bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the rationality of certain type A Galois representations
Authors: Hui Chun Yin 
Published: February 2017

Let

X
X

be a complete smooth variety defined over a number field

K
K

and let

i
i

be an integer. The absolute Galois group

G
a
l

K

\mathrm {Gal}_K

of

K
K

acts on the

i
i

th étale cohomology group

H

e
´

t

i

(

X

K
¯

,

Q

ℓ

)

H^i_{\mathrm {\acute {e}t}}(X_{\bar K},\mathbb {Q}_\ell )

for all primes

ℓ
\ell

, producing a system of

ℓ
\ell

-adic representations

{

Φ
ℓ

}
ℓ

\{\Phi _\ell \}_\ell

. The conjectures of Grothendieck, Tate, and Mumford-Tate predict that the identity component of the algebraic monodromy group of

Φ
ℓ

\Phi _\ell

admits a reductive

Q

\mathbb {Q}

-form that is independent of

ℓ
\ell

if

X
X

is projective. Denote by

Γ
ℓ

\Gamma _\ell

and

G

ℓ

\mathbf {G}_\ell

respectively the monodromy group and the algebraic monodromy group of

Φ
ℓ

s
s

\Phi _\ell ^{\mathrm {ss}}

, the semisimplification of

Φ
ℓ

\Phi _\ell

. Assuming that

G

ℓ
0

\mathbf {G}_{\ell _0}

satisfies some group theoretic conditions for some prime

ℓ
0

\ell _0

, we construct a connected quasi-split

Q

\mathbb {Q}

-reductive group

G

Q

\mathbf {G}_{\mathbb {Q}}

which is a common

Q

\mathbb {Q}

-form of

G

ℓ
∘

\mathbf {G}_\ell ^\circ

for all sufficiently large

ℓ
\ell

. Let

G

Q

s
c

\mathbf {G}_{\mathbb {Q}}^{\mathrm {sc}}

be the universal cover of the derived group of

G

Q

\mathbf {G}_{\mathbb {Q}}

. As an application, we prove that the monodromy group

Γ
ℓ

\Gamma _\ell

is big in the sense that

Γ
ℓ

s
c

≅

G

Q

s
c

(

Z

ℓ

)

\Gamma _\ell ^{\mathrm {sc}}\cong \mathbf {G}_{\mathbb {Q}}^{\mathrm {sc}}(\mathbb {Z}_\ell )

for all sufficiently large

ℓ
\ell

.
Spring diet of ringed seals (Phoca hispida) from northwestern Spitsbergen, Norway
Authors: Labansen Aili L. , Lydersen Christian , Haug Tore , Kovacs Kit M. 
Published: February 2017

AbstractLabansen, A. L., Lydersen, C., Haug, T., and Kovacs, K. M. 2007. Spring diet of ringed seals (Phoca hispida) from northwestern Spitsbergen, Norway. – ICES Journal of Marine Science, 64: 1246–1256. Complete gastro-intestinal tracts (GITs) from 267 ringed seals from five different locations in Spitsbergen were collected during spring of the years 2002–2004. Diet was assessed based on hard part remains from prey. Invertebrates constituted <2% of all prey (relative frequency, Ni). Fish otoliths were found in all seals; 1.7, 34.3, and 64.0% of the recovered otoliths were found in the stomach, small and large intestines, respectively, emphasizing the importance of analysing the whole GIT, not only the stomach. Otoliths from stomachs and small intestines with minimal signs of erosion were measured to back-calculate pre-ingested prey size and biomass. Based on measured polar cod (Boreogadus saida) otoliths (n = 7007), the ringed seals fed on fish in the length range 44.4–229.2 mm, primarily consuming the youngest year classes. Adult females ate smaller polar cod more often than adult males or juveniles. Polar cod dominated the diet, with a frequency of occurrence (FO) of 100%, Ni of 71.9%, and a biomass contribution of 77.2%. The taxon Stichaeidae was the second most frequent prey type (FO = 55.6%) followed by Cottidae (FO = 35.6%). The diet of ringed seals from one locality markedly differed from the others, with a greater species diversity, low Ni of polar cod (15%), and a dominance of Stichaeidae (Ni = 67%). Location of sampling, as well as sex and age of the seals, had significant influences on ringed seal diet in spring.
Infections caused by KPC-producing Klebsiella pneumoniae: differences in therapy and mortality in a multicentre study
Authors: Tumbarello Mario , Trecarichi Enrico Maria , De Rosa Francesco Giuseppe , Giannella Maddalena , Giacobbe Daniele Roberto , Bassetti Matteo , Losito Angela Raffaella , Bartoletti Michele , Del Bono Valerio , Corcione Silvia , Maiuro Giuseppe , Tedeschi Sara , Celani Luigi , Cardellino Chiara Simona , Spanu Teresa , Marchese Anna , Ambretti Simone , Cauda Roberto , Viscoli Claudio , Viale Pierluigi ,   on behalf of ISGRI-SITA (Italian Study Group on Resistant Infections of the Società Italiana Terapia Antinfettiva)
Published: February 2017

