bluuebunny/crossref_metadata_2025 huggingface dataset:
Karl Heim se verstaan van ruimte in die debat tussen die teologie en natuurwetenskap
Authors: Buitendag J.
Published: August 2013

Karl Heim’s understanding of ‘space’ in the debate between theology and natural sciences This article gives a brief synopsis of Karl Heim’s understanding of space in terms of its present and past spheres and the overarching metapolar sphere of God where all dichotomies are being resolved. The rather clas-sical booklet of Edwin Abbott, ‘Flatland’, is used as an introduction to indicate the importance of understanding reality in terms of dimensions and the expanding thereof. It makes sense to consider this as a point on the agenda in the dialogue between theology and natural sciences. The author points out thatHeim’s concept of space finds its way both in phi-losophy and theology inter alia in the works of Deleuze and Kasper re-spectively.
‘n Kerk wat getuig is ‘n kerk wat leef (1) ‘n Bybels-teologiese perspektief op die missionêre karakter van die kerk
Authors: Dreyer D. J.
Published: August 2013

A witnessing church is a living church (1) A biblical-theological perspective on the missionary character of the church. In this, the first of two articles, we focus on the identity of the church as it is revealed in the Old and New Testaments. Since the sixties of the previous century, it is widely accepted that mission is the essence of the church. The church was no longer seen as the institution which sends people into the world, but was no longer the one who is sent into the world. According to the Old Testament, Israel was elected to be God’s witness to the nations. In exile they recognised that Jahwe is not a national God, but God of the whole world. The four Gospels, Acts and the letters of Paul make it very clear that the church of Jesus Christ is either a missionary church or not a church at all. The church is, in all its activities per se an instrument in bringing God's kingdom to this world.
Hans-Georg Gadamer en die Ou Testament
Authors: Le Roux J. H.
Published: August 2013

Hans-George Gadamer and the Old Testament Some aspects of Gadamer’s hermeneutics are discussed below: his view on method, the finiteness of being human, the value of prejudices and so forth. With Gadamer’s help we are also able to think anew about our South African Old Testament tradition. He has perspectives and concepts which can help us to reword the basic questions of Old Testament scholarship. Of course, Gadamer is but one possibility, but he was one of the most important thinkers of the twentieth century. Whoever struggles with him also gains insight into the hermeneutical perspectives of the twentieth century.
Die betekenis en funksie van die himnes in Openbaring 12-22
Authors: Viljoen F. V.
Published: August 2013

The meaning and function of the hymns in Revelation 12-22 The hymns in Revelation 12-22 function as type of commentary, as they interpret the narrative events of the kernel plot. Being separated spatially and in some instances temporally, the hymns offer interpretations on the events and emphasise the basic themes of God’s accomplishment of salvation and judgement through Jesus Christ in the narrative. The final set of hymns in 19:1-8 recall the prior themes recounted through the hymns to form a musical climax. The hymns function as both prolepsis and analepsis in the narrative time, to the creation of the cosmos by God on the one hand, and the final victory of God on the other. As satellelites, the hymns maintain contact with the readers. The hymns function in an assuring sense throughout, constantly reminding of the final victory, one in which the implied reader plays an active role. A better understanding of the use of hymns in Revelation could enrich the use of songs in our liturgy today.
A hermeneutical-homiletic reading of Psalm 37 with reference to H J C Pieterse's homiletics
Authors: Vos C. J. A.
Published: August 2013

In this article Psalm 37 is viewed hermeneutic-homiletically. The socio-historical context of Psalm 37 is considered. Furthermore, the structure of the Psalm receives attention, as does its posture. Particular emphasis is placed on the term "righteous" as it functions in the Psalm. More specifically, manifestation of the Psalm is traced in the homiletics of H J C Pieterse. The "just man” serves as the sermon's homiletic context within his homiletics, and preaching the gospel to the victims of social injustice stands central to it. This article expresses an appreciation for the valued contribution, particularly in homiletics, that has been made by Pieterse.
Leadership in the world of the Bible: (De)institutionalisation as an ongoing process
Authors: Dreyer Y.
Published: August 2013

This article discusses the development of leadership in the biblical world in light of structuration theory. The use of the structuration theory is embedded in the theoretical work of Max Weber. Max Weber distinguishes three types of authority: legal, traditional and charismatic authority. In order to differentiate between the more nurturing and the more institutionalised aspects of authority (with the innate possibility of the abuse of power), Latin, rather than Western languages, provides the most useful terminology. The article traces the development from auctoritas (nurturing authority) to potestas (coercive power). It focuses on how authority manifested in the Near- and Middle-East, the Hellenistic Emperor Cult and early Christianity. The aim is to explain the ways in which power and authority function in society by reflecting on the development from charismatic to institutionalised leadership. The potential danger that the message of Jesus can be adapted to the power structures of the world, is highlighted. Deinstitutionalisation is a postmodern demystifying process, by means of which church and society can be restructured today.
Shifting styles of church leadership: Paul’s pragmatic leadership style in 1 and 2 Corinthians during the organization of the collection for Jerusalem
Authors: Joubert S. J.
Published: August 2013

