Artificial Reef Development Along the Atlantic Coast of Guatemala

A visual census of a four year old artificial reef in the Bahia de Amatique off Guatemala\u27s Atlantic coast indicates a substantial standing number of fishes. The fish fauna is comprised chiefly of juvenile grunts (Haemulon aurolineatum; 7.39/m2) accounting for the reef\u27s low species diversity (H\u27 = 0.68). A considerable portion of the assemblage is composed of commercially exploitable adults of Lutjanus griseus (0.38/m2) and Haemulon plumieri (0.03/m2). The proximate grassbeds have large populations of juveniles and small adults of all the commercially exploitable species. Further development of the reef is indicated providing the grassbed biotope remains healthy and fishing pressure does not become excessive

Gulf-Wide Decreases in the Size of Large Coastal Sharks Documented by Generations of Fishermen

Large sharks are top predators in most coastal and marine ecosystems throughout the world, and evidence of their reduced prominence in marine ecosystems has been a serious concern for fisheries and ecosystem management. Unfortunately, quantitative data to document the extent, timing, and consequences of changes in shark populations are scarce, thwarting examination of long-term (decadal, century) trends, and reconstructions based on incomplete data sets have been the subject of debate. Absence of quantitative descriptors of past ecological conditions is a generic problem facing many fields of science but is particularly troublesome for fisheries scientists who must develop specific targets for restoration. We were able to use quantitative measurements of shark sizes collected annually and independently of any scientific survey by thousands of recreational fishermen over the last century to document decreases in the size of large sharks from the northern Gulf of Mexico. Based on records from fishing rodeos in three U.S. coastal states, the size (weight or length) of large sharks captured by fishermen decreased by 50-70% during the 20 years after the 1980s. The pattern is largely driven by reductions in the occurrence and sizes of Tiger Sharks Galeocerdo cuvier and Bull Sharks Carcharhinus leucas and to a lesser extent Hammerheads Sphyrna spp. This decrease occurred despite increasing fishing effort and advances in technology, but it is coincident with the capitalization of the U.S. commercial shark long-line fishery in the GOM. Received April 10, 2012; accepted March 7, 2013

Data Mining Approaches to Diffuse Large B–Cell Lymphoma Gene Expression Data Interpretation

This paper presents a comprehensive study of gene expression patterns originating from a diffuse large B–cell lymphoma (DLBCL) database. It focuses on the implementation of feature selection and classification techniques. Thus, it firstly tackles the identification of relevant genes for the prediction of DLBCL types. It also allows the determination of key biomarkers to differentiate two subtypes of DLBCL samples: Activated B–Like and Germinal Centre B–Like DLBCL. Decision trees provide knowledge–based models to predict types and subtypes of DLBCL. This research suggests that the data may be insufficient to accurately predict DLBCL types or even detect functionally relevant genes. However, these methods represent reliable and understandable tools to start thinking about possible interesting non–linear interdependencies

Comparison of gamma densitometer detectors used in loss of coolant studies

Ionization chamber type gamma detectors are used in water-steam density measurements in loss of coolant studies at Oak Ridge National Laboratory. Ionization chambers have replaced current-mode scintillation detectors to obtain stability and freedom from magnetic field interference. However, this change results in some loss of fast transient response. Results of studies comparing the transient response of ionization chamber detectors, plastic scintillation detectors, and sodium iodide (NaI) detectors to rapid changes in gamma intensity demonstrate that plastic scintillation detectors have the fastest response and most closely reproduce the transient; ionization chambers have an initial fast response followed by a slower response, which may produce errors in fast transient measurements; and NaI scintillation detectors have a moderately fast initial response followed by an extremely slow response, which produces errors in even slow transient measurements

Artificial Reef Development Along the Atlantic Coast of Guatemala

A visual census of a four year old artificial reef in the Bahia de Amatique off Guatemala\u27s Atlantic coast indicates a substantial standing number of fishes. The fish fauna is comprised chiefly of juvenile grunts (Haemulon aurolineatum; 7.39/m2) accounting for the reef\u27s low species diversity (H\u27 = 0.68). A considerable portion of the assemblage is composed of commercially exploitable adults of Lutjanus griseus (0.38/m2) and Haemulon plumieri (0.03/m2). The proximate grassbeds have large populations of juveniles and small adults of all the commercially exploitable species. Further development of the reef is indicated providing the grassbed biotope remains healthy and fishing pressure does not become excessive