bluuebunny/crossref_metadata_2025 huggingface dataset:
Issues with Determinig of Mean Time to Dangerous Failure and Diagnostic Coverage in Safety Functions of Machine Tools
Authors: Zahálka Jiří , Bradáč František , Tůma Jiří , Synek Miloš
Published: January 2016

Safety is currently a widely discussed topic in the design and construction of machine tools. Similarly important is the area of functional safety. This article focuses on determining the mean time to dangerous failure and diagnostic coverage in safety function of machine tools. Legislative requirements (2006/42/EC [1]) and requirements of current standards (EN ISO 12100 [2], EN ISO 13849-1 [3], EN 62061 [4]) are discussed. The current state of calculating the mean time to dangerous failure and diagnostic coverage and the shortcomings of current approach is presented. A new methodology for determining of mean time to dangerous failure and diagnostic coverage is outlined.
Experimental Verification of Balanced Control Valve
Authors: Miczán Martin , Bednář Lukáš , Hoznedl Michal , Tajč Ladislav
Published: January 2016

Findings are presented from the tests of balanced control valve mounted on the steam piping with experimental turbine. The forces applied on the spindle are recorded and compared to design calculation. The forces are evaluated from the pressures on a servo drive piston or they are measured directly using force transducers. The real operational characteristics are compared with characteristics defined for constant inlet pressure.
Sensitivity of Acoustic Resonance Properties to a Change in Volume of Piriform Sinuses
Authors: Radolf Vojtěch
Published: January 2016

Piriform sinuses (PS), side branches of the human vocal tract, produce extra resonances and antiresonances which influence the quality of produced voice. These acoustic resonant characteristics can be numerically simulated by 3D finite element models of the vocal tract with lateral cavities. Computations that use these accurate methods are very time consuming, therefore this study introduces a simplified 1D mathematical model to analyse acoustical effects of side branches. Although the 1D model cannot capture higher-frequency transversal mode shapes, the resulted changes caused by piriform sinuses partially correspond to recent findings of 3D computational models. New pair of resonances around 5 kHz followed by an antiresonance frequency were detected in the results of the model including PS. The first four resonance frequencies lying below the first new resonance of PS decreased with increasing PS volume and similarly both the new resonances of PS. The higher original resonances increased with increasing PS volume.
Simple Model of the Cajal-Like Interstitial Cell and its Analysis
Authors: Rosenberg Josef , Štengl Milan , Byrtus Miroslav
Published: January 2016

Cajal-like interstitial cells (IC-LC) can be detected e.g. in the bladder wall tissue. The current research proves their important role in both physiological and pathological function of this organ. The authors developed relative simple mathematical model consisting of five nonlinear ODEs. The model accuracy was verified using published experimental results. Presented nonlinear dynamical system was then analyzed using software MATCONT. This analysis allowed to simulate the effects of various drugs on the function of the bladder. The drug effects were compared with the experimental results.
Numerical Simulation of Interaction of Fluid Flow and Elastic Structure Modelling Vocal Fold
Authors: Valášek Jan , Sváček Petr , Horáček Jaromír
Published: January 2016

This paper deals with an interaction of the viscous incompressible fluid flow with a simplified model of the human vocal fold. In order to capture deformation of the elastic body the arbitrary Lagrangian-Euler method is used. The linear elasticity model is considered. The problem is solved by the developed finite element method based solver. For the flow approximation the crossgrid elements are used. The elastic structure motion is approximated by the piecewise linear elements. Numerical results are shown.
Safety Evaluation of EC2 and MC 2010 Models for Assessment of Punching Resistance of Footings
Authors: Hanzel Ján , Majtánová Lucia , Halvonik Jaroslav
Published: January 2016

Model for assessment of punching resistance in Eurocode 2 has been taken over from Model Code 1990. The model is fully empirical and was developed in 70s based on the experimental results obtained on flat slab specimens mainly loaded under axis-symmetric conditions. Therefore some doubts are soaring about applicability of the model for assessment of slab members exposed to the different conditions. Spread footings and foundation slabs represent such members. Growing number of experiments carried out on the footings last two decades allowed us to check safety of current model and compare it with the safety of the new models e.g. mechanical model based on the Critical Shear Crack Theory (CSCT) published in Model Code 2010 or amendments of EC2 model proposed by German group.
Probabilistic Assessment of Historic Reinforced Concrete Bridge
Authors: Krejsa Jan , Sýkora Miroslav , Drahorád Michal
Published: January 2016

This paper is aimed at the reliability analysis of an existing reinforced concrete bridge from 1908. The load bearing capacity is assessed in accordance with valid standards using the partial factor method and probabilistic approach. Load bearing capacities obtained by these methods are critically compared. The application of probabilistic method leads to 40 % higher load bearing capacity then the partial factor method used for structural design.
Numerical Calculation of the Force Coefficient for Cylindrical Shape Smokestack Covered with Corrugated Iron
Authors: Michalcova Vladimira , Lausova Lenka
Published: January 2016

