bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spectral and morphological study of the gamma radiation of the middle-aged supernova remnant HB 21
Authors: Ambrogi L. , Zanin R. , Casanova S. , De Oña Wilhelmi E. , Peron G. , Aharonian F. 
Published: January 2019

Aims. We investigate the nature of the accelerated particles responsible for the production of the gamma-ray emission observed from the middle-aged supernova remnant (SNR) HB 21.
Methods. We present the analysis of more than nine years of Fermi LAT data from the SNR HB 21. We performed morphological and spectral analysis of the SNR by means of a three-dimensional binned likelihood analysis. To assess the intrinsic properties of the parent particle models, we fit the obtained gamma-ray spectral energy distribution of the SNR by both hadronic- and leptonic-induced gamma-ray spectrum.
Results. We observe an extended emission positionally in agreement with the SNR HB 21. The bulk of this gamma-ray emission is detected from the remnant; photons up to ~10 GeV show clear evidence of curvature at the lower energies. The remnant is characterized by an extension of 0°.83, that is, 30% smaller than claimed in previous studies. The increased statistics allowed us also to resolve a point-like source at the edge of the remnant, in proximity to a molecular cloud of the Cyg OB7 complex. In the southern part of the remnant, a hint of an additional gamma-ray excess in correspondence to shocked molecular clouds is observed.
Conclusions. The spectral energy distribution of the SNR shows evidence of a break around 400 MeV, which can be properly fitted within both the hadronic and leptonic scenario. The pion-decay mechanism reproduces well the gamma rays, postulating a proton spectrum with a slope ~2.5 and with a steepening around tens of GeV, which could be explained by the energy-dependent escape of particles from the remnant. In the leptonic scenario the electron spectrum within the SNR matches closely the locally measured spectrum. This remarkable and novel result shows that SNR HB 21 could be a direct contributor to the population of Galactic electrons. In the leptonic scenario, we find that the local electron spectrum with a break around 2 GeV, closely evokes the best-fitting parental spectrum within this SNR. If such a scenario is confirmed, this would indicate that the SNR might be a source of Galactic background electrons.
A 3D view of the Hyades stellar and sub-stellar population
Authors: Lodieu N. , Smart R. L. , Pérez-Garrido A. , Silvotti R. 
Published: January 2019

Aims. Our scientific goal is to provide a 3D map of the nearest open cluster to the Sun, the Hyades, combining the recent release ofGaiaastrometric data, ground-based parallaxes of sub-stellar member candidates and photometric data from surveys which cover large areas of the cluster.Methods. We combined the secondGaiarelease with ground-basedH-band parallaxes obtained with the infrared camera on the 2 m robotic Liverpool telescope to astrometrically identify stellar and sub-stellar members of the Hyades, the nearest open cluster to the Sun.Results. We find 1764 objects within 70° radius from the cluster centre from theGaiasecond data release, whose kinematic properties are consistent with the Hyades. We limit our study to 30 pc from the cluster centre (47.03 ± 0.20 pc) where we identify 710 candidate members, including 85 and 385 in the core and tidal radius, respectively. We determine proper motions and parallaxes of eight candidate brown dwarf members and confirm their membership. Using the 3D positions and a model-based mass-luminosity relation we derive a luminosity and mass function in the 0.04–2.5M⊙range. We confirm evidence for mass segregation in the Hyades and find a dearth of brown dwarfs in the core of the cluster. From the white dwarf members we estimate an age of 640−49+67Myr.Conclusions. We identify a list of members in the Hyades cluster from the most massive stars down to the brown dwarfs. We produce for the first time a 3D map of the Hyades cluster in the stellar and sub-stellar regimes and make available the list of candidate members.
Predicting the broad-lines polarization emitted by supermassive binary black holes
Authors: Savić D. , Marin F. , Popović L. Č. 
Published: January 2019

