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Responding to Joint Attention (RJA) involves an infant's ability to follow a gaze or point by a partner. Prenatal cocaine exposure (PCE), which places a child in danger of numerous risks, has been accepted as having subtle effects on developmental outcomes such as social competence and associated socio-emotional outcomes. The current study looked at a sample of 166 children prenatally exposed to cocaine who were attending an early intervention program. The study established group and individual trajectories of responding to joint attention from 12, 15, and 18 months of age. Hierarchical modeling identified two groups, a delay group and an average group, while individual trajectories identified a linear pattern of growth of RJA. Both individual and group trajectories indicated that children with higher RJA from 12 to 18 months demonstrated better social competence at three years of age and first grade. The delay and average group showed significant differences on later social competence measures, but not problem behaviors, such that RJA, a positive behavior, may connect more closely with later positive behaviors than with behavior problems. RJA may therefore be useful in a preventative intervention targeted at enhancing positive social behaviors and as an important and simple screening tool for possible delay early in a child's life, helping to deliver early intervention services in a targeted and effective manner.

This is the first large-scale modelling study of iceberg trajectories and melt rates in the Southern Ocean. An iceberg model _ was seeded with climatological iceberg calving rates based on a calculation of the net surface accumulation from each snow catchment area on the Antarctic continent. In most areas modelled trajectories show good agreement with observed patterns of iceberg motion, though discrepancies in the Weddell Sea have highlighted problems in the ocean general circulation model output used to force the iceberg model. The Coriolis force is found to be important in keeping bergs entrained in the coastal current around Antarctica, and topographic features are important in causing bergs to depart from the coastal regions. The modelled geographic distribution of iceberg meltwater joining the ocean has been calculated, and is found in many near coastal regions to be comparable in magnitude to the excess of precipitation over evaporation (P-E). A remote sensing study of icebergs has been carried out in two locations in the Weddell Sea using SAR. This study has, for the first time, been able to calculate iceberg fluxes from satellite. The southwestwards flux of icebergs within 20 km of the coast at around 18°W, based on a one month period of observations, has been calculated at 50 to 70 Gta-1 (1Gt = 1012kg). This is 4 to 5% of the total iceberg discharge from Antarctica. The question of Antarctic mass balance is considered through comparison of modelresults and observations. Although a conclusion is not reached here, plans are presented for an iceberg observing programme and further model development which could resolve the problem

The transition from high school into college is a critical period in the life course, reflecting past history and forecasting future prospects. How this transition unfolds can influence who persists in college and who does not, as it is a time of socioemotional vulnerability as well as a foundation of the highly cumulative path through higher education. The aim of this study was to look at variation in emotional adjustment during the transition from high school into college and how relates to the match/mismatch of academic context and pathways from high school to college as well as parental support. Using data from the National Longitudinal Study of Adolescent Health (Add Health), latent growth curve and growth mixture modeling were used to estimate trajectories of emotional distress and identify basic categories of trajectories among college goers. Aspects of high school and college context and performance variables—as well as combination among them—were then used to predict the types of trajectories individual college students followed. The results revealed significant heterogeneity in how college-goers fared emotionally, with some experiencing increased depressive symptomatology and others experiences declines. Those who appeared to fare the worst emotionally during the transition to college had consistently low academic demands from high school into college and lacked support social support from their parents. / text

Commonly held opinion is that particle trajectory descriptions are incompatible with quantum mechanics. Louis de Broglie (1926) first proposed a way to include trajectories in quantum mechanics, but the idea was abandoned until David Bohm (1952) re-invented and improved the theory. Bohm interprets the particle trajectories as physically real; for example, an electron actually is a particle moving on a well defined trajectory with a position and momentum at all times. By design, Bohm's trajectories never make predictions that differ from standard quantum mechanics, and their existence cannot be experimentally verified. Three new methods to obtain Bohm's particle trajectories are presented. The methods are non-dynamical, and utilize none of Bohm's equations of motion; in fact, two of the methods have no equations for a particle's trajectory. Instead, all three methods use only the evolving probability density ρ=ψ*ψ to extract the trajectories. The first two methods rest upon probability conservation and density sampling, while the third method employs the informational or geometrical construction of centroidal Voronoi tessellations. In one-dimension all three methods are proved to be equivalent to Bohm's particle trajectories. For higher dimensional configuration spaces, the first two methods can be used in limited situations, but the last method can be applied in all cases. Typically, the resulting higher dimensional non-dynamical trajectories are also identical to Bohm. Together the three methods point to a new interpretation of Bohm's particle trajectories, namely, the Bohm trajectories are simply a kinematic portrayal of the evolution of the probability density. In addition, the new methods can be used to measure Schrödinger's wave function and Planck's constant. / text

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