The article deals with the influence of a shape of the smokestacks casing on the final load from wind effects. It describes possibilities of defining an equivalent aerodynamic roughness and aerodynamic drag coefficient for numerical modelling of the flow around a circular cylinder. The aim is to determine the force coefficient for a smokestack of a cylindrical shape, which is sheeted with corrugated sheet metal. The flow around a smokestack is solved in software Ansys Fluent using the DES model.
Experimental Study of Gas Dispersion over Complex Terrain
Authors: Michálek Petr , Zacho David
Published: January 2016

Experimental study of gas dispersion over complex terrain model was performed in VZLU Prague. A complex terrain model was mounted into a boundary layer wind tunnel and equipped with ground-level gas emission source. Concentration field of the emitted gas was measured using comb suction probe and flame ionization detectors. The results will serve for verification and validation of a new computational dispersion model.
Orthodontic management of a periodontally compromised dentition
Authors: Zaveri Prashant K.
Published: January 2016

Malocclusion superimposed with severe periodontitis may present a great challenge to clinicians while providing orthodontic treatment due the episodic and site-specific nature of the disease with risk of rapid tissue breakdown. However, orthodontic treatment in such situation may contribute significantly to the overall rehabilitation both functionally and esthetically. In this article, a case report outlines a combined periodontic-orthodontic management of compromised dentition. A 37-year-old female patient with significant medical history was treated for Class II Division 1 type of malocclusion associated with spaced upper and lower anterior teeth, deep overbite, and increased overjet, superimposed with chronic generalized periodontitis and bone loss. Treatment was completed using temporary anchorage devices assisted strategically applied force and modified tandem retraction biomechanics amidst management of acute inflammatory episodes during and mucogingival complication after treatment. Affected areas healed very well after post-orthodontic periodontal treatment with minimal pocket depth, and bleeding on probing, and a healthy zone of attached gingiva at the follow up visits. The orthodontic results lead to improvement in patient’s facial profile, lip posture, and correction of protrusion which addressed her main concern. One year follow-up shows good orthodontic and periodontic stability. The report highlights the importance of identifying “at risk” individuals and continuous monitoring of disease status during treatment. Despite all precautionary measures, a flare-up during the treatment can be anticipated.
Generalized Goldberg Formula
Authors: De Nicola Antonio , Yudin Ivan
Published: January 2016

In this paper we prove a useful formula for the graded commutator of the Hodge codifferential with the left wedge multiplication by a fixed p-form acting on the de Rham algebra of a Riemannian manifold. Our formula generalizes a formula stated by Samuel I. Goldberg for the case of 1-forms. As first examples of application we obtain new identities on locally conformally Kähler manifolds and quasi-Sasakian manifolds. Moreover, we prove that under suitable conditions a certain subalgebra of differential forms in a compact manifold is quasi-isomorphic as a CDGA to the full de Rham algebra.
On Karamata’s proof of the Landau–Ingham Tauberian theorem
Authors: Müger Michael
Published: January 2016

This is a self-contained exposition of (a generalization of) Karamata’s little known elementary proof of the Landau–Ingham Tauberian theorem, a result in real analysis from which the Prime Number theorem follows in a few lines.
On the Van Est homomorphism for Lie groupoids
Authors: Li-Bland David , Meinrenken Eckhard
Published: January 2016

The Van Est homomorphism for a Lie groupoid

G \rightrightarrows M

, as introduced by Weinstein–Xu, is a cochain map from the complex

C^\infty (BG)

of groupoid cochains to the Chevalley–Eilenberg complex

\mathsf C(A)

of the Lie algebroid

A

of

G

. It was generalized by Weinstein, Mehta, and Abad-Crainic to a morphism from the Bott–Shulman–Stasheff complex

\Omega (BG)

to a (suitably defined) Weil algebra

\mathsf W(A)

. In this paper, we will give an approach to the Van Est map in terms of the Perturbation Lemma of homological algebra. This approach is used to establish the basic properties of the Van Est map. In particular, we show that on the normalized subcomplex, the Van Est map restricts to an algebra morphism.
A true relative of Suslin’s normality theorem
Authors: Nica Bogdan
Published: January 2016

We prove a normality theorem for the “true” elementary subgroups of

\mathrm {SL}_n (A)

defined by the ideals of a commutative unital ring A. Our result is an analogue of a normality theorem, due to Suslin, for the standard elementary subgroups, and it greatly generalizes a theorem of Mennicke.
A functorial extension of the abelian Reidemeister torsions of three-manifolds
Authors: Florens Vincent , Massuyeau Gwénaël
Published: January 2016

Let

\mathbb F

be a field and let

G \subset \mathbb F \setminus \{0\}

be a multiplicative subgroup. We consider the category

\mathsf {Cob}_G

of

3

-dimensional cobordisms equipped with a representation of their fundamental group in

G

, and the category

\mathsf {Vect}_{\mathbb F, \pm G}

of

\mathbb F

-linear maps defined up to multiplication by an element of

\pm G

. Using the elementary theory of Reidemeister torsions, we construct a "Reidemeister functor" from

\mathsf {Cob}_G

to

\mathsf {Vect}_{\mathbb F, \pm G}

. In particular, when the group

G

is free abelian and

\mathbb F

is the field of fractions of the group ring

\mathbb Z [G]

, we obtain a functorial formulation of an Alexander-type invariant introduced by Lescop for

