Red Tides In the Gulf of Mexico: Where, When, and Why?

Independent data from the Gulf of Mexico are used to develop and test the hypothesis that the same sequence of physical and ecological events each year allows the toxic dinoflagellate Karenia brevis to become dominant. A phosphorus-rich nutrient supply initiates phytoplankton succession, once deposition events of Saharan iron-rich dust allow Trichodesmium blooms to utilize ubiquitous dissolved nitrogen gas within otherwise nitrogen-poor sea water. They and the co-occurring K. brevis are positioned within the bottom Ekman layers, as a consequence of their similar diel vertical migration patterns on the middle shelf. Upon onshore upwelling of these near-bottom seed populations to CDOM-rich surface waters of coastal regions, light-inhibition of the small red tide of similar to 1 ug chl l(-1) of ichthytoxic K. brevis is alleviated. Thence, dead fish serve as a supplementary nutrient source, yielding large, self-shaded red tides of similar to 10 ug chl l(-1). The source of phosphorus is mainly of fossil origin off west Florida, where past nutrient additions from the eutrophied Lake Okeechobee had minimal impact. In contrast, the P-sources are of mainly anthropogenic origin off Texas, since both the nutrient loadings of Mississippi River and the spatial extent of the downstream red tides have increased over the last 100 years. During the past century and particularly within the last decade, previously cryptic Karenia spp. have caused toxic red tides in similar coastal habitats of other western boundary currents off Japan, China, New Zealand, Australia, and South Africa, downstream of the Gobi, Simpson, Great Western, and Kalahari Deserts, in a global response to both desertification and eutrophication

Customer emotions in service failure and recovery encounters

Emotions play a significant role in the workplace, and considerable attention has been given to the study of employee emotions. Customers also play a central function in organizations, but much less is known about customer emotions. This chapter reviews the growing literature on customer emotions in employee–customer interfaces with a focus on service failure and recovery encounters, where emotions are heightened. It highlights emerging themes and key findings, addresses the measurement, modeling, and management of customer emotions, and identifies future research streams. Attention is given to emotional contagion, relationships between affective and cognitive processes, customer anger, customer rage, and individual differences

Saharan dust and phosphatic fidelity: A three-dimensional biogeochemical model of Trichodesmium as a nutrient source for red tides on the West Florida Shelf

The availability of iron within the surface waters of the broad, oligotrophic West Florida Shelf (WFS) controls periodic blooms of the pelagic marine cyanobacterium Trichodesmium. Summer delivery of Saharan dust provided adequate iron (Fe) to shift limitation of growth to the availability of phosphorus (P). Florida's rivers drain Miocene phosphorus deposits to provide the WFS with freshwater nutrient supplies at molar dissolved inorganic nitrogen/phosphate (DIN/PO 4) ratios of <6. These diazotrophs draw upon ubiquitous stocks of dissolved nitrogen gas, once stimulated by Fe-deposition within P-replete waters of the WFS. An extensive in situ data set collected between 1998 and 2001 (NEGOM/ECOHAB) provided plankton taxonomy, hydrographic, nutrient, dissolved organic matter (DOM), pigment, and optical properties on the shelf. We constructed a three-dimensional numerical model to analyze the impact of iron fertilization of the diazotroph Trichodesmium and the resultant effect upon the elemental cycles of N, P, and Fe. The coupled physical and ecological models show that the wet deposition of Fe-rich Saharan dust was necessary to stimulate enough nitrogen fixation to initialize the toxic red tide ( Karenia brevis) of ∼20 μg chl a l −1 that occurred in October 1999. The simulation suggests that the magnitude and longevity of the Trichodesmium population, and therefore this source of ‘new’ nitrogen, was controlled by both phosphorus and iron availability