This essay focuses on Paul’s shifting leadership styles in his relationship with the church in Corinth during the organization of an ecumenical collection for the believers in Jerusalem (cf 1 Cor 16:1-4; 2 Cor 8-9). Paul’s basic textual strategy in 2 Corinthians 8-9, which involves the assignment of new roles to the interlocutors, serves to anti-structurally bridge the hierarchical gap between him (as the mild patriarchal figure) and the Corinthians (as his spiritually mature children) within the intratextual discourse. This pragmatic adjustment of the apostle’s autocratic leadership role in 1 Corinthians 16, in order to salvage the collection project in Corinth, serves as an example to modern church leaders to take cognizance of the impact of social and ideological contexts on their own styles of leadership.
Nelson Mandela on leadership and the role of the churches: An interview
Authors: Mandela N. R.
Published: August 2013

In October 2002 the editor of Die Kerkbode, official newspaper of the Dutch Reformed Church (N G Kerk) paid a visit to ex-president Nelson Mandela. He talked about his life, leadership, as well as the challenges to the churches in our day. His gracious remarks on the role of the Dutch Reformed Church is of special significance, in view of the fact that during many years the church not only supported the policy of Apartheid, but provided a theological argument for doing so. During the 1990s the church, on a number of occasions, confessed guilt in this regard. Dr Frits Gaum, editor, provided a transcript of the interview to Verbum et Ecclesia for this special edition on leadership.
Attributes of leadership
Authors: Tutu D. M.
Published: August 2013

In 1988 Nelson Mandela was still in South Africa's apartheid prison system, where he had been incarcerated for a quarter of a century. He would turn 70 that July, and his friend, the doughty president of the Anti-Apartheid Movement, Archbishop Trevor Huddleston, C R, had suggested that the world should celebrate this birthday. Many young people started pilgrimages from various parts of the United Kingdom, and they converged on Hyde Park Corner in London on Nelson's birthday. The crowd that gathered to celebrate this prisoner's birthday was about a quarter million strong, mostly youngsters who had not even been born when Mandela went to prison. And yet here they were gathered to honour this prisoner as if he were a pop star.
The dynamics of leadership
Authors: Vos C. J. A.
Published: August 2013

The dynamics of leadership This article reflects on the need for dynamic leadership. An organisation'sfunctionality is dependent on the intellectual, emotional andphysical energy which the people involved in the organisation arewilling to contribute. The process of energy release is determined mainlyby two concepts: vision and mission. A vision is inextricably linked to astrategy. Leadership plays an essential part in the realisation of anorganisation's vision and mission. In this article different leadershipmodels are discussed. Autocratic leadership is critically analysed.Dynamic leadership, which encompasses inspirational and imaginativeleadership is discussed. The community of faith and society both have alife-long need for inspirational leadership.
Die geboorte van 'n Nederduitse Gereformeerde Kerk in Botswana
Authors: Crafford D.
Published: August 2013

In Mei 1877 het die sendingwerk van die Ned. Geref. Kerk in Botswana ’n aanvang geneem toe Pieter Brink hom op Mochudi gaan vestig het as pioniersendeling. Hy het onder toesig van die Kaapse Kerk se Sendingkommissie gaan werk onder die Bakgotla-volk. Hulle het onder leiding van hulle hoofman Khomanyane uit die Saulspoort-gebied weggetrek en hulle in Botswana gaan vestig. Pieter Brink het hulle vanaf Saulspoort gevolg en die werk onder die Bakgotla-stam voortgesit. Na bietjie meer as 'n eeu, op 20 November 1979, is 'n afsonderlike "Dutch Reformed Church in Botswana" gekonstitueer. Hierdie jongste lid van die familie van Ned. Geref. Kerke in ons buurstaat Botswana het 'n interessante geskiedenis waarvan ons slegs enkele hoogtepunte wil uitlig.
Die dialogiese prinsipe
Authors: De Klerk J. J.
Published: August 2013

Met die dialogiese prinsipe word daardie beginsel bedoel, waarin die tweerigtingverkeer of kommunikasie onder, of met, of deur die mense op 'n heel besondere gesprekmatige wyse gereël word. Tot die wese van die dialogiese prinsipe behoort "als Grundvoraussetzung das Ernstnehmen des Gesprachspartners und das darin enthaltene zuhoren-konnen. Dialog ist also etwas anderes als Disput oder Diskussion. Er setzt gegenseitiges Vertrauen und Hochachtung voraus."
Vier tipes of modelle vir evangelisasie
Authors: Nel M.
Published: August 2013

Evangelisasie word op meer as een manier bedryf. Die gevaar is nie denkbeeldig nie dat sekere metodes verabsoluteer word en dat ’n gemeente byna vasval in een of twee maniere. Wat hier volg, is slegs 'n bekendstelling van vier moontlike wyses van evangelisasie sonder dat die modelle beoordeel word - lg. deels as gevolg van 'n gebrek aan ruimte.
Dimensies van vreemdheid in die evangelieverkondiging aan Afrika
Authors: Du Preez J.
Published: August 2013