3

-manifolds with boundary; when

G

is trivial, the Reidemeister functor specializes to the TQFT developed by Frohman and Nicas to enclose the Alexander polynomial of knots. The study of the Reidemeister functor is carried out for any multiplicative subgroup

G\subset \mathbb F \setminus \{0\}

. We obtain a duality result and we show that the resulting projective representation of the monoid of homology cobordisms is equivalent to the Magnus representation combined with the relative Reidemeister torsion.
Bilinear pairings on elliptic curves
Authors: Enge Andreas
Published: January 2016

We give an elementary and self-contained introduction to pairings on elliptic curves over finite fields. The three different definitions of the Weil pairing that can be found in the literature are stated and proved to be equivalent using Weil reciprocity. Pairings with shorter loops, such as the ate, ate

_i

, R-ate and optimal pairings, together with their twisted variants, are presented with proofs of their bilinearity and non-degeneracy. Finally, we review different types of pairings in a cryptographic context. This article can be seen as an update chapter to A. Enge,
Elliptic Curves and Their Applications to Cryptography – An Introduction
, Kluwer Academic Publishers 1999.
The controversies of self – from (info) ethics to cyber terror
Authors: Azevedo Jefferson Cabral , Istoe Rosalee Santos , Souza Carlos Henrique Medeiros , Marques Bruna Moraes
Published: January 2016

The media relations make possible new structural arrangements regarding the constructions of identities and new paradigms relating to ethical and moral assumptions. Psychic formation processes are influenced by several variables that are interrelated in an open system, converging in anthropological, environmental, genetic, psychological, historical and social factors that determine relational interaction behaviors. However, in virtual cities where flow-image, timelessness and non-place reign, they enable new psychic arrangements and a greater plasticity and speed in processing information and generating knowledge. At this conjectural point, where technology is a key factor that permeates the interactions and offers unknowns in the construction of identities, a new order without standards is established, which rules ethical parameters. The results catalyzed by the speed of exchanges of information characterize deviant and antisocial behaviors that can bring uncountable damage to every human being basic rights.
Information technology service management processes maturity in the Brazilian Federal direct administration
Authors: Vieira Vitoriano Maria Albeti , Souza Neto João
Published: January 2016

This work aims at the scrutiny of the current situation of the Information Technology Service Management practices within the Brazilian Federal Direct Administration, from the perceptions of the Information Technology Managers of twelve Ministries. The methodology used followed the Process Maturity Framework as a guideline, which is a maturity model whose patterns are described in ITIL v3. The work consists of interviews with questions related to the five maturity levels, as follows: initial, repetitive, defined, managed and optimized. Information on the five basic Information Technology Service Management processes was collected. Besides the classification of the maturity levels of the processes, the interviews allowed us to gather information about the possible causes that hinder the improvement of the maturity of the processes. The outcomes of the survey on the researched ministries showed low maturity level in all the assessed service management processes. The Incident Management Process presented the highest level of maturity, while Problem Management proved to be the most flawed one, in relation to maturity. The other assessed processes, like Change Management, Service Assets and Configuration Management and Release and Deployment Management presented some sort of homogeneity among the ministries. As for the probable causes that hinder the improvement of the maturity level of the Information Technology Service Management processes, pointed by the managers, the following one stand out: the reduced staff, the lack of resources, the gap between the organizational targets and their processes aims, and the lack of skilled labor.
The architectural design in time of crisis. A research of "roots" to support the development
Authors: Forlani Maria Cristina
Published: January 2016

Vitruvius wrote the first treatise of Architecture and in it we find the fundamental recommendations for a good design. In the past 50 years it seems, instead, that each of these directions had been lost and there is today the need of promoting a new design paradigm that is attentive to nowadays criticalities and directed to sustainable development.
The term sustainability starts to configure the quality of human actions since the 80’s following reflections on the resources limit (raw materials and fossil fuels) and the environment capacity limit of absorbing emissions and waste.
The concept of sustainable development was elaborated in 1987 in the Brundtland report according to the need of distinguishing it from the concept of growth, that is to say with the goal of tending simultaneously toward the quality verification of programs in the environmental, social and economic dimensions.
All that invited the whole society to reconsider its "lifestyle" that, in the specific field of architecture, meant finding a new design approach geared to a lower consumption and greater caution and responsibility in the choices.
The configuration of a new design paradigm can trace their roots in the study of history and can proceed to evaluate the actions in a broad context of skills to ensure the quality of the products.
Preservice Agriculturl Education Teachers' Experiences in and Anticipation of Content Knowledge Preparation
Authors: Rice Amber H. , Kitchel Tracy
Published: January 2016

This study explored the experiences of preservice agriculture teachers in content knowledge preparation for pedagogical content knowledge (PCK) development. The researchers employed a phenomenological approach in which six preservice teachers were interviewed the semester prior to student teaching. The researchers found there was general dissatisfaction with the majority of agriculture content courses among preservice teachers in terms of quality, quantity, and transferability of content. Interest in agriculture content areas, their views of expertise, and what they want their students to gain from their teaching were found to be possible influencers affecting the PCK development of preservice agriculture teachers. These findings provide support for further research to explore gaps in content knowledge and the professions’ understanding of PCK development in novice agriculture teachers. Recommendations include considering ways to incorporate content knowledge in pedagogy courses or working with content faculty on developing assignments to help preservice teachers learn content in meaningful ways.
Examining the Commn Core State Standards in Agricultural Education
Authors: McKim Aaron J. , Lambert Misty D. , Sorenson Tyson J. , Velez Jonathan J.
Published: January 2016

