We report on the follow-up and recovery of 100 program NEAs, PHAs and VIs using the ESO/MPG 2.2 m, Swope 1 m and INT 2.5 m telescopes equipped with large field cameras. The 127 fields observed during ...11 nights covered 29 square degrees. Using these data, we present the incidental survey work which includes 558 known MBAs and 628 unknown moving objects mostly consistent with MBAs from which 58 objects became official discoveries. We planned the runs using six criteria and four servers which focus mostly on faint and poorly observed objects in need of confirmation, follow-up and recovery. We followed 62 faint NEAs within one month after discovery and we recovered 10 faint NEAs having big uncertainties at their second or later opposition. Using the INT we eliminated four PHA candidates and VIs. We observed in total 1286 moving objects and we reported more than 10,000 positions. All data were reduced by the members of our network in a team effort, and reported promptly to the MPC. The positions of the program NEAs were published in 27 MPC and MPEC references and used to improve their orbits. The O- C residuals for known MBAs and program NEAs are smallest for the ESO/MPG and Swope and about four times larger for the INT whose field is more distorted. For the astrometric reduction, the UCAC-2 catalog is recommended instead of USNO-B1. The incidental survey allowed us to study statistics of the MBA and NEA populations observable today with 1-2 m facilities. We calculate preliminary orbits for all unknown objects, classifying them as official discoveries, later identifications and unknown outstanding objects. The orbital elements a, e, i calculated by FIND_ORB software for the official discoveries and later identified objects are very similar with the published elements which take into account longer observational arcs; thus preliminary orbits were used in statistics for the whole unknown dataset. We present a basic model which can be used to distinguish between MBAs and potential NEAs in any sky survey. Based on three evaluation methods, most of our unknown objects are consistent with MBAs, while up to 16 unknown objects could represent NEO candidates and four represent our best NEO candidates. We assessed the observability of the unknown MBA and NEA populations using 1 and 2 m surveys. Employing a 1 m facility, one can observe today fewer unknown objects than known MBAs and very few new NEOs. Using a 2 m facility, a slightly larger number of unknown than known asteroids could be detected in the main belt. Between 0.1 and 0.8 new NEO candidates per square degree could be discovered using a 2 m telescope.
Autism is classified as a pervasive developmental disorder, with several cardinal features including sensory disturbances, obsessive–compulsive-like behavior, lack of bonding to caregivers and motor ...disturbances. To date, there is a lack of an animal model of the disease. The current work is aimed at producing such a model by treating developing rat pups with a serotonergic agonist, 5-methoxytryptamine (5-MT; 1 mg/kg) during development (from gestational age 12 days to postnatal day 20), thus mimicking one of the hallmark neurochemical features of the illness—increases in the neurotransmitter, serotonin. Animals were then tested in behavioral paradigms that may resemble the human illness. Treated rat pups were found to be overreactive to auditory or tactile sensory stimuli, to display changes in the negative geotaxic test of motor development, to show lack of separation-induced vocalizations when their dam was removed and to show decreased alternation in the spontaneous alternation task. As well, the animals showed metabolic abnormalities in the brain using in vivo proton magnetic resonance spectroscopy, which are consistent with those observed in autistic children. In summary, the model we are proposing shows some of the behavioral and metabolic features of autism, as well as being produced through alteration of a neurochemical system known to be altered in autism.
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Background: The typical 1-2 min low temporal resolution (tRes) of conventional gradient-echo (GRE) breast dynamic contrast-enhanced (DCE) MRI precludes accurate quantitative ...pharmacokinetic (PK) analysis. The commercially available GRE-based TWIST (time-resolved angiography with stochastic trajectories) sequence employs an alternative k-space sampling scheme to provide high spatial and temporal resolution for dynamic imaging, originally intended for time-resolved MR angiography. Here we sought to evaluate the feasibility of breast DCE-MRI with the TWIST sequence, using both tumor morphology and quantitative PK analyses.
