Bilingual Picture–Word Studies Constrain Theories of Lexical Selection

Whether lexical selection is by competition is the subject of current debate in studies of monolingual language production. Here, I consider whether extant data from bilinguals can inform this debate. In bilinguals, theories that accept the notion of lexical selection by competition are divided between those positing competition among all lexical nodes vs. those that restrict competition to nodes in the target language only. An alternative view rejects selection by competition altogether, putting the locus of selection in a phonological output buffer, where some potential responses are easier to exclude than others. These theories make contrasting predictions about how quickly bilinguals should name pictures when non-target responses are activated. In Part 1, I establish the empirical facts for which any successful theory must account. In Part 2, I evaluate how well each theory accounts for the data. I argue that the data do not support theories that reject lexical selection by competition, and that although theories where competition for selection is restricted to the target language can be altered to fit the data, doing so would fundamentally undermine the distinctness of their position. Theories where selection is by competition throughout both target and non-target language lexicons must also be modified to account for the data, but these modifications are relatively peripheral to the theoretical impetus of the model. Throughout, I identify areas where our empirical facts are sparse, weak, or absent, and propose additional experiments that should help to further establish how lexical selection works, in both monolinguals and bilinguals

From “communication options” to global language proficiency

This work was posted as a Reader Comment in Pediatrics for the article, "Opportunities and Shared Decision-Making to Help Children Who Are Deaf to Communicate" Karl R. White, Louis Z. Cooper, Pediatrics Jun 2017, e20171287; DOI: 10.1542/peds.2017-1287

Addressing Imbalances in US Nuclear Economic and Nonproliferation Policies

Foreign civilian nuclear start-ups have an increasing number of international partners capable of supplying fuel cycle technologies. The desire to prevent the spread of dual-use enrichment and reprocessing technology by asking partner states to rely on international fuel markets is a major obstacle for US negotiating civilian nuclear trade agreements, leading to delays. US participation in emerging nuclear markets is being undercut by foreign competition, leading to decreasing economic competition and influence in international nonproliferation issues. It is therefore necessary for the US to reinvest and complete its domestic nuclear fuel cycle and modify its process for implementing civilian nuclear cooperation agreements with other states. By reducing delays in negotiations, having a larger stake in the uranium fuel supply provided to international markets, and outlining a clear waste policy, Washington will advance both its economic and nonproliferation goals

Differential jumping performance in newly metamorphosed Blanchard\u27s cricket frogs, Acris blanchardi (Anura: Hylidae), from fish- and invertebrate-dominated ponds

Organisms that adopt phenotypically plastic anti-predator strategies during larval stages may incur fitness costs later in development. These costs are typically difficult to define in many species. The difficulty of identifying ecological trade-offs may result from experimental comparisons that do not adequately mirror naturally occurring predator-prey relatioships. To examine this, we captured 61 newly metamorphosed Acris blanchardi from ponds dominated either by fish or invertebrate predators. These predators are known to induce alternate phenotypic anti-predator responses at the larval stage. We use jumping performance as a measure of post-metamorphic fitness, and compared the morphological traits and jumping ability of frogs from ponds with and without fish. Frogs from fishless ponds can jump significantly farther than frogs from fish-dominated ponds. Morphological measurements indicated that overall frog size determined differences in jumping ability, with hind-leg length primarily explaining jumping performance. Differences in hind-leg length positively correlated with overall body size, which differed between the two types of ponds and did not result from allometric growth between them. Differences in frog sizes presumably are related to differences in developmental anti-predator morphologies in larvae

Effects of urbanization on the occurrence of Batrachochytrium dendrobatidis: do urban environments provide refuge from the amphibian chytrid fungus?

Batrachochytrium dendrobatidis (Bd) is a widespread pathogenic fungus that is known to cause the disease, chytridiomycosis, which can be lethal to many amphibians. We compared occurrence rates on spring peepers (Pseudacris crucifer) in urban and forested breeding sites in eastern Texas, USA. All study sites were at approximately the same latitude and altitude, and samples were collected at the same time of year to isolate differences in Bd infection rates between habitat types. We found significant differences (p\u3c0.001) in the occurrence of Bd between habitats; with dramatically lower rates of occurrence at urban sites (19.5 %), compared to forested sites (62.9 %). The exact reason for the observed differences in the occurrence of Bd is not known, however, we suspect that warmer temperatures or lower population densities and lower species richness at urban sites all could play a role in our results. Our findings suggest that urban environments may provide a refuge for some amphibians from the pathogen

