bluuebunny/crossref_metadata_2025 huggingface dataset:
The Body of Evidence. Psychoanalysis and Sex Difference
Authors: Ayouch Thamy
Published: July 2013

Le corps, un témoin ? Psychanalyse et différence des sexes Dans cet article, l’auteur examine si le corps est bien un témoin de la différence sexuelle, et comment opèrerait ce témoignage sur le plan de la structuration psychique. Il s’agit de faire porter la question sur les concepts analytiques de sexuation et de sexualité en demandant comment la différence des sexes s’articule à la visibilité des corps, quelle inscription de l’ordre symbolique elle permet et comment elle est convoquée par la théorie analytique. L’examen de la plurivocité de la théorie freudienne à ce sujet, en prenant appui sur les écrits de Monique Schneider, permet d’aboutir à la notion d’assignation de sexe par le regard. Est alors tenté un dialogue entre la psychanalyse et la perspective de Judith Butler, qui rend compte des modalités de cette assignation et redistribue les sens de la différence des sexes. Le concept lacanien de phallus est enfin analysé dans sa dé-naturalisation de la différence des sexes, puis appréhendé dans sa détermination sociale-historique.
Vision et Narcissisme
Authors: Putois Olivier
Published: July 2013

Nous diagnostiquons critique lacanienne du dernier Merleau-Ponty le refus d’une identification du visible à l’image d’un sens suivant lequel le sujet pourrait le reconnaître (narcissisme charnel). Le stade du miroir montre au contraire qu’aucune image – même celle, spéculaire, du corps propre –, n’a de valeur représentative tant qu’elle ne reçoit pas son sens inconscient par une réponse signifiante proférée au lieu de l’Autre ; et que, corrélativement, le primat d’une telle réponse signifiante opacifie l’image, en mettant en évidence l’absence de sens immanent qui découle de son conditionnement diacritique. La fascination schizophrénique pour l’image spéculaire caractéristique du signe du miroir confirme a contrario le primat d’une telle réponse, en manifestant la dépersonnalisation que produit son absence ; elle permet ainsi d’invalider cliniquement la thèse merleau-pontyenne.
Is the Gain in Psychoanalysis a Grain of Time, the Object “a” in “-”?
Authors: Lenoir Olivier , Poggi Paul
Published: July 2013

Le gain de la psychanalyse est-il un grain de temps, l’objet « a » en « - » ? Formaliser un gain pour la psychanalyse n’est-il pas aujourd’hui un enjeu ? Le gain n’est-il pas alors un lien que la psychanalyse peut faire entre un formalisme comme celui d’un modèle macroéconomique avec une possible dynamique du sujet. Nous partirons de cette idée de gain pour réexaminer, sous l’angle du jeu notamment, le pari pascalien vers une articulation logique de la rencontre clinique.
Ahiqar tra leggenda e rielaborazione letteraria. Una tradizione e i suoi riflessi
Authors: Toloni Giancarlo
Published: July 2013

La leyenda de Ajicar, poderoso primer ministro de Senaquerib, aparece contada en la Historia homónima y Proverbios. Su testimonio más antiguo es la versión de Elefantina (siglo V a.C.). La figura del sabio asirio se introdujo más tarde en el libro de Tobit como un importante compañero de Tobit, de manera que para dar prestigio a su libro, el autor de Tobit explotó la fama de la Historia de Ajicar e historizó a su protagonista. Esta leyenda cortesana era también conocida entre las comunidades de la diáspora egipcia, incluida la de Elefantina; en el periodo helenístico fue adaptada a la tradición judía como novela sapiencial. Ajicar también aparece en algunos escritos en lengua demótica: en dos fragmentos de papiro del siglo III d.C. y en las Instrucciones de Anchsheshonqy, pero especialmente en una inscripción encontrada en Uruk-Warka en una tablilla babilónica (165 a.C.) que contiene una lista de ummānū, ‘sabios (de la corte)’. Entre ellos está Ajicar con un nombre arameo Aḫu ͗aqari. Es, por tanto, una identificación apócrifa: se sitúa al sabio Ajicar bajo el poder de Asarhaddón y en Asiria, por una espúrea historización, muy semejante a la que hizo el autor del libro de Tobit.
͗Iggeret ha-musar: estudio preliminar, edición y traducción de un pseudo-Aristóteles hebreo
Authors: Salvatierra Ossorio Aurora , Urrutia Sánchez Tomás
Published: July 2013

