299 research outputs found
The Marysville, Montana Geothermal Project
Drilling the first geothermal well in Montana presented many challenges, not only in securing materials and planning strategies for drilling the wildcat well but also in addressing the environmental, legal, and institutional issues raised by the request for permission to explore a resource which lacked legal definition. The Marysville Geothermal Project was to investigate a dry hot rock heat anomaly. The well was drilled to a total depth of 6790 feet and many fractured water bearing zones were encountered below 1800 feet
Improvement in the performance of the X-ray source based on parametric X-ray radiation using a wedge-shaped target crystal
The properties of parametric X-ray radiation (PXR) emitted from a wedge-shaped Si(111) crystal plate were experimentally investigated using the PXR generator at the Laboratory for Electron Beam Research and Application (LEBRA) of Nihon University. The wedge surface was imposed on a symmetric-cut Si(111) plate and has an asymmetric cut-surface with respect to the (111) crystal planes. As a result of the experiment, it was found that the PXR intensity improved can be obtained suppressing the degradation of the X-ray performance using a wedgeshaped
target. With this improvement, phase-contrast images without absorption contrast could be obtained from DEI images taken with the exposure of severalten seconds. The reduction of the exposure time made it possible to carry out a computed tomography (CT) experiment by DEI within a practical machine time, and phase-contrast tomograms of a biological sample were obtained at the PXR energy of 17.5 keV
Transgenic Zebrafish Recapitulating tbx16 Gene Early Developmental Expression
We describe the creation of a transgenic zebrafish expressing GFP driven by a 7.5 kb promoter region of the tbx16 gene. This promoter segment is sufficient to recapitulate early embryonic expression of endogenous tbx16 in the presomitic mesoderm, the polster and, subsequently, in the hatching gland. Expression of GFP in the transgenic lines later in development diverges to some extent from endogenous tbx16 expression with the serendipitous result that one line expresses GFP specifically in commissural primary ascending (CoPA) interneurons of the developing spinal cord. Using this line we demonstrate that the gene mafba (valentino) is expressed in CoPA interneurons
A user's guide to optimal transport
This text is an expanded version of the lectures given by the first author in the 2009 CIME summer school of Cetraro. It provides a quick and reasonably account of the classical theory of optimal mass transportation and of its more recent developments, including the metric theory of gradient flows, geometric and functional inequalities related to optimal transportation, the first and second order differential calculus in the Wasserstein space and the synthetic theory of metric measure spaces with Ricci curvature bounded from below
Pancreatic (pro)enzymes treatment suppresses BXPC-3 pancreatic Cancer Stem Cell subpopulation and impairs tumour engrafting
Cancer stem cells (CSCs) subpopulation within the tumour is responsible for metastasis and cancer
relapse. Here we investigate in vitro and in vivo the effects of a pancreatic (pro)enzyme mixture
composed of Chymotrypsinogen and Trypsinogen (PRP) on CSCs derived from a human pancreatic
cell line, BxPC3. Exposure of pancreatic CSCs spheres to PRP resulted in a significant decrease of
ALDEFLUOR and specific pancreatic CSC markers (CD 326, CD 44 and CxCR4) signal tested by flow
cytometry, further CSCs markers expression was also analyzed by western and immunofluorescence
assays. PRP also inhibits primary and secondary sphere formation. Three RT2 Profiler PCR Arrays
were used to study gene expression regulation after PRP treatment and resulted in, (i) epithelialmesenchymal
transition (EMT) inhibition; (ii) CSCs related genes suppression; (iii) enhanced expression
of tumour suppressor genes; (iv) downregulation of migration and metastasis genes and (v) regulation
of MAP Kinase Signalling Pathway. Finally, in vivo anti-tumor xenograft studies demonstrated high
anti-tumour efficacy of PRP against tumours induced by BxPC3 human pancreatic CSCs. PRP impaired
engrafting of pancreatic CSC’s tumours in nude mice and displayed an antigrowth effect toward
initiated xenografts. We concluded that (pro)enzymes treatment is a valuable strategy to suppress the
CSC population in solid pancreatic tumours
Glycerol Hypersensitivity in a Drosophila Model for Glycerol Kinase Deficiency Is Affected by Mutations in Eye Pigmentation Genes
Glycerol kinase plays a critical role in metabolism by converting glycerol to glycerol 3-phosphate in an ATP dependent reaction. In humans, glycerol kinase deficiency results in a wide range of phenotypic variability; patients can have severe metabolic and CNS abnormalities, while others possess hyperglycerolemia and glyceroluria with no other apparent phenotype. In an effort to help understand the pathogenic mechanisms underlying the phenotypic variation, we have created a Drosophila model for glycerol kinase deficiency by RNAi targeting of dGyk (CG18374) and dGK (CG7995). As expected, RNAi flies have reduced glycerol kinase RNA expression, reduced phosphorylation activity and elevated glycerol levels. Further investigation revealed these flies to be hypersensitive to fly food supplemented with glycerol. Due to the hygroscopic nature of glycerol, we predict glycerol hypersensitivity is a result of greater susceptibility to desiccation, suggesting glycerol kinase to play an important role in desiccation resistance in insects. To evaluate a role for genetic modifier loci in determining severity of the glycerol hypersensitivity observed in knockdown flies, we performed a preliminary screen of lethal transposon insertion mutant flies using a glycerol hypersensitive survivorship assay. We demonstrate that this type of screen can identify both enhancer and suppressor genetic loci of glycerol hypersensitivity. Furthermore, we found that the glycerol hypersensitivity phenotype can be enhanced or suppressed by null mutations in eye pigmentation genes. Taken together, our data suggest proteins encoded by eye pigmentation genes play an important role in desiccation resistance and that eye pigmentation genes are strong modifiers of the glycerol hypersensitive phenotype identified in our Drosophila model for glycerol kinase deficiency
Auditory temporal resolution of a wild white-beaked dolphin (Lagenorhynchus albirostris)
Author Posting. © The Author(s), 2009. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Journal of Comparative Physiology A: Neuroethology, Sensory, Neural, and Behavioral Physiology 195 (2009): 375-384, doi:10.1007/s00359-009-0415-x.Adequate temporal resolution is required across taxa to properly utilize amplitude modulated acoustic signals. Among mammals, odontocete marine mammals are considered to have relatively high temporal resolution, which is a selective advantage when processing fast traveling underwater sound. However, multiple methods used to estimate auditory temporal resolution have left comparisons among odontocetes and other mammals somewhat vague. Here we present the estimated auditory temporal resolution of an adult male white-beaked dolphin, (Lagenorhynchus albirostris), using auditory evoked potentials and click stimuli. Ours is the first of such studies performed on a wild dolphin in a capture-and-release scenario. The white-beaked dolphin followed rhythmic clicks up to a rate of approximately 1125-1250 Hz, after which the modulation rate transfer function (MRTF) cut-off steeply. However, 10% of the maximum response was still found at 1450 Hz indicating high temporal resolution. The MRTF was similar in shape and bandwidth to that of other odontocetes. The estimated maximal temporal resolution of white-beaked dolphins and other odontocetes was approximately twice that of pinnipeds and manatees, and more than ten-times faster than humans and gerbils. The exceptionally high temporal resolution abilities of odontocetes are likely due primarily to echolocation capabilities that require rapid processing of acoustic cues.We wish to thank the Danish Natural Science Research Council for major financial support (grant no. 272-05-0395)
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