bluuebunny/crossref_metadata_2025_split huggingface dataset:
Testing of Statistical Procedures for Use in Optimization of Reactor Performance Under Aged Conditions
Authors: Serghiuta Dumitru , Tholammakkil John , Hammouda Naj , O’Hagan Anthony 
Published: November 2014

This paper discusses a framework for designing artificial test problems, evaluation criteria, and two of the benchmark tests developed under a research project initiated by the Canadian Nuclear Safety Commission to investigate the approaches for qualification of tolerance limit methods and algorithms proposed for application in optimization of CANDU reactor protection trip setpoints for aged conditions. A significant component of this investigation has been the development of a series of benchmark problems of gradually increased complexity, from simple “theoretical” problems up to complex problems closer to the real application.
The first benchmark problem discussed in this paper is a simplified scalar problem which does not involve extremal, maximum or minimum, operations, typically encountered in the real applications. The second benchmark is a high dimensional, but still simple, problem for statistical inference of maximum channel power during normal operation.
Bayesian algorithms have been developed for each benchmark problem to provide an independent way of constructing tolerance limits from the same data and allow assessing how well different methods make use of those data and, depending on the type of application, evaluating what the level of “conservatism” is. The Bayesian method is not, however, used as a reference method, or “gold” standard, but simply as an independent review method.
The approach and the tests developed can be used as a starting point for developing a generic suite (generic in the sense of potentially applying whatever the proposed statistical method) of empirical studies, with clear criteria for passing those tests. Some lessons learned, in particular concerning the need to assure the completeness of the description of the application and the role of completeness of input information, are also discussed.
It is concluded that a formal process, which should include extended and detailed benchmark tests, but targeted to the context of the particular application and aimed at identifying the domain of validity of the proposed tolerance limit method and algorithm, is needed and might provide the necessary confidence in the proposed statistical procedure.
Re-Establishment of the Nuclear Engineering Program at Virginia Tech
Authors: Brown Eugene F. , Haghighat Alireza , Pierson Mark 
Published: November 2014

One of the first nuclear engineering programs in the United States was established at Virginia Tech in the mid-1950’s and continued until the mid-1980’s when it was abandoned due to a drop both in student interest and government support. In 2006, as a result of interest shown by the nuclear industry in Virginia, discussions were undertaken that led to the approval to offer Master’s and Doctorate Degrees in nuclear engineering in 2013. In parallel with these efforts, we began teaching undergraduate courses in anticipation of offering a minor in nuclear engineering to all Virginia Tech engineering and science students. Currently we have 140 undergraduate students taking nuclear engineering classes, nuclear engineering undergraduate research hours, and participating in nuclear-engineering-related senior design activities.
Our program has been conceived and designed with the objective of providing the nuclear engineering workforce required to address the most important nuclear-related issues of our time including: enhancing the safe and productive use of nuclear energy; contributing to the development of advanced technologies for national and international nuclear security and safeguards; developing advanced medical devices for nuclear diagnostics and therapy; and the establishment of effective policies for the utilization of nuclear energy and its regulation.
The Master’s degree program involves 7 courses and the equivalent of two semesters of thesis research for a total of 30 credit hours. The PhD program, which builds on the Master’s degree program, requires 5 additional courses, and the equivalent of 4 semesters of dissertation research for a total of 60 credit hours beyond the Master’s degree. The curriculum is supported by a rigorous, benchmarked assessment and evaluation process to assure that the goals of the program are attained.
Currently five faculty members support the nuclear engineering program, and typical total enrollment in our graduate programs runs between 35 and 50 students. When we reach full strength, with the addition of two more nuclear engineering faculty members, we expect to be graduating 12 Master’s students and 7 PhD students per year.
What is the Relationship Between Quality, Quality Assurance and the Section III Design Specification
Authors: Barnes Richard W. 
Published: November 2014

