695 research outputs found
Oil and Gas Platforms in the Gulf of Mexico: Their Relationship to Fish and Fisheries
There are over 2300 standing oil and gas platforms in the northern Gulf of Mexico (GOM). It has been argued that platforms provide reef-like habitat that increases the growth and survival rates of fishes by increasing prey availability and affording shelter for protection from predators, provide additional spawning substrate, and by acting as a visual attractant for organisms not otherwise dependent upon hard bottom. Platforms differ from most natural habitats, and from traditional artificial reefs, in that their vertical profile extends upward through the water column into the photic zone and the sea surface. Increased habitat quality on, or immediately around, oil and gas platforms are thought to be derived from increased in situ food production associated with encrustation by fouling organisms. In this chapter, we address the issue of how to evaluate the role of artificial reefs by first establishing levels of evaluation for individual fish species found on oil and gas platforms in the GOM. The levels of evaluation relate to the amount and adequacy of the available information, which was populated with an extensive literature and data search. Three levels of assessment are established, analogous to the levels of analysis established National Oceanographic and Atmospheric Administration (NOAA) Fisheries for identification of Essential Fish Habitat. More than 1300 documents, including reports, stock assessments, other gray literature, and papers published in the primary literature, were used to complete this chapter. When available, published literature was the preferred source of information
Situation Report on Simplified Forage Harvesters
Fsrm interest is centered primarily on their relatively low cost and versatility. Other considerations include their operating characteristics and power requirements as well as the kind of product produced
The fractal dimension as a petrophysical parameter.
http://archive.org/details/fractaldimension00cow
Approaches to an understanding of aphasia: neurolinguistic studies in the British Isles, 1793-1894
No abstract available
Mitogen-activated protein kinases: New signaling pathways functioning in cellular responses to environmental stress
The mitogen-activated protein kinase (MAPK) superfamily consists of three main protein kinase families: the extracellular signal-regulated protein kinases (ERKs), the c-Jun N-terminal kinases (JNKs) and the p38 family of kinases. Each is proving to have major roles in the regulation of intracellular metabolism and gene expression and integral actions in many areas including growth and development, disease, apoptosis and cellular responses to external stresses. To date, this cellular signal transduction network has received relatively little attention from comparative biochemists, despite the high probability that MAPKs have critical roles in the adaptive responses to thermal, osmotic and oxygen stresses. The present article reviews the current understanding of the roles and regulation of ERKs, JNKs and p38, summarizes what is known to date about MAPK roles in animal models of anoxia tolerance, freeze tolerance and osmoregulation, and highlights the potential that studies of MAPK pathways have for advancing our understanding of the mechanisms of biochemical adaptation
The genome of polymorphonuclear neutrophils maintains normal coding sequences
Genetic studies often use genomic DNA from whole blood cells, of which the majority are the polymorphonuclear myeloid cells. Those cells undergo dramatic change of nuclear morphology following cellular differentiation. It remains elusive if the nuclear morphological change accompanies sequence alternations from the intact genome. If such event exists, it will cause a serious problem in using such type of genomic DNA for genetic study as the sequences will not represent the intact genome in the host individuals. Using exome sequencing, we compared the coding regions between neutrophil, which is the major type of polymorphonuclear cells, and CD4+ T cell, which has an intact genome, from the same individual. The results show that exon sequences between the two cell types are essentially the same. The minor differences represented by the missed exons and base changes between the two cell types were validated to be mainly caused by experimental errors. Our study concludes that genomic DNA from whole blood cells can be safely used for genetic studies
Recommended from our members
N-cadherin prevents the premature differentiation of anterior heart field progenitors in the pharyngeal mesodermal microenvironment
The cardiac progenitor cells (CPCs) in the anterior heart field (AHF) are located in the pharyngeal mesoderm (PM), where they expand, migrate and eventually differentiate into major cell types found in the heart, including cardiomyocytes. The mechanisms by which these progenitors are able to expand within the PM microenvironment without premature differentiation remain largely unknown. Through in silico data mining, genetic loss-of-function studies, and in vivo genetic rescue studies, we identified N-cadherin and interaction with canonical Wnt signals as a critical component of the microenvironment that facilitates the expansion of AHF-CPCs in the PM. CPCs in N-cadherin mutant embryos were observed to be less proliferative and undergo premature differentiation in the PM. Notably, the phenotype of N-cadherin deficiency could be partially rescued by activating Wnt signaling, suggesting a delicate functional interaction between the adhesion role of N-cadherin and Wnt signaling in the early PM microenvironment. This study suggests a new mechanism for the early renewal of AHF progenitors where N-cadherin provides additional adhesion for progenitor cells in the PM, thereby allowing Wnt paracrine signals to expand the cells without premature differentiation
Family-specific, novel, deleterious germline variants provide a rich resource to identify genetic predispositions for BRCAx familial breast cancer
BACKGROUND: Genetic predisposition is the primary risk factor for familial breast cancer. For the majority of familial breast cancer, however, the genetic predispositions remain unknown. All newly identified predispositions occur rarely in disease population, and the unknown genetic predispositions are estimated to reach up to total thousands. Family unit is the basic structure of genetics. Because it is an autosomal dominant disease, individuals with a history of familial breast cancer must carry the same genetic predisposition across generations. Therefore, focusing on the cases in lineages of familial breast cancer, rather than pooled cases in disease population, is expected to provide high probability to identify the genetic predisposition for each family. METHODS: In this study, we tested genetic predispositions by analyzing the family-specific variants in familial breast cancer. Using exome sequencing, we analyzed three families and 22 probands with BRCAx (BRCA-negative) familial breast cancer. RESULTS: We observed the presence of family-specific, novel, deleterious germline variants in each family. Of the germline variants identified, many were shared between the disease-affected family members of the same family but not found in different families, which have their own specific variants. Certain variants are putative deleterious genetic predispositions damaging functionally important genes involved in DNA replication and damaging repair, tumor suppression, signal transduction, and phosphorylation. CONCLUSIONS: Our study demonstrates that the predispositions for many BRCAx familial breast cancer families can lie in each disease family. The application of a family-focused approach has the potential to detect many new predispositions
- …