Abstract

Objectives
Infections caused by Klebsiella pneumoniae (Kp) carbapenemase (KPC)-producing strains of Kp have become a significant threat in recent years. To assess their outcomes and identify risk factors for 14 day mortality, we conducted a 4 year (2010–13) retrospective cohort study in five large Italian teaching hospitals.

Methods
The cohort included 661 adults with bloodstream infections (BSIs; n = 447) or non-bacteraemic infections (lower respiratory tract, intra-abdominal structure, urinary tract or other sites) caused by a KPC-Kp isolate. All had received ≥48 h of therapy (empirical and/or non-empirical) with at least one drug to which the isolate was susceptible.

Results
Most deaths occurred within 2 weeks of infection onset (14 day mortality: 225/661, 34.1%). Logistic regression analysis identified BSI (OR, 2.09; 95% CI, 1.34–3.29), presentation with septic shock (OR, 2.45; 95% CI, 1.47–4.08), inadequate empirical antimicrobial therapy (OR, 1.48; 95% CI, 1.01–2.18), chronic renal failure (OR, 2.27; 95% CI, 1.44–3.58), high APACHE III score (OR, 1.05; 95% CI, 1.04–1.07) and colistin-resistant isolates (OR, 2.18; 95% CI, 1.37–3.46) as independent predictors of 14 day mortality. Combination therapy with at least two drugs displaying in vitro activity against the isolate was associated with lower mortality (OR, 0.52; 95% CI, 0.35–0.77), in particular in patients with BSIs, lung infections or high APACHE III scores and/or septic shock at infection onset. Combinations that included meropenem were associated with significantly higher survival rates when the KPC-Kp isolate had a meropenem MIC of ≤8 mg/L.

Conclusions
KPC-Kp infections are associated with high mortality. Treatment with two or more drugs displaying activity against the isolate improves survival, mainly in patients who are critically ill.
Technical and Administrative Anomalies in a Large TL Dosimetry Service
Authors: Grogan D. , Bradley R.P. , Scott J.G. 
Published: February 2017

Abstract
Thermoluminescence dosimetry is widely used for occupational monitoring of radiation workers and it has significant advantages when compared with more traditional methods such as film. However, there are also disadvantages caused by technical anomalies which appear in dosemeter signals. The Canadian Department of National Health and Welfare has provided personnel monitoring services for radiation workers since 1950, and in the period 1976 to 1981 converted all its monitoring, with the exception of neutron dosimetry, from film to TLD. The treatment of anomalous TLD data is described in this paper. While emphasis is placed on technically anomalous results including contamination, faulty holder, damage, thermal neutrons, ultraviolet exposures and other questionable results, the handling of administrative anomalies such as exposed control monitors, late dosemeters, non-personal exposures and return of dosemeters previously declared lost is also addressed. The statistical occurrence of such anomalies for the period 1981 to 1985 inclusive is shown.
Automated Counting and Analysis of Etched Tracks in CR-39 Plastic
Authors: Majborn B. 
Published: February 2017

Abstract
An image analysis system has been set up which is capable of automated counting and analysis of etched nuclear particle tracks in plastic. The system is composed of an optical microscope, CCD camera, frame grabber, personal computer, monitor, and printer. The frame grabber acquires and displays images at video rate. It has a spatial resolution of 512 x 512 pixels with 8 bits of digitisation corresponding to 256 grey levels. The software has been developed for general image processing and adapted for the present purpose. Comparisons of automated and visual microscope counting of tracks in chemically etched CR-39 detectors are presented with emphasis on results of interest for practical radon measurements or neutron dosimetry, e.g. calibration factors, background track densities and variations in background.
A TL Dosemeter that Estimates the Dose and Energy Distribution of Environmental Gamma Radiation
Authors: Bøtter-Jensen L. , Furuta S. , Nielsen S.P. 
Published: February 2017