Allerlei dimensies van vreemdheid kan in die aanvanklike verkondiging van die evangelie aan Afrika aangedui word, maar 'n mens moet besef dat hierdie gevarieerde vreemdheid hom in mindere of raeerdere mate tot op hierdie dag kan voordoen, veral in gevalle waar daar tot vandag toe van suiwer missionere situasies in die verkondiging sprake is. Minstens ses aspekte of dimensies van vreemdheid kan onderskei word.
Preekteks of preteks
Authors: Smuts A. J.
Published: August 2013

Die leser van hierdie artikel sou met reg kon opmerk: "Wat ’n preekteks is, weet ek, maar wat is "n preteks?" Hierdie on-Afrikaanse woord vir voorwendsel wil wys op die gevaar dat die teks in die prediking misbruik kan word, sodat dit nie die bron is waaruit die preek groei nie, maar bloot ’n voorwendsel wat origens maar min met die inhoud van die preek te doen het. Dit gryp terug op ’n opmerking van A. van Veldhuizen dat die teks wat deur die prediker gekies word geen "praetextus" mag wees nie en dat ons nie so mag preek dat die preek van teks sou kon verwissel soos ’n trein van lokomotief verwissel nie.
Kategismusprediking (I)
Authors: Barnard A. C.
Published: August 2013

Kategismusprediking - 'n gebruik op die kerklike erf wat weerspreek word. By predikante wissel die beoordeling daarvan van 'n sterk verdediging daarvan by 'n klein minderheid, tot 'n dowwe besef van die waarde daarvan, na 'n gevoel van belangeloosheid en onbehaaglikheid daarteenoor. By lidmate is diegene wat dit waardeer veel kleiner.
Grammatikale kanttekeninge by die Markusevangelie
Authors: Breytenbach C.
Published: August 2013

Opgedra aan diegene wat die ondankbare taak het om 'n teologiese student Grieks te leer, met dank aan prof Jannie Louw en dr Herman du Toit - my leermeesters.
Die raad van die Nederduitse Gereformeerde Kerke
Authors: Grobler H. S.
Published: August 2013

Die Raad van die Nederduitse Gereformeerde Kerke (1907-1962) kan tereg as 'n unieke liggaam bestempel word. Dit was geen sinode wat bindende besluite kon neem nie en tog veel meer as 'n blote advieskommissie. Vir 55 jaar het hierdie raad, wat in die omgang bekend gestaan het as "Die Raad van die Kerke" of "Die Federale Raad" groot invloed binne die Ned Geref Kerk uitgeoefen en op talle terreine leiding gegee en die koers waarin die kerk beweeg het, aangewys.
Oriënterende opmerkings oor Artikel 36 van die Nederlandse Geloofsbelydenis
Authors: Strauss S. A.
Published: August 2013

Sedert 1966 verskyn die moontlike wysiging van Artikel 36 van die Nederlandse Geloofsbelydenis aanhoudend op die agenda van die Algemene Sinode van die Nederduitse Gereformeerde Kerk. Hoe dit daar gekom het en wat in die afgelope byna twee dekades daaraan gedoen is, kan kortliks soos volg weergegee word:
Die Evangelie en die kultuur
Authors: Boshoff C. W. H.
Published: August 2013

Die belangrikheid van die kultuur as lewensruimte van die mens, ook die christenmens het meteens ontplof. In Mei 1984 het in Rome die sogenaamde Riano-konsultasie oor Evangelie en Kultuur plaasgevind. Die byeenkoms is deur die Kommissie vir Wêreldsending en Evangelisasie van die Wêreldraad van Kerke en deur die Sekretariaat vir Eenheid van die Rooms Katolieke Kerk byeengeroep.
Wetenskap en etiek
Authors: Heyns J. A.
Published: August 2013

Vanuit 'n bepaalde opvatting van wetenskap en etiek kan die vraag met reg gevra word of daar enige verband hoegenaamd tussen weten­skap en etiek bestaan. Het ons hier nie met twee eiesoortige geestes-handelinge van die mens te doen waarvan één, nl. die wetenskap, volledig waardevry is, terwyl die ander, nl. die etiek volledig waarde-bepaald is nie?
Praktiese Teologie mondig?
Authors: Pieterse H. J. C.
Published: August 2013

Sedert die Praktiese Teologie in 1774 as universiteitsvak in Oostenryk ingestel is, was sy legitimiteit as 'n wáárdige universiteitsvak steeds twyfelagtig. Daar loop 'n dik lyn deur die geskiedenis van die vak wat daarop dui dat die Praktiese Teologie ten diepste maar net die uitsprake van die ander teologiese vakke, hoe ook al, prakties moes maak en toepas. Selfs die pas gepubliseerde Practical Theology van Amerikaanse sy, waaroor hoog opgegee word, is op die keper beskou maar net weer 'n indiensstelling van die Praktiese Teologie om etiese doelstellings te verwesenlik.
Voorbereiding vir en danksegging na die nagmaalsviering
Authors: Barnard A. C.
Published: August 2013

Die kerk van Jesus Christus het oor die eeue heen aangevoel dat saam met die nagmaalsviering ook 'n voorbereiding daarop en dankbaarheid daaroor moes gaan. Hierdie aanvoeling het egter in die praktyk op verskillende tye van die geskiedenis van die kerk op verskillende maniere en met verskillende aksente gestalte gekry.
The righteousness of God — Justification today
Authors: Slenczka R.
Published: August 2013

