Coccoliths are major contributors to the particulate inorganic carbon in the
ocean that is a key part of the carbon cycle. The coccoliths are a few micrometres
in length and weigh a few picogrammes. ...Their birefringence characteristics in
polarized optical microscopy have been used to estimate their mass. This
method is rapid and precise because camera sensors produce excellent
measurements of light. However, the current method is limited because it
requires a precise and replicable set-up and calibration of the light in the
optical equipment. More precisely, the light intensity, the diaphragm
opening, the position of the condenser and the exposure time of the camera
have to be strictly identical during the calibration and the analysis of
calcite crystal. Here we present a new method that is universal in the sense
that the thickness estimations are independent from a calibration but
result from a simple equation. It can be used with different cameras and
microscope brands. Moreover, the light intensity used in the microscope does
not have to be strictly and precisely controlled. This method permits the
measurement of crystal thickness up to 1.7 µm. It is based on the use of one
left circular polarizer and one right circular polarizer with a
monochromatic light source using the following equation: d=λπΔnarctanILRILL, where d is the thickness, λ the wavelength of the light used,
Δn the birefringence, and ILR and ILL the light intensity
measured with a right and a left circular polarizer. Because of the
alternative and rotational motion of the quarter-wave plate of the circular
polarizer, we coined the name of this method “bidirectional circular
polarization” (BCP).
Identification of microfossils is usually done by expert taxonomists and requires time and a significant amount of systematic knowledge developed over many years. These studies require manual ...identification of numerous specimens in many samples under a microscope, which is very tedious and time-consuming. Furthermore, identification may differ between operators, biasing reproducibility. Recent technological advances in image acquisition, processing and recognition now enable automated procedures for this process, from microscope image acquisition to taxonomic identification.
The CPLEAR detector at CERN Adler, R.; Albrecht, W.; Alhalel, T. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
09/1996, Letnik:
379, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The CPLEAR collaboration has constructed a detector at CERN for an extensive programme of CP-, T- and CPT-symmetry studies using K
0 and
K
0 produced by the annihilation of
p
's in a hydrogen gas ...target. The K
0 and
K
0 are identified by their companion products of the annihilation K
±
π
∓ which are tracked with multiwire proportional chambers, drift chambers and streamer tubes. Particle identification is carried out with a liquid Cherenkov detector for fast separation of pions and kaons and with scintillators which allow the measurement of time of flight and energy loss. Photons are measured with a lead/gas sampling electromagnetic calorimeter. The required antiproton annihilation modes are selected by fast online processors using the tracking chamber and particle identification information. All the detectors are mounted in a 0.44 T uniform field of an axial solenoid of diameter 2 m and length 3.6 m to form a magnetic spectrometer capable of full on-line reconstruction and selection of events. The design, operating parameters and performance of the subdetectors are described.
The Bugey 3 neutrino detector Abbes, M; Achkar, B; Ait-Boubker, S ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
05/1996, Letnik:
374, Številka:
2
Journal Article
Recenzirano
The Bugey 3 experiment, designed to measure oscillations of reactor neutrinos, has used 3 identical detection modules, each of 600 liters, filled with a new
6Li-loaded liquid scintillator. These ...modules were located in two shielding bunkers, respectively 15 and 40 m away from the reactor core. We describe here the mechanical characteristics of these modules, their shielding, the associated electronics, the trigger, the acquisition systems, the calibration and monitoring of these detectors, and the Monte Carlo simulations of their response to particles. We conclude on the overall performance of this new detection technique which has allowed the recording of 120000 neutrino interactions with good neutron efficiency (49%), low background (2.5 evts/hr) and good energy resolution (4% at 4.4 MeV).
Gate arrays are used for parallel processing and fast shower foot recognition, in the electromagnetic calorimeter of the CP violation experiment at LEAR, CERN.
To define and validate a classification of favorable high-risk prostate cancer that could be used to personalize therapy, given that consensus guidelines recommend similar treatments for all ...radiation-managed patients with high-risk disease.
We studied 3618 patients with cT1-T3aN0M0 high-risk or unfavorable intermediate-risk prostate adenocarcinoma treated with radiation at a single institution between 1997 and 2013. Favorable high-risk was defined as T1c disease with either Gleason 4 + 4 = 8 and prostate-specific antigen <10 ng/mL or Gleason 6 and prostate-specific antigen >20 ng/mL. Competing risks regression was used to determine differences in the risk of prostate cancer–specific mortality (PCSM) after controlling for baseline factors and treatment. Our results were validated in a cohort of 13,275 patients using the Surveillance, Epidemiology, and End Results (SEER)-Medicare linked database.
Patients with favorable high-risk disease had significantly better PCSM than other men with high-risk disease (adjusted hazard ratio AHR 0.42, 95% confidence interval CI 0.18-0.996, P=.049) and similar PCSM as men with unfavorable intermediate-risk disease (AHR 1.17, 95% CI 0.50-2.75, P=.710). We observed very similar results within the SEER-Medicare cohort (favorable high-risk vs other high-risk: AHR 0.21, 95% CI 0.11-0.41, P<.001; favorable high-risk vs unfavorable intermediate-risk: AHR 0.67, 95% CI 0.33-1.36, P=.268).
Patients with favorable high-risk prostate cancer have significantly better PCSM than other patients with high-risk disease and similar PCSM as those with unfavorable intermediate-risk disease, who are typically treated with shorter-course androgen deprivation therapy. This new classification system may allow for personalization of treatment within high-risk disease, such as consideration of shorter-course androgen deprivation therapy for favorable high-risk disease.
Résumé Cet article réactualise les observations empiriques formulées il y a plus de cinquante ans sur l’organisation corporatiste de la haute fonction publique en France en les réinsérant dans une ...analyse comparée des marchés du travail administratifs. En nous appuyant sur les travaux de Neil Fligstein, nous proposons de considérer les marchés du travail administratifs comme des constructions institutionnelles, produits des interactions entre trois types d’acteurs : des groupes professionnels, des organisations administratives et des dirigeants politiques. Nous construisons ensuite trois idéaux-types de marchés du travail administratifs pouvant servir de guide à la comparaison des trajectoires d’institutionnalisation de la haute fonction publique dans différents pays.
An asynchronous version of a binary pixel readabout circuit has been implemented in an array with 16 columns at 500 mu m pitch and 63 rows at 75 mu m pitch. This readabout chip has been bonded with ...solder bumps to a silicon detector with matching pixel elements. Event information in a pixel can be strobed into a local memory by a trigger signal and subsequently read out. Without a strobe the information is continuously cleared. The complete hybrid detector has been successfully tested with ionizing particles from a radioactive source. Three such devices have been put in the CERN heavy-ion experiment WA94 in the Omega spectrometer, where they recorded particle tracks from high-multiplicity /sup 32/S interactions. Preliminary data indicate a noise of approximately 60 e/sup -/ and a threshold spread of approximately 500 e/sup -/. The timing characteristics are adequate for a fixed-target experiment.< >
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