Abstract
Nuclear power accidents have demonstrated the need for reliable passive dosemeters that can estimate the doses from effluent gamma emitters with a wide range of energies, and give information on the energy distribution of the environmental gamma radiation. For this purpose, experimentally obtained energy responses from a TL dosemeter combination consisting of five CaSO4:Dy dosemeters with different filters were used as input for the SAND II computer code (Spectrum Analysis by Neutron Detectors) that had been adapted to evaluate the energy distribution of environmental gamma radiation and related doses. The dosemeters were exposed to radiation from the natural environment as well as that produced by artificial sources, and the estimated gamma ray energy distributions and doses were tested against results from measurements made with a sodium iodide spectrometer and a high pressure ionisation chamber.
Present State of Art of TSEE Dosimetry
Authors: Scharmann A. , Kriegseis (INVITED) W. 
Published: February 2017

Abstract
The principles and application potentials of the TSEE method for dosimetry are reviewed. The physical and dosimetric properties of BeO thin film detectors, the most advanced TSEE dosemeters at present, are described in detail. These detectors differ in their TSEE behaviour from ceramic BeO because of their smaller grain size, which reduces spurious effects caused by the pyroelectric properties of BeO.
Mechanism of Thermally Stimulated Luminescence in LiF (TLD-100) Below Room Temperature
Authors: Jain V.K. 
Published: February 2017

Abstract
The thermoluminescence of LiF (TLD-100) has been studied from liquid nitrogen temperatures to room temperature. The glow curve contains at least nine peaks (137, 149, 166, 187, 202, 228, 254, 275 and 287K). Four of which (137, 149, 187 and 254K) are isolated by partial thermal annealing and their activation energies are determined. Up to a temperature of about 140K, the emission spectrum consists of three bands at 250, 305, and 420 nm, up to about 200K of two bands at 305 and the 420 nm and at still higher temperatures only the 420 nm band. Two peaks, 149 and 275K, are also produced by phototransfer from filled traps above RT with two emission bands (315 and 440/450 nm). Mayhugh's model delivers a 420 nm emission. The 250 nm emission band is explained by the recombination of Vk holes at another luminescence centre and the 305 nm emission by the recombination of Vk holes with electrons.
TSEE and TL of Crystallised Tetraborate Glasses Irradiated at LNT
Authors: Kutomi Y. , Tomita A. , Takeuchi N. 
Published: February 2017

Abstract
TSEE and TL of Li2B4O7 crystallised glasses X irradiated at liquid nitrogen temperature were investigated and also the effects of activators in these materials. It was found that AgCl, CuCl2 or TbCl3 doped samples as well as an undoped one showed strong TSEE peaks at about -40 and 100 oC. They also showed less intense TSEE peaks at about -100, 200, 230 and 300 oC. TL glow peaks were also observed (the heating rate was 20 oC.min-1). The TSEE peaks were observed even from samples without previous X irradiation at LNT. This may have been due to the thermal release of stress induced in Li2B4O7 micro-crystals by the quenching to LNT from RT, because Li2B4O7 single crystals belong to the 4 mm point group and are piezoelectric. Some TL glow peaks were also observed in these quenched samples without X irradiation. A slight change in the X ray powder diffraction pattern analysis was observed for quenched Li2B4O7 sample around 100 oC, which was not observed for unquenched samples.
Field Calibration Technique for Albedo Neutron Dosemeters
Authors: Burgkhardt B. , Piesch E. 
Published: February 2017

Abstract
For field calibrations of a two-component albedo dosemeter, a polyethylene sphere of 30 cm diameter with the same type of TL detector in the centre serves as a reference dosemeter and as a phantom for the albedo dosemeter. With respect to angular dependence, the reference dosemeter indicates the ambient dose equivalent H*(10) and the personnel dosemeter the individual dose equivalent H'(10). The problem of calibration in nearly isotropic radiation fields has been overcome by (a) the assumption that personal dosemeters should preferably indicate H'(10) for irradiations from the front half space only and, (b) the field calibration technique which adds the reading of two albedo dosemeters irradiated in diametrically opposed positions on the surface of the sphere. Thus, the albedo response has sufficient angular independence and a conservative characteristic for the indication of H'(10) in personnel dosimetry. The results of field calibrations here show that the variety of neutron fields can be classified into four typical application areas. Within one of these types of neutron fields, the albedo response does not vary by more than a factor of two. For reactors, linacs and the fuel element cycle, a constant calibration factor is used. For radionuclide sources and particle accelerators the albedo response relative to the actual reading ratio of the thermal neutron and the albedo detector in the personal dosemeter is used to correct for local or workplace dependent changes of the albedo response. The calibration data are applicable to other TLD systems and to stray neutron fields.
Numerical Study of the Influence of Phantom Material and Shape on the Calibration of Individual Dosemeters for Neutrons
Authors: Bauer B.W. , Hollnagel R. , Siebert B.R.L. 
Published: February 2017

