1-dependent spindle checkpoint: Topics by WorldWideScience.org

Overexpression of MAD2 predicts clinical outcome in primary lung cancer patients

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2007-01-01

British Library Electronic Table of Contents (United Kingdom)

High-level expression of mitotic arrest defective protein 2 (MAD2), a central component of the spindle assembly checkpoint, has been observed in a variety of human malignancies. Aim of the present study was to observe the expression of MAD2 in human non-small-cell lung cancer (NSCLC) and explore its clinicopathologic significance and evaluate MAD2 expression as a prognostic marker. MAD2 transcript was found to be overexpressed in the great majority of lung cancers by semi-quantitative RT-PCR. A total of 358 NSCLCs were analyzed immunohistochemically on tissue microarrays. High-level MAD2 expression was observed in 26.3% (94 of 358 cases), and correlated with male sex (P=0.0002), tumor progression (pT status) (P=0.0009), visceral or parietal pleural invasion (P=0.0151), non-adenocarcinoma, ...

2011-01-01

G2 checkpoint siRNA screen in irradiated cancer cells: validation of candidate positive hits

Norwegian Open Research Archives (NORA)

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Misregulation of the Kinesin-like Protein Subito Induces Meiotic Spindle Formation in the Absence of Chromosomes and Centrosomes

Research in Reliability, Availability and Maintainability for ...

Bipolar spindles assemble in the absence of centrosomes in the oocytes of many species. In Drosophila melanogaster oocytes, the chromosomes have been proposed to initiate spindle assembly...Full Text Available

2007-09-01

Border Protection and National Security of Mongolia

... Effect of checkpointing and queueing on program performance ... and a large class of stochastic linear ... problem is intrinsically related to K-terminal ...

1990-01-01

The utility of the SH01-195 spindle deflector

... outposts, the border batalion of Kosh-Agach, and the Tashanta checkpoint of Aktash border-control detachment. The border ...

2006-09-01

Spindle cell carcinoma of head and neck: an immunohistochemical and molecular approach to its pathogenesis

The All Union Scientific Research Institute of Drilling Techniques has developed the SH01-195 spindle deflector designed for use with the 195 millimeter turbodrill sections in place of the standard spindle. This spindle deflector is an axial support for the turbodrill, manufactured as a separate unit that attaches to the turbosections using the standard attachment configuration for series manufactured turbodrills, using the sub for attachment to the frame and a splined half coupling for attachment to the shaft. The spindle deflector itself consists of two parts connected by a curved sub through the frame and by a double hinge to the shaft. The hinge is isolated from axial forces by mounting radial support ball bearings above and below it.

1984-01-01

G?i generates multiple Pins activation states to link cortical polarity and spindle orientation in Drosophila neuroblasts

BackgroundSpindle cell carcinoma (SpCC) is a rare microscopic type of cancer of the mouth and oropharynx. Although SpCC is thought to arise from squamous cell carcinoma (SCC), it...Full Text Available

2007-05-01

Biphasic Low-Grade Nasopharyngeal Papillary Adenocarcinoma with a Prominent Spindle Cell Component: Report of a Case Localized to the Posterior Nasal Septum

Drosophila neuroblasts divide asymmetrically by aligning their mitotic spindle with cortical cell polarity to generate distinct sibling cell types. Neuroblasts asymmetrically localize...Full Text Available

2007-09-04

British Library Electronic Table of Contents (United Kingdom)

A case (female, 39?years of) of thyroid-like nasopharyngeal low-grade papillary adenocarcinoma with a significant spindle cell component is presented. The tumor was located on the posterior nasal septum. The spindle cells displayed nuclear features very much similar to the epithelial component and the two cell types merged imperceptibly. Immunohistochemically, the neoplastic cells (including the spindle cell component) were strongly and diffusely positive for TTF-1, cytokeratins (AE1-3), cytokeratin 19 and vimentin. C-kit immunohistochemistry showed diffuse mild to moderate membranous positivity with focal areas displaying moderate to strong immunoreactivity. EMA was strongly positive in the epithelial component with membranous and cytoplasmic reactivity whereas the spindle cell component ...

