792 research outputs found
Testing the Waters: Using Collective Real Options To Manage the Social Dilemma Of Strategic Alliances
We extend real options research by introducing the concept of collective real options and model how collective real options provide strategic alliances a mechanism to manage social uncertainty. Collective real options manage social uncertainty by producing relational small wins that develop trust. The amount of trust developed by acquiring a collective real option depends on the exposure of alliance partners. Alliance partner reputation also plays an important role in the impact of collective real options
On the Statistical Distribution of Epidermal Papillomata in Mice
IN a previous investigation reported from this laboratory (Ball and McCarter, 1960) it was noted that tumours produced in the skin of the CFW mouse by treatment with 7,12-dimethylbenz(a)anthracene (DMBA) and croton oil, were not distributed among the mice in accordance with the expected Poisson's distribution. Animals bearing no tumours and those bearing many were much more numerous than expected. A quantitative analysis of induced primary adenomatous pulmonary tumours in mice was reported by Polissar and Shimkin (1954). They showed that the occurrence of such tumours was subject to Poisson's distribution and that deviations from this distribution could be attributed to heterogeneity of susceptibility in the animals. We have now analyzed the data obtained in our laboratory in three populations of mice undergoing epidermal carcinogenesis. MATERIALS AND METHODS Strain CFW.-These mice were females, purchased from Carworth Farms Inc., New City, New York. They were housed in groups of 10 in acrylic plastic boxes with stainless steel tops. The bedding was sawdust. Water and Purina Fox Chow Cubes were freely available. Strain CFW/D.-This strain originated when, through error, a male was included among the female CFW mice purchased from the supplier in 1958. Since that time, brother-sister mating has been carried out with a view to obtaining a single inbred line. Litters selected for brother-sister mating were chosen on the basis of health, number in the litter and even distribution of the sexes and not for sensitivity to carcinogenesis. The mice were in the thirteenth and fourteenth inbred generations when used. They were cared for as described above. Strain I.-This strain was obtained several years ago through the kindness of Dr. H. B. Andervont. The mice had been mated brother-to-sister for 71 to 72 generations when the experiment was begun. Chemicals. 7,1 2-dimethylbenz(a)anthracene and benzo((a)pyrene were obtained from Eastman Organic Chemicals. Croton oil was obtained from Bush and Co., Canada. Paraffin oil viscosity 125/135 NF was a product of Fisher Scientific Co., Montreal, Canada. Meprobamate (Miltown) was kindly supplied by Dr. F. M
Investigating hookworm genomes by comparative analysis of two Ancylostoma species
Background
Hookworms, infecting over one billion people, are the mostly closely related major human parasites to the model nematode Caenorhabditis elegans. Applying genomics techniques to these species, we analyzed 3,840 and 3,149 genes from Ancylostoma caninum and A. ceylanicum.
Results
Transcripts originated from libraries representing infective L3 larva, stimulated L3, arrested L3, and adults. Most genes are represented in single stages including abundant transcripts like hsp-20 in infective L3 and vit-3 in adults. Over 80% of the genes have homologs in C. elegans, and nearly 30% of these were with observable RNA interference phenotypes. Homologies were identified to nematode-specific and clade V specific gene families. To study the evolution of hookworm genes, 574 A. caninum / A. ceylanicum orthologs were identified, all of which were found to be under purifying selection with distribution ratios of nonsynonymous to synonymous amino acid substitutions similar to that reported for C. elegans / C. briggsae orthologs. The phylogenetic distance between A. caninum and A. ceylanicum is almost identical to that for C. elegans / C. briggsae.
Conclusion
The genes discovered should substantially accelerate research toward better understanding of the parasites' basic biology as well as new therapies including vaccines and novel anthelmintics
Cardiovascular disease risk factor responses to a type 2 diabetes care model including nutritional ketosis induced by sustained carbohydrate restriction at 1 year: An open label, non-randomized, controlled study
Additional file 1: Table S1. Detailed baseline characteristics for participants in the continuous care intervention (CCI) and usual care (UC) groups
Theory of periodic swarming of bacteria: application to Proteus mirabilis
The periodic swarming of bacteria is one of the simplest examples for pattern
formation produced by the self-organized collective behavior of a large number
of organisms. In the spectacular colonies of Proteus mirabilis (the most common
species exhibiting this type of growth) a series of concentric rings are
developed as the bacteria multiply and swarm following a scenario periodically
repeating itself. We have developed a theoretical description for this process
in order to get a deeper insight into some of the typical processes governing
the phenomena in systems of many interacting living units. All of our
theoretical results are in excellent quantitative agreement with the complete
set of available observations.Comment: 11 pages, 8 figure
Nematode.net update 2008: improvements enabling more efficient data mining and comparative nematode genomics
Nematode.net (http://nematode.net) is a publicly available resource dedicated to the study of parasitic nematodes. In 2000, the Genome Center at Washington University (GC) joined a consortium including the Nematode Genomics group in Edinburgh, and the Pathogen Sequencing Unit of the Sanger Institute to generate expressed sequence tags (ESTs) as an inexpensive and efficient solution for gene discovery in parasitic nematodes. As of 2008 the GC, sampling key parasites of humans, animals and plants, has generated over 500 000 ESTs and 1.2 million genome survey sequences from more than 30 non-Caenorhabditis elegans nematodes. Nematode.net was implemented to offer user-friendly access to data produced by this project. In addition to sequence data, the site hosts: assembled NemaGene clusters in GBrowse views characterizing composition and protein homology, functional Gene Ontology annotations presented via the AmiGO browser, KEGG-based graphical display of NemaGene clusters mapped to metabolic pathways, codon usage tables, NemFam protein families which represent conserved nematode-restricted coding sequences not found in public protein databases, a web-based WU-BLAST search tool that allows complex querying and other assorted resources. The primary aim of Nematode.net is the dissemination of this diverse collection of information to the broader scientific community in a way that is useful, consistent, centralized and enduring
Developments in Performance Monitoring of Concrete Exposed to Extreme Environments.
The performance of the surface zone of concrete is acknowledged as a major factor governing the rate of deterioration of reinforced concrete structures because it provides the only barrier to the ingress of water containing dissolved ionic species such as chlorides, which ultimately initiate corrosion of the reinforcement. In situ monitoring of cover-zone concrete is therefore critical in attempting to make realistic predictions as to the in-service performance of the structure. To this end, this paper presents developments in a remote interrogation system to allow for continuous, real-time monitoring of the cover-zone concrete from an office setting. Use is made of a multi electrode array embedded within cover-zone concrete to acquire discretized electrical resistivity and temperature measurements, with both parameters monitored spatially and temporally. On-site instrumentation, which allows for the remote interrogation of concrete samples placed at a marine exposure site, is detailed together with data handling and processing procedures. Site measurements highlight the influence of temperature on electrical resistivity and an Arrhenius-based temperature correction protocol is developed using on-site measurements to standardize resistivity data to a reference temperature; this is an advancement over the use of laboratory-based procedures. The testing methodology and interrogation system represent a robust, low-cost, and high-value technique that could be deployed for intelligent monitoring of reinforced concrete structures
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