Structure of human urokinase plasminogen activator in complex with its receptor

The urokinase plasminogen activator binds to its cellular receptor with high affinity and initiates signaling cascades that are implicated in pathological processes including tumor growth, metastasis, and inflammation. We report the crystal structure at 1.9 angstroms of the urokinase receptor complexed with the urokinase amino-terminal fragment and an antibody against the receptor. The three domains of urokinase receptor form a concave shape with a central cone-shaped cavity where the urokinase fragment inserts. The structure provides insight into the flexibility of the urokinase receptor that enables its interaction with a wide variety of ligands and a basis for the design of urokinase-urokinase receptor antagonists.     

Field sampling of cork value before extraction in Portuguese ‘montados’

The assessment of cork quality and the estimation of cork value are very important to forest landowners, for management purposes and for cork commercialisation. The Forest Producers Associations have been using a sampling scheme with the objective of estimating cork value (price per unit of weight, usually kg) before extraction, based on the sampling of individual trees along a zigzag transect that covers the entire stand. The sampling error is usually too high, but, from a practical standpoint, it is difficult to increase the sampling intensity if it would imply an increase in sampling costs. The aim of this work was to propose, from data collected in six stands representative of the cork oak stands in Portugal, an alternative sampling methodology with a more efficient precision/cost ratio. Precision and costs of alternative sampling designs based on clusters of different sizes, complemented with analysis of the intracluster correlation coefficient, were studied in order to propose the most adequate sampling strategy. Single-stage cluster sampling with clusters of 5–7 trees guarantees a reasonable sampling error (10–15%) and can be conducted without a large increase in cost.     

Laparoscopic-assisted colopexy and sterilization in male dogs: short-term results and physiologic consequences

Objective: To describe laparoscopic‐assisted colopexy and sterilization, and evaluate outcome and effects in healthy male dogs. Study Design: Experimental study. Animals: Male Beagle dogs (n=7). Methods: A laparoscopic‐assisted, extracorporeally sutured colopexy, and sterilization by ligation and section of the testicular vessels and ductus deferens were evaluated 11 weeks after surgery. Ex vivo tensile tests were performed on the colopexy sites and loss of testicular function was assessed by monitoring serum testosterone, and by ultrasonographic and histologic examinations of the testes. Systemic inflammation and potential iatrogenic colonic functional disorders were investigated by monitoring serum C‐reactive protein (CRP) in the perioperative period and from a sulfapyridine (SP) kinetic profile obtained before and 10 weeks after surgery. Results: No intraoperative complications were recorded and clinical outcome was considered fair in all dogs. A mean tensile force of 42 N was required to disrupt colopexies. No relevant postoperative increase in CRP concentrations or changes in SP kinetics were observed. Testicular function was lost. Conclusions: Laparoscopic‐assisted colopexy achieved adhesion of the colon to the abdominal wall and testicular endocrine function and spermatogenesis were eliminated by laparoscopic castration.     

Annual and spatial variation in coning shown by the Forest Condition Monitoring programme data for Norway spruce, Sitka spruce and Scots pine in Britain

Conifer seed is a valuable forest resource; as well as beingreproductive material, it is an important foodstuff for manywoodland species. Information on cone and therefore seed productionof the main forest species are useful in the fields of bothforest management and forest ecology. Coning has been recordedsince 1989 in plots of Norway spruce, Sitka spruce and Scotspine across Britain as part of the Forestry Commission's ForestCondition Monitoring programme. An 11-year period of these recordswas analysed and a summary of annual cone production by speciesand coning synchrony is presented. Both Norway spruce and Sitkaspruce coned sporadically, with a 4-year period between mastcrops during which cone density was very low or cone productionabsent, whereas Scots pine produced a good cone crop in mostyears throughout Britain. Coning was synchronous within andbetween Norway and Sitka spruce across the whole of Britain(at distances >600 km) but coning within Scots pine was insynchrony only over distances of up to 200 km. Synchrony ofcone production was not evident between the spruce species andScots pine. These findings have implications when planning andinterpreting monitoring used to predict cone crops and in thedesign of forests for wildlife conservation.     