2011-01-01

Use of polarized light microscopy in porcine reproductive technologies

British Library Electronic Table of Contents (United Kingdom)

The meiotic spindle in the oocyte is composed of microtubules and plays an important role during chromosome alignment and separation at meiosis. Polarized light microscopy (PLM) could be useful for a non-invasive evaluation of the meiotic spindle and may allow removal of nuclear structures without fluorochrome staining and ultraviolet exposure. In this study, PLM was used to assess its potential application in porcine reproductive technologies. The objectives of the present study were to assess the efficiency of PLM to detect microtubule-polymerized protein in in vitro-matured porcine oocytes; to examine its effects on the oocyte developmental competence; to select oocytes based on the presence of the meiotic spindle detected by PLM; and to assess the efficiency oocyte enucleation assisted...

2011-01-01

Nonlinear response and stability of a spindle system supported by Ball bearings

Identification of AFAP1L1 as a prognostic marker for spindle cell sarcomas

In this effort, the nonlinear responses and stability of a spindle system supported by ball bearings are presented. The dynamics of this system is described by a set of second order differential equations with a nonlinear piecewise smooth force. The Floquet theory is applied to investigate the stability of the periodic solution. Due to the loss of contact between the raceways and balls in the ball bearing, the bending of the frequency response curves switch to the left at the weak resonance region, which is similar to the frequency response curves of a system with a soft spring. With the decrease of the bearing clearance, the bending of the frequency response curves switch to the right, which is similar to the frequency response curves of a system with a hard spring. Increase of the frequency ratio, the bending of frequency response curves transforms from left to right. The route to chaos through a period doubling process is also observed in this ...

2010-09-15

British Library Electronic Table of Contents (United Kingdom)

Spindle cell sarcomas consist of tumors with different biological features, of which distant metastasis is the most ominous sign for a poor prognosis. However, metastasis is difficult to predict on the basis of current histopathological analyses. We have identified actin filament-associated protein 1-like 1 (AFAP1L1) as a candidate for a metastasis-predicting marker from the gene expression profiles of 65 spindle cell sarcomas. A multivariate analysis determined that AFAP1L1 was an independent factor for predicting the occurrence of distant metastasis (P=0.0001), which was further confirmed in another set of 41 tumors by a quantitative mRNA expression analysis. Immunohistochemical staining using paraffin-embedded tumor tissues revealed that the metastasis-free rate was significantly better...

2011-01-01

Temperature profiles and bathymetry of some high mountain lakes

THE STRUCTURE AND FUNCTION OF CENTRIOLES AND THEIR SATELLITES IN THE JELLYFISH PHIALIDIUM GREGARIUM

The ice cover in high mountain lakes breaks up and disappears in about an hour, in part because it has been divided into fragile vertical spindles, which are individual crystals. Contributing to this...Full Text Available

2000-06-06

A Spindle Cell Predominant Pancreatic Solid-pseudopapillary Tumor

Testes of jellyfish Phialidium gregarium were fixed in 2 per cent OsO₄ in Veronal-acetate buffer at pH 7.4. Thin sections showed that in young spermatids the spindle fibers...Full Text Available

1964-06-01

Variations in Mre11/Rad50/Nbs1 status and DNA damage-induced S-phase arrest in the cell lines of the NCI60 panel

A hitherto unrecognized variant of solid-pseudopapillary tumor (SPT) of the pancreas is reported. The tumor presented in the pancreatic tail of a 44-year-old female patient. It was a well-defined, solid...Full Text Available

2008-08-30

Functions of mammalian Cdc7 kinase in initiation/monitoring of DNA replication and development

BackgroundThe Mre11/Rad50/Nbs1 (MRN) complex is a regulator of cell cycle checkpoints and DNA repair. Defects in MRN can lead to defective S-phase arrest when cells are damaged....Full Text Available

Ionizing radiation is a potent inducer of mitotic recombination in mouse embryonic stem cells

Cdc7 kinase plays an essential role in firing of replication origins by phosphorylating components of the replication complexes. Cdc7 kinase has also been implicated in S phase checkpoint signaling downstream of the ATR and Chk1 kinases. Inactivation of Cdc7 in yeast results in arrest of cell growth with 1C DNA content after completion of the ongoing DNA replication. In contrast, conditional inactivation of Cdc7 in undifferentiated mouse embryonic stem (ES) cells leads to growth arrest with rapid cessation of DNA synthesis, suggesting requirement of Cdc7 functions for continuation of ongoing DNA synthesis. Furthermore, loss of Cdc7 function induces recombinational repair (nuclear Rad51 foci) and G2/M checkpoint responses (inhibition of Cdc2 kinase). Eventually, p53 becomes highly activated and the cells undergo massive p53-dependent apoptosis. Thus, defective origin activation in mammalian cells can generate DNA replication ...