Context. Some Type-1 active galactic nuclei (AGN) show extremely asymmetric Balmer lines with the broad peak redshifted or blueshifted by thousands of km s−1. These AGN may be good candidates for supermassive binary black holes (SMBBHs). The complex line shapes can be due to the complex kinematics of the two broad line regions (BLRs). Therefore other methods should be applied to confirm the SMBBHs. One of them is spectropolarimetry.Aims. We rely on numerical modeling of the polarimetry of binary black holes systems, since polarimetry is highly sensitive to geometry, in order to find the specific influence of supermassive binary black hole (SMBBH) geometry and dynamics on polarized parameters across the broad line profiles. We apply our method to SMBBHs in which both components are assumed to be AGN with distances at the subparsec scale.Methods. We used a Monte Carlo radiative transfer code that simulates the geometry, dynamics, and emission pattern of a binary system where two black holes are getting increasingly close. Each gravitational well is accompanied by its own BLR and the whole system is surrounded by an accretion flow from the distant torus. We examined the emission line deformation and predicted the associated polarization that could be observed.Results. We modeled scattering-induced broad line polarization for various BLR geometries with complex kinematics. We find that the presence of SMBBHs can produce complex polarization angle profilesφand strongly affect the polarized and unpolarized line profiles. Depending on the phase of the SMBBH, the resulting double-peaked emission lines either show red or blue peak dominance, or both the peaks can have the same intensity. In some cases, the whole line profile appears as a single Gaussian line, hiding the true nature of the source.Conclusions. Our results suggest that future observation with the high resolution spectropolarimetry of optical broad emission lines could play an important role in detecting subparsec SMBBHs.
Kryotherapie in der Behandlung ausgedehnter Lidpapillome
Authors: Termühlen Julia , Diener Raphael , Eter Nicole , Grenzebach Ulrike 
Published: January 2019

Zusammenfassung
Hintergrund Die Kryotherapie ist ein destruierendes Verfahren und stellt eine wichtige Therapieoption zur chirurgischen Lidtumorexzision dar.
Befunde Wir berichten über eigene Erfahrungen in der Anwendung der Kältebehandlung bei außergewöhnlich großen Oberlidpapillomen, die mittels Kontakt- und Sprühverfahren therapiert wurden.
Ergebnis/Diskussion Durch den Einsatz der Kryotherapie lassen sich ausgedehnte Papillome behandeln. Während eine chirurgische Exzision in einigen Fällen mit einem Verlust der Oberlidfunktion einhergeht, stellt die Kältebehandlung ein alternatives Verfahren dar. Durch den Erhalt von Kollagenstrukturen werden gute funktionelle und ästhetische Ergebnisse erzielt.
Present perfect or simple past?
Authors: Farghal Mohammed 
Published: January 2019

AbstractThe present study aims to examine the claim that the preverbal particleqadin the perfective is an aspectual marker of near past in Arabic, hence it corresponds to the present perfect in English. The authentic translational corpus drawn from two works (journalistic/scientific and literary discourse) clearly indicates that the preverbalqadis employed as a cohesive marker whose main function is to smooth and naturalize Arabic discourse. The study demonstrates that the translator’s choice between an Arabic simple past with or withoutqadis governed by the requirements of the flow of discourse rather than by aspectual marking. Failure to account for this discursive function ofqadwhen translating from English into Arabic would in Arabic translations produce cohesion gaps which in English are usually taken care of by punctuation.
“We must unite now or perish!”
Authors: Nartey Mark 
Published: January 2019

Abstract
This paper presents a discourse-mythological analysis of the rhetoric of a pioneering Pan-African and Ghana’s
independence leader, Kwame Nkrumah, drawing on Ruth Wodak’s discourse-historical approach to critical discourse analysis. The
thesis of the paper is that Nkrumah’s discourse, in its focus on the emancipation and unification of Africa, can be characterized
as mythic, a discursive exhortation of Africa to demonstrate to the world that it can better govern itself than the colonizers. In
this vein, the paper analyzes four discursive strategies employed by Nkrumah in the creation and projection of his mythology: the
introduction or creation of new discourse events, presupposition and implication, involvement (the use of indexicals) and lexical
structuring and reiteration. This study is, therefore, presented as a case study of mythic discourse within the domain of
politics.
Corpus-based research on English in Africa
Authors: Fuchs Robert , van Rooy Bertus , Gut Ulrike 
Published: January 2019