Methods: 22 patients with 25 mammography-detected suspicious lesions underwent TWIST DCE-MRI on a 3T Siemens system prior to biopsy. The axial bilateral images were acquired with 20 s tRes and 1.0x1.0x1.4 mm
3
spatial resolution (sRes). Immediately after TWIST DCE-MRI, a single DCE image set was acquired in 68 s using a conventional GRE sequence with the same sRes. Blinded to pathology, 3 radiologists compared lesion morphology assessments from the last TWIST DCE and the conventional images, and gave MRI BIRADS scores based on morphology and qualitative kinetic curve analyses. The TWIST DCE lesion signal time-courses were also subjected to Shutter-Speed Model PK analysis.
Results: Normal parenchyma S/N ratios were not statistically different between TWIST and conventional GRE images. All readers indicated 88% 95% CI: (68%, 97%) agreement in morphology evaluation between the TWIST and conventional DCE images. The degree of inter-reader agreement was substantial (κ = 0.75), as was the agreement in BIRADS scores (κ = 0.76). Pathology revealed 8 malignant and 17 benign lesions. Based on MRI BIRADS scores, all 3 readers attained 100% sensitivity and 82% specificity. With PK analysis, a K
trans
(contrast agent plasma/interstitium transfer rate constant) cut-off value of 0.1 min
-1
further improved specificity to 94%.
Conclusions: TWIST breast DCE-MRI provides both high tRes and sRes for accurate quantitative PK analysis and morphology evaluation, respectively. Utilizing TWIST for clinical breast DCE-MRI with quantitative PK analysis is feasible and may improve MRI interpretation.
We report on the follow-up and recovery of 100 program NEAs, PHAs and VIs using the ESO/MPG 2.2m, Swope 1m and INT 2.5m telescopes equipped with large field cameras. The 127 fields observed during 11 ...nights covered 29 square degrees. Using these data, we present the incidental survey work which includes 558 known MBAs and 628 unknown moving objects mostly consistent with MBAs from which 58 objects became official discoveries. We planned the runs using six criteria and four servers which focus mostly on faint and poorly observed objects in need of confirmation, follow-up and recovery. We followed 62 faint NEAs within one month after discovery and we recovered 10 faint NEAs having big uncertainties at their second or later opposition. Using the INT we eliminated four PHA candidates and VIs. We observed in total 1286 moving objects and we reported more than 10,000 positions. All data were reduced by the members of our network in a team effort, and reported promptly to the MPC. The positions of the program NEAs were published in 27 MPC and MPEC references and used to improve their orbits. The O-C residuals for known MBAs and program NEAs are smallest for the ESO/MPG and Swope and about four times larger for the INT whose field is more distorted. For the astrometric reduction, the UCAC-2 catalog is recommended instead of USNO-B1. The incidental survey allowed us to study statistics of the MBA and NEA populations observable today with 1-2m facilities. We calculate preliminary orbits for all unknown objects, classifying them as official discoveries, later identifications and unknown outstanding objects. The orbital elements a, e, i calculated by FIND_ORB software for the official discoveries and later identified objects are very similar with the published elements which take into account longer observational arcs; thus preliminary orbits were used in statistics for the whole unknown dataset. We present a basic model which can be used to distinguish between MBAs and potential NEAs in any sky survey. Based on three evaluation methods, most of our unknown objects are consistent with MBAs, while up to 16 unknown objects could represent NEO candidates and four represent our best NEO candidates. We assessed the observability of the unknown MBA and NEA populations using 1 and 2m surveys. Employing a 1m facility, one can observe today fewer unknown objects than known MBAs and very few new NEOs. Using a 2m facility, a slightly larger number of unknown than known asteroids could be detected in the main belt. Between 0.1 and 0.8 new NEO candidates per square degree could be discovered using a 2m telescope.