This paper explores the relationship between the Design Specification required for each Section III component and the terms Quality, Quality Assurance, Quality Product, and Management System (Quality Management System). The author’s experience indicates that the relationship between Quality and Quality Assurance is poorly understood and that the resistance experienced to the implementation of a Quality Assurance Program is often due to the person’s lack of understanding that a Quality Assurance Program really does help people do their work “right the first time”.
This lack of understanding often results in poorly defined requirements in the purchasing documents, inadequate definition of scope and a product that does not meet requirements. Even more importantly it can lead to the development of poor relationships between the purchaser and the supplier and particularly in the nuclear field, poor relationships with Regulators. The economic impact is also significant, delays in schedule, delays in product acceptance and payment results in costs that are eventually passed on to the consumer.
Once the above relationships are properly understood and appreciated resistance can turn into positive acceptance. The Section III concept of providing a Design Specification as a complete basis for construction also takes on new meaning.
Mathematical Modeling for Contingency Determination for Nuclear Power Plant Construction Projects
Authors: Zhao Wei , Xu Shenjun 
Published: November 2014

This paper uses the China AP1000 project as an example to exhibit the application of quantitative risk management in nuclear power plant construction projects. For those lump sum contracts, one of the most significant purposes of quantitative risk management is to determine the contingency, i.e. the reserved money and time for projects. This paper studies the application of Monte Carlo simulation in determining the contingency, taking into account the distinctive features of nuclear power projects.
Most nuclear power projects, especially advanced ones such as Generation III and above, meet one common obstacle in estimating key economic indicators — the absence of historical data due to its avant-garde design. As cost estimators of the coal power plant contractors may collect their data from thousands of previous cases, nuclear power plant contractors, especially in many developing countries, do not have a shared database of financial data. Some first-of-a-kind nuclear power plants have absolutely no historical data to look up.
This paper aims to provide a resolution to this problem. First, the feasibility and representativeness of different probability distributions are compared based on their respective skewness and kurtosis to determine the best-suited distribution in nuclear power projects. This paper also analyzes the use of second-order Monte Carlo simulation in reducing the error caused by the biased estimation of inexperienced risk assessment engineers.
Development of a 6DOF robotic motion phantom for radiation therapy
Authors: Belcher Andrew H. , Liu Xinmin , Grelewicz Zachary , Pearson Erik , Wiersma Rodney D. 
Published: November 2014

Purpose:The use of medical technology capable of tracking patient motion or positioning patients along 6 degree‐of‐freedom (6DOF) has steadily increased in the field of radiation therapy. However, due to the complex nature of tracking and performing 6DOF motion, it is critical that such technology is properly verified to be operating within specifications in order to ensure patient safety. In this study, a robotic motion phantom is presented that can be programmed to perform highly accurate motion along any X (left–right), Y (superior–inferior), Z (anterior–posterior), pitch (around X), roll (around Y), and yaw (around Z) axes. In addition, highly synchronized motion along all axes can be performed in order to simulate the dynamic motion of a tumor in 6D. The accuracy and reproducibility of this 6D motion were characterized.Methods:An in‐house designed and built 6D robotic motion phantom was constructed following the Stewart–Gough parallel kinematics platform archetype. The device was controlled using an inverse kinematics formulation, and precise movements in all 6 degrees‐of‐freedom (X, Y, Z, pitch, roll, and yaw) were performed, both simultaneously and separately for each degree‐of‐freedom. Additionally, previously recorded 6D cranial and prostate motions were effectively executed. The robotic phantom movements were verified using a 15 fps 6D infrared marker tracking system and the measured trajectories were compared quantitatively to the intended input trajectories. The workspace, maximum 6D velocity, backlash, and weight load capabilities of the system were also established.Results:Evaluation of the 6D platform demonstrated translational root mean square error (RMSE) values of 0.14, 0.22, and 0.08 mm over 20 mm in X and Y and 10 mm in Z, respectively, and rotational RMSE values of 0.16°, 0.06°, and 0.08° over 10° of pitch, roll, and yaw, respectively. The robotic stage also effectively performed controlled 6D motions, as well as reproduced cranial trajectories over 15 min, with a maximal RMSE of 0.04 mm translationally and 0.04° rotationally, and a prostate trajectory over 2 min, with a maximal RMSE of 0.06 mm translationally and 0.04° rotationally.Conclusions:This 6D robotic phantom has proven to be accurate under clinical standards and capable of reproducing tumor motion in 6D. Such functionality makes the robotic phantom usable for either quality assurance or research purposes.
Few‐view cone‐beam CT reconstruction with deformed prior image
Authors: Zhang Hua , Ouyang Luo , Huang Jing , Ma Jianhua , Chen Wufan , Wang Jing 
Published: November 2014