Abstract
The use of appropriate phantoms for the calibration of individual neutron monitors is necessary, as the shape and the material of the phantom significantly influence the reading of such monitors. The International Commission on Radiation Units and Measurements (ICRU) considers the ICRU sphere to be suitable. This in practice may be questionable. A systematic numerical study of the influence of various phantoms on the readings of thermoluminescent detectors (TLDs) and etched track detectors (TEDs) has been performed. Elliptical cylinders consisting of ICRU soft tissue or polyethylene and resembling the trunk of an exposed person, with or without a cavity simulating the lung volume, have been compared with the ICRU sphere. In certain irradiation situations the readings of dosemeters exposed on elliptical cylindrical phantoms can be appreciably higher than on the ICRU sphere. If fast neutrons cannot be neglected, it may be necessary to use an anthropomorphic calibration phantom for both albedo dosemeters and etched track detectors.
Calibration Procedures for Determining the Radiation Response Characteristics of Neutron Measuring Devices Used for Radiation Protection
Authors: Schraube H. , Chartier J.L. , Cosack M. , Delafield H.J. , Hunt J.B. , Schwartz R.B. 
Published: February 2017

Abstract
The proposals of an ISO working group (ISO-TC85/SC2/WG2) for standardising the procedures to be used for the calibration of neutron measuring devices are summarised. Definitions and techniques are given both for type testing and routine calibration. The aim of the standard is to obtain calibration factors independent of the particular calibration facility or experimental technique employed.
CIRCEG, A Portable Device for Photon-Neutron Dosimetry
Authors: Marchetto A. , Leroux J.B. , Herbaut Y. , Latu M. , Tinelli P. 
Published: February 2017

Abstract
A portable photon-neutron dosemeter has been developed for working area and environmental monitoring. The electronic device called CIRCEG consists of a 256-channel pulse height analyser and a microprocessor system. Associated with a tissue equivalent proportional counter it gives the absorbed dose and the dose equivalent for photons and neutrons in a single measurement. Moreover, it computes the quality factor and displays the microdosimetric distributions in lineal energy (y). The materials, methods and experimental results are described. The range of dose equivalent rates due to neutrons is from 1 µSv.h-1 to 0.1 Sv.h-1.
Measurement of Neutrons from High Energy Electron Linear Accelerators
Authors: Sherwin A.G. , Pearson A.J. , Richards D.J. , O'Hagan J.B. 
Published: February 2017

Abstract
Electron linear accelerators (linacs) above 10 MeV are capable of generating significant neutron fluxes, particularly when operating in the X ray mode. This paper describes a prototype passive, integrating system for neutron measurements, based on the plastic etch-pit technique, and the methodology used to determine neutron leakage from linacs. Results are presented from measurements on several machines, and are compared with those obtained using an established gold activation technique. Close agreement was observed. The results also indicate that neutron leakage may be a function of machine age and state of adjustment.
Clinical Dosimetry of High Energy Neutron Beams: Future Developments
Authors: Mijnheer (INVITED) B.J. 
Published: February 2017

Abstract
Accuracy requirements for the assessment of absorbed dose in a patient irradiated by high energy neutron beams will be formulated by analysing dose-effect curves for local tumour control and for normal tissue complications. Uncertainties in the various steps in the delivery of the prescribed absorbed dose in a patient will then be estimated for both fast neutron and megavoltage X ray beams. At present, even for simple treatment conditions, the proposed accuracy in absorbed dose delivery cannot be fully achieved in photon therapy while fast neutron therapy is even less accurate. Reduction of type A uncertainties can be obtained by an extensive quality control programme, including dosimetry intercomparisons under actual treatment conditions applying dose calculations using the computer planning system. Reduction of type B uncertainties can be obtained by performing dosemeter calibrations directly in neutron beams and by better knowledge of the physical parameters employed in ionisation chamber dosimetry. Recommendations given in the new ICRU Report on Clinical Neutron Dosimetry, and accepted by both US and European groups, will be discussed. With the increasing clinical interest in three dimensional dose distributions, methods for dose calculations have to be refined. Some recent developments for photon beams will be discussed and possible application of these procedures in neutron dosimetry will be indicated.
Dosimetry Research Using Low Pressure Proportional Counters for Neutrons with Energies up to 60 MeV
Authors: Menzel H.G. , Pihet P. , Folkerts K.H. , Dahmen P. , Grillmaier R.E. 
Published: February 2017