2003-11-27

British Library Electronic Table of Contents (United Kingdom)

Maintenance of genomic integrity in embryonic cells is pivotal to proper embryogenesis, organogenesis and to the continuity of species. Cultured mouse embryonic stem cells (mESCs), a model for early embryonic cells, differ from cultured somatic cells in their capacity to remodel chromatin, in their repertoire of DNA repair enzymes, and in the regulation of cell cycle checkpoints. Using 129XC3HF1 mESCs heterozygous for Aprt, we characterized loss of Aprt heterozygosity after exposure to ionizing radiation. We report here that the frequency of loss of heterozygosity mutants in mESCs can be induced several hundred-fold by exposure to 5-10Gy of X-rays. This induction is 50-100-fold higher than the induction reported for mouse adult or embryonic fibroblasts. The primary mechanism underlying the...

2011-01-01

Disturbance Rejection Control of an Electromagnetic Bearing Spindle

Primary leiomyosarcoma of the prostate with lung metastasis: Report of a case diagnosed by fine-needle aspiration cytology

The force exerted on the rotor by an active magnetic bearing (AMB) is determined by the current flow in the magnet coils. This force can be controlled very precisely, making magnetic bearings a potential benefit for grinding, where cutting forces act as external disturbances on the shaft, resulting in degraded part finish. It is possible to achieve precise shaft positioning, reduce vibration of the shaft caused by external disturbances, and even damp out resonant modes. Adaptive control is an appealing approach for these systems because the controller can tune itself to account for an unknown periodic disturbance, such as cutting or grinding forces, injected into the system. In this paper the authors show how one adaptive control algorithm can be applied to an AMB system with a periodic disturbance applied to the rotor. An adaptive algorithm was developed and implemented in both simulation and hardware, yielding significant reductions in rotor displacement in the presence of an ...

2000-08-31

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British Library Electronic Table of Contents (United Kingdom)

Abstract Prostate leiomyosarcoma is an extremely rare and highly aggressive neoplasm that accounts for less than 0.1% of primary prostate malignancies. Herein, we present a patient with primary leiomyosarcoma of the prostate with lung metastasis diagnosed primarily on fine-needle aspiration cytology. Characteristic cytological features such as small fascicles of spindle cells with blunt-ended nuclei, positivity for desmin and smooth muscle actin along with the radiological features are helpful in the correct diagnosis. Diagn. Cytopathol. 2010. 2010 Wiley-Liss, Inc.

2011-01-01

Manipulator for internal testing of a container. Manipulator zur Innenpruefung eines Behaelters

Identification of protein phosphorylation sites within Ser/Thr-rich cluster domains using site-directed mutagenesis and hybrid linear quadrupole ion trap Fourier transform ion cyclotron resonance mass spectrometry

A manipulator for checking the inside of a vertical, flange-shaped collector of a horizontal steam generator consists of a rotating mast with bearings at the top and bottom ends with a support that can be moved along the length of the mast for the checking system mountings. The support is propelled by a drive spindle placed parallel to the mast with its drive head bearing in the support and locked into a toothed rack attached to the mast. The checking system mountings are fitted in or on the walls of the support and are very close to the box-shaped support. Their retractable arms are hinged.

1985-04-11

British Library Electronic Table of Contents (United Kingdom)

We describe a method for the analysis of multi-site phosphorylation in serine/threonine (Ser/Thr)-rich protein sequences. Site-specific mutagenesis was used to introduce tryptic cleavage sites in the serine glutamine/threonine glutamine cluster domain (SCD) of the human checkpoint protein kinase (Chk2). The mutant proteins were shown to autophosphorylate on residues that are inducibly phosphorylated when mammalian cells are exposed to ionizing radiation (serine 33/35, serine 516, threonine 68 and threonine 432). Five Ser/Thr clusters within the SCD were flanked by arginine or lysine residues to produce tryptic peptides for nanospray liquid chromatography (nanoLC)/linear quadrupole ion trap Fourier transform ion cyclotron resonance mass spectrometry. Phosphorylation sites were assigned usin...