Abstract
This chapter provides linguists and students not yet familiar with corpus-based research on varieties of English in Africa with a practical introduction to the field. After explaining the rationale and aims of corpus-based research on varieties of English (in Africa), we introduce methods, tools and resources commonly used and applied in the field in order to provide readers with a point of entry into the field. Most of the corpora and software that are introduced can be obtained free of charge. The software is introduced in a practical way to permit readers to use it in their own research. The application and value of corpus linguistics are exemplified with three case studies. These examples are based in part on previous research, retracing the methodological steps, but are also expanded with more data from across Africa. Case study 1 shows how corpora allow researchers to investigate lexical differences between African varieties of English, arguably an area that is amenable to scholarly inquiry with relatively limited methodological means. Case study 2 considers a grammatical phenomenon, the present perfect in African Englishes, and demonstrates how a corpus tagged for parts of speech permits syntactic analyses. Case study 3 illustrates the analysis of a phonological corpus with an investigation of the optional deletion of the phoneme /h/ in words such as house in Nigerian English. The chapter concludes with recommendations for further reading, allowing readers to explore selected topics in more depth according to their interests.
The purpose, design and use of the Corpus of Nigerian and Cameroonian English Learner Language (Conacell)
Authors: Esimaje Alexandra U. 
Published: January 2019

Abstract
This chapter reports on a new learner corpus project, describes its purpose and design, and demonstrates its use: the error-annotated corpus of 442,939 words of Nigerian and Cameroonian English Learner Language (Conacell) (Esimaje 2016). The aim of the project is to produce a resource for measuring learners’ language development and to enhance the teaching-learning process. The corpus data comprises the language output of 998 students; 383 university and 615 secondary students. The specific uses of the corpus to explore lexical form and tense usages by learners in Nigeria and Cameroon are shown. Corpus analysis reveals, for instance, that the lexical form of capitalisation and tense are hard to learn, and therefore remain learning needs in the contexts.
Introducing a corpus of English(es) spoken in post-independence Namibia
Authors: Steigertahl Helene 
Published: January 2019

Abstract
The possibility of an evolving “Namibian English” was already suggested more than 30 years ago (Chamberlain 1981: 46). However, detailed analyses of the English(es) used in Namibia were only recently initiated (e.g. Otaala 2006; Buschfeld & Kautzsch 2014; Kautzsch & Schröder 2016; Steigertahl 2017). The present chapter adds to previous research on morphosyntactic structures, introducing the Corpus of English(es) Spoken by Black Namibians post Independence (ESBNaPI). First, the Namibian linguistic situation will be introduced before procedures of data collection and methodology will be presented. Afterwards, morphosyntactic examples from the corpus will be given and compared to South African English(es) (SAE) to address potential generalizations of post-Independence English(es). The overall goal is to raise awareness of corpus resources in southern Africa.
The historical corpus of English in Ghana (HiCE Ghana)
Authors: Brato Thorsten 
Published: January 2019

Abstract
This chapter discusses various aspects relevant to the compilation of the Historical Corpus of English in Ghana (HiCE Ghana), a 600,000-word corpus of written Ghanaian English (GhE) from the period 1966 to 1975. The corpus captures written GhE in the early years of its nativization phase and by comparison to the relevant sections of the Ghanaian component of ICE makes it possible to trace structural nativization in real time. The paper addresses the motivation for such a corpus and shows how methodological and theoretical concerns and challenges have affected the final corpus design. The paper is rounded off with contemporary examples of GhE.
Practical corpus linguistics
Authors: Nkemleke Daniel 
Published: January 2019