The Common Core State Standards (CCSS) represent a shift in the American education system. Included in the CCSS are opportunities for agriculture teachers to integrate math and English language arts content into their curriculum. Using the theory of planned behavior, we sought to identify Oregon agriculture teachers’ attitudes, familiarity with, current level of integration, and professional development needs related to the Common Core State Standards. Our research identified the majority of responding teachers were somewhat familiar with the CCSS. Additionally, teachers had varying levels of agreement that the CCSS would help their teaching, yet the majority of agriculture teachers in our study reported they had somewhat implemented the CCSS. In an effort to identify the professional development needs of teachers concerning these standards, we used the CCSS to develop 11 needs assessment competencies related to math, reading, and writing. Respondents identified the highest professional development need areas in topics related to developing students’ abilities to write and do mathematics problems in the context of agriculture. These findings are discussed using the theory of planned behavior; recommendations for practice and future research are also highlighted.
Bridging Water Issue Knowledge Gaps Between the General Public and Opinion Leaders
Authors: Lamm Kevan W. , Lamm Alexa J. , Carter Jnnah S.
Published: January 2016

Global conflicts have rapidly made water the most contentious issue in the world today. Considering water drives health, industry, recreation, and the agricultural food system it is no surprise that it has become such a hot topic. As a result, the general public has an increased interest in water-focused policy; policy that can have a large impact on the agriculture industry. Agricultural and natural resource opinion leaders may differ or agree with the general public on water related issues, as well as perceptions of government influence. Identifying similarities and differences will allow agricultural educators to identify ways to resolve disagreements through improved education, communication and messaging, and leadership development of agricultural and natural resource opinion leaders. The findings indicated there are significant differences between agricultural and natural resource opinion leaders and the general public as it related to their knowledge of water issues and perceptions of government support for individual decision- making regarding environmental issues. Based on these findings it is suggested agricultural educators establish a common language that can be used with all audiences to discuss water issues, develop educational programming to assist opinion leaders when addressing observed knowledge gaps, and create educational coalitions to provide source credibility across audiences.
A Measure of Students' Motivation to Learn Science through Agricultural STEM Emphasis
Authors: Chumbley Steven Boot , Haynes J. Chris , Stofer Kathryn A.
Published: January 2016

There is an increased demand for motivated high school students to enter postsecondary STEM fields. Agriscience education is an innovative curriculum that can motivate students and spark interest in STEM. To recruit students to such programs, we must understand what motivates them. The purpose of this study was to determine how the secondary agriculture students conceptualized their motivation to learn agriscience. A descriptive-correlational research design was utilized with a modified version of the Science Motivation Questionnaire II (SMQ II) used as the survey instrument. Overall, students were found to have moderate levels of motivation in agriscience courses. Grade motivation and self-efficacy were found to be the motivational constructs that meant the most to students. Students were least motivated by self-determination. Getting an A and the chance to receive higher grades in their agriculture science courses were found to be the highest motivators. Researchers found that there were no significant correlations between gender or grade level and motivation to learn science. Females generally had higher motivation within self- determination and grade motivation than males. Additional research is needed in this area to determine what factors may exist that are preventing highly efficacious females from choosing STEM careers.
Hepatitis C Virus Infection Screening Within Community Health Centers
Authors: Cook Nicole , Turse Erica P. , Garcia Angela S. , Hardigan Patrick , Amofah Saint Anthony
Published: January 2016

Context: Approximately 2.7 million people in the United States currently live with chronic hepatitis C virus (HCV) infection, and many are unaware that they have the disease. Community health centers (CHCs) serve as the primary care safety net for more than 22 million patients who are at risk for health inequities and represent an important frontline resource for early screening and treatment for HCV infection.

Objective: To understand HCV infection screening rates among CHC patients, and to quantify the screening gap by demographic characteristics.

Methods: The authors analyzed a deidentified dataset obtained through electronic health records from a large national network of CHCs. All adults at risk for HCV infection, according to the US Preventive Services Task Force (USPSTF) birth cohort screening guidelines for HCV infection, were considered eligible if they had a patient office visit between January 1, 2013, and December 31, 2013. Data were reviewed to determine the documentation of HCV infection screening from January 1, 2010, to December 31, 2013, and HCV infection screening rates were analyzed by age, race/ethnicity, and sex.

Results: Among 60,722 eligible patients, 5033 (8.3%) had an HCV infection screen in accordance with USPSTF birth cohort screening guidelines. Women were less likely to be screened than men in every race/ethnic group, including white Hispanic (9.3% in women vs 5.4% in men), black Hispanic (15.1% in women vs 9.0% in men), white non-Hispanic (13.6% in women vs 8.1% in men), black non-Hispanic (14.9% in women vs 8.9% in men), Caribbean Islander or Haitian (6.5% in women vs 3.7% in men), and other races/ethnicities (6.3% in women vs 3.6% in men).