2007-01-01

Malignant solitary fibrous tumor of the thyroid gland: Report of a case and review of the literature

British Library Electronic Table of Contents (United Kingdom)

Abstract Solitary fibrous tumors of the thyroid gland (T-SFT) are rarely described, with only 21 cases being reported in the English literatures, all showing benign clinical characteristics. We herein present a 76-year-old woman presenting with a 3-month history of rapidly enlarging neck masses and the CT showed masses with partial calcification in the right thyroid lobe. We performed right hemithyroidectomy and isthmectomy with negative margin under general anesthesia. Histologically, the masses consisted of pleomorphic spindle cells with high mitoses and collagen bands. Immunohistochemically, the tumor cells showed positive reactions for CD34, vimentin and bcl-2, then a diagnosis of malignant solitary fibrous tumor of the right thyroid was made. Six months postoperatively, the CT showed ...

2011-01-01

Ceramic bearings for application to hard disc drives (HDD); HDD yo ceramic ball bearing

A study of reconstruction algorithms and filters for an industrial X-ray tomography system

Ceramic ball bearings of silicon nitride are used for hard disk drive (HDD) spindle motors, to increase seed, reliability and memory capacity of the HDDs. Silicon nitride ceramics have advantages of lightweight, high strength and hardness over the conventional steel for bearings, but is expensive. A new process of high cost performance has been developed for mass production of the small-size ceramic balls. The company plans to apply these bearings to higher devices, e.g., servers, for the time being, and to expand the applicable areas, e.g., common devices and other small-size motors. The ceramic bearings have been developed jointly with Koyo Seiko Co. Ltd. (translated by NEDO)

2000-03-01

A simple one-step fabrication of micrometer-scale hierarchical TiO2 hollow spheres

Computed tomography (CT) has been incorporated in an industrial Diode-Array Digital Radiography (DADR) system. An input data size of 512 pixel points x 400 projections yielded a 400x400 output image matrix. Reconstruction algorithms used are the filtered backprojection (FBP) and the direct Fourier reconstruction (DFR). Various filters were used in the FBP reconstruction process and their effects on image quality were evaluated. A spatial resolution of 100 {mu}m was measured with a block of plates and a minimum detectable feature size in the range of 10-100 {mu}m was measured using thin wires. Industrial specimens imaged have included ceramic samples, ball bearings and integrated circuits. A number of engineering problems have been solved, such as adjustment of the X-ray source, centering of the rotator spindle in the view field and beam-hardening corrections. (orig.).

1990-12-20

British Library Electronic Table of Contents (United Kingdom)

Hierarchical TiO2 hollow spheres had been prepared based on bubble templates by a simple one-step hydrothermal method. The diameter of hollow spheres was about 700nm and the shell thickness of them was 69nm. They were composed of similar spindle- or needle-like building units. Furthermore, hydrothermal time had an important influence on the morphology and crystallinity of hollow spheres. Moreover, the UV-Vis diffuse reflectance spectra of TiO2 hollow spheres heated at 150^oC for 10h showed the strongest absorption in the UV-Vis region and the Raman spectrum demonstrated the anatase sample. Additionally, a possible formation mechanism of TiO2 hollow spheres was proposed. So this novel and simple method would provide a development direction to fabricate all kinds of inorganic hollow spheres ...

2010-01-01

EGFR Signaling Through an Akt-SREBP-1-Dependent, Rapamycin-Resistant Pathway Sensitizes Glioblastomas to Anti-Lipogenic Therapy

Results of third regular inspection of No. 2 plant in Sendai Nuclear Power Station, Kyushu Electric Power Co. , Inc

Glioblastoma, the most common malignant brain tumor, is among the most lethal and difficult cancers to treat. Although epidermal growth factor receptor (EGFR) mutations are frequent in glioblastoma,...Full Text Available

Precise characterisation of nanochannels in track etched membranes by SAXS and SANS

The third regular inspection of No.2 plant in Sendai Nuclear Power Station was carried out from December 27, 1988 to May 25, 1989. The parallel operation was resumed on April 28, 1989, 123 days after the parallel off. The facilities which were the object of inspection were the reactor proper, reactor cooling system, measurement and control system, fuel facilities, radiation control facilities, waste facilities, reactor containment installation and emergency electric power generation system. On the facilities which were the object of inspection, the appearance, disassembling, leak, function, performance and other inspections were carried out. As the results, significant in indication was observed in 8 bolts for fixing the flow-changing vanes of primary coolant pumps, and broken valve spindles were found, but other abnormality was not found. The works related to this regular inspection were accomplished within the range of the limit of radiation dose equivalent based ...