Purpose:Prior images can be incorporated into the image reconstruction process to improve the quality of subsequent cone‐beam CT (CBCT) images from sparse‐view or low‐dose projections. The purpose of this work is to develop a deformed prior image‐based reconstruction (DPIR) strategy to mitigate the deformation between the prior image and the target image.Methods:The deformed prior image is obtained by a projection‐based registration approach. Specifically, the deformation vector fields used to deform the prior image are estimated through iteratively matching the forward projection of the deformed prior image and the measured on‐treatment projections. The deformed prior image is then used as the prior image in the standard prior image constrained compressed sensing (PICCS) algorithm. A simulation study on an XCAT phantom and a clinical study on a head‐and‐neck cancer patient were conducted to evaluate the performance of the proposed DPIR strategy.Results:The deformed prior image matches the geometry of the on‐treatment CBCT more closely as compared to the original prior image. Consequently, the performance of the DPIR strategy from few‐view projections is improved in comparison to the standard PICCS algorithm, based on both visual inspection and quantitative measures. In the XCAT phantom study using 20 projections, the average root mean squared error is reduced from 14% in PICCS to 10% in DPIR, and the average universal quality index increases from 0.88 in PICCS to 0.92 in DPIR.Conclusions:The present DPIR approach provides a practical solution to the mismatch problem between the prior image and target image, which improves the performance of the original PICCS algorithm for CBCT reconstruction from few‐view or low‐dose projections.
Role of Secondary Metabolites in Establishment of the Mutualistic Partnership between Xenorhabdus nematophila and the Entomopathogenic Nematode Steinernema carpocapsae
Authors: Singh Swati , Orr David , Divinagracia Emmanuel , McGraw Joseph , Dorff Kellen , Forst Steven 
Published: November 2014

ABSTRACT

Xenorhabdus nematophila
engages in a mutualistic partnership with the nematode
Steinernema carpocapsae
, which invades insects, migrates through the gut, and penetrates into the hemocoel (body cavity). We showed previously that during invasion of
Manduca sexta
, the gut microbe
Staphylococcus saprophyticus
appeared transiently in the hemocoel, while
Enterococcus faecalis
proliferated as
X. nematophila
became dominant.
X. nematophila
produces diverse secondary metabolites, including the major water-soluble antimicrobial xenocoumacin. Here, we study the role of
X. nematophila
antimicrobials in interspecies competition under biologically relevant conditions using strains lacking either xenocoumacin (Δ
xcnKL
strain), xenocoumacin and the newly discovered antibiotic F (Δ
xcnKL
:F strain), or all
ngrA
-derived secondary metabolites (
ngrA
strain). Competition experiments were performed in Grace's insect medium, which is based on lepidopteran hemolymph.
S. saprophyticus
was eliminated when inoculated into growing cultures of either the Δ
xcnKL
strain or Δ
xcnKL
:F strain but grew in the presence of the
ngrA
strain, indicating that
ngrA
-derived antimicrobials, excluding xenocoumacin or antibiotic F, were required to eliminate the competitor. In contrast,
S. saprophyticus
was eliminated when coinjected into
M. sexta
with either the Δ
xcnKL
or
ngrA
strain, indicating that
ngrA
-derived antimicrobials were not required to eliminate the competitor
in vivo
.
E. faecalis
growth was facilitated when coinjected with either of the mutant strains. Furthermore, nematode reproduction in
M. sexta
naturally infected with infective juveniles colonized with the
ngrA
strain was markedly reduced relative to the level of reproduction when infective juveniles were colonized with the wild-type strain. These findings provide new insights into interspecies competition in a host environment and suggest that
ngrA
-derived compounds serve as signals for
in vivo
nematode reproduction.
A Previously Uncharacterized, Nonphotosynthetic Member of the Chromatiaceae Is the Primary CO
2
-Fixing Constituent in a Self-Regenerating Biocathode
Authors: Wang Zheng , Leary Dagmar H. , Malanoski Anthony P. , Li Robert W. , Hervey W. Judson , Eddie Brian J. , Tender Gabrielle S. , Yanosky Shelley G. , Vora Gary J. , Tender Leonard M. , Lin Baochuan , Strycharz-Glaven Sarah M. 
Published: November 2014

