1,721,109 research outputs found
Morphological identification of Rhinoestrus purpureus vs. Rhinooestrus usbekistanicus nasal bot flies of horse: more doubts than evidence
Neural Network Pattern Recognition Experiments Toward a Fully Automatic Detection of Anomalies in InSAR Time Series of Surface Deformation
We present a neural network-based method to detect anomalies in time-dependent surface deformation fields given a set of geodetic images of displacements collected from multiple viewing geometries. The presented methodology is based on a supervised classification approach using combinations of line of sight multitemporal, multi-geometry interferometric synthetic aperture radar (InSAR) time series of displacements. We demonstrate this method with a set of 170 million time series of surface deformation generated for the entire Italian territory and derived from ERS, ENVISAT, and COSMO-SkyMed Synthetic Aperture Radar satellite constellations. We create a training dataset that has been compared with independently validated data and current state-of-the-art classification techniques. Compared to state-of-the-art algorithms, the presented framework provides increased detection accuracy, precision, recall, and reduced processing times for critical infrastructure and landslide monitoring. This study highlights how the proposed approach can accelerate the anomalous points identification step by up to 147 times compared to analytical and other artificial intelligence methods and can be theoretically extended to other geodetic measurements such as GPS, leveling data, or extensometers. Our results indicate that the proposed approach would make the anomaly identification post-processing times negligible when compared to the InSAR time-series processing
MRI study of small bowel in Crohn’s disease: evaluation of disease activity with oral preparation and e.v. gadolinium diethylenetriamine pentaacetic acid.
Biological and environmental factors affecting the survival of Otodectes cynotis (Acarina, Psoroptidae) off the host in natural and laboratory conditions
Species composition of Gasterophilus spp. (Diptera, Oestridae) causing equine gastric myiasis in southern Italy: parasite biodiversity and risks for extinction
Horse gastrointestinal myiasis caused by larvae of Gasterophilus spp. (Diptera, Oestridae) flies has a worldwide distribution and, where present, it is primarily caused by larvae of Gasterophilus intestinalis and Gasterophilus nasalis. Other species, i.e., Gasterophilus inermis, Gasterophilus pecorum and Gasterophilus haemorrhoidalis, present in different or in the same regions of the gastrointestinal tract, were only occasionally reported in very limited areas of eastern European Countries and in central Italy. With the aim to contribute data on the species composition of Gasterophilus and on the seasonal variation of the infection pattern in southern Italy, 152 native horses were necropsied from January to December 2003 and Gasterophilus larvae were collected from the stomach, the small intestine and the rectum of each of them. On the whole, 125 (82.2%) horses were infected by larvae of Gasterophilus spp. and 214 second stage larvae (L2) and 13,342 third stage larvae (L3) collected. Five species of Gasterophilus were identified with the following prevalence: G. intestinalis=95.2%, G. nasalis=44.8%, G. inermis=15.2%, G. pecorum=2.6% and G. haemorrhoidalis=0.8%. L3 were retrieved throughout the observation period with the highest mean burdens from January to August 2003 while the lowest mean was registered from September to November 2003. L2 were collected in February-March 2003 and from September to December 2003. The majority of the animals (n=66, 43.4%) were infected with a single Gasterophilus species, however, 45 animals (29.6%) harboured 2 species, 12 animals (7.9%) 3 species and 2 animals (1.3%) 4 species. The trend of abundance in the L3 of G. intestinalis and G. nasalis, the most represented species, was highly concordant (r=0.5, p<0.001). A retrospective comparison of our results and of other data from four seasons of observation (1983-1986) in central Italy showed that the number of G. inermis, G. pecorum and G. haemorrhoidalis have been decreasing relative to G. intestinalis and G. nasalis which may suggest tendency toward the extinction of the three former species of Gasterophilus
Double-contrast MRI (DC-MRI) in the study of the cirrhotic liver: utility of administering Gd-DTPA as a complement to examinations in which SPIO liver uptake and distribution alterations (SPIO-LUDA) are present and in the identification and characterisation of focal lesions.
Purpose. The aim of this study was to compare the performance of
double-contrast magnetic resonance imaging (DC-MRI) with the
sequential use of superparamagnetic iron oxide (SPIO) and
gadolinium-diethylenetriaminepentaacetic acid (Gd-DTPA)
contrast agents compared with unenhanced MRI and SPIOenhanced
MRI (SPIO-MRI) in the study of the cirrhotic liver.
Special attention was paid to cases in which alterations of liver
uptake and distribution of the SPIO contrast medium [SPIO-liver
uptake and distribution alterations (SPIO-LUDA)] could lead to
diagnostic errors at SPIO-MRI.
Materials and methods. We used DC-MRI to study 67 patients
suffering from hepatic cirrhosis and on a waiting list for liver
transplant. The study was performed with a 1.5-Tesla device and
characterised by three phases: the first phase without contrast
material (unenhanced MRI), the second after the administration of
ferumoxides (SPIO-MRI), and the third, a double-contrast study
following the injection of a bolus of paramagnetic contrast
material (DC-MRI). The sensitivity of unenhanced MRI, SPIOMRI
and DC-MRI in identifying and characterising hepatic focal
lesions was assessed, together with the diagnostic increment of
one technique with respect to the others. The gold standard was
histological confirmation in 38 cases and clinical–radiological
follow-up in all cases. Liver function, kidney function, blood tests
and urinalysis were performed in all patients 24–48 h before and
after the MRI examination.
Results. In 14/67 cases (20.8%), SPIO-LUDA were present, which
posed a limitation to the SPIO-MRI examination. Focal lesions
were absent in 44 patients, and the action of the ferumoxides was
reduced by the presence of SPIO-LUDA in nine cases. There were
five cases of confluent fibrosis, two of decompensated cirrhosis,
one of vascular thrombosis, and one of scarring in a patient who had undergone hepatic resection for hepatocellular carcinoma
(HCC). In all these cases, completion of the MR examination with
the DC technique clarified the MR picture, confirming the absence
of focal lesions. Twenty-three patients had a total of 68 lesions,
which consisted of 37 dysplastic nodules (DN), 19 HCC nodules,
two relapses of HCC following chemoembolisation, two HCC
associated with portal thrombosis, one cancer-cirrhosis, two
angiomas and five small cysts. SPIO-LUDA were present in five
patients, thus limiting the identification, characterisation or
assessment of the real size of the lesions. SPIO-LUDA were the
result of vascular thrombosis in one case and fibrosis in four cases.
In all of these cases, DC-MRI proved useful for diagnosis. The
sensitivity of unenhanced MRI, SPIO-MRI and DC-MRI for
lesion detection was 57.3%, 67.6% and 75%, respectively. The
results obtained in the characterisation of the lesions were 20.5%,
63.2% and 73.5% for unenhanced MRI, SPIO-MRI and DC-MRI,
respectively. The diagnostic increment of SPIO-MRI over
unenhanced MRI for lesion identification and characterisation was
9% and 42.7%, respectively, whereas the diagnostic increment of
DC-MRI over SPIO-MRI was 7.4% and 10.3%, respectively.
Conclusions. In our study, the combined use of two contrast
agents, negative and positive, provided greater diagnostic
confidence and caused no side effects in the patients.
Key words MR • Liver • Cirrhosis • Contrast • Mediu
Morphological variability and genetic identity in Rhinoestrus spp. causing horse nasal myiasis
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