As a motto to the subject "The Righteousness of God — Justification Today", I would like to begin by quoting a part of Luther's opening speech to a graduation-dispute of the Dane Petrus Palladius and of Tilemann coming from Kleve, a small town in the lowlands of the Rhine river.
Die herkoms en betekenis van die naam Elkana
Authors: Van Zyl A. H.
Published: August 2013

Dit is algemeen bekend dat name in die antieke tyd sterk verbind is aan betekenis. Name uit die Semitiessprekende gebied het in die reel een of ander godsdienstige konnotasie gehad: 'n gebed tot 'n god, of 'n belydenis oor 'n god, of 'n toewyding van die naamdraer aan 'n god, of vertroue in 'n God.
Gemeentebediening en evangelisasieperspektief
Authors: Nel M.
Published: August 2013

The Local Church and Evangelism For more than one reason local churches often miss true perspective of Evangelism. Too often its Evangelism ministry consists of a course, a program or an isolated rally. Some of the issues that have to be put right are; a lack of vision regarding the cosmological consequences of the Gospel; a deterministic view on the election; a neglect of the many estranged people; a "volkskirche''-mentality where estranged members are accepted as normal. What is needed is a new awareness of the calling of the total body of Christ to bear witness to the Gospel. Evangelism should be part and parcel of the daily life of a healthy Church.
Wetenskapsteorie en Inleidingswetenskap
Authors: Bosman H. L.
Published: August 2013

Philosophy of science and Introduction to the Old Testament The study of the Old Testament has always taken place in a context of theological and philosophical presuppositions about knowledge, truth, history, religion, etc. This article investigates the relationship between the Introduction to the Old Testament's theoretical base and modern trends in the philosophy of science. In the end the conclusion is reached that the Introduction to the Old Testament has not kept track of current questions in the philosophy of science and this emphasises the need to bring the study of the Old Testament up to date with the modern view of science as a socially and historically determined human activity.
Johannes Coccejus en Campegius Vitringa se beginsels vir die uitleg van Jesaja en die Kaap
Authors: Fensham F. C.
Published: August 2013

Johannes Coccejus and the Principles of Exegesis of Isaiah by Campegius Vitringa and the Cape A survey is given of the work of Vitringa (1658—1722) and Coccejus (1603—1668) especially in the Old Testament field. Both scholars laid emphasis on the necessity of grammatical study and to try and understand what is written. Coccejus works out a system of interpretation of Scripture by accepting that God's revelation was given in different covenants of a progressive nature. It is important to consider history in each progressive step. In this he is followed by Vitringa.
Die oorgeblewe sendingtaak in Suid-Afrika
Authors: Kritzinger J. J.
Published: August 2013

The remaining missionary task in South Africa This article is based on the results of a research project of the Institute for Missiological Research at the University of Pretoria which was recently concluded. The author and a team of co-workers researched practically the whole of South Africa in an endeavour to describe the contemporary situation of its population and the unfinished task of the church. The understanding of the missionary task which formed the basis of this project, and a sample of the kind of results obtained are illustrated in this article by means of 12 representative or typical scenarios which together indicate the dimensions of the future task for the South African church.
Matteus 18:15—20: 'n Diachroniese en sinchroniese ondersoek met besondere verwysing na kerklike dissipline
Authors: Van Zyl H. C.
Published: August 2013

Matthew 18:15—20: A diachronic and synchronic investigation with special reference to church discipline It is well known that gospel material consists of traditional matter as well as the evangelists' own input. A thorough exegesis should contain both the aspects of the investigation into the growth of the tradition (diachrony), and the study of the text in its final stage (synchrony). Matthew 18:15—20 is subjected to such an approach. As part of the diachrony these verses are studied by means of the historical critical paradigm. Special attention is paid to source and redaction criticism. Under the synchronic aspect this pericope is investigated structurally, historically and theologically. Discourse and narrative analyses are used for the structural component.
Teologiese weerbaarheid as kerklike vereiste. Ons teologiese opleiding onder die loep
Authors: Du Toit A. B.
Published: August 2013

Theological preparedness as ecclesiastical requirement. Our theological training Reconsidered The theological and spiritual aspects of training for the ministry belong inseparably together. Likewise theological training and endowment by the Spirit should not be seen as alternatives, but as complementing each other. In order to identify the theological requirements for the ministry eight typical functions of a minister of the Word are discussed. The effective implementation of these functions is, however, greatly impeded by fundamental changes in modern society. This increases the responsibility of theological faculties. In conclusion tentative guidelines for a revised theological curriculum are presented.
'n Multidimensionele benadering tot die kommunikasie van ou gekanoniseerde tekste
Authors: Rousseau J.
Published: August 2013

A multidimensional approach towards the communication of ancient canonised texts This article suggests that the implementation of a multidimensional approach towards ancient canonised texts is a reality-orientated, problem-solving and progressive-effective alternative to the futile exercise of a one-dimensional approach. The over- and underexposure of the text by either an absolutised text-immanent or historical analysis is comparable to someone trying to solve Rubic's cube by turning only one level of squares. The multidimensional analysis of the relief-mapping function of the static thrust, the cosmologic-orientational function of the dynamic perspective and the persuasive function of the dialectic strategy of 1 Peter, illustrated new possibilities of experiencing a meaningful communication of ancient canonised texts as "a cosmologic battle between perspectives".
Uitbranding in die bediening
Authors: Smuts A. J.
Published: August 2013