Sedation in digestive endoscopy: The Athens international position statements

Aliment Pharmacol Ther 2010; 32: 425-442 SummaryBackground Guidelines and practice standards for sedation in endoscopy have been developed by various national professional societies. No attempt has been made to assess consensus among internationally recognized experts in this field. Aim To identify areas of consensus and dissent among international experts on a broad range of issues pertaining to the practice of sedation in digestive endoscopy. Methods Thirty-two position statements were reviewed during a 1-day meeting. Thirty-two individuals from 12 countries and four continents, representing the fields of gastroenterology, anaesthesiology and medical jurisprudence heard evidence-based presentations on each statement. Level of agreement among the experts for each statement was determined by an open poll. Results The principle recommendations included the following: (i) sedation improves patient tolerance and compliance for endoscopy, (ii) whenever possible, patients undergoing endoscopy should be offered the option of having the procedure either with or without sedation, (iii) monitoring of vital signs as well as the levels of consciousness and paindiscomfort should be performed routinely during endoscopy, and (iv) endoscopists and nurses with appropriate training can safely and effectively administer propofol to low-risk patients undergoing endoscopic procedures. Conclusions While the standards of practice vary from country to country, there was broad agreement among participants regarding most issues pertaining to sedation during endoscopy. © 2010 Blackwell Publishing Ltd

Sedation in digestive endoscopy: The Athens international position statements

Aliment Pharmacol Ther 2010; 32: 425-442 SummaryBackground Guidelines and practice standards for sedation in endoscopy have been developed by various national professional societies. No attempt has been made to assess consensus among internationally recognized experts in this field. Aim To identify areas of consensus and dissent among international experts on a broad range of issues pertaining to the practice of sedation in digestive endoscopy. Methods Thirty-two position statements were reviewed during a 1-day meeting. Thirty-two individuals from 12 countries and four continents, representing the fields of gastroenterology, anaesthesiology and medical jurisprudence heard evidence-based presentations on each statement. Level of agreement among the experts for each statement was determined by an open poll. Results The principle recommendations included the following: (i) sedation improves patient tolerance and compliance for endoscopy, (ii) whenever possible, patients undergoing endoscopy should be offered the option of having the procedure either with or without sedation, (iii) monitoring of vital signs as well as the levels of consciousness and paindiscomfort should be performed routinely during endoscopy, and (iv) endoscopists and nurses with appropriate training can safely and effectively administer propofol to low-risk patients undergoing endoscopic procedures. Conclusions While the standards of practice vary from country to country, there was broad agreement among participants regarding most issues pertaining to sedation during endoscopy. © 2010 Blackwell Publishing Ltd.SCOPUS: ar.jFLWINinfo:eu-repo/semantics/publishe

Red Tides in the Gulf of Mexico: Where, When, and Why?

Independent data from the Gulf of Mexico are used to develop and test the hypothesis that the same sequence of physical and ecological events each year allows the toxic dinoflagellate Karenia brevis to become dominant. A phosphorus‐rich nutrient supply initiates phytoplankton succession, once deposition events of Saharan iron‐rich dust allow Trichodesmium blooms to utilize ubiquitous dissolved nitrogen gas within otherwise nitrogen‐poor sea water. They and the co‐occurring K. brevis are positioned within the bottom Ekman layers, as a consequence of their similar diel vertical migration patterns on the middle shelf. Upon onshore upwelling of these near‐bottom seed populations to CDOM‐rich surface waters of coastal regions, light‐inhibition of the small red tide of ∼1 ug chl l−1 of ichthytoxic K. brevis is alleviated. Thence, dead fish serve as a supplementary nutrient source, yielding large, self‐shaded red tides of ∼10 ug chl l−1.The source of phosphorus is mainly of fossil origin off west Florida, where past nutrient additions from the eutrophied Lake Okeechobee had minimal impact. In contrast, the P‐sources are of mainly anthropogenic origin off Texas, since both the nutrient loadings of Mississippi River and the spatial extent of the downstream red tides have increased over the last 100 years. During the past century and particularly within the last decade, previously cryptic Karenia spp. have caused toxic red tides in similar coastal habitats of other western boundary currents off Japan, China, New Zealand, Australia, and South Africa, downstream of the Gobi, Simpson, Great Western, and Kalahari Deserts, in a global response to both desertification and eutrophication