12 research outputs found
Predicting Harmful Algal Blooms: A Case Study with Dinophysis ovum in the Gulf of Mexico
Blooms of Dinophysis ovum and Mesodinium spp. have been observed in the Gulf of Mexico since 2007 using Imaging FlowCytobot technology. Bloom dynamics of these two organisms in conjunction with ancillary environmental data for a 5 year period were analyzed to identify the conditions necessary for bloom initiation or presence with the goal of predicting future blooms of Dinophysis. I determined that a narrow range of temperature and salinity may be necessary for bloom initiation of Dinophysis and Mesodinium in the Gulf of Mexico. Using time series analysis, I observed a positive time-lagged correlation between the two organisms in each year when both were present, which indicates that presence of Mesodinium can be used as a leading indicator for a Dinophysis bloom. Analysis of images over the time series also revealed a wide range in the size of Mesodinium cells, which suggests that species other than M. rubrum may be present in the Gulf of Mexico. Finally, based on the occurrence of a Dinophysis bloom preceded by low abundances of Mesodinium, I believe that Dinophysis is able to utilize ciliates other than M. rubrum as prey. My observations indicate that these factors can affect initiation, presence or abundance of Dinophysis and thus may help in the prediction of future blooms
Climate variability and Dinophysis acuta blooms in an upwelling system
Dinophysis acuta is a frequent seasonal lipophilic toxin producer in European Atlantic coastal waters associated with thermal stratification. In the Galician Rías, populations of D. acuta with their epicentre located off Aveiro (northern Portugal), typically co-occur with and follow those of Dinophysis acuminata during the upwelling transition (early autumn) as a result of longshore transport. During hotter than average summers, D. acuta blooms also occur in August in the Rías, when they replace D. acuminata. Here we examined a 30-year (1985–2014) time series of D. acuta from samples collected by the same method in the Galician Rías. Our main objective was to identify patterns of distribution and their relation with climate variability, and to explain the exceptional summer blooms of D. acuta in 1989–1990. A dome-shaped relationship was found between summer upwelling intensity and D. acuta blooms; cell maxima were associated with conditions where the balance between upwelling intensity and heating, leading to deepened thermoclines, combined with tidal phase (3 days after neap tides) created windows of opportunity for this species. The application of a generalized additive model based on biological (D. acuta inoculum) and environmental predictors (Cumulative June–August upwelling CUIJJA, average June–August SSTJJA and tidal range) explained more than 70% of the deviance for the exceptional summer blooms of D. acuta, through a combination of moderate (35,000–50,000 m3 s−1 km−1) summer upwelling (CUIJJA), thermal stratification (SSTJJA > 17 °C) and moderate tidal range (∼2.5 m), provided D. acuta cells (inoculum) were present in July. There was no evidence of increasing trends in D. acuta bloom frequency/intensity nor a clear relationship with NAO or other long-term climatic cycles. Instead, the exceptional summer blooms of 1989–1990 appeared linked to extreme hydroclimatic anomalies (high positive anomalies in SST and NAO index), which affected most of the European Atlantic coast.Versión del editor3,083
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The Relationship between Intelligence Test Results and Achievement in Latin-American Children
The purpose of this study is to investigate the accuracy of intelligence tests when they have been prepared for Anglo-American children and applied to Latin-American children and to find the type of test that is best for Latin-American children
THE ARTFUL DETECTIVES OF DASHIELL HAMMETT, RAYMOND CHANDLER, AND ROSS MACDONALD: THE USES OF LITERARY STYLE
All the world loves a mystery, and much of the reading public has always loved detective stories. That devotion has several sources: the challenge of the puzzle, the charm of the characters, and the telling of the tale. One attraction in detective fiction lies in the conflict between chaotic events and characters\u27 attempts to order and explain these events correctly. The telling aspect of detective works is another significant, but less-discussed, source of interest in this resilient genre. Dashiell Hammett\u27s novels all present expansions of the conventions of the detective novel with his presentation of certain recurring themes and motifs; the novels also depict some of the complexities of human personality and action through the presentation of the complicated feelings and motivations of Hammett\u27s characters by means of his sensitive use of two narrative stances and his studied and evocative use of ambiguity and irony in the language and structure of the novels. Raymond Chandler refined certain characteristics of the hard-boiled detective novel to provide a second-level literary interest. His development of a complex, less rational pattern of mystery and method of resolution, his consistent use of an emotionally and psychologically complex narrator, his experiments with figurative language and literary allusions, and his attention to and development of significant literary themes that reflect problems common to the human condition are all features used to expand and change our expectations of what a detective novel could and should contain. Ross Macdonald\u27s consistent attention to the human dimensions of the mystery is the distinctive feature of his works. The Archer novels describe characters caught up in the interplay of individual, familial, and societal demands, and in the works we see the causes, effects, and consequences of such tensions. His attention to themes, character, and setting and a flexible and expressive style combine to make his works fine examples of complicated detective novels that function equally well on the mystery and literary levels. The novels of writers like Robert B. Parker and James Crumley illustrate the continuing vitality of the literary hard-boiled tradition begun by Hammett and Chandler and extended by Macdonald
Do we need photonic-based instruments to characterize multiscale processes in marine environments?
Ocean Optics XXI, 8-12 October 2012, Glasgow, Scotland, United KingdomTime- or space-series analysis is the one of the essential methods for marine science to understand the dynamics of ocean processes. It not only helps to identify the phenomenon represented by sequences of observations, but also helps to forecast events by feeding models. One of the first questions to address regarding the sampling strategy to obtain a time/space data series is the sampling frequency and the number of samples to measure. In many cases the answers to these questions are based mainly on logistic or operational restrictions (maximum number of samples that it is possible to process, instrumental capabilities, etc.). However, it is important to take into account the principles of Information Theory in order to avoid potential artefacts derived from improper sampling design. Furthermore, in those cases where the processes are not stationary (a common situation in marine environments) the sampling frequency and the number of samples play an important role in determining the time-frequency resolution required to characterize their dynamical properties. To address these problems of scale, two data sets are used as examples: (a) the analysis of a time series measured 3 samples/hr by the Imaging FlowCytobot (IFCB) installed at the entrance to the Mission-Aransas estuary (Port Aransas, TX, USA) during 2008 and (b) the high resolution spatial series of fluorescence data obtained 1 sample/m with an autonomous underwater vehicle (AUV) in Alfacs Bay (Ebro delta, Spain) during 2011. The final results indicate the need for measurements with sampling rates much higher than those commonly used in conventional methods (such as those relying on manual microscopy or pigment analysis) even in those cases in which the main goal is to characterize the dynamics at large spatial (order of km) or temporal (order of month-year) scales. These results reinforce the idea that the regular use of photonic-based instruments (optical, imaging or holographic systems) is necessary to characterize multiscale processes in marine environments due to the fact that, at present time, these are the only technologies capable of sampling at the required ratesPeer Reviewe