Ministry burnout Burnout is a hazard to which professional care-givers in the various helping professions are exposed. In this article burnout is described as a multidimensional construct, characterised by a state of emotional overload and subsequent exhaustion, resulting in a state of emotional detachment and depersonalisation. This must be differentiated from related conditions, such as tedium, stress and depression. Burnout as an occupational hazard in the ministry is then discussed. In his daily work the minister is confronted with a situation in which a variety of factors are present which may lead to the state of burnout. The risk increases when a combination of factors leading up to it are present. Interpersonal relations, job setting and personal characteristics all play a part in the development of this problem.
Diens en diensbaarheid tot opbou van die kerk
Authors: Barnard A. C.
Published: August 2013

Service and Servitude in View of the Edification of the Church The most important change Christ brings about is that people who, in the past, desired to be served, are now willing to serve. The believer is a person who serves and the church is a service community. The service is comprehensive: we serve God, we serve our fellow believers, we serve in the church, we serve in the world, we serve people when they are in need, wherever they are, and we serve God in our services of worship.
Die departement Ou Testament, 'n halwe eeu
Authors: Le Roux J. H.
Published: August 2013

The department of Old Testament, fifty years The department of Old Testament (Section B) at the University of Pretoria is celebrating its fiftieth year. At the beginning of 1938 the faculty opened with four professors and six students. This article briefly investigates the contribution of four professors who taught the Old Testament. As a rather conservative theologian J H Kritzinger strongly emphasized the importance of a scientific approach to Old Testament and of sound exegetical study. He was succeeded by A H van Zyl who had a more historical approach to the Old Testament, took the historical critical method seriously and made its results useful to the church. W S Prinsloo focussed on the text as we have it today and paid much attention to its structure by means of syntactical analysis. To a certain extent W Vosloo continued the line of Van Zyl and Prinsloo: he emphasized the importance of a historical approach, but also investigated the structure of a text to determine its theology.
Mini-Workshop: Nichols Algebras and Weyl Groupoids
Authors: Andruskiewitsch Nicolás , Cuntz Michael , Heckenberger István , Witherspoon Sarah
Published: August 2013

Nichols algebras are graded braided Hopf algebras satisfying a universal property. Many structural results of a Nichols algebra can be obtained by studying itsWeyl groupoid and its homology. In the mini-workshop, introductions to and recent developments on these structures were presented and open problems were discussed.
Mini-Workshop: Topology of Real Singularities and Motivic Aspects
Authors: Comte Georges , Tibăr Mihai
Published: August 2013

This workgroup focusses on some recent issues in real singularities, concerning the topology of the Milnor fibre of a singular map and several motivic aspects of singularities of sets definable in some structures over the reals or even over some valued field, with the ambition to develop the interplay between the two domains.
Mini-Workshop: Cohomology Rings and Fundamental Groups of Hyperplane Arrangements, Wonderful Compactifications, and Real Toric Varieties
Authors: Denham Graham , Suciu Alexander I.
Published: August 2013

The purpose of this workshop was to bring together researchers with a common interest in the objects mentioned in the title from, respectively, the points of view of toric and tropical geometry, arrangement theory, and geometric group theory.
Arbeitsgemeinschaft: Ergodic Theory and Combinatorial Number Theory
Authors: Bergelson Vitaly , Frantzikinakis Nikos , Tao Terence , Ziegler Tamar
Published: August 2013

The aim of this Arbeitsgemeinschaft was to introduce young researchers with various backgrounds to the multifaceted and mutually perpetuating connections between ergodic theory, topological dynamics, combinatorics, and number theory.
Arbeitsgemeinschaft: Ergodic Theory and Combinatorial Number Theory
Authors: Ammari Habib , Borcea Liliana , Hohage Thorsten , Kaltenbacher Barbara
Published: August 2013

Inverse problem typically deal with the identification of unknown quantities from indirect measurements and appear in many areas in technology, medicine, biology, finance, and econometrics. The computational solution of such problems is a very active, interdisciplinary field with close connections to optimization, control theory, differential equations, asymptotic analysis, statistics, and probability. The focus of this workshop was on hybrid methods, model reduction, regularization in Banach spaces, and statistical approaches.
Non-Archimedean Analytic Geometry
Authors: Berkovich Vladimir G. , Gubler Walter , Werner Annette
Published: August 2013

The workshop focused on recent developments in non-Archimedean analytic geometry with various applications to arithmetic and algebraic geometry. These applications include questions in Arakelov theory, p-adic differential equations, p-adic Hodge theory and the geometry of moduli spaces. Various methods were used in combination with analytic geometry, in particular perfectoid spaces, model theory, skeleta, formal geometry and tropical geometry.
Mini-Workshop: Efficient and Robust Approximation of the Helmholtz Equation
Authors: Melenk Jens Markus , Monk Peter , Wieners Christian
Published: August 2013

