Population connectivity among Dry Tortugas, Florida, and Caribbean populations of mutton snapper (Lutjanus analis), inferred from multiple microsatellite loci

Determining patterns of population connectivity is critical to the evaluation of marine reserves as recruitment sources for harvested populations. Mutton snapper (Lutjanus analis) is a good test case because the last known major spawning aggregation in U.S. waters was granted no-take status in the Tortugas South Ecological Reserve (TSER) in 2001. To evaluate the TSER population as a recruitment source, we genotyped mutton snapper from the Dry Tortugas, southeast Florida, and from three locations across the Caribbean at eight microsatellite loci. Both Fstatistics and individual-based Bayesian analyses indicated that genetic substructure was absent across the five populations. Genetic homogeneity of mutton snapper populations is consistent with its pelagic larval duration of 27 to 37 days and adult behavior of annual migrations to large spawning aggregations. Statistical power of future genetic assessments of mutton snapper population connectivity may benefit from more comprehensive geographic sampling, and perhaps from the development of less polymorphic DNA microsatellite loci. Research where alternative methods are used, such as the transgenerational marking of embryonic otoliths with barium stable isotopes, is also needed on this and other species with diverse life history characteristics to further evaluate the TSER as a recruitment source and to define corridors of population connectivity across the Caribbean and Florida

Determining the change in welfare estimates from introducing measurement error in non-linear choice models

Observed and unobserved characteristics of an individual are often used by researchers to explain choices over the provision of environmental goods. One means for identifying what is typically an unobserved characteristic, such as an attitude, is through some data reduction technique, such as factor analysis. However, the resultant variable represents the true attitude with measurement error, and hence, when included into a non-linear choice model, introduces bias in the model. There are well established methods to overcome this issue, which are seldom implemented. In an application to preferences over two water source alternatives for Perth in Western Australia, we use structural equation modeling within a discrete choice model to determine whether welfare measures are significantly impacted by ignoring measurement error in latent attitudes, and the advantage to policy makers from understanding what drives certain attitudes.contingent valuation, attitudes, structural equation modeling, recycled water, Environmental Economics and Policy, Research Methods/ Statistical Methods, Q51, Q53, C13,

Shocked H2 and Fe+ Dynamics in the Orion Bullets

Observations of H2 velocity profiles in the two most clearly defined Orion bullets are extremely difficult to reconcile with existing steady-state shock models. We have observed [FeII] 1.644um velocity profiles of selected bullets and H2 1-0 S(1) 2.122um velocity profiles for a series of positions along and across the corresponding bow-shaped shock fronts driven into the surrounding molecular cloud. Integrated [FeII] velocity profiles of the brightest bullets are consistent with theoretical bow shock predictions. However, observations of broad, singly-peaked H2 1-0 S(1) profiles at a range of positions within the most clearly resolved bullet wakes are not consistent with molecular shock modelling. A uniform, collisionally broadened background component which pervades the region in both tracers is inconsistent with fluorescence due to the ionizing radiation of the Trapezium stars alone.Comment: 20 pages including 18 figures, published in MNRA

Population assessment of the vermilion snapper, Rhomboplites aurorubens, from the Southeastern United States

Changes in the age structure and population size of vermilion snapper, Rhornboplites aurorubens, from North Carolina through the Florida Keys were examined using records of landings and size frequencies of fish from commercial, recreational, and headboat fisheries from 1986-1996. Population size in numbers at age was estimated for each year by applying separable virtual population analysis (SVPA) to the landings in numbers at age. SVPA was used to estimate annual, age-specific fishing mortality (F) for four levels of natural mortality (M = 0.20, 0.25, 0.30, and 0.35). Although landings of vermilion snapper for the three fisheries have declined, minimum fish size regulations have resulted in an increase in the mean size of fish landed. Age at entry and age at full recruitment were age-1 andage-3 fDr 1986-1991, compared with age-1 and age-4, respectively, for 1992-1996. Levels of mortality from fishing (F) ranged from 0.38 - 0.61 for the entire period. Current spawning potential ratio (SPR) is 21% or 27% depending on the natural mortality estimate. SPR could be raised to 30% or 40% with a reduction in F, or by increasing the age at entry to the fisheries. The latter could be enhanced now if fishermen, particularly recreational, comply with minimum size regulations. However, released fish mortality, modeled in the assessment at 27%, will continue to make the achievement of 30% and 40% SPR more difficult. (PDF contains 63 pages

