 t SOC ha-1). The results suggest the use of QR as a comprehensive method to map SOC stock using legacy data in agro-ecosystems and to investigate SOC and inherited uncertainty with respect to specific subdomains. The R code scripted in this study for QR is included
Cardiovascular disease risk burden in primary Sjögren's syndrome: results of a population-based multicentre cohort study.
No full textCardiovascular disease risk burden in primary Sjögren's syndrome: results of a population-based multicentre cohort study.
Bartoloni E1, Baldini C, Schillaci G, Quartuccio L, Priori R, Carubbi F, Bini V, Alunno A, Bombardieri S, De Vita S, Valesini G, Giacomelli R, Gerli R.
Author information
Abstract
OBJECTIVE:
Systemic autoimmune diseases, in particular systemic lupus erythematosus and rheumatoid arthritis, are characterized by a high risk of premature cardiovascular (CV) events. Disease-related characteristics and traditional CV disease risk factors may contribute to atherosclerotic damage. However, there are limited data on the risk of overt CV events in primary Sjögren's syndrome (pSS).
METHODS:
We retrospectively analysed a cohort of patients with 1343 pSS. Disease-related clinical and laboratory data, traditional CV disease risk factors and overt CV events were recorded. Prevalence of traditional CV disease risk factors and of major CV events was compared between a subgroup of 788 female patients with pSS aged from 35 to 74 years and 4774 age-matched healthy women.
RESULTS:
Hypertension and hypercholesterolaemia were more prevalent, whereas smoking, obesity and diabetes mellitus were less prevalent, in women with pSS than in control subjects. Cerebrovascular events (2.5% vs. 1.4%, P = 0.005) and myocardial infarction (MI) (1.0% vs. 0.4%, P = 0.002) were more common in patients with pSS. In the whole population, central nervous system involvement (odds ratio (OR) 5.6, 95% confidence interval (CI) 1.35-23.7, P = 0.02) and use of immunosuppressive therapy (OR 1.9, 95% CI 1.04-3.70, P = 0.04) were associated with a higher risk of CV events. Patients with leucopenia had a higher risk of angina (P = 0.01).
CONCLUSIONS:
pSS is associated with an increased risk of cerebrovascular events and MI. Disease-related clinical and immunological markers may have a role in promoting CV events.
© 2015 The Association for the Publication of the Journal of Internal Medicine.
KEYWORDS:
Sjögren's syndrome; atherosclerosis; autoimmune disease; cardiovascular disease risk factor
Indium-111 pentetreotide scintigrapy in the detection of insulinomas: importance of SPECT imaging
No full textJ Nucl Med. 2000 Mar;41(3):459-62.
111In-pentetreotide scintigraphy in the detection of insulinomas: importance of SPECT imaging.
Schillaci O, Massa R, Scopinaro F.
SourceDepartment of Sciences and Biomedical Technologies, University of L'Aquila, Rome, Italy.
Abstract
The aim of this study was to determine whether the systematic use of SPECT can increase the reported low sensitivity of somatostatin receptor scintigraphy (SRS) in detecting insulinomas.
METHODS: Fourteen patients were evaluated. After 111In-pentetreotide injection (approximately 250 MBq intravenously), abdominal SPECT images were obtained at 4 h and multiple planar images were obtained at 4 and 24 h. MRI and CT were performed within 1 mo of SRS. Sixteen tumors were histologically verified after surgery in 14 patients.
RESULTS: SPECT revealed 14 lesions in 12 patients (sensitivity, 87.5%), both planar SRS and MRI revealed 7 tumors in 7 patients (sensitivity, 43.8%), and CT revealed only 5 lesions in 4 patients (sensitivity, 31.3%). Moreover, in 4 patients SPECT was the only examination with positive findings.
CONCLUSION: SPECT at 4 h is mandatory for preoperative detection of insulinomas using SRS because the images are more sensitive than planar images and are superior to images from other conventional methods.
PMID:10716319[PubMed - indexed for MEDLINE] Free full tex
99mTc sestamibi single-photon emission tomography detects subclinical myocardial perfusion abnormalities in patients with systemic lupus erytematosus
No full textTechnetium-99m sestamibi single-photon emission tomography detects subclinical myocardial perfusion abnormalities in patients with systemic lupus erythematosus.
Schillaci O, Laganà B, Danieli R, Gentile R, Tubani L, Baratta L, Scopinaro F.
SourceNuclear Medicine, University of L'Aquila, Italy.
