Time transfer between the Goddard Optical Research Facility and the U.S. Naval Observatory using 100 picosecond laser pulses

A horizontal two-way time comparison link in air between the University of Maryland laser ranging and time transfer equipment at the Goddard Optical Research Facility (GORF) 1.2 m telescope and the Time Services Division of the U.S. Naval Observatory (USNO) was established. Flat mirrors of 25 cm and 30 cm diameter respectively were placed on top of the Washington Cathedral and on a water tower at the Beltsville Agricultural Research Center. Two optical corner reflectors at the USNO reflect the laser pulses back to the GORF. Light pulses of 100 ps duration and an energy of several hundred microjoules are sent at the rate of 10 pulses per second. The detection at the USNO is by means of an RCA C30902E avalanche photodiode and the timing is accomplished by an HP 5370A computing counter and an HP 1000 computer with respect to a 10 pps pulse train from the Master Clock

Ultrasound of acquired posterior fossa abnormalities in the newborn

Neonatal brain sonography is part of routine clinical practice in neonatal intensive care units, but ultrasound imaging of the posterior fossa has gained increasing attention since the burden of perinatal acquired posterior fossa abnormalities and their impact on motor and cognitive neurodevelopmental outcome have been recognized. Although magnetic resonance imaging (MRI) is often superior, posterior fossa abnormalities can be suspected or detected by optimized cranial ultrasound (CUS) scans, which allow an early and bed-side diagnosis and monitoring through sequential scans over a long period of time. Different ultrasound appearances and injury patterns of posterior fossa abnormalities are described according to gestational age at birth and characteristics of the pathogenetic insult. The aim of this review article is to describe options to improve posterior fossa sequential CUS image quality, including the use of supplemental acoustic windows, to show standard views and normal ultrasound anatomy of the posterior fossa, and to describe the ultrasound characteristics of acquired posterior fossa lesions in preterm and term infants with effect on long-term outcome. The limitations and pitfalls of CUS and the role of MRI are discussed

Sex Differences in the Chronology of Deciduous Tooth Emergence in White and Black Children

Tooth emergence in 376 black and white children between the ages of 4 and 33 months was studied in southeastern Michigan. The results indicate a trend in both groups for boys to show earlier tooth emergence in early stages and for girls to show earlier tooth emergence in later stages of deciduous tooth emergence.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66947/2/10.1177_00220345740530024001.pd

State-of-the-art neonatal cerebral ultrasound: technique and reporting

In the past three decades, cerebral ultrasound (CUS) has become a trusted technique to study the neonatal brain. It is a relatively cheap, non-invasive, bedside neuroimaging method available in nearly every hospital. Traditionally, CUS was used to detect major abnormalities, such as intraventricular hemorrhage (IVH), periventricular hemorrhagic infarction, post-hemorrhagic ventricular dilatation, and (cystic) periventricular leukomalacia (cPVL). The use of different acoustic windows, such as the mastoid and posterior fontanel, and ongoing technological developments, allows for recognizing other lesion patterns (e.g., cerebellar hemorrhage, perforator stroke, developmental venous anomaly). The CUS technique is still being improved with the use of higher transducer frequencies (7.5-18\u2009MHz), 3D applications, advances in vascular imaging (e.g. ultrafast plane wave imaging), and improved B-mode image processing. Nevertheless, the helpfulness of CUS still highly depends on observer skills, knowledge, and experience. In this special article, we discuss how to perform a dedicated state-of-the-art neonatal CUS, and we provide suggestions for structured reporting and quality assessment

Preterm white matter injury : ultrasound diagnosis and classification

White matter injury (WMI) is the most frequent form of preterm brain injury. Cranial ultrasound (CUS) remains the preferred modality for initial and sequential neuroimaging in preterm infants, and is reliable for the diagnosis of cystic periventricular leukomalacia. Although magnetic resonance imaging is superior to CUS in detecting the diffuse and more subtle forms of WMI that prevail in very premature infants surviving nowadays, recent improvement in the quality of neonatal CUS imaging has broadened the spectrum of preterm white matter abnormalities that can be detected with this technique. We propose a structured CUS assessment of WMI of prematurity that seeks to account for both cystic and non-cystic changes, as well as signs of white matter loss and impaired brain growth and maturation, at or near term equivalent age. This novel assessment system aims to improve disease description in both routine clinical practice and clinical research. Whether this systematic assessment will improve prediction of outcome in preterm infants with WMI still needs to be evaluated in prospective studies

Classroom-evaluated school performance at nine years of age after very preterm birth

