Children's acquisition of science terms: does fast mapping work?

About the book: This proceedings contains 99 selected papers from the 8th Conference of the International Association for the Study of Child Language (IASCL) held in Donostia-San Sebastián in the Spanish Basque Country in July 1999. The proceedings includes the plenary addresses by Jean-Paul Bronckart, Brian MacWhinney, and Miquel Siguan. The other 96 papers are organized into sections on bilingualism, discourse, phonology, language disorders, lexicon, morphology, syntax, and signed languages. Several of these sections include symposia with introductions as well as individual papers

Observations and Scaling of Tidal Mass Transport Across the Lower Ganges-Brahmaputra Delta Plain: Implications for Delta Management and Sustainability

The landscape of southwest Bangladesh, a region constructed primarily by fluvial processes associated with the Ganges River and Brahmaputra River, is now maintained almost exclusively by tidal processes as the fluvial system has migrated east and eliminated the most direct fluvial input. In natural areas such as the Sundarbans National Forest, year-round inundation during spring high tides delivers sufficient sediment that enables vertical accretion to keep pace with relative sea-level rise. However, recent human modification of the landscape in the form of embankment construction has terminated this pathway of sediment delivery for much of the region, resulting in a startling elevation imbalance, with inhabited areas often sitting \u3e1 m below mean high water. Restoring this landscape, or preventing land loss in the natural system, requires an understanding of how rates of water and sediment flux vary across timescales ranging from hours to months. In this study, we combine time series observations of water level, salinity, and suspended sediment concentration with ship-based measurements of large tidal-channel hydrodynamics and sediment transport. To capture the greatest possible range of variability, cross-channel transects designed to encompass a 12.4 h tidal cycle were performed in both dry and wet seasons during spring and neap tides. Regional suspended sediment concentration begins to increase in August, coincident with a decrease in local salinity, indicating the arrival of the sediment-laden, freshwater plume of the combined Ganges–Brahmaputra–Meghna rivers. We observe profound seasonality in sediment transport, despite comparatively modest seasonal variability in the magnitude of water discharge. These observations emphasize the importance of seasonal sediment delivery from the main-stem rivers to this remote tidal region. On tidal timescales, spring tides transport an order of magnitude more sediment than neap tides in both the wet and dry seasons. In aggregate, sediment transport is flood oriented, likely as a result of tidal pumping. Finally, we note that rates of sediment and water discharge in the tidal channels are of the same scale as the annually averaged values for the Ganges and Brahmaputra rivers. These observations provide context for examining the relative importance of fluvial and tidal processes in what has been defined as a quintessentially tidally influenced delta in the classification scheme of Galloway (1975). These data also inform critical questions regarding the timing and magnitude of sediment delivery to the region, which are especially important in predicting and preparing for responses of the natural system to ongoing environmental change

Increasing Retention in STEM: Results from a STEM Talent Expansion Program at the University of Memphis

MemphiSTEP is a five-year STEM Talent Expansion Program at the University of Memphis sponsored by the National Science Foundation. The project focuses on retention and persistence to graduation to increase the number of STEM majors and graduates. The project includes a range of student retention programs, including a Summer Mathematics Bridge Bootcamp, Networking Program, Research Award Program, Travel Award program and STEM Learning Communities; Results from the first four years of the project suggest that MemphiSTEP is making a positive impact on student retention and performance in STEM fields. Our data indicate that even after controlling for gender, race, and prior performance, STEM students taking part in MemphiSTEP activities are retained at higher rates and perform better than University of Memphis STEM students who have not participated in MemphiSTEP activities

Implementing and Evaluating a Gaussian Mixture Framework for Identifying Gene Function from TnSeq Data

The rapid acceleration of microbial genome sequencing increases opportunities to understand bacterial gene function. Unfortunately, only a small proportion of genes have been studied. Recently, TnSeq has been proposed as a cost-effective, highly reliable approach to predict gene functions as a response to changes in a cell\u27s fitness before-after genomic changes. However, major questions remain about how to best determine whether an observed quantitative change in fitness represents a meaningful change. To address the limitation, we develop a Gaussian mixture model framework for classifying gene function from TnSeq experiments. In order to implement the mixture model, we present the Expectation-Maximization algorithm and a hierarchical Bayesian model sampled using Stan\u27s Hamiltonian Monte-Carlo sampler. We compare these implementations against the frequentist method used in current TnSeq literature. From simulations and real data produced by E.coli TnSeq experiments, we show that the Bayesian implementation of the Gaussian mixture framework provides the most consistent classification results