Conclusion: To the authors’ knowledge, this is the first large-scale study among CHCs to assess the screening gap of the USPSTF birth cohort screening guidelines for HCV infection. This study suggests that CHCs should consider opportunities to improve HCV infection screening, thereby contributing to the reduction of health inequities resulting from untreated HCV infection.
Occurrence of ferredoxin:NAD+oxidoreductase activity and its ion specificity in several Gram-positive and Gram-negative bacteria
Authors: Hess Verena , Gallegos Rene , Jones J Andrew , Barquera Blanca , Malamy Michael H , Müller Volker
Published: January 2016

A ferredoxin:NAD+oxidoreductase was recently discovered as a redox-driven ion pump in the anaerobic, acetogenic bacteriumAcetobacterium woodii. The enzyme is assumed to be encoded by thernfgenes. Since these genes are present in the genomes of many bacteria, we tested for ferredoxin:NAD+oxidoreductase activity in cytoplasmic membranes from several different Gram-positive and Gram-negative bacteria that have annotatedrnfgenes. We found this activity inClostridium tetanomorphum,Clostridium ljungdahlii,Bacteroides fragilis, and Vibrio choleraebut not inEscherichia coliandRhodobacter capsulatus. As inA. woodii, the activity was Na+-dependent inC. tetanomorphumandB. fragilisbut Na+-independent inC. ljungdahliiandV. cholerae. We deleted thernfgenes fromB. fragilisand demonstrated that the mutant has greatly reduced ferredoxin:NAD+oxidoreductase activity. This is the first genetic proof that thernfgenes indeed encode the reduced ferredoxin:NAD+oxidoreductase activity.
One-step multiplex real-time RT-PCR assay for detecting and genotyping wild-type group A rotavirus strains and vaccine strains (Rotarix® and RotaTeq®) in stool samples
Authors: Gautam Rashi , Mijatovic-Rustempasic Slavica , Esona Mathew D. , Tam Ka Ian , Quaye Osbourne , Bowen Michael D.
Published: January 2016

Background.Group A rotavirus (RVA) infection is the major cause of acute gastroenteritis (AGE) in young children worldwide. Introduction of two live-attenuated rotavirus vaccines, RotaTeq® and Rotarix®, has dramatically reduced RVA associated AGE and mortality in developed as well as in many developing countries. High-throughput methods are needed to genotype rotavirus wild-type strains and to identify vaccine strains in stool samples. Quantitative RT-PCR assays (qRT-PCR) offer several advantages including increased sensitivity, higher throughput, and faster turnaround time.Methods.In this study, a one-step multiplex qRT-PCR assay was developed to detect and genotype wild-type strains and vaccine (Rotarix® and RotaTeq®) rotavirus strains along with an internal processing control (Xeno or MS2 RNA). Real-time RT-PCR assays were designed for VP7 (G1, G2, G3, G4, G9, G12) and VP4 (P[4], P[6] and P[8]) genotypes. The multiplex qRT-PCR assay also included previously published NSP3 qRT-PCR for rotavirus detection and Rotarix® NSP2 and RotaTeq® VP6 qRT-PCRs for detection of Rotarix® and RotaTeq® vaccine strains respectively. The multiplex qRT-PCR assay was validated using 853 sequence confirmed stool samples and 24 lab cultured strains of different rotavirus genotypes. By using thermostablerTthpolymerase enzyme, dsRNA denaturation, reverse transcription (RT) and amplification (PCR) steps were performed in single tube by uninterrupted thermocycling profile to reduce chances of sample cross contamination and for rapid generation of results. For quantification, standard curves were generated using dsRNA transcripts derived from RVA gene segments.Results.The VP7 qRT-PCRs exhibited 98.8–100% sensitivity, 99.7–100% specificity, 85–95% efficiency and a limit of detection of 4–60 copies per singleplex reaction. The VP7 qRT-PCRs exhibited 81–92% efficiency and limit of detection of 150–600 copies in multiplex reactions. The VP4 qRT-PCRs exhibited 98.8–100% sensitivity, 100% specificity, 86–89% efficiency and a limit of detection of 12–400 copies per singleplex reactions. The VP4 qRT-PCRs exhibited 82–90% efficiency and limit of detection of 120–4000 copies in multiplex reaction.Discussion.The one-step multiplex qRT-PCR assay will facilitate high-throughput rotavirus genotype characterization for monitoring circulating rotavirus wild-type strains causing rotavirus infections, determining the frequency of Rotarix® and RotaTeq® vaccine strains and vaccine-derived reassortants associated with AGE, and help to identify novel rotavirus strains derived by reassortment between vaccine and wild-type strains.
A statistical study of plasmaspheric plumes and ionospheric outflows observed at the dayside magnetopause
Authors: Lee S. H. , Zhang H. , Zong Q.‐G. , Otto A. , Rème H. , Liebert E.
Published: January 2016