ABSTRACT

Biocathode extracellular electron transfer (EET) may be exploited for biotechnology applications, including microbially mediated O
2
reduction in microbial fuel cells and microbial electrosynthesis. However, biocathode mechanistic studies needed to improve or engineer functionality have been limited to a few select species that form sparse, homogeneous biofilms characterized by little or no growth. Attempts to cultivate isolates from biocathode environmental enrichments often fail due to a lack of some advantage provided by life in a consortium, highlighting the need to study and understand biocathode consortia
in situ
. Here, we present metagenomic and metaproteomic characterization of a previously described biocathode biofilm (+310 mV versus a standard hydrogen electrode [SHE]) enriched from seawater, reducing O
2
, and presumably fixing CO
2
for biomass generation. Metagenomics identified 16 distinct cluster genomes, 15 of which could be assigned at the family or genus level and whose abundance was roughly divided between
Alpha
- and
Gammaproteobacteria
. A total of 644 proteins were identified from shotgun metaproteomics and have been deposited in the the ProteomeXchange with identifier PXD001045. Cluster genomes were used to assign the taxonomic identities of 599 proteins, with
Marinobacter
,
Chromatiaceae
, and
Labrenzia
the most represented. RubisCO and phosphoribulokinase, along with 9 other Calvin-Benson-Bassham cycle proteins, were identified from
Chromatiaceae
. In addition, proteins similar to those predicted for iron oxidation pathways of known iron-oxidizing bacteria were observed for
Chromatiaceae
. These findings represent the first description of putative EET and CO
2
fixation mechanisms for a self-regenerating, self-sustaining multispecies biocathode, providing potential targets for functional engineering, as well as new insights into biocathode EET pathways using proteomics.
Up against the Wall: Is Yeast Cell Wall Integrity Ensured by Mechanosensing in Plasma Membrane Microdomains?
Authors: Kock Christian , Dufrêne Yves F. , Heinisch Jürgen J. 
Published: November 2014

ABSTRACT
Yeast cell wall integrity (CWI) signaling serves as a model of the regulation of fungal cell wall synthesis and provides the basis for the development of antifungal drugs. A set of five membrane-spanning sensors (Wsc1 to Wsc3, Mid2, and Mtl1) detect cell surface stress and commence the signaling pathway upon perturbations of either the cell wall structure or the plasma membrane. We here summarize the latest advances in the structure/function relationship primarily of the Wsc1 sensor and critically review the evidence that it acts as a mechanosensor. The relevance and physiological significance of the information obtained for the function of the other CWI sensors, as well as expected future developments, are discussed.
Draft Genome Sequence of Lactobacillus plantarum CMPG5300, a Human Vaginal Isolate
Authors: Malik Shweta , Siezen Roland J. , Renckens Bernadet , Vaneechoutte Mario , Vanderleyden Jos , Lebeer Sarah 
Published: November 2014

ABSTRACT

The draft genome of a highly auto-aggregating
Lactobacillus plantarum
strain isolated from a human vagina is reported. The peculiar phenotype also provides an adhesive and co-aggregative potential with various pathogens, which could be of significance in the vaginal niche. Detailed genome analysis could aid in identifying the adhesins of the strain.
A population-based observational study of diabetes during pregnancy in Victoria, Australia, 1999–2008
Authors: Abouzeid Marian , Versace Vincent L , Janus Edward D , Davey Mary-Ann , Philpot Benjamin , Oats Jeremy , Dunbar James A 
Published: November 2014