The accurate and efficient treatment of wave propogation phenomena is still a challenging problem. A prototypical equation is the Helmholtz equation at high wavenumbers. For this equation, Babuˇska & Sauter showed in 2000 in their seminal SIAM Review paper that standard discretizations must fail in the sense that the ratio of true error and best approximation error has to grow with the frequency. This has spurred the development of alternative, non-standard discretization techniques. This workshop focused on evaluating and comparing these different approaches also with a view to their applicability to more general wave propagation problems.
Mini-Workshop: Frontiers in Quantile Regression
Authors: Chernozhukov Victor , Dette Holger , He Xuming , Koenker Roger W.
Published: August 2013

Quantiles play an essential role in modern statistics, as emphasized by the fundamental work of Parzen (1978) and Tukey (1977). Quantile regression was introduced by Koenker and Bassett (1978) as a complement to least squares estimation (LSE) or maximum likelihood estimation (MLE) and leads to far-reaching extensions of ”classical” regression analysis by estimating families of conditional quantile surfaces, which describe the relation between a one-dimensional response y and a high dimensional predictor x. Since its introduction quantile regression has found great attraction in mathematical and applied statistics because of its natural interpretability and robustness, which yields attractive applications in such important areas as medicine, economics, engineering and environmental modeling. Although classical quantile regression theory is very well developed, the implicit definition of quantile regression still yields many new mathematical challenges such as multivariate, censored and longitudinal data, which were discussed during the workshop.
Mini-Workshop: Geometries, Shapes and Topologies in PDE-based Applications
Authors: Hintermüller Michael , Leugering Günter , Sokolowski Jan
Published: August 2013

The aim of the workshop was to study geometrical objects and their sensitivities in applications based on partial differential equations or differential variational inequalities. Focus topics comprised analytical investigations, numerical developments, issues in applications as well as new and future directions. Particular emphasis was put on: (i) combined shape and topological sensitivity; (ii) extended topological expansions and their numerical realization; (iii) level set based shape and topology optimization.
Mathematical and Algorithmic Aspects of Atmosphere-Ocean Data Assimilation
Authors: Griewank Andreas , Reich Sebastian , Roulstone Ian , Stuart Andrew M.
Published: August 2013

The nomenclature “data assimilation” arises from applications in the geosciences where complex mathematical models are interfaced with observational data in order to improve model forecasts. Mathematically, data assimilation is closely related to filtering and smoothing on the one hand and inverse problems and statistical inference on the other. Key challenges of data assimilation arise from the high-dimensionality of the underlying models, combined with systematic spatio-temporal model errors, pure model uncertainty quantifications and relatively sparse observation networks. Advances in the field of data assimilation will require combination of a broad range of mathematical techniques from differential equations, statistics, probability, scientific computing and mathematical modelling, together with insights from practitioners in the field. The workshop brought together a collection of scientists representing this broad spectrum of research strands.
Convex Geometry and its Applications
Authors: Ball Keith M. , Henk Martin , Ludwig Monika
Published: August 2013

The geometry of convex domains in Euclidean space plays a central role in several branches of mathematics: functional and harmonic analysis, the theory of PDE, linear programming and, increasingly, in the study of other algorithms in computer science. High-dimensional geometry is an extremely active area of research: the participation of a considerable number of talented young mathematicians at this meeting is testament to the fact that the field is flourishing.
Dynamics of Patterns
Authors: Beyn Wolf-Jürgen , Fiedler Bernold , Sandstede Björn
Published: August 2013

Patterns and nonlinear waves arise in many applications. Mathematical descriptions and analyses draw from a variety of fields such as partial differential equations of various types, differential and difference equations on networks and lattices, multi-particle systems, time-delayed systems, and numerical analysis. This workshop brought together researchers from these diverse areas to bridge existing gaps and to facilitate interaction.
Comparing predictions made by a prediction model, clinical score, and physicians
Authors: Farion K.J. , Michalowski W. , O’Sullivan D. , Sayyad-Shirabad J. , Wilk S.
Published: August 2013

Background: Asthma exacerbations are one of the most common medical reasons for children to be brought to the hospital emergency department (ED). Various prediction models have been proposed to support diagnosis of exacerbations and evaluation of their severity.

Objectives: First, to evaluate prediction models constructed from data using machine learning techniques and to select the best performing model. Second, to compare predictions from the selected model with predictions from the Pediatric Respiratory Assessment Measure (PRAM) score, and predictions made by ED physicians.

Design: A two-phase study conducted in the ED of an academic pediatric hospital. In phase 1 data collected prospectively using paper forms was used to construct and evaluate five prediction models, and the best performing model was selected. In phase 2 data collected prospectively using a mobile system was used to compare the predictions of the selected prediction model with those from PRAM and ED physicians.

Measurements: Area under the receiver operating characteristic curve and accuracy in phase 1; accuracy, sensitivity, specificity, positive and negative predictive values in phase 2.

Results: In phase 1 prediction models were derived from a data set of 240 patients and evaluated using 10-fold cross validation. A naive Bayes (NB) model demonstrated the best performance and it was selected for phase 2. Evaluation in phase 2 was conducted on data from 82 patients. Predictions made by the NB model were less accurate than the PRAM score and physicians (accuracy of 70.7%, 73.2% and 78.0% respectively), however, according to McNemar’s test it is not possible to conclude that the differences between predictions are statistically significant.