Abstract
In patients with systemic lupus erythematosus, involvement of the cardiovascular system is the third leading cause of death. However, although autopsy studies have demonstrated a high incidence of abnormalities in both the myocardium and coronary vessels, clinical manifestations have been reported in only a small percentage of cases. The aim of this study was to evaluate myocardial perfusion in asymptomatic lupus patients using technetium-99m sestamibi single-photon emission tomography (SPET). Twenty-eight patients without overt cardiac involvement and risk factors were studied with 99mTc-sestamibi SPET at rest and after dipyridamole infusion. Perfusion abnormalities were detected in 18 cases: six had persistent defects, three had reversible defects, seven had both persistent and reversible defects, and two showed rest defects which normalized on dipyridamole images ("reverse redistribution pattern"). Coronary angiography was performed in eight patients with positive 99mTc-sestamibi SPET, and showed normal epicardial vessels in all the cases. These results indicate that 99mTc-sestamibi SPET reveals a high prevalence (18 out of 28 patients in this study, i.e. 64%) of myocardial perfusion abnormalities in asymptomatic lupus patients, probably due to the primary immunological damage of this autoimmune disease. In conclusion, rest/dipyridamole 99mTc-sestamibi SPET can be a useful non-invasive method to identify subclinical myocardial involvement in systemic lupus erythematosus, and patients potentially at risk of later cardiac events.
PMID:10398819[PubMed - indexed for MEDLINE
Yttrium-90 resin microspheres and their use in the treatment of intrahepatic cholangiocarcinoma
No full textIntrahepatic cholangiocarcinoma (ICC) is a severe and rapidly progressive hepatic tumor. Surgery is often impracticable due to locally advanced presentation. On the other hand, chemotherapy has demonstrated only limited effectiveness. For these reasons, liver-directed therapies have been successfully applied for treating ICC. In particular, radioembolization with Yttrium-90 (Y-90)-labeled spheres has been reported to be a promising therapeutic approach for this neoplasia. Two commercial forms of Y-90-labeled spheres are available: glass (TheraSphere (R)) and resin (SIR-Spheres (R)) microspheres. The aim of the present paper is to review the existing literature on the use of the resin microspheres for the treatment of unresectable and chemorefractory ICC, focusing on the methodology, clinical applications and side effects
Assessment of present day geomorphological dynamics to decipher landscape evolution around the Paleolithic sites of Melka Kunture, Ethiopia.
No full textAssessment of present day geomorphological dynamics to decipher
landscape evolution around the Paleolithic sites of Melka Kunture,
Ethiopia
Michael Maerker (1,2), Calogero Schillaci (1), Rita Melis (3), and Margherita Mussi (4)
(1) Heidelberg Academy of Sciences and Humanities, Germany ([email protected]), (2)
Department of Earth Sciences, Università degli studi di Firenze, Italy, (3) Department of Earth Sciences, Università degli studi
di Cagliari. Italy, (4) Dipartimento Scienze dell’Antichità. Università di Roma la Sapienza, Italy
The area of Melka Kunture (central Ethiopia) is one of the most important clusters of Paleolithic sites in Eastern
Africa. The archaeological record spans from c. 1.7 Ma onwards, with a number of stratified occurrences of
Oldowan, Acheulean, Middle Stone Age and Late Stone Age industries, together with faunal remains and human
fossils. However, the archaeological sites are endangered by flooding and soil erosion. The main excavation area
lies close to the convergence of the Awash river with the Atabella river, one of the main tributaries of the upper
Awash catchment. In the semi-arid Ethiopian highlands, gully networks develop especially in the vicinity of the
active and inactive river meanders. Various erosion processes are linked to specific driving factors such as the
rainfall regime, the land use/cover changes and vertic soils with a specific hydrological behaviour. It was documented
in the field and by previous research that the origin of most of the man made erosion channels is due to
animal pathways and car tracks. However, paleolandscape features increase the general erosion risk. Former wetland
areas and deposition zones are particularly affected by soil erosion processes. Hence, the spatial distribution
and characteristics of present day geomorphic processes also reveal information on the paleolandscape. In order to
assess landscape evolution and present day geomorphologic dynamics, we mapped the geomorphology describing
in detail the present-day slope processes at a 10.000 scale. We performed a detailed terrain analysis based on high
resolution DEMs such as SRTM-X with 25m resolution and ALOS/PRISM with 10m resolution to characterize
the main erosion processes and surface runoff dynamics. The latter ones are simulated using a Soil Conservation
Service Curve Number method. Landuse was delineated for a larger area using ASTER 25m multispectral data.
Finally, using calibrated topographic indices and a simple hydrological model we were able to detect and quantify
the major present day soil erosion and surface runoff processes. Based on the analysis of the processes and the
respective terrain features derived from the digital elevation models we also identified the major paelolandscape
features. This will be the basis for assessing conservation risks related to modern land use and climate
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