Severe combined hyperlipidaemia and retinal lipid infiltration in a patient with Type 2 diabetes mellitus

Severe combined hyperlipidaemia has occasionally been associated with infiltration of tissues in addition to arteries and the skin. We report a woman with Type 2 diabetes mellitus (DM) and severe combined hyperlipidaemia who developed retinal lipid infiltration, resulting in blindness. A 61-year-old woman with a 15-year history of Type 2 DM was admitted following a two-week history of progressive visual loss. Examination identified lipid infiltration into the retina. Phenotypically she had severe combined hyperlipidaemia with elevated IDL cholesterol and a broad beta band on lipoprotein electrophoresis, raising the possibility of familial dysbetalipoproteinaemia. However, gene sequencing analysis indicated that the patient was homozygous for the E3/E3 allele of the ApoE gene with no mutations detected in either the coding region or intron-exon boundaries. Her lipid profile improved following dietary therapy and gemfibrozil treatment, but this had little effect on either her fundal appearances or her visual acuity. Type 2 DM plays a vital role both in allowing expression of severe combined hyperlipoproteinaemia, in addition to serving as a risk factor for complications such as tissue infiltration

Evaluating the Efficacy of Point-of-Use Water Filtration Units in Fiji

Background: To develop and evaluate a strategy for reducing the prevalence and impact of waterborne disease, a water quality intervention was developed for Fiji by Give Clean Water, Inc. in partnership with the Fiji Ministry of Health. Residents were provided and trained on how to use a Sawyer® PointONE™ filter, while also being taught proper handwashing techniques. At the time of the filter installation, all households were surveyed inquiring about the prior 2- to 4-week period. Households were measured a second time between 19 and 225 days later (mean = 66 days). Results: To date, five economic and health outcomes have been tracked on 503 households to evaluate the efficacy of the intervention. When comparing baseline to follow-up among the 503 households, the 2-week diarrhea prevalence decreased in households from 17.5% at baseline to 1.8% at follow-up. Also, the 2-week prevalence of severe diarrhea decreased per household from 9.7% at baseline to 0.6% at follow-up. Finally, monthly diarrhea-related medical costs reduced by an average of Fijian (FJ) $3.54 per person, and monthly water expenses reduced by FJ$0.63 per person. All estimated values are obtained from general linear and logistic mixed-effect models, which adjusted for location, season, time to follow-up, household size, water source, and respondent changing. Changes in economic and health outcomes from installation to follow-up were statistically significant (p \u3c 0.05) in all cases, in both unadjusted and adjusted models. Conclusions: The installation of water filters shows promise for the reduction of diarrhea prevalence in Fiji, as well as the reduction of diarrhea-related medical costs and water expenses. Future work entails evaluation in other countries and contexts, long-term health monitoring, and comparison to alternative water quality interventions

The Rise and Fall of Galaxy Activity in Dark Matter Haloes

We use a SDSS galaxy group catalogue to study the dependence of galaxy activity on stellar mass, halo mass, and group hierarchy (centrals vs. satellites). We split our galaxy sample in star-forming galaxies, galaxies with optical AGN activity and radio sources. We find a smooth transition in halo mass as the activity of central galaxies changes from star formation to optical AGN activity to radio emission. Star-forming centrals preferentially reside in haloes with M<10^{12} Msun, central galaxies with optical-AGN activity typically inhabit haloes with M \sim 10^{13} Msun, and centrals emitting in the radio mainly reside in haloes more massive than 10^{14} Msun. Although this seems to suggest that the environment (halo mass) determines the type of activity of its central galaxy, we find a similar trend with stellar mass: central star formers typically have stellar masses below 10^{10} Msun, while optical-AGN hosts and central radio sources have characteristic stellar masses of 10^{10.8} Msun and 10^{11.6} Msun, respectively. Since more massive haloes typically host more massive centrals, it is unclear whether the activity of a central galaxy is causally connected to its stellar mass or to its halo mass. In general, satellite galaxies have their activity suppressed wrt central galaxies of the same stellar mass. At fixed stellar mass, we find that the activity of satellite galaxies depends only weakly on halo mass. In fact, for satellite galaxies the dependence of galaxy activity on halo mass is more than four times weaker than the dependence on stellar mass. As we discuss, all these results are consistent with a picture in which low mass haloes accrete cold gas, while massive haloes have coronae of hot gas that promote radio activity of their central galaxies. [Abridged]Comment: 17 pages, 13 figures. Submitted for publication in MNRA