We present a statistical study of plasmaspheric plumes and ionospheric outflows observed by the Cluster spacecraft near the dayside magnetopause. Plasmaspheric plumes are identified when the low‐energy ions (<1 keV) with ∼90° pitch angle distributions are observed by the Cluster Ion Spectrometer/Hot Ion Analyzer instrument. The ionospheric outflows are characterized by unidirectional or bidirectional field‐aligned pitch angle distributions of low‐energy ions observed in the dayside magnetosphere. Forty‐three (10%) plasmaspheric plume events and 32 (7%) ionospheric outflow events were detected out of the 442 times that C3 crossed the dayside magnetopause between 2007 and 2009. The occurrence rate of plumes at duskside is significantly higher than that at dawnside. The occurrence rate of outflows shows a weak dawn‐dusk asymmetry. We investigate the dependence of the occurrence rates of plumes and ionospheric outflows on geomagnetic activity and on solar wind/interplanetary magnetic field (IMF) conditions. The plume events tend to occur during southward IMF (duskward solar wind electric field) and moderate geomagnetic activity (Kp = 3,−30≤Dst <− 10 nT). However, the ionospheric outflow events tend to occur during northward IMF (dawnward solar wind electric field). The ionospheric outflows do not occur when Kp = 0, and the occurrence rate of the ionospheric outflows does not have a clear Dst dependence. Seventy‐five percent (46%) of the outflows are observed in the duskside for negative (positive) IMF By. Conversely, 54% (25%) of the outflows are observed in the dawnside for positive (negative) IMF By. Finally, the occurrence rates of both plumes and outflows increase with solar wind dynamic pressure.
Distortion of thermospheric air masses by horizontal neutral winds over Poker Flat Alaska measured using an all‐sky scanning Doppler imager
Authors: Dhadly M. S. , Conde M.
Published: January 2016

An air mass transported by a wind field will become distorted over time by any gradients present in the wind field. To study this effect in Earth's thermosphere, we examine the behavior of a simple parameter that we describe here as the “distortion gradient.” It incorporates all of the wind field's departures from uniformity and is thus capable of representing all contributions to the distortion or mixing of air masses. The distortion gradient is defined such that it is always positive, so averaging over time and/or space does not suppress small‐scale features. Conventional gradients, by contrast, are signed quantities that would often average to zero. To analyze the climatological behavior of this distortion gradient, we used three years (2010, 2011, and 2012) of thermospheric F region wind observations from a high‐latitude ground‐based all‐sky wavelength scanning Doppler Fabry‐Perot interferometer located at Poker Flat Alaska. Climatological averaging of the distortion gradient allowed us to investigate its diurnal and seasonal (annual) behaviors at our observing location. Distortion was observed to be higher before local magnetic midnight and to be seasonally dependent. While maximum distortion occurred before local magnetic midnight under all geomagnetic conditions, the peak distortion occurred earlier under moderate geomagnetic conditions as compared to the quiet geomagnetic conditions and even earlier still when geomagnetic conditions were active. Peak distortion was stronger and appeared earlier when interplanetary magnetic field (IMF) was southward compared to northward. By contrast, we could not resolve any time‐shift effect due to the IMF component tangential to Earth's orbit.
Substorm simulation: Quiet and N‐S arcs preceding auroral breakup
Authors: Ebihara Y. , Tanaka T.
Published: January 2016

Auroral breakup at the onset of substorm expansion is sometimes preceded by auroral forms known as quiet arcs and N‐S arcs. Observations have shown that both the auroral forms tend to move equatorward, and the initial brightening takes place in or near one of the quiet arcs. The auroral forms attract great attention, but generation of auroral forms and their association with the initial brightening are poorly understood. Recent global magnetohydrodynamic simulations are capable of producing upward field‐aligned currents (FACs) that resemble the auroral forms in both shape and temporal evolution. Based on the simulation results, we propose the following scenarios: (1) When the convection electric field is weak (northward interplanetary magnetic field (IMF)), the high‐pressure region is elongated from the plasma sheet toward higher latitudes and is structured by a coupling between the magnetosphere and the ionosphere (interchange‐like instabilities). (2) When the convection electric field is strong (southward IMF), the structured high‐pressure region moves equatorward (toward the plasma sheet). Upward currents are generated around it, which can be observed as arcs in the ionosphere. The upward current can be tentatively intensified in the course of the equatorward movement before the formation of a near‐Earth neutral line (NENL). (3) The NENL releases magnetic tension and results in the enhancement of plasma pressure at off‐equator in the near‐Earth region. Sudden formation of the off‐equatorial high‐pressure region generates the onset current system that manifests initial brightening. Our scenario can explain the observational fact that poleward arcs remained undisturbed at the onset.
High‐spatial‐resolution velocity measurements derived using Local Divergence‐Free Fitting of SuperDARN observations
Authors: Bristow W. A. , Hampton D. L. , Otto A.
Published: January 2016

