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The ability to accurately measure the timing of migration is fundamental in testing hypotheses in marine ecology that deal with migration and movement of fish populations. Timing and patterns of movement in larval and juvenile fish have been estimated using life history scans of the chemical signatures encoded in their otoliths. We provide a quantitative approach to analyzing life history scan data using spectral analysis, which retrospectively measures the timing of ingress for individual fish. Saggital otoliths from juvenile Atlantic croaker (Micropogonias undulatus) were sampled using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Spectral analyses on these data estimate the timing of ingress at 68 days on average using strontium and 85 days using barium. Based on the inflection points of their nonlinear mixing curves, these data reveal entry and subsequent movement up-estuary. Moreover, we use these spectrally derived estimates to show that growth rates did not drive ingress timing for our samples. These data thus lend no support to the critical-size hypothesis in this instance. Pour verifier des hypotheses en ecologie marine touchant a la migration et aux deplacements de populations de poissons, il est essentiel de pouvoir mesurer avec exactitude le moment de la migration. Le moment et les patrons des deplacements de poissons larvaires et juveniles ont ete estimes a l'aide de sequences des signatures chimiques enregistrees dans les otolithes de poissons durant leur cycle vital. Nous presentons une approche quantitative d'analyse des donnees de sequence du cycle vital reposant sur l'analyse spectrale, qui permet de mesurer retrospectivement le moment de l'entree dans une riviere d' individus donnes. Des otolithes sagittaux de tambours bresiliens (Micropogonias undulatus) juveniles ont ete echantillonnes par spectrometrie de masse avec plasma a couplage inductif combinee a l'ablation laser (LA-ICP-MS). L'analyse spectrale de ces donnees permet d'estimer l'age a l'entree a 68 jours en moyenne avec le strontium et a 85 jours avec le baryum. A la lumiere des points d' inflexion de leurs courbes de melange non lineaires, ces donnees revelent le moment de l' entree et des deplacements subsequents vers l' amont dans l' estuaire. Nous avons en outre utilise ces estimations tirees de l'analyse spectrale pour demontrer que, pour nos echantillons, le moment de l'entree dans l'estuaire n'est pas controle par le taux de croissance. Aussi, ces donnees n'appuient pas l'hypothese de la taille critique dans le cas present. [Traduit par la Redaction], Introduction The ability to accurately measure the timing of migration is fundamental in testing hypotheses in marine ecology that deal with migration and movement of fish populations. For example, the [...]

Health disparities exist along lines of race/ethnicity and socioeconomic class in US society. I argue that we should work to eliminate these health disparities because their existence is a moral wrong that needs to be addressed. Health disparities are morally wrong because they exemplify historical injustices. Contractarian ethics, Kantian ethics, and utilitarian ethics all provide theoretical justification for viewing health disparities as a moral wrong, as do several ethical principles of primary importance in bioethics. The moral consequences of health disparities are also troubling and further support the claim that these disparities are a moral wrong. The Universal Declaration of Human Rights provides additional support that health disparities are a moral wrong, as does an analogy with the generally accepted duty to provide equal access to education. In this article, I also consider and respond to 3 objections to my thesis. (Am J Public Health. 2010;100:S47-S51. doi: 10.2105/AJPH.2009. 171181)

Abstract: The accuracy of age interpretations on a deep-sea, Arctic fish species, the Greenland halibut (Reinhardtius hippoglossoides) was tested using several age validation methods. Consistent annual growth increments were either [...]

Abstract: Radiocarbon generated by atmospheric testing of nuclear weapons (bomb radiocarbon) produced a strong signal with an abrupt onset in the 1950s, which serves as a dated marker for tracing [...]

Abstract: Large-scale transport of seawater in ocean currents may generate spatially complex population structure through the advection of life stages of marine fish species. To test this, we compared the [...]

Abstract: Although laboratory studies confirm that otoliths incorporate trace elements and stable isotopes from surrounding waters, few studies explore the relationship of otolith chemistry to water chemistry in the field [...]

Abstract--Black drum, Pogonias cromis, along the U.S. East Coast is subject to commercial and recreational harvest. However, prior to this study no modeling had been undertaken to examine the potential [...]