1990-03-01

Electronic structure and nesting-driven enhancement of the RKKY interaction at the magnetic ordering propagation vector in Gd_2PdSi_3 and Tb_2PdSi_3

Poster session: Abstract is full text. Track membranes are thin polymer foils irradiated by heavy ions. The defects created by the heavy ions are located along the ions trajectory, the track. It is possible to open channels by etching with a chemical agent. These channels are very uniform. Small Angle Scattering (of X rays and neutrons) give global information about the characteristics of the channel shape. As the nanochannels are strictly parallel, an excellent sample orientation is required to obtain interpretable spectra. Then shoulders due to the oscillations of the Bessel function (radial part of the channel shape Fourier transform) are easily seen in the scattered intensity in the PXY data treatment software of SAS spectra allow to determine the channel diameter with its dispersion law, to demonstrate the existence of a wall thickness with a linearly varying density, and to assess the roughness. PXY can also detect non cylindric shapes like single or double cones or ...

2003-05-01

International Nuclear Information System (INIS)

We present first-time measurements of the Fermi surface and low-energy electronic structure of intermetallic compounds Gd_2PdSi_3 and Tb_2PdSi_3 by means of angle-resolved photoelectron spectroscopy (ARPES). We show that the Fermi surface in both compounds consists of an electron barrel at the #GAMMA# point surrounded by spindle-shaped electron pockets originating from the same band, with the band bottom of both features lying at 0.5 eV below the Fermi level. From the experimentally measured band structure, we estimate the momentum-dependent RKKY coupling strength and demonstrate that it is peaked at the 1/2#GAMMA# K wave vector. Comparison with neutron diffraction data from the same crystals shows perfect agreement of this vector with the propagation vector of the low-temperature in-plane magnetic order, thereby demonstrating the decisive role of the Fermi surface geometry in explaining the complex magnetically ordered ground state of ternary rare earth silicides.

2009-03-22

Local chromatin structure of heterochromatin regulates repeatedDNA stability, nucleolus structure, and genome integrity

Forkhead Box Transcription Factor FOXO3a Regulates Estrogen Receptor Alpha Expression and Is Repressed by the Her-2/neu/Phosphatidylinositol 3-Kinase/Akt Signaling Pathway

Heterochromatin constitutes a significant portion of the genome in higher eukaryotes; approximately 30% in Drosophila and human. Heterochromatin contains a high repeat DNA content and a low density of protein-encoding genes. In contrast, euchromatin is composed mostly of unique sequences and contains the majority of single-copy genes. Genetic and cytological studies demonstrated that heterochromatin exhibits regulatory roles in chromosome organization, centromere function and telomere protection. As an epigenetically regulated structure, heterochromatin formation is not defined by any DNA sequence consensus. Heterochromatin is characterized by its association with nucleosomes containing methylated-lysine 9 of histone H3 (H3K9me), heterochromatin protein 1 (HP1) that binds H3K9me, and Su(var)3-9, which methylates H3K9 and binds HP1. Heterochromatin formation and functions are influenced by HP1, Su(var)3-9, and the RNA interference (RNAi) pathway. My thesis project investigates how ...

2007-05-05

Structure, Function, and Evolution of Rice Centromeres

The expression status of the estrogen receptor alpha (ERα) and that of the epidermal growth factor receptor Her-2/neu frequently correlate inversely in breast cancers. While ER;1;-dependent...Full Text Available

2004-10-01

Design of High-speed Wear Lifetime Tester of the Instrument Ball Bearings

The centromere is the most characteristic landmark of eukaryotic chromosomes. Centromeres function as the site for kinetochore assembly and spindle attachment, allowing for the faithful pairing and segregation of sister chromatids during cell division. Characterization of centromeric DNA is not only essential to understand the structure and organization of plant genomes, but it is also a critical step in the development of plant artificial chromosomes. The centromeres of most model eukaryotic species, consist predominantly of long arrays of satellite DNA. Determining the precise DNA boundary of a centromere has proven to be a difficult task in multicellular eukaryotes. We have successfully cloned and sequenced the centromere of rice chromosome 8 (Cen8), representing the first fully sequenced centromere from any multicellular eukaryotes. The functional core of Cen8 spans ~800 kb of DNA, which was determined by chromatin immunoprecipitation (ChIP) using an antibody ...