Creating Options: Forming a Marshallese Community in Orange County, California

Founded by individuals pursuing higher education in the United States, the Marshallese community in Orange County today also represents family and national interests in access to business opportunities, employment, education, medical services, and other goals. This community has become an “official” Marshallese overseas community, site of the first Marshallese consulate in the mainland United States, and a link between overseas Marshallese and the home islands. Individuals and family units traverse networks of inter-linked households, highlighting processes of Islanders’ investments, including at least a short-term reversal of theoretically expected remittance flows. We explore the process of community formation, and compare rural and urban sites in the Marshall Islands to call attention to the community’s place in a system of geographically dispersed locations within the global political economy

Biased estimates in discrete choice models: the appropriate inclusion of psychometric data into the valuation of recycled wastewater

The introduction of measurement bias in parameter estimates into non-linear discrete choice models, as a result of using factor analysis, was identified by Train et al. (1987). They found that the inclusion of factor scores, used to represent relationships amongst like variables, into a subsequent discrete choice models introduced measurement bias as the measurement error associated with each factor score is excluded. This is an issue for non-market valuation given the increase in popularity of including psychometric data, such as primitive beliefs, attitudes and motivations, in willingness to pay estimates. This study explores the relationship between willingness to pay and primitive beliefs through a case study eliciting Perth community values for drinking recycled wastewater. The standard discrete decision model, with sequential inclusion of factor scores, is compared to an equivalent discrete decision model, which corrects for the measurement bias by simultaneously estimating the underlying latent variables using a measurement model. Previous research has focused on the issue of biased parameters. Here we also consider the implications for willingness to pay estimates.discrete choice models, attitudes, factor analysis, measurement models, recycled wastewater,

Models of Speech Processing

One of the fundamental questions about language is how listeners map the acoustic signal onto syllables, words, and sentences, resulting in understanding of speech. For normal listeners, this mapping is so effortless that one rarely stops to consider just how it takes place. However, studies of speech have shown that this acoustic signal contains a great deal of underlying complexity. A number of competing models seek to explain how these intricate processes work. Such models have often narrowed the problem to mapping the speech signal onto isolated words, setting aside the complexity of segmenting continuous speech. Continuous speech has presented a significant challenge for many models because of the high variability of the signal and the difficulties involved in resolving the signal into individual words. The importance of understanding speech becomes particularly apparent when neurological disease affects this seemingly basic ability. Lesion studies have explored impairments of speech sound processing to determine whether deficits occur in perceptual analysis of acoustic-phonetic information or in stored abstract phonological representations (e.g., Basso, Casati,& Vignolo, 1977; Blumstein, Cooper, Zurif,& Caramazza, 1977). Furthermore, researchers have attempted to determine in what ways underlying phonological/phonetic impairments may contribute to auditory comprehension deficits (Blumstein, Baker, & Goodglass, 1977). In this chapter, we discuss several psycholinguistic models of word recognition (the process of mapping the speech signal onto the lexicon), and outline how components of such models might correspond to the functional anatomy of the brain. We will also relate evidence from brain lesion and brain activation studies to components of such models. We then present some approaches that deal with speech perception more generally, and touch on a few current topics of debate.National Institutes of Health under grant NIH DC R01–3378 to the senior author (SLS

Infrared images of reflection nebulae and Orion's bar: Fluorescent molecular hydrogen and the 3.3 micron feature

Images were obtained of the (fluorescent) molecular hydrogen 1-0 S(1) line, and of the 3.3 micron emission feature, in Orion's Bar and three reflection nebulae. The emission from these species appears to come from the same spatial locations in all sources observed. This suggests that the 3.3 micron feature is excited by the same energetic UV-photons which cause the molecular hydrogen to fluoresce