Conclusion: Both the PRAM score and the NB model were less accurate than physicians. The NB model can handle incomplete patient data and as such may complement the PRAM score. However, it requires further research to improve its accuracy.
Improved simulation of regional CO2 surface concentrations using GEOS-Chem and fluxes from VEGAS
Authors: Chen Z. H. , Zhu J. , Zeng N.
Published: August 2013

Abstract. CO2 measurements have been combined with simulated CO2 distributions from a transport model in order to produce the optimal estimates of CO2 surface fluxes in inverse modeling. However, one persistent problem in using model–observation comparisons for this goal relates to the issue of compatibility. Observations at a single station reflect all underlying processes of various scales. These processes usually cannot be fully resolved by model simulations at the grid points nearest the station due to lack of spatial or temporal resolution or missing processes in the model. In this study the stations in one region were grouped based on the amplitude and phase of the seasonal cycle at each station. The regionally averaged CO2 at all stations in one region represents the regional CO2 concentration of this region. The regional CO2 concentrations from model simulations and observations were used to evaluate the regional model results. The difference of the regional CO2 concentration between observation and modeled results reflects the uncertainty of the large-scale flux in the region where the grouped stations are. We compared the regional CO2 concentrations between model results with biospheric fluxes from the Carnegie-Ames-Stanford Approach (CASA) and VEgetation-Global-Atmosphere-Soil (VEGAS) models, and used observations from GLOBALVIEW-CO2 to evaluate the regional model results. The results show the largest difference of the regionally averaged values between simulations with fluxes from VEGAS and observations is less than 5 ppm for North American boreal, North American temperate, Eurasian boreal, Eurasian temperate and Europe, which is smaller than the largest difference between CASA simulations and observations (more than 5 ppm). There is still a large difference between two model results and observations for the regional CO2 concentration in the North Atlantic, Indian Ocean, and South Pacific tropics. The regionally averaged CO2 concentrations will be helpful for comparing CO2 concentrations from modeled results and observations and evaluating regional surface fluxes from different methods.
Investigation of the diurnal pattern of the vertical distribution of pollen in the lower troposphere using LIDAR
Authors: Noh Y. M. , Lee H. , Mueller D. , Lee K. , Shin D. , Shin S. , Choi T. J. , Choi Y. J. , Kim K. R.
Published: August 2013

Abstract. The diurnal pattern of the vertical distribution of biogenic pollen in the lower troposphere was investigated by LIDAR. Meteorological data were taken at the ground. Pollen concentrations were measured at the surface using a Burkard 7-day-recording volumetric spore sampler. Aerosol extinction coefficients and depolarization ratios at 532 nm were obtained from LIDAR measurements in spring (4 May–2 June) 2009 in Gwangju, South Korea. Linear volume depolarization ratios varied between 0.08 and 0.14 and were observed only during daytime (09:00–17:00 local time (LT)) during days of high pollen concentration (4 to 9 May). Daily average pollen concentrations ranged 1000–2500 cm−3 in the same period. The temporal evolution of the vertical distribution of the linear volume depolarization ratio showed a specific diurnal pattern. Linear volume depolarization ratios of more than 0.06, were measured near the surface in the morning. High depolarization ratios were detected up to 2 km aboveground between 12:00 and 14:00 LT, whereas high depolarization ratios were observed only close to the surface after 17:00 LT. Low values of depolarization ratios (≤0.05) were detected after 18:00 LT until the next morning. During the measurement period, the daily variations of the high depolarization ratios close to the surface showed correlation to number concentration measurements of pollen. This finding suggests that high depolarization ratios could be attributed to enhanced pollen concentrations. The diurnal characteristics of the high values of depolarization ratios are thought to be closely associated with turbulent transport. Diurnal and vertical characteristics of pollen, if measured continuously, could be used to improve the accuracy of pollen-forecasting models via data assimilation studies.
Characteristics of regional new particle formation in urban and regional background environments in the North China Plain
Authors: Wang Z. B. , Hu M. , Sun J. Y. , Wu Z. J. , Yue D. L. , Shen X. J. , Zhang Y. M. , Pei X. Y. , Wiedensohler A.
Published: August 2013

Abstract. Long-term measurements of particle number size distributions were carried out in the North China Plain both at an urban background site (Peking University, PKU) and a regional Global Atmospheric Watch station (Shangdianzi, SDZ) from March to November in 2008. In total, 52 new particle formation events were observed simultaneously at both sites, indicating that this is a regional phenomenon in the North China Plain. On average, the mean condensation sink value before the nucleation event start was 0.025 s−1 in the urban environment, which was 1.6 times higher than that at regional site. However, higher particle formation and growth rates were observed at PKU (10.8 cm−3 s−1 an 5.2 nm h−1) compared with those at SDZ (4.9 cm−3 s−1 and 4.0 nm h−1). These results implied that more precursors are needed to participate in the nucleation process to observe the occurrence of new particle formation event in a more polluted urban environment. Different from the observations in clean environments, the background condition of the observed nucleation events in the North China Plain could be characterized as the co-existing of the higher source and sink. The condensational growth of newly formed particles results in an increase in the particle mass concentration, particle light scattering coefficient, and CCN number concentration, with consequences on climate effects and air quality. In 34 investigated new particle formation cases at both sites, a significant particle nucleation and subsequent growth over a sufficient long time period were observed and investigated in terms of the particle light scattering and the number concentration of "potential" CCN. The results revealed that the new particle formation increases the particle light scattering coefficient and CCN number concentration in the North China Plain by factors in the range of 6.3–7.6 and 5.6–8.7, respectively. Moreover, the potential contribution of anthropogenic emissions to the CCN number concentration is more than 50%, which should be drawn more attentions in the regional and global climate model, especially in the polluted urban areas.
Atmospheric organic matter in clouds: exact masses and molecular formula identification using ultrahigh resolution FT-ICR mass spectrometry
Authors: Zhao Y. , Hallar A. G. , Mazzoleni L. R.
Published: August 2013