2010-02-04

Total nuclear photoabsorption cross section in the range 0.2-1.0 GeV for nuclei throughout the periodic table

The instrument ball bearings are the key components of movable components for various kinds of measuring and control instruments; they often operate in the environmental condition of high-speed and light preload. In general, the non metal, disposable oilimpregnated retainer material has been used for these kinds of high precision miniature bearing. The engineering practice shows that the common failure mode of them is the wear which appears under the condition of insufficient lubrication condition. As the results, the vibration and noise will be enlarged, so does the frictional torque, which makes the ball bearings to lose its original working accuracy. It is the lifetime test of bearings that can enable the designers and manufacturers to chose the material of the bearing properly, optimize the product structure, mend the manufacturing technique process, and to enhance the technical level of the bearing products significantly. In this paper, the wear lifetime tester has been designed ...

2006-10-15

International Nuclear Information System (INIS)

An analysis of the total photoabsorption cross section for nuclei ranging from "4He up to "2"3"8U has been performed in the energy range 0.2-1.0 GeV. Mean total photoabsorption cross sections have been obtained by summing up the contributions from partial photoreactions, and found to follow an A"1-dependence in the 0.2-1.0 GeV range. A review of the available total photoabsorption cross section data is also presented. Comparisons have been made with cross section values calculated by considering both the quasi-deuteron and #pi#-meson photoproduction mechanism of primary nuclear photointeraction. (orig.).

Light-dependent regulation of DEL1 is determined by the antagonistic action of E2Fb and E2Fc.

Surfactant based sol-gel approach to nanostructured LiFePO{sub 4} for high rate Li-ion batteries

Endoreduplication represents a cell cycle variant during which multiple rounds of DNA replication occur without subsequent chromosome separation and cytokinesis, resulting into a cellular increase of the DNA content. Although the DNA ploidy level of cells is controlled by external stimuli such as light, currently limited knowledge is available on how environmental signals regulate the endoreduplication cycle at the molecular level. Previously, we have demonstrated that the conversion from the mitotic cell cycle into an endoreduplication cycle is mediated by the atypical E2F transcription factor DEL1 that operates as a repressor of endocycle onset. Here, we identified DEL1 as a transcriptional target of the classical E2Fb and E2Fc transcription factors that antagonistically control DEL1 transcript levels through competition for a single E2F cis-acting binding site. Correspondingly with the reported opposite effect of light on the E2Fb and E2Fc protein levels, the transcription of ...

2011-09-01

Dosimetric Implications of Atmospheric Dispersal of Tritium Near a Heavy-water Research Reactor Facility

Porous nanostructured LiFePO{sub 4} powder with a narrow particle size distribution (100-300nm) for high rate lithium-ion battery cathode application was obtained using an ethanol based sol-gel route employing lauric acid as a surfactant. The synthesized LiFePO{sub 4} powders comprised of agglomerates of crystallites <65nm in diameter exhibiting a specific surface area ranging from 8m{sup 2}g{sup -1} to 36m{sup 2}g{sup -1} depending on the absence or presence of the surfactant. The LiFePO{sub 4} obtained using lauric acid resulted in a specific capacity of 123mAhg{sup -1} and 157mAhg{sup -1} at discharge rates of 10C and 1C with less than 0.08% fade per cycle, respectively. Structural and microstructural characterization were performed using X-ray diffraction (XRD), scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM) with energy dispersive X-ray (EDX) analysis while electronic conductivity and ...

2007-01-01

A study of D{sup 0} production from 500 GeV pi{sup -}--nucleon interactions

An estimate of the tritium dose to the public in the vicinity of the heavy water research reactor facility at AECL-Chalk River Laboratories, Ontario, Canada, has largely been accomplished from analyses on regularly-collected samples of air, precipitation, drinking water and foodstuffs (pasture, fruit, vegetables and milk) and environmental dose models. To increase the confidence with which public doses are calculated, tritium doses were estimated directly from the ratio of tritiated species in urine samples from members of the general public. Single cumulative 24 h urine samples from a few adults living in the vicinity of the heavy-water research reactor facility at Chalk River Laboratories, Canada were collected and analysed for tritiated water and organically bound tritium. The participants were from Ottawa (200 km east), Deep River (10 km west) and Chalk River Laboratories. Tritiated water concentrations in urine ranged from 6.5 Bq.l{sup -1} for the Ottawa resident to 15.9 Bq.l{sup ...

2001-07-01