Abstract
One major contribution of the corpus-based approach to language study is the facility with which linguists can access large amounts of data and search for regularities across text types and varieties of English on the basis of observed frequencies. Such regularities of features, if based on well-designed and/or specialised corpora, can be useful for classroom activities and material design. This chapter describes the basic steps involved in corpus design and corpus exploitation. Section 1 defines the corpus and briefly states the relevance of investigating English second language (ESL) varieties via a corpus. Section 2 describes key steps involved in simple corpus compilation and how students can compile their own corpora for research. Section 3 presents results of two studies on the frequency and use of modals in the corpus of Cameroonian English. These results are intended to illustrate the point that the corpus approach is indispensable if certain types of linguistic information are investigated in a particular variety.
Evaluating explanations for past-time reference with unmarked verb forms in African Englishes
Authors: van Rooy Bertus 
Published: January 2019

Abstract
Previous research suggests that some varieties of English in Africa do not mark the past tense consistently with an inflectional suffix. Various explanations are offered for this state of affairs, including the option of the historical present tense, non-marking because the context already makes clear that the verb denotes a past event, phonological reduction, and limited English language proficiency. This chapter reports on a corpus analysis of spoken conversation in Nigerian English and Black South African English, which indicates that the non-marking of the past tense occurs in about one in every five contexts where an event in the past is represented. However, no convincing support is found for any of the explanations in the previous research on the topic.
Namibian English on the web
Authors: Kautzsch Alexander 
Published: January 2019

Abstract
The present chapter introduces the Corpus of Namibian Online Newspapers (CNamON), which encompasses the contents of seventeen news sources as available on the Internet from May to June 2016. These sources add up to roughly 44 million words of text. The corpus was compiled to facilitate taking a systematic account of the lexical and structural properties of Namibian English, which have not been investigated to date. This chapter focusses on the technical details of the compilation process of CNamON as well as its set-up and its usefulness for linguistic research. To demonstrate the corpus’ potential for analyses on the linguistic levels of lexis and (morpho-)syntax, both a qualitative stock-taking and exemplary quantitative analyses of structural characteristics of English in Namibia are provided.
Capturing the lexicon of Ugandan English
Authors: Isingoma Bebwa , Meierkord Christiane 
Published: January 2019

Abstract
This paper discusses corpus linguistics as one method to investigate the lexicon of Ugandan English, which is characterised by borrowing, calquing, semantic extension, narrowing, and shift. It documents how analysing a well-balanced corpus, such as the Uganda component of the International Corpus of English, allows for a contextualisation of observations made from current uses of English and for an assessment of the textual genres in which such innovations occur. At the same time, it critically discusses the limitations and biases associated with a comparatively small corpus and argues for a multi-method approach that involves using larger, though less well controlled, corpora as well as supplementing corpus analyses with experimental data, which tap into the spread of lexical innovations.
In polytocous mammals, weakling neonates, but not their stronger littermates, benefit from specialized foraging
Authors: Skok Janko , Prevolnik Povše Maja 
Published: January 2019

Abstract
Adjusting foraging strategies is a common phenomenon within groups of animals competing for the same resource. In polytocous mammals, neonates concurrently compete for limited milk and alternate between two foraging (suckling) strategies: adaptable exploratory foraging with random sampling of teats, and ordered foraging with a tendency towards exploiting a particular suckling position. Some theoretical (game theory) models have shown that weaker siblings in particular benefit from foraging specialization (suckling order). Neonate piglets establish a well-defined suckling order that develops gradually and fluctuates throughout the lactation period, implying the existence of inter-individual differences in foraging strategies. We therefore analyzed suckling behavior in pigs to determine whether one foraging strategy was more beneficial to neonates in terms of their body weight and foraging environment. We found that intermediate and heavy littermates tended to adjust their suckling strategy according to the foraging environment; however, the selected foraging strategy did not affect their overall growth performance. Lighter individuals that consumed significantly less milk did not greatly alternate their foraging strategy according to the foraging environment, but their growth rate was significantly higher whenever they performed less-exploratory foraging behavior. Although suckling order appeared to be a relatively stable behavioral phenotype, it was beneficial exclusively for weaklings. These results confirm theoretical predictions and indicate that specializing in a suckling position is a beneficial strategy for weaker, light neonates. These findings suggest that physically weaker neonates might have driven the evolution of neonatal foraging specialization.
The Ellestad Protocol
Authors: Ellestad Myrvin H. , Thomas Gregory S. 
Published: January 2019