ObjectivesThis paper reports secular trends in diabetes in pregnancy in Victoria, Australia and examines the effect of including or excluding women with pre-existing diabetes on gestational diabetes (GDM) prevalence estimates.DesignPopulation-based observational study.SettingAll births in Victoria, Australia between 1999 and 2008Participants634 932 pregnancies resulting in a birth registered with the Victorian Perinatal Data CollectionOutcome measuresCrude and age-standardised secular trends in pre-existing diabetes and GDM prevalence; secular GDM trends by maternal birthplace; effects on GDM prevalence of including and excluding pre-existing diabetes from the denominator.ResultsOf the 634 932 pregnancies, 2954 (0.5%) occurred in women with pre-existing diabetes and 29 147 (4.6%) were complicated by GDM. Mean maternal age increased from 29.7 years in 1999 to 30.8 years in 2008. GDM prevalence increased in most maternal age groups. In 2008, age-standardised GDM prevalence was 31% higher than in 1999; secular increases were greater for Australian-born non-Indigenous (29% increase) than immigrant women (12.3% increase). The annual number of pregnancies in women with pre-existing diabetes almost doubled from 1999 to 2008 and prevalence increased from 0.4% to 0.6%. However, including or excluding pre-existing diabetes had little effect on GDM prevalence estimates.ConclusionsPre-existing diabetes and GDM prevalence increased in Victoria between 1999 and 2008 and rising maternal age does not fully explain these trends. These findings have important implications for preventive initiatives. Including or excluding small numbers of women with pre-existing diabetes resulted in minimal changes in GDM estimates. As pre-existing diabetes in young women increases, this methodological issue will likely become important.
Multicentre study of investigation and management of inpatient hyponatraemia in the UK
Authors: Tzoulis Ploutarchos , Evans Rhys , Falinska Agnieszka , Barnard Maria , Tan Tricia , Woolman Emma , Leyland Rebecca , Martin Nick , Edwards Rebecca , Scott Rebecca , Gurazada Kalyan , Parsons Marie , Nair Devaki , Khoo Bernard , Bouloux Pierre Marc 
Published: November 2014

Abstract

Purpose
Hyponatraemia is associated with significant morbidity and mortality. The objectives of this study were to evaluate the investigation and management of hyponatraemia and to assess the use of different therapeutic modalities and their effectiveness in routine practice.

Study design
This multicentre, retrospective, observational study was conducted at three acute NHS Trusts in March 2013. A retrospective chart review was performed on the first 100 inpatients with serum sodium (sNa) ≤128 mmol/L during hospitalisation.

Results
One hundred patients (47 male, 53 female) with a mean±SD age of 71.3±15.4 years and nadir sNa of 123.4±4.3 mmol/L were included. Only 23/100 (23%) had measurements of paired serum and urine osmolality and sodium, while 31% had an assessment of adrenal reserve. The aetiology of hyponatraemia was unrecorded in 58% of cases. The mean length of hospital stay was 17.5 days with an inpatient mortality rate of 16%. At hospital discharge, 53/84 (63.1%) patients had persistent hyponatraemia, including 20/84 (23.8%) with sNa &lt;130 mmol/L. Overall 37/100 (37%) patients did not have any treatment for hyponatraemia. Among 76 therapeutic episodes, the most commonly used treatment modalities were isotonic saline in 38/76 cases (50%) and fluid restriction in 16/76 (21.1%). Fluid restriction failed to increase sNa by &gt;1 mmol/L/day in 8/10 (80%) cases compared with 4/26 (15.4%) for isotonic saline.

Conclusions
Underinvestigation and undertreatment of hyponatraemia is a common occurrence in UK clinical practice. Therefore, development of UK guidelines and introduction of electronic alerts for hyponatraemia should be considered to improve clinical practice.
Hydromechanical properties of bentonite–sand block assemblies with interfaces in engineered barrier systems
Authors: Popp Till , Rölke Christopher , Salzer Klaus 
Published: November 2014

Abstract
Deep underground repositories for radioactive waste generally rely on a multibarrier system to isolate the waste from the biosphere. It consists of the natural geological barrier provided by the repository host rock and its surroundings, the waste container and an engineered barrier system (EBS): that is, the backfilling and sealing of shafts and galleries to block any preferential path for radioactive contaminants. Bentonite emplaced in compacted block form is the preferred option for the clay buffer for most waste management organizations. In assessing the performance of bentonite block masonries, conductive discrete interfaces inside the sealing elements (i.e. contacts between blocks) and to the host rock may act not only as mechanical weakness planes but also as preferential fluid pathways. We performed hydraulic tests on prefabricated bentonite–sand block assemblies (60:40). The results document that despite existing interfaces, the investigated bentonite block assembly behaves no different to that of the homogenous matrix during the saturation of the buffer. This has been confirmed by gas-injection tests on the former interface, as well by shear tests. The outstanding observation is that our results convincingly demonstrate that interfaces between bentonite bricks may ‘heal’ (not only seal), as was physically verified by confirmation of cohesion after presaturation.