En este artículo se ofrece un estudio preliminar, la edición crítica basada en dieciséis manuscritos, y la traducción castellana de ͗Iggeret ha-musar atribuida a Yehudá al-Ḥarizí (siglos XII-XIII). Este texto hebreo, de extraordinaria difusión en círculos judíos, reúne reflexiones y enseñanzas del conocido médico egipcio ͗Alī Ibn Riḍwān (siglo X) junto a una supuesta carta de Aristóteles que constituye el núcleo del escrito. Conservado en al menos treinta y seis manuscritos, este heterogéneo texto reúne materiales de muy diversa procedencia con los que se pretende proporcionar códigos de conducta basados en principios universales.
Una sinagoga desvelada en Sevilla: estudio arquitectónico
Authors: Gil Delgado Óscar
Published: July 2013

La iglesia de Santa María la Blanca de Sevilla se levanta en el mismo solar donde, entre 1248 y 1391, estuvo la sinagoga mayor de la judería, situada, a su vez, sobre una mezquita anterior, próxima a una de las puertas de la ciudad. Hasta hoy no se habían identificado con claridad vestigios ni de la sinagoga ni de la mezquita que, salvo unos escasos restos formados por unos pocos fustes y dos capiteles reaprovechados, se creían desaparecidos. Los trabajos que he llevado a cabo desde 1999 en la iglesia y, sobre todo, a raíz de las obras y el proyecto de restauración que he dirigido, han puesto de manifiesto estructuras y restos de las etapas anteriores del edificio. El presente artículo tiene por objeto la descripción razonada y documentada gráficamente de estos episodios.
Conflicto entre judíos y conversos en Aragón tras los tumultos de 1391: nuevos testimonios extraídos de la colección epistolar de Yom Tob Ben Ḥanná de Montalbán
Authors: Ben-Shalom Ram
Published: July 2013

Poco después de los tumultos de 1391, los responsables de la aljama aragonesa de Montalbán remitían a los de la de Daroca una carta escrita por el escriba local e incluida en la colección epistolar de Yom Tob Ben Ḥanná. El propósito de esa carta era solicitar dinero de Yosef Caro, artesano judío de Montalbán, que había huido a Daroca a consecuencia de una disputa con otro artesano judío apóstata. El análisis del texto hebreo que aquí se edita muestra que el conflicto trasciende la simple disputa profesional, y debe entenderse en el marco de disputas entre judíos y sus antiguos correligionarios, ahora cristianos. La tensión entre judíos y conversos aparece corroborada por un poema hebreo de este escriba judío de Montalbán, que también se edita y traduce.
Reyes, acreedores y conversos: el impacto de la política real y de la deuda corporativa en la identidad colectiva de los conversos de Mallorca después de 1391
Authors: Oeltjen Natalie
Published: July 2013

Un examen detallado de la correspondencia real relativa a Mallorca muestra que factores económicos «externos» y directivas políticas reales obligaron a la primera generación de conversos de 1391 a permanecer como grupo social distintivo. Poco después de producirse la violencia anti-judía y las conversiones masivas de 1391, los conversos de Mallorca tuvieron que otorgar un porcentaje de sus propiedades al rey Juan I. Al mismo tiempo, conversos y judíos supervivientes debían seguir pagando los «censalers» de la aljama de judíos que había sido disuelta tras el ataque en 1391 contra la judería. Estas dos obligaciones financieras colectivas obligaron a los conversos a organizarse, siguiendo el precedente de la aljama, como grupo con líderes elegidos que administraron la colección fiscal interna a fin de pagar esas deudas, e interviniendo a favor de los conversos ante el rey y sus acreedores. Esta estructura administrativa puso los fundamentos de la cofradía conversa de Sant Miquel, establecida en 1404.
Los romanceamientos castellanos de la Biblia Hebrea compuestos en la Edad Media: manuscritos y traducciones
Authors: Pueyo Mena F. Javier , Arias Andrés Enrique
Published: July 2013