Fumonisin disruption of ceramide biosynthesis in maize roots and the effects on plant development and Fusarium verticillioides-induced seedling disease

The fungus Fusarium verticillioides infects maize and produces fumonisins, inhibitors of ceramide synthase. Seeds of the cultivar Silver Queen were inoculated with fumonisin-producing or non-fumonisin-producing strains of F. verticillioides. Leaf lesion incidence and severity of effects on root and stalk growth were significantly correlated with fumonisin in roots and disruption of sphingolipid metabolism in roots. Uninoculated seeds grown in soil watered with solutions of fumonisin B1 exhibited above-ground symptoms indicative of F. verticillioides-induced seedling disease and dose-dependent reduction in root mass that was inversely correlated with fumonisin B1, sphingoid bases, and sphingoid base 1-phosphates in roots. There was also evidence of an adaptive response to disrupted sphingolipid metabolism in both the virulence and watering assays, suggesting induction of pathways responsible for metabolism of sphingoid base 1-phosphates after prolonged exposure. The results suggest that fumonisin, and its effects on sphingolipids, could contribute to all aspects of F. verticillioides maize seedling disease.     

Cadmium and lead residue control in a hazard analysis and critical control point (HACCP) environment

In 2003-2004, the U.S. Department of Agriculture Food Safety and Inspection Service (FSIS) conducted an exploratory assessment to determine the occurrence and levels of cadmium and lead in randomly collected samples of kidney, liver, and muscle tissues of mature chickens, boars/stags, dairy cows, and heifers. The data generated in the study were qualitatively compared to data that FSIS gathered in a 1985-1986 study in order to identify trends in the levels of cadmium and lead in meat and poultry products. The exploratory assessment was necessary to verify that Hazard Analysis and Critical Control Point plans and efforts to control exposure to these heavy metals are effective and result in products that meet U.S. export requirements. A comparison of data from the two FSIS studies suggests that the incidence and levels of cadmium and lead in different slaughter classes have remained stable since the first study was conducted in 1985-1986. This study was conducted to fulfill FSIS mandate to ensure that meat, poultry, and egg products entering commerce in the United States are free of adulterants, including elevated levels of environmental contaminants such as cadmium and lead.     

Pathogenesis of a Texas feline immunodeficiency virus isolate: an emerging subtype of clade B

We have recently provided evidence that Texas feline immunodeficiency virus (FIV-TX) isolates are an emerging subtype sharing a common ancestry with clade B isolates. Specific, pathogen-free cats were infected, intravenously, with 500, 2000 or 8000TCID(50) of the FIV-TX53 virus to study the acute stage of infection. Infection of cats resulted in lymphadenopathy at 10 days post-infection (p.i.). By 7 weeks p.i., gag specific antibody could be detected from sera of all infected cats. Virus could be detected by culturing PBMC and by nested capsid PCR. A reduction in the absolute numbers of lymphocytes and neutrophils was observed in infected cats although there was no trend identified between this reduction and the viral dose administered. By 11 weeks p.i., the CD4(+)/CD8(+) T cell ratios from all infected cats had dropped from approximately 2 to below 1. While decrease in the ratio was dependent on the viral dose, the T cell ratios of cats receiving the highest dose had significantly dropped below 1 by 4-7 weeks p.i. This decrease in the ratio was accompanied by a sharp and temporal decline in the absolute CD4(+) T cells and a slight increase in the absolute CD8(+) T cell numbers with a dramatic expansion of cells with CD8beta(low) chain expression.     

Tyrannosaur life tables: an example of nonavian dinosaur population biology

The size and age structures for four assemblages of North American tyrannosaurs-Albertosaurus, Tyrannosaurus, Gorgosaurus, and Daspletosaurus-reveal a pronounced, bootstrap-supported pattern of age-specific mortality characterized by relatively high juvenile survivorship and increased mortality at midlife and near the maximum life span. Such patterns are common today in wild populations of long-lived birds and mammals. Factors such as predation and entrance into the breeding population may have influenced tyrannosaur survivorship. This survivorship pattern can explain the rarity of juvenile specimens in museum collections.     

Genetic data from avian influenza and avian paramyxoviruses generated by the European network of excellence (EPIZONE) between 2006 and 2011--review and recommendations for surveillance

Since 2006, the members of the molecular epidemiological working group of the European "EPIZONE" network of excellence have been generating sequence data on avian influenza and avian paramyxoviruses from both European and African sources in an attempt to more fully understand the circulation and impact of these viruses. This review presents a timely update on the epidemiological situation of these viruses based on sequence data generated during the lifetime of this project in addition to data produced by other groups during the same period. Based on this information and putting it all into a European context, recommendations for continued surveillance of these important viruses within Europe are presented.