A new technique for analysis of Super Dual Auroral Radar Network (SuperDARN) line‐of‐sight velocity observations enables resolving plasma convection with unprecedented spatial resolution. The technique, Local Divergence‐Free Fitting (LDFF), can be used to produce maps with a spatial resolution that is determined by the resolution of the observations rather than an arbitrary fit order. Other techniques, which express the potential as a sum of harmonic functions, limit the number of functions in the expansion to the fit order. Doing so imposes a limit on the minimum size of features that will be represented in the results. The LDFF technique is not limited by this constraint. Rather, it is limited by the resolution of the observations and the amount of regularization required by the observed noise level, which generally allows finer‐scale features to be represented. The LDFF technique is described and then applied to a synthetic data set to demonstrate its validity. Then high‐resolution convection maps are presented from an interval during which auroral observations over Alaska showed poleward boundary intensifications (PBIs) and auroral streamers. Overlays of the convection vectors on the auroral images illustrate correspondence between flow features and the auroral luminosity. Detailed comparison between the flows and images showed that the PBIs originated from polar cap boundary arcs that extended away from midnight toward earlier local times. As the arcs extended they were accompanied by enhanced shear flow. The arcs intensified then moved equatorward becoming streamers. As the arcs moved, the region of shear flow followed their motion, indicating a pattern of field‐aligned current associated with the moving arc. The observations are the most comprehensive and detailed known to the authors for such an interval and agree well with the expected plasma flows based upon magnetospheric simulations. Flow vectors generated for the interval by the spherical harmonic fit technique for the most part do not show the direct relationship between the convection and the localized luminosity features nearly as well as the LDFF results. Some of the features found in the LDFF fitting are simply not present in the results from the global fits. The LDFF technique should find application in a variety of studies where high‐spatial‐resolution estimates of plasma flows are required. The example study presented here, which examined the details of flows in the region of auroral arcs, is representative of such problems.
Response of the incompressible ionosphere to the compression of the magnetosphere during the geomagnetic sudden commencements
Authors: Kikuchi T. , Hashimoto K. K. , Tomizawa I. , Ebihara Y. , Nishimura Y. , Araki T. , Shinbori A. , Veenadhari B. , Tanaka T. , Nagatsuma T.
Published: January 2016

The ionospheric plasma in midlatitude moves upward/downward during the geomagnetic sudden commencement causing the HF Doppler frequency changes; SCF (+ −) and (− +) on the dayside and nightside, respectively, except for the SCF (+ −) in the evening as found by Kikuchi et al. (1985). Although the preliminary and main frequency deviations (PFD, MFD) of the SCF have been attributed to the dusk‐to‐dawn and dawn‐to‐dusk potential electric fields, there still remain questions if the positive PFD can be caused by the compressional magnetohydrodynamic (MHD) wave and what causes the evening anomaly of the SCF. With the HF Doppler sounder, we show that the dayside ionosphere moves upward toward the Sun during the main impulse (MI) of the SC, when the compressional wave is supposed to push the ionosphere downward. The motion of the ionosphere is shown to be correlated with the equatorial electrojet, matching the potential electric field transmitted with the ionospheric currents from the polar ionosphere. We confirmed that the electric field of the compressional wave is severely suppressed by the conducting ionosphere and reproduced the SC electric fields using the global MHD simulation in which the potential solver is employed. The model calculations well reproduced the preliminary impulse and MI electric fields and their evening anomaly. It is suggested that the electric potential is transmitted from the polar ionosphere to the equator by the zeroth‐order transverse magnetic (TM0) mode waves in the Earth‐ionosphere waveguide. The near‐instantaneous transmission of the electric potential leads to instantaneous global response of the incompressible ionosphere.
Tropospheric ozonesonde profiles at long‐term U.S. monitoring sites: 1. A climatology based on self‐organizing maps
Authors: Stauffer Ryan M. , Thompson Anne M. , Young George S.
Published: January 2016

Sonde‐based climatologies of tropospheric ozone (O3) are vital for developing satellite retrieval algorithms and evaluating chemical transport model output. Typical O3 climatologies average measurements by latitude or region, and season. A recent analysis using self‐organizing maps (SOM) to cluster ozonesondes from two tropical sites found that clusters of O3 mixing ratio profiles are an excellent way to capture O3 variability and link meteorological influences to O3 profiles. Clusters correspond to distinct meteorological conditions, e.g., convection, subsidence, cloud cover, and transported pollution. Here the SOM technique is extended to four long‐term U.S. sites (Boulder, CO; Huntsville, AL; Trinidad Head, CA; and Wallops Island, VA) with 4530 total profiles. Sensitivity tests on k‐means algorithm and SOM justify use of 3 × 3 SOM (nine clusters). At each site, SOM clusters together O3 profiles with similar tropopause height, 500 hPa height/temperature, and amount of tropospheric and total column O3. Cluster means are compared to monthly O3 climatologies. For all four sites, near‐tropopause O3 is double (over +100 parts per billion by volume; ppbv) the monthly climatological O3 mixing ratio in three clusters that contain 13–16% of profiles, mostly in winter and spring. Large midtropospheric deviations from monthly means (−6 ppbv, +7–10 ppbv O3 at 6 km) are found in two of the most populated clusters (combined 36–39% of profiles). These two clusters contain distinctly polluted (summer) and clean O3 (fall‐winter, high tropopause) profiles, respectively. As for tropical profiles previously analyzed with SOM, O3 averages are often poor representations of U.S. O3 profile statistics.
Indirect evidence of the composition of nucleation mode atmospheric particles in the high Arctic
Authors: Giamarelou Maria , Eleftheriadis Konstantinos , Nyeki Stephan , Tunved Peter , Torseth Kjetil , Biskos George
Published: January 2016

