27 research outputs found

    An operational satellite scatterometer for wind vector measurements over the ocean

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    Performance requirements and design characteristics of a microwave scatterometer wind sensor for measuring surface winds over the oceans on a global basis are described. Scatterometer specifications are developed from user requirements of wind vector measurement range and accuracy, swath width, resolution cell size and measurement grid spacing. A detailed analysis is performed for a baseline fan-beam scatterometer design, and its performance capabilities for meeting the SeaSat-A user requirements. Various modes of operation are discussed which will allow the resolution of questions concerning the effects of sea state on the scatterometer wind sensing ability and to verify design boundaries of the instrument

    Obliterated cavum septi pellucidi: Clinical significance and role of fetal magnetic resonance

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    Introduction: The objective of this study was to describe a cohort of fetuses with an ultrasound prenatal diagnosis of obliterated cavum septi pellucidi (oCSP) with the aim to explore the rate of associated malformations, the progression during pregnancy and the role of fetal magnetic resonance imaging (MRI).Material and methods: This was a retrospective multicenter international study of fetuses diagnosed with oCSP in the second trimester with available fetal MRI and subsequent ultrasound and/or fetal MRI follow-up in the third trimester. Where available, postnatal data were collected to obtain information on neurodevelopment.Results: We identified 45 fetuses with oCSP at 20.5 weeks (interquartile range 20.1-21.1). oCSP was apparently isolated at ultrasound in 89% (40/45) and fetal MRI found additional findings in 5% (2/40) of cases, including polymicrogyria and microencephaly. In the remaining 38 fetuses, fetal MRI found a variable amount of fluid in CSP in 74% (28/38) and no fluid in 26% (10/38). Ultrasound follow-up at or after 30 weeks confirmed the diagnosis of oCSP in 32% (12/38) while fluid was visible in 68% (26/38). At follow-up MRI, performed in eight pregnancies, there were periventricular cysts and delayed sulcation with persistent oCSP in one case. Among the remaining cases with normal follow-up ultrasound and fetal MRI findings, the postnatal outcome was normal in 89% of cases (33/37) and abnormal in 11% (4/37): two with isolated speech delay, and two with neurodevelopmental delay secondary to postnatal diagnosis of Noonan syndrome at 5 years in one case and microcephaly with delayed cortical maturation at 5 months in the other.Conclusions: Apparently isolated oCSP at mid-pregnancy is a transient finding with the visualization of the fluid later in pregnancy in up to 70% of cases. At referral, associated defects can be found in around 11% of cases at ultrasound and 8% at fetal MRI indicating the need for a detailed evaluation by expert physicians when oCSP is suspected

    Investimenti, capitale pubblico e dotazione fisica di infrastrutture nelle regioni italiane

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    Il lavoro che qui si presenta, di carattere essenzialmente metodologico, costituisce un tentativo di argomentare una risposta alla domanda: i metodi di stima del capitale pubblico a livello territorialmente disaggregato conducono a risultati perfettamente fungibili come input di analisi regionali della crescita? In particolare, si fa qui riferimento ai due approcci di gran lunga prevalenti nella letteratura in argomento: il metodo dell’inventario permanente, che produce risultati in termini monetari, e il metodo dell’inventario comune, nella variante che contempla la produzione di dati espressi in termini fisici. Dopo avere richiamato le caratteristiche essenziali dei due metodi, il lavoro focalizza l’attenzione sulle differenze di impostazione e di risultato ad essi imputabili e ne verifica le potenzialità di utilizzazione nell’ambito di un’ottica di analisi regionale. Il riscontro di diverse quantificazioni applicate alla realtà territoriale italiana consente di dare supporto empirico alle considerazioni di ordine metodologico. La conclusione del lavoro è che i due approcci, singolarmente presi, non possono considerarsi fungibili per l’analisi regionale, mentre invece può essere utile e opportuno l’esame integrato delle loro evidenze empiriche.The infrastructure endowment (or public capital) is usually considered as an important factor contributing to the regional development. Consequently, the public capital indicators are often used in the regional analysis to quantify the role of this factor on the regional growth. The problem is: do the alternatives methods of determining public capital produce the same acceptable results in order to the regional analysis? Two methods are considered: the Perpetual Inventory Method, based on the past investments, whose results are expressed in monetary terms; the Common Inventory Method, in a particular version based on infrastructure endowment survey, whose results are expressed in physical terms. After a brief description of their essential characteristics, the paper is focused on the use possibility for two considered approaches, with particular reference to the sphere of regional growth or regional productivity. The methodological considerations on this problem are supported by an empirical check on several quantifications of public capital indicators in Italian regions. The paper conclusions underline that the indifferent use of the two approaches in the regional analysis is not correct, while it is convenient an integrated consideration of results produced by both methods

    American Meteorological Society

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    NC, and was associated with the crash of USAir Flight 101

    Simulation of the 1994 Charlotte Microburst with Look-Ahead Windshear Radar

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    this paper reports briefly on the reconstruction of the event based on numerical results generated by the Terminal Area Simulation System (TASS) as presented at the National Transportation Safety Board (NTSB) public hearing (Proctor 1994). Section-3 discusses the simulation of this event with a look-ahead windshear radar

    Airborne Doppler radar detection of low-altitude wind shear

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    Prenatal phenotype of Williams-Beuren syndrome and of the reciprocal duplication syndrome.

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    Copy losses/gains of the Williams-Beuren syndrome (WBS) region cause neurodevelopmental disorders with variable expressivity. The WBS prenatal diagnosis cannot be easily performed by ultrasound because only few phenotypic features can be assessed. Three WBS and the first reciprocal duplication prenatal cases are described with a review of the literature

    Outcomes in pregnancies with a confined placental mosaicism and implications for prenatal screening using cell-free DNA

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    Purpose: To assess the association between confined placental mosaicism (CPM) and adverse pregnancy outcome. Methods: A retrospective cohort study was carried out evaluating the outcome of pregnancies with and without CPM involving a rare autosomal trisomy (RAT) or tetraploidy. Birthweight, gestational age at delivery, fetal growth restriction (FGR), Apgar score, neonatal intensive care admission, preterm delivery, and hypertensive disorders of pregnancy were considered. Results: Overall 181 pregnancies with CPM and 757 controls were recruited. Outcome information was available for 69% of cases (n = 124) and 62% of controls (n = 468). CPM involving trisomy 16 (T16) was associated with increased incidence of birthweight <3rd centile (P = 0.007, odds ratio [OR] = 11.2, 95% confidence interval [CI] = 2.7–47.1) and preterm delivery (P = 0.029, OR = 10.2, 95% CI = 1.9–54.7). For the other RATs, an association with prenatally diagnosed FGR was not supported by birthweight data and there were no other strong associations with adverse outcomes. Conclusion: Excluding T16, the incidence of adverse pregnancy outcomes for pregnancies carrying a CPM is low. RATs can also be identified through genome-wide cell-free DNA screening. Because most of these will be attributable to CPMs, we conclude that this screening is of minimal benefit
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