We report on the follow-up and recovery of 100 program NEAs, PHAs and VIs using the ESO/MPG 2.2m, Swope 1m and INT 2.5m telescopes equipped with large field cameras. The 127 fields observed during 11 ...nights covered 29 square degrees. Using these data, we present the incidental survey work which includes 558 known MBAs and 628 unknown moving objects mostly consistent with MBAs from which 58 objects became official discoveries. We planned the runs using six criteria and four servers which focus mostly on faint and poorly observed objects in need of confirmation, follow-up and recovery. We followed 62 faint NEAs within one month after discovery and we recovered 10 faint NEAs having big uncertainties at their second or later opposition. Using the INT we eliminated four PHA candidates and VIs. We observed in total 1286 moving objects and we reported more than 10,000 positions. All data were reduced by the members of our network in a team effort, and reported promptly to the MPC. The positions of the program NEAs were published in 27 MPC and MPEC references and used to improve their orbits. The O−C residuals for known MBAs and program NEAs are smallest for the ESO/MPG and Swope and about four times larger for the INT whose field is more distorted. For the astrometric reduction, the UCAC-2 catalog is recommended instead of USNO-B1. The incidental survey allowed us to study statistics of the MBA and NEA populations observable today with 1–2m facilities. We calculate preliminary orbits for all unknown objects, classifying them as official discoveries, later identifications and unknown outstanding objects. The orbital elements a, e, i calculated by FIND_ORB software for the official discoveries and later identified objects are very similar with the published elements which take into account longer observational arcs; thus preliminary orbits were used in statistics for the whole unknown dataset. We present a basic model which can be used to distinguish between MBAs and potential NEAs in any sky survey. Based on three evaluation methods, most of our unknown objects are consistent with MBAs, while up to 16 unknown objects could represent NEO candidates and four represent our best NEO candidates. We assessed the observability of the unknown MBA and NEA populations using 1 and 2m surveys. Employing a 1m facility, one can observe today fewer unknown objects than known MBAs and very few new NEOs. Using a 2m facility, a slightly larger number of unknown than known asteroids could be detected in the main belt. Between 0.1 and 0.8 new NEO candidates per square degree could be discovered using a 2m telescope.
► ESO/MPG and INT are successful to follow and recover faint NEAs up to V=22 mag. ► Most of 628 unknown objects are consistent with MBAs and 4–16 are NEO candidates. ► Published orbital elements are similar to calculated orbits based on small arcs. ► We give some statistics to assess the observability of the unknown MBAs and NEAs. ► We provide a basic orbital model to check any large sky survey for NEO candidates.
Three dimensional bilateral imaging is the standard for most clinical breast dynamic contrast-enhanced (DCE) MRI protocols. Because of high spatial resolution (sRes) requirement, the typical 1–2 min ...temporal resolution (tRes) afforded by a conventional full-k-space-sampling gradient echo (GRE) sequence precludes meaningful and accurate pharmacokinetic analysis of DCE time-course data. The commercially available, GRE-based, k-space undersampling and data sharing TWIST (time-resolved angiography with stochastic trajectories) sequence was used in this study to perform DCE-MRI exams on thirty one patients (with 36 suspicious breast lesions) before their biopsies. The TWIST DCE-MRI was immediately followed by a single-frame conventional GRE acquisition. Blinded from each other, three radiologist readers assessed agreements in multiple lesion morphology categories between the last set of TWIST DCE images and the conventional GRE images. Fleiss’ κ test was used to evaluate inter-reader agreement. The TWIST DCE time-course data were subjected to quantitative pharmacokinetic analyses. With a four-channel phased-array breast coil, the TWIST sequence produced DCE images with 20 s or less tRes and ~ 1.0×1.0×1.4 mm
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sRes. There were no significant differences in signal-to-noise (P = 0.45) and contrast-to-noise (P = 0.51) ratios between the TWIST and conventional GRE images. The agreements in morphology evaluations between the two image sets were excellent with the intra-reader agreement ranging from 79% for mass margin to 100% for mammographic density and the inter-reader κ value ranging from 0.54 (P < 0.0001) for lesion size to 1.00 (P < 0.0001) for background parenchymal enhancement. Quantitative analyses of the DCE time-course data provided higher breast cancer diagnostic accuracy (91% specificity at 100% sensitivity) than the current clinical practice of morphology and qualitative kinetics assessments. The TWIST sequence may be used in clinical settings to acquire high spatiotemporal resolution breast DCE-MRI images for both precise lesion morphology characterization and accurate pharmacokinetic analysis.
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