RESUMEN
Florida red tide is a natural phenomenon caused by the dinoflagellate, Karenia brevis. Karenia brevis blooms produce potent toxins (brevetoxins) that can cause neurotoxic and respiratory illness in humans and marine life. Red tides were recorded by Spanish explorers as early as the 17th century, however published red tide studies before 1940 are unavailable. Recent studies have suggested that red tide events may be becoming more frequent, intense, and longer lasting, which may be linked to modern land development and changing water quality. While the scientific record of modern red tides is relatively short, the distributions and concentrations of chemical biomarkers (e.g., brevetoxins produced by K. brevis) in coastal-marine sediments can potentially be used to study historic red tides. This study aims to quantify the concentration and vertical distribution of brevetoxins in coastal Southwest Florida (SWFL) sediment cores in order to determine if downcore brevetoxins may potentially be used to reconstruct historic red tide events. Sediment samples were radiometrically dated using 210Pb and subsamples were analyzed utilizing liquid chromatography/triple quadrupole mass spectrometry (LC-MS/MS) for brevetoxin congeners, namely, PbTx-1, PbTx-2, PbTx-3, and PbTx-5. The 210Pb-dated sediment cores represent â¼60-80 years of brevetoxin accumulation and total brevetoxin (ΣPbTx) concentrations in sediment cores varied from below detection limits to 25.3 ng g - 1 of dry sediments. Highest concentrations were found in surficial sediments (top 0-3 cm) and may indicate brevetoxin preservation from the 2017-2019 red-tide event. The down-core preservation and variability of brevetoxin indicate its potential use as a chemical biomarker to assess long-term red tide intensities and frequencies. This research is a first step towards reconstructing historic red tide events from sedimentary chemical biomarkers and may allow for future assessment of the human impacts on red tide frequency, intensity and duration.
Asunto(s)
Dinoflagelados , Plomo , Cromatografía Liquida , Dinoflagelados/química , Toxinas Marinas , Oxocinas , Espectrometría de Masas en TándemRESUMEN
The "motherhood earnings penalty" is a well-established finding in many Western countries. However, a divide between mothers and nonmothers might oversimplify reality given that the family life course has diversified over the last decades. In addition, whether family choices have consequences for women's employment and earnings in later life is not well known, particularly in a comparative perspective. Using data on 50- to 59-year-old women from the Generations and Gender Programme, the British Household Panel Survey, and SHARELIFE for 22 European countries, we derive a typology of women's family trajectories and estimate its association with women's later-life employment and earnings. Whereas family trajectory-related differences with regard to employment were relatively small, our findings reveal a clear, long-lasting family trajectory gradient in earnings. Childless women (with or without a partner) as well as single mothers had higher personal earnings than women whose family trajectories combined parenthood and partnership. Moreover, in societies in which reconciliation of work and family during midlife is less burdensome, labor market outcomes of women following different family trajectories converge. Our findings show that women's fertility and partnership behavior are inevitably interrelated and jointly influence employment and earning patterns until later in life. The results imply that promoting equal employment opportunities could have long-lasting effects on women's economic independence.