Abstract
Low pressure proportional counters (PC) with walls made of A-150 plastic and graphite were used to measure ionisation yield spectra and kerma in radiation fields designed to produce monoenergetic neutrons in the energy range of 20-70 MeV at the Swiss Institute for Nuclear Research (SIN). The investigation at nominal energies of 27.8, 39.7 and 60.3 MeV has shown that the PC is a suitable instrument for dosimetry research in this energy range also. The spectrum information can be used to study absorbed dose build-up in detail. The combined graphite and A-150 measurements were used to evaluate gas-to-wall absorbed dose conversion factors. The kerma ratio of carbon to A-150 follows the shape of curves for theoretical values but is systematically lower. This is explained by a contamination of the beam with low energy neutrons.
Microdosimetric Investigations for Neutron Therapy
Authors: Schmidt R. , Hess A. 
Published: February 2017

Abstract
Microdosimetric investigations are commonly performed to determine the radiation quality of neutron sources applied in radiotherapy. At the DT neutron therapy unit of the University Hospital at Hamburg-Eppendorf, microdosimetric spectra were measured with spherical proportional counters at different positions in a solid tissue-equivalent phantom. Counters with different types of wall materials were used to analyse the spectra with respect to the relative contribution of the different types of charged particles to the total absorbed dose. An iterative procedure usually applied for activation analysis was modified to evaluate RBEs relative to lineal energy functions from radiobiological and microdosimetric data. A set of RBE values obtained with the Withers system at various neutron sources was used together with the corresponding microdosimetric spectra. A second set of data resulting from an earlier biological and microdosimetric intercomparison is used to show the sensitivity of the unfolding procedure to changes in the data base.
Experimental Verification of the Accuracy of A 2-D Dose Calculation Algorithm for A d(8)D2(8) Neutron Beam Incident on Curved Surfaces
Authors: Kuchnir F.T. , Pelizzari C.A. , Reft C.S. 
Published: February 2017

Abstract
The computerised treatment planning algorithm used at the University of Chicago Neutron Therapy Facility is based on linear interpolation of experimental beam data. These were obtained by relative ionisation measurements with a TE chamber in TE solution contained in a large square phantom with the beam incident normally onto a flat surface. Under these conditions, the d(50%) for a beam 12 x 12 cm2 at 105 cm from the target is 10.2 g.cm-2. In the dose calculation algorithm, surface curvature is taken into account by using the ratio of TPRs for the density weighted path lengths for the oblique and central rays. The purpose of this work is to test this calculation approximation by comparing measurements and calculations in a cylindrical, water-filled phantom with variable curvature cross section. Results of measurements and calculations are presented for two beam geometries.
Treatment Planning Comparison of Low and High Energy Neutron Therapy
Authors: Chen G.T.Y. , Reft C. , Spelbring D , Kuchnir F.T. , Rosenberg I. , Sutton H. 
Published: February 2017

Abstract
A treatment planning comparison between rival plans using low and high energy neutron beams in a mixed photon/neutron treatment plan for carcinoma of the prostate has been analysed. Dose volume histograms of critical structures and the target are presented. It is concluded that differences in the composite dose distribution are small when mixed beams are used.
Electrical Charge in Radon Daughter Deposition: A Critical Review
Authors: Marlow (INVITED) W.H. 
Published: February 2017

Abstract
The roles that electric charges play in the various deposition processes of radon daughter atoms has been a matter of conjecture for many years. In this review, several possible effects of charge are described. The sources of cluster ions in indoor air and their attachment to aerosol particles are then considered. Since the 'background' aerosol is central to the questions of deposition, its physical behaviour is discussed in the context of charge attachment and other properties. Data from experiments on decay product neutralisation during the first few seconds after birth, room air interactions from several different types of experiments, and deposition following inhalation are then reviewed. The interpretation of these experiments is given and directions for research needed better to identify critical issues are isolated.