The relationship between MEG and fMRI

In recent years functional neuroimaging techniques such as fMRI, MEG, EEG and PET have provided researchers with a wealth of information on human brain function. However none of these modalities can measure directly either the neuro-electrical or neuro-chemical processes that mediate brain function. This means that metrics directly reflecting brain ‘activity’ must be inferred from other metrics (e.g. magnetic fields (MEG) or haemodynamics (fMRI)). To overcome this limitation, many studies seek to combine multiple complementary modalities and an excellent example of this is the combination of MEG (which has high temporal resolution) with fMRI (which has high spatial resolution). However, the full potential of multi-modal approaches can only be truly realised in cases where the relationship between metrics is known. In this paper, we explore the relationship between measurements made using fMRI and MEG. We describe the origins of the two signals as well as their relationship to electrophysiology. We review multiple studies that have attempted to characterise the spatial relationship between fMRI and MEG, and we also describe studies that exploit the rich information content of MEG to explore differing relationships between MEG and fMRI across neural oscillatory frequency bands. Monitoring the brain at “rest” has become of significant recent interest to the neuroimaging community and we review recent evidence comparing MEG and fMRI metrics of functional connectivity. A brief discussion of the use of magnetic resonance spectroscopy (MRS) to probe the relationship between MEG/fMRI and neurochemistry is also given. Finally, we highlight future areas of interest and offer some recommendations for the parallel use of fMRI and MEG

3D localisation of mosquitoes using digital holography over an extended field of view

Understanding mosquito interaction with long-lasting insecticidal bednets is crucial in the development of more effective intervention methods to protect humans from malaria transmission. Accurate 3D time-series imaging of mosquito-bednet interaction has not previously been possible, but has the potential to offer full kinematic analysis of mosquito flight, accurately determine in situ insecticide dosages, and examine behaviours not yet welldocumented. The work presented in this thesis relates to utilising digital holography for the accurate 3D imaging of mosquito flight using a single-view recording setup. A scalable digital methodology for single object reconstruction and localisation is developed through simulations and physical validation, and a novel focus metric, based on the zero-crossing of the reconstructed complex wavefront, is introduced. This work examines the boundaries presented by a digital hologram recording setup, and utilises the lowest imaging resolution that still yields acceptable localisation errors. Real-world problems typical in mosquito imaging, such as multi-object close proximity and occlusions, and obscured-object localisation, are examined in detail. The methods provided to overcome these obstacles largely involve the development of novel post-process software solutions. Finally, a large field of view digital holographic experiment is developed and preliminary qualitative data of livemosquito reconstruction and localisation is presented. Further work involving techniques to improved the calibration of the large field of view system are suggested to improve the quantitative analysis of the data. The result of this study is a scalable digital holographic methodology to examine mosquito-bednet interaction in 3D at a level of accuracy previously only seen in 2D planar imaging of mosquitoes in a much smaller volume, as well as introducing novel post-processing techniques for accurate localisation

Measurement of Dynamics in Strontlum Magnetc-Optical Trap

Summary form only given. The experiment consists of a Sr vapor cell magneto optical trap (MOT). Since for laser-cooled alkaline earth atoms the even isotopes have no hyperfine structure, they provide an ideal system for testing Doppler-cooling theory. (Alkali atoms are subject to sub-Doppler cooling mechanisms.) We have measured the spring constant (k) and damping coefficient (/spl alpha/) in a strontium MOT by observing the damped oscillation response of the trapped atom location to a square-wave chopped pushing beam

Suicide Screening in Primary Care: Use of an Electronic Screener to Assess Suicidality and Improve Provider Follow-Up for Adolescents

Purpose The purpose of this study was to assess the feasibility of using an existing computer decision support system to screen adolescent patients for suicidality and provide follow-up guidance to clinicians in a primary care setting. Predictors of patient endorsement of suicidality and provider documentation of follow-up were examined. Methods A prospective cohort study was conducted to examine the implementation of a CDSS that screened adolescent patients for suicidality and provided follow-up recommendations to providers. The intervention was implemented for patients aged 12–20 years in two primary care clinics in Indianapolis, Indiana. Results The sample included 2,134 adolescent patients (51% female; 60% black; mean age = 14.6 years [standard deviation = 2.1]). Just over 6% of patients screened positive for suicidality. A positive endorsement of suicidality was more common among patients who were female, depressed, and seen by an adolescent−medicine board-certified provider as opposed to general pediatric provider. Providers documented follow-up action for 83% of patients who screened positive for suicidality. Documentation of follow-up action was correlated with clinic site and Hispanic race. The majority of patients who endorsed suicidality (71%) were deemed not actively suicidal after assessment by their provider. Conclusions Incorporating adolescent suicide screening and provider follow-up guidance into an existing computer decision support system in primary care is feasible and well utilized by providers. Female gender and depressive symptoms are consistently associated with suicidality among adolescents, although not all suicidal adolescents are depressed. Universal use of a multi-item suicide screener that assesses recency might more effectively identify suicidal adolescents