Abstract
The chapter The Ellestad Protocol reviews the performance of a maximal exercise test from start to finish using the Ellestad protocol as an example. Patient preparation should include caffeine avoidance should a vasodilator myocardial perfusion imaging (MPI) test be necessary secondary to inadequate exercise. A light meal prior to exercise testing is acceptable. The Bruce and Ellestad protocols both begin with a stage each investigator regarded as a warm-up, 3 minutes of exercise at 1.7 mph at a 10% grade. With two minute stages, primarily of increasing grade, the Ellestad protocol is completed approximately one minute earlier than the Bruce protocol. The use of the Borg scale of perceived exertion is helpful in determining a patient’s effort. If ancillary MPI is not being performed, an abrupt stop for a motion-free electrocardiogram (ECG) and then immediately placing the patient supine or semi-supine increases pre-load and, via the law of Laplace, increases left ventricular end-diastolic pressure, myocardial oxygen demand and thus ischemia. ST segment depression is observed earlier in recovery than if a cool-down walk is performed. Case examples are provided.
Interpretation of the ECG during Exercise and Recovery
Authors: Thomas Gregory S. , Samtani Sonia R. , Ellestad Myrvin H. 
Published: January 2019

Abstract
The chapter Interpretation of the ECG During Stress Testing reviews the electrocardiographic changes of ischemia during exercise testing. Normal ECG changes during exercise are reviewed and include the Ta wave of atrial repolarization which is directed in the opposite direction of the P wave. Its duration extends into the ST segment, resulting in a false positive exercise test in some patients. The type, severity and duration of ST depression predicts CAD severity and outcome. Downsloping ST depression is more ominous than horizontal which is worse than upsloping. As Ellestad has long posited, an abnormal ST segment response is &gt;1 mm of downsloping and horizontal and &gt;1.5 mm of upsloping ST depression. The 12 lead ECG leads most predictive of myocardial ischemia are leads V4-6, I, and aVR. ST elevation in leads without Q waves occurs secondary to transmural ischemia and localizes to the stenotic coronary artery.
Exercise Testing in a Limited Resource Environment
Authors: Allam Adel H. A. , Mandour Ali Mohamed A. 
Published: January 2019

Abstract
Using Egypt as an example, the chapter Stress Testing in a Limited Financial Resource Environment reviews how exercise testing can serve as the cornerstone of noninvasive evaluation of coronary artery disease (CAD) in developing countries. Its wide availability, low cost, and safety makes it the test of choice for patients at low to intermediate likelihood of CAD. Proper patient selection and skin preparation, simple and clear patient education, and reassurance as to the purpose of the test and the crucial importance of achieving a near maximal heart rate are necessary to obtain optimal sensitivity and specificity, either as a stand-alone test or in conjunction with cardiac imaging. The use of provisional MPI in patients unable to achieve 10 metabolic equivalents without chest pain or ischemic electrocardiographic changes is reviewed.
Nuclear Cardiology
Authors: Thomas Gregory S. , Wann L. Samuel 
Published: January 2019

Abstract
The Nuclear Cardiology chapter reviews the opportunity to increase sensitivity and specificity of stress testing for the diagnosis of coronary artery disease with exercise or pharmacologic myocardial perfusion imaging (MPI). Case presentations highlight the concepts presented. Based on the extraction fraction of thallium-201 and technetium-99m sestamibi and tetrofosmin, optimal timing of radioisotope injection at near peak exercise is reviewed. The importance of achieving ≥85% of maximal heart rate or an ischemic endpoint and when to convert to vasodilator testing is discussed. Multiple well-tested protocols are reviewed to add exercise to adenosine or regadenoson to minimize adverse effects and improve imaging quality and throughput. Data from the 1,147 patient EXERRT study are reviewed demonstrating that a technetium-99m radioisotope dose ratio of 1:3 is too low for 1-day low-dose rest/high-dose stress MPI secondary to shine through of the resting study into the stress study. A dose ratio minimum of 1:4 is recommended for 1-day low-dose rest/high-dose stress protocols.