Objective: To determine classroom-evaluated school performance nine years after preterm birth, predicted by perinatal risk factors and neonatal brain abnormalities.Study design: Children were recruited from a consecutive cohort of 113 preterm infants (<32 weeks’ gestation), participating in a longitudinal prospective study, investigating brain injury and neurodevelopmental outcome. Data on perinatal risk factors, presence of brain injury at term-equivalent age, and maternal education were collected. Information on school performance included enrollment in special (primary) education, grade repetition and school results from the nationwide standardized Dutch Pupil Monitoring System regarding reading comprehension, spelling, and mathematics.Results: Information on school enrollment was available for 87 children (77%), of whom 7 (8%) were in special primary education and 19 (22%) repeated a grade. This was significantly higher compared to national rates (p ≤ .05). Results on school performance were available for 74 children (65%) and showed clearly below average scores in reading comprehension (p = .006), spelling (p = .014) and mathematics (p <.001). Univariate analysis showed that lower performance in reading comprehension was predicted by male sex and low maternal education; spelling by male sex; and mathematics by BPD, white matter injury and maternal education. In a multivariate model, male sex and maternal education were predictive for reading comprehension and white matter injury for mathematics. Conclusion: Preterm born children more often need special primary education and have higher grade repeat rates. They perform poorer on reading comprehension, spelling and mathematics. Regular follow-up remains important for preterm born children during school age. New methods for child psychiatric diagnosis and treatment outcome evaluatio

Longitudinal follow-up of children born preterm: neurodevelopment from 2 to 10 years of age

Objective: To investigate the rate and stability of impairments in children born preterm by assessing (1) early and school-age outcome in four developmental domains and (2) individual changes in outcome at both timepoints. Design: Prospective, longitudinal cohort study in children born in 2006-2007, <32 weeks' gestation. Follow-up at 2 and 10 years of age included standardized neurological, motor, cognitive and behavioral assessments. Children were categorized as having no, mild or moderate-severe impairment in these four domains. A composite impairment score was composed and the number of domains with impairments counted. For each child, individual outcomes at both timepoints were compared. Results: Follow-up at both time-points was available in 71/113(63%) children. At group level, there were no significant changes in the severity of impairments per domain. However, at individual level, there were less children with a mild abnormal composite score at 10 years of age (44 vs. 20%; p = 0.006), and more with a moderate-severe abnormal composite score (12 vs. 35%; p = 0.001). Especially children with normal/mild outcome at 2 years were likely to shift to other outcome categories over time. Conclusions: Children with early severe impairment are likely experiencing impairments later on, but early normal/mild abnormal outcomes should be interpreted with care, considering the large individual shifts over time. Long-term follow-up in all children born very preterm should therefore be continued to at least school-age.Developmen

Associations between neonatal magnetic resonance imaging and short- and long-term neurodevelopmental outcomes in a longitudinal cohort of very preterm children

Objective To assess associations between neonatal brain injury assessed by magnetic resonance imaging and cognitive, motor, and behavioral outcomes at 2 and 10 years of age, in a longitudinal cohort of children born very preterm.Study design There were 112 children born at <32 weeks of gestation who participated in a longitudinal prospective study on brain injury and neurodevelopmental outcome. Using the Kidokoro score, neonatal brain injury and altered brain growth in white matter, cortical and deep gray matter, and the cerebellum were assessed. Cognitive, motor, and behavioral outcomes were assessed during follow-up visits at both 2 (corrected) and 10 years of age.Results After adjusting for perinatal factors and level of maternal education, the global brain abnormality score was associated with cognition (B = -1.306; P = .005), motor skills (B = -3.176; P < .001), and behavior (B = 0.666; P = .005) at 2 years of age, but was not associated with cognition at 10 years of age. In the subgroup of children with a moderate-severe global brain abnormality score, magnetic resonance imaging was independently associated with cognitive impairment at 10 years of age. For children with milder forms of brain injury, only birth weight and level of maternal education were associated with cognitive outcomes.Conclusions Neonatal brain injury, assessed by a standardized scoring system, was associated with short-term neurodevelopmental outcomes, but only with motor skills and behavior in childhood. Environmental factors, such as level of maternal education, become more important for cognitive development as children grow older, especially for children with relatively mild neonatal brain injury.Developmen

Economic Feasibility and Market Readiness of Solar Technologies. Draft Final Report. Volume I.

Systems descriptions, costs, technical and market readiness assessments are reported for ten solar technologies: solar heating and cooling of buildings (SHACOB), passive, agricultural and industrial process heat (A/IPH), biomass, ocean thermal (OTEC), wind (WECS), solar thermal electric, photovoltaics, satellite power station (SPS), and solar total energy systems (STES). Study objectives, scope, and methods. are presented. of Joint Task The cost and market analyses portion 5213/6103 will be used to make commercialization assessments in the conclusions of. the final report