Abstract. Clouds alter the composition of atmospheric aerosol by acting as a medium for interactions between gaseous and particulate phase substances. To determine the cloud water atmospheric organic matter (AOM) composition and study the cloud processing of aerosols, two samples of supercooled clouds were collected at Storm Peak Laboratory near Steamboat Spring, Colorado (3220 m a.s.l.). Approximately 3000 molecular formulas were assigned to ultrahigh resolution mass spectra of the samples after using a reverse phase extraction procedure to isolate the AOM components from the cloud water. Nitrogen containing compounds (CHNO compounds), sulfur containing compounds (CHOS and CHNOS compounds) and other oxygen containing compounds (CHO compounds) with molecular weights up to 700 Da were observed. Average oxygen-to-carbon ratios of ~0.6 indicate a slightly more oxidized composition than most water-soluble organic carbon identified in aerosol studies, which may result from aqueous oxidation in the clouds. The AOM composition indicates significant influences from biogenic secondary organic aerosol (SOA) and residential wood combustion. We observed 60% of the cloud water CHO molecular formulas to be identical to SOA samples of α-pinene, β-pinene, d-limonene, and β-caryophyllene ozonolysis. CHNO compounds had the highest number frequency and relative abundances and are associated with residential wood combustion and NOx oxidation. We observed multiple nitrogen atoms in the assigned molecular formulas for the nighttime cloud sample composite indicating the significance of nighttime emissions or NOx oxidation on the AOM composition. Several CHOS and CHNOS compounds with reduced sulfur (in addition to the commonly observed oxidized sulfur containing compounds) were also observed, however further investigation is needed to determine the origin of the reduced sulfur containing compounds. Overall, the molecular composition determined using ultrahigh resolution Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry provides an unambiguous identification of the cloud water organic composition in the Rocky Mountain area which could help to improve the understanding of aqueous phase processes.
Modelling the chemistry and transport of bromoform within a sea breeze driven convective system during the SHIVA Campaign
Authors: Hamer P. D. , Marécal V. , Hossaini R. , Pirre M. , Warwick N. , Chipperfield M. , Samah A. A. , Harris N. , Robinson A. , Quack B. , Engel A. , Krüger K. , Atlas E. , Subramaniam K. , Oram D. , Leedham E. , Mills G. , Pfeilsticker K. , Sala S. , Keber T. , Bönisch H. , Peng L. K. , Nadzir M. S. M. , Lim P. T. , Mujahid A. , Anton A. , Schlager H. , Catoire V. , Krysztofiak G. , Fühlbrügge S. , Dorf M. , Sturges W. T.
Published: August 2013

Abstract. We carry out a case study of the transport and chemistry of bromoform and its product gases (PGs) in a sea breeze driven convective episode on 19 November 2011 along the North West coast of Borneo during the "Stratospheric ozone: Halogen Impacts in a Varying Atmosphere" (SHIVA) campaign. We use ground based, ship, aircraft and balloon sonde observations made during the campaign, and a 3-D regional online transport and chemistry model capable of resolving clouds and convection explicitly that includes detailed bromine chemistry. The model simulates the temperature, wind speed, wind direction fairly well for the most part, and adequately captures the convection location, timing, and intensity. The simulated transport of bromoform from the boundary layer up to 12 km compares well to aircraft observations to support our conclusions. The model makes several predictions regarding bromine transport from the boundary layer to the level of convective detrainment (11 to 12 km). First, the majority of bromine undergoes this transport as bromoform. Second, insoluble organic bromine carbonyl species are transported to between 11 and 12 km, but only form a small proportion of the transported bromine. Third, soluble bromine species, which include bromine organic peroxides, hydrobromic acid (HBr), and hypobromous acid (HOBr), are washed out efficiently within the core of the convective column. Fourth, insoluble inorganic bromine species (principally Br2) are not washed out of the convective column, but are also not transported to the altitude of detrainment in large quantities. We expect that Br2 will make a larger relative contribution to the total vertical transport of bromine atoms in scenarios with higher CHBr3 mixing ratios in the boundary layer, which have been observed in other regions. Finally, given the highly detailed description of the chemistry, transport and washout of bromine compounds within our simulations, we make a series of recommendations about the physical and chemical processes that should be represented in 3-D chemical transport models (CTMs) and chemistry climate models (CCMs), which are the primary theoretical means of estimating the contribution made by CHBr3 and other very short-lived substances (VSLS) to the stratospheric bromine budget.