Este trabajo presenta un análisis exhaustivo de 28 lemas hebreos y de sus correspondientes traducciones al castellano en los once códices medievales que contienen romanceamientos cuatrocentistas de la Biblia hebrea. El objetivo es determinar, mediante la comparación cuantitativa de la coherencia léxica de los textos transmitidos en cada uno de estos manuscritos, cuántos traductores participaron en las traducciones que ahora se conservan o bien mezcladas o bien diseminadas en los distintos códices. Se concluye que se preservan solamente seis traducciones diferentes del siglo xv hechas a partir del hebreo: la Biblia completa de E3, el Pentateuco de E19, la Biblia completa que supone la combinación de la traducción contenida en los códices E7 y E5, la Biblia completa que denominamos Biblia del Marqués de Santillana (y que es una combinación de partes del códice E4 y del códice completo de BNE), la Biblia de Arragel y los Profetas Anteriores contenidos en el códice de Oxford.
Acertijos y adivinanzas en el periódico sefardí Ilustra Güerta de Historia (Viena, 1880-1882)
Authors: Sánchez Pérez María
Published: July 2013

El periódico sefardí Ilustra Güerta de Historia fue publicado en Viena entre 1880 y 1882. Estaba dirigido por Šem Tob Semo, una de las personalidades más importantes de la comunidad sefardí de Viena. Este periódico publicaba, fundamentalmente, novelas por entregas, pero también diferentes muestras de la cultura popular en la sección titulada «Sala de pasatiempo». En esta sección apareció un buen número de adivinanzas y acertijos en judeoespañol, casi todos ellos desconocidos en los estudios sefardíes. El objetivo de este artículo es dar a conocer esos acertijos, mostrar sus paralelos con la tradición hispánica e intentar rastrear sus posibles fuentes.
Primitiewe elemente vir kommutatiewe ringuitbreidings
Authors: Schutte H. J.
Published: July 2013

The existence of primitive elements for integral domain extensions is considered with reference to the well known theorem about primitive elements for field extensions. Primitive elements for extensions of a commutative ring R with identity are considered, where R has only a finite number of minimal prime ideals with zero intersection. This case is reduced to the case for ring extensions of integral domains.
Die metatese van alkyne
Authors: Vosloo H. C. M. , Du Plessis J. A. K.
Published: July 2013

The alkyne metathesis reaction is a direct result of the known and intensively studied alkene or olefin metathesis reaction. Unfortunately this reaction was never studied as intensively as the alkene metathesis reaction, mainly because of a lack of active catalytic systems. In the alkyn metathesis reaction the carbon-carbon triple bonds are broken and rearranged to give a redistribution of alkylidyne groups.
Die plantgemeenskappe van die Ba-landtipe in die Mooirivieropvanggebied, Transvaal
Authors: Bezuidenhout H.
Published: July 2013

The aim of this study was to identify, characterize and interpret ecologically, by using habitat characteristics, the major vege­tation units and their variations of the Ba land type. Six plant communities were successfully distinguished through applying a numerical classification (TWINSPAN) and Braun-Blanquet procedures. The plant communities could easily be correlated with specific habitat types. A clear distinction could be made between plant communities of the upland and lowland areas. Vegetation gradients and associated gradients in habitat were identified by using an ordination technique (DECORANA). The studv emphasized the importance of topography and soil type for the delimitation of management units for farming or nature conservation practices.
Draaikolke suid van die Mosambiekkanaal
Authors: Office Editorial
Published: July 2013