Previous long‐term observations have shown that nanoparticle formation events are common in the summer‐time high Arctic and linked to local photochemical activity. However, current knowledge is limited with respect to the chemical precursors of resulting nanoparticles and the compounds involved in their subsequent growth. Here we report case‐study measurements during new particle formation (NPF) events of the particle size distribution (diameter > 7 nm) and for the first time the volatility of monodisperse particles having diameter ≤40 nm, providing indirect information about their composition. Volatility measurements provide indirect evidence that a predominant fraction of the 12 nm particle population is ammoniated sulfates in the summertime high Arctic. Our observations further suggest that the majority of the sub‐40 nm particle population during NPF events does not exist in the form of sulfuric acid but rather as partly or fully neutralized ammoniated sulfates.
Luminosity in the initial breakdown stage of cloud‐to‐ground and intracloud lightning
Authors: Wilkes R. A. , Uman M. A. , Pilkey J. T. , Jordan D. M.
Published: January 2016

We present simultaneously measured luminosity and electric field data from the initial breakdown (IB) stage in seven cloud‐to‐ground (CG) and eight intracloud (IC) lightning discharges along with, in three cases, radar and Lightning Mapping Array (LMA) data. The data were taken in north‐central Florida in 2013 and 2014. Seven CG discharges had an arithmetic mean (standard deviation, SD) IB stage luminosity pulse train duration of 3 ms (2 ms), and within the seven CG discharges, 30 luminosity pulses had the following means (SD): 10% to 90% risetime 25 µs (16 µs), full width at half maximum 68 µs (21 µs), and delay between onset of the electric field pulse and associated luminosity pulse 8 µs (8 µs). Eight IC discharges had a mean (SD) IB stage luminosity pulse train duration of 11 ms (4 ms), and within the 8 IC discharges, 37 luminosity pulses exhibited mean risetimes, widths, and delays of 59 µs (36 µs), 176 µs (70 µs), and 34 µs (20 µs), all significantly greater than in the CG case. The roughly 10 LMA sources associated with each of the three IB stages in 2014 are grouped horizontally within about 1 km2. The mean altitude (SD) of the LMA points during two CG IB stages is 5 km (600 m) and 4.3 km (250 m) and during one IC discharge is 6.2 km (550 m). We discuss the role of optical scattering in delaying and distorting the observed luminosity waveforms.
Representation of topography by partial steps using the immersed boundary method in a vector vorticity equation model (VVM)
Authors: Chien Mu‐Hua , Wu Chien‐Ming
Published: January 2016

In this study, representation of surface topography in the vector vorticity equation model (VVM) is updated with a partial step approach using the immersed boundary method. Compared with the full step approach, the partial step approach provides additional topography forcing to represent micro mountains while preserving the same grid structure through interpolating from adjacent grid points. It maintains the characteristics of dynamics and physics of VVM and improves the representation of gentle slope topography without increasing vertical resolution. This approach produces reasonable results on the simulation of classical mountain waves with coarse vertical resolution. Additional experiments are performed to verify our approach including density driven flow using a cold bubble and 3‐D orographic precipitation over a ridge. The results show that vorticity fields in the partial step approach have a smoother response to the gentle slopes due to the improvement in the topography representation.
Safety in Numbers: A Policy‐Capturing Study of the Alibi Assessment Process
Authors: Eastwood Joseph , Snook Brent , Au David
Published: January 2016

A policy‐capturing analysis of alibi assessments was conducted. University students (N = 65), law enforcement students (N = 21), and police officers (N = 11) were provided with 32 statements from individuals supporting a suspect's alibi (i.e., alibi corroborators) and asked to assess the believability of the alibi, the suspect's guilt, and whether they would arrest the suspect. Each statement was composed of five binary features (i.e., relationship between corroborator and accused, age of corroborator, amount of available corroborators, alibi corroborator's confidence in their account, and memorability of the target event). Results showed that there was much parity in the type of information used to assess alibis across the samples. Specifically, we found that 90% of participants' decision policies included the amount of corroborators. Participants also relied upon, albeit to a lesser extent, the suspect–corroborator relationship and the age of the corroborator when assessing the alibi. The potential implications of these findings for understanding how people assess alibi corroborators are discussed. Copyright © 2016 John Wiley & Sons, Ltd.
How Red, Blue, and Green are Affectively Judged
Authors: Briki Walid , Hue Olivier
Published: January 2016

The present study aimed at examining how the colors red, blue, and green were affectively judged through three variables: dominance, arousal, and pleasure. All participants were exposed to red, blue, green, and white (control condition), which were created using the hue–saturation–value color model. Then, participants were invited to rate their perceptions using the self‐assessment manikin. Results showed that (a) red was strongly associated with dominance and arousal; (b) blue was moderately and slightly associated with dominance and arousal, respectively; (c) green was slightly associated with arousal; and (d) blue and green were slightly more pleasurable than red. These results provide initial insights into how people perceive colors through the notions of dominance, arousal, and pleasure. Important practical implications for the use of colors are discussed. Copyright © 2016 John Wiley & Sons, Ltd.