Data collected during a cruise of the RV Meiring Naudé in September 1985 indicated the existence of two cyclonic eddies situated south of the Mozambique Channel. The western eddy interrupted the layer of Subtropical Surface Water and trans­ported 17-25 X 10⁶m³s¯­­­­¹ (relative to a reference level of 1 000 db). The eastern eddy was not surveyed sufficiently to obtain a realistic impression of its transport.
Openingsrede
Authors: Van Staden J. F.
Published: July 2013

Ekonomiese groei as voorvereiste vir ’n nuwe Suid-Afrika word sterk beklemtoon. Daar behoort dus ’n voortdurende groei van die chemiese bedryf te wees.
Oordrag van energie in nielineêre elektriese netwerke - ’n moderne beskouing van drywing
Authors: De Beer A. S. , Van Wyk J. D.
Published: July 2013

Networks for electric power distribution contain many nonlinear elements in conversion equipment, loads and power electronic converters. This leads to distorted currents and voltages in the network. Several contributions regarding a general power theory for nonlinear networks are evaluated for determining the different power components. A new theoretical proposal for determining these components, including the concept of scattered current is discussed. The appli­cation of this theory to the control of distortion compensators in power networks is discussed in principle.
Spanningsverdeling tussen seriegekoppelde hoogspanning - skakelelemente tydens oorgangstoestande
Authors: Office Editorial
Published: July 2013

For switching voltages in excess of the maximum blocking voltage of a switching element (for example, thyristor, MOSFET or bipolar transistor) such elements are often coupled in series - and additional circuitry has to be provided to ensure equal voltage sharing. Between each such series element and system ground there is a certain parasitic capacitance that may draw a significant current during high-speed voltage transients. The "open" switch is modelled as a ladder network. Analy­sis reveals an exponential progression in the distribution of the applied voltage across the elements. Overstressing thus oc­curs in some of the elements at levels of the total voltage that are significantly below the design value. This difficulty is overcome by grading the voltage sharing circuitry, coupled in parallel with each element, in a prescribed manner, as set out here.
Tegnologie en kommunikasie
Authors: Clark J. B.
Published: July 2013

Communication is a field in which technological developments have had and still have an important impact. More and more economic and other human activities benefit from advances in communications technology. These activities are therefore much more dependent upon the level of technology used in communication. Countries (and enterprises) that do not keep up with these technological developments are increasingly being excluded from such benefits, and will eventually not be able to participate effectively in these activities.
Supersimmetriese kwantummeganika
Authors: Fiedeldey H.
Published: July 2013

This is a review of supersymmetric nonrelativistic quantum mechanics. Successful applications of the removal of Pauli-forbidden states occurring in the semi-microscopic Resonating Group Model for two-cluster scattering are discussed. The case of neutron- deuteron scattering in the context of the exact Faddeev theory and the Efimov effect are then discussed. Other interesting applications are also briefly mentioned.
Die kliniese farmakologie van hirudien - 'n nuwe antistolmiddel
Authors: Meyer B. H. , Muller F. O. , Luus H. G. , De la Rey N.
Published: July 2013

Increasing doses of 0,05, 0,1, 0,15 and 0,2 mg/kg of rDNA hirudin, a new anti-coagulant, were given subcutaneously to 20 volunteers (5 per dose) in order to investigate the tolerance and pharmacokinetics of the compound and its effects on coagulation. Hirudin was tolerated very well, the elimination half-life after subcutaneous injections is about 2 hours, about 40% of a given dose is excreted through the kidneys, and an excellent linear relationship was found between the area under the plasma concentration­ time curve and the dose. Hirudin increased partial thromboplastin time in a dose-related fashion.
Die struktuur en moontlike aandrywingskragte van die 1991 - 1992 - droogte in Suidelike Afrika
Authors: Jury M. R.
Published: July 2013

A diagnostic model is used to investigate the underlying atmospheric processes that gave rise to the 1991-1992 drought over Southern Africa. The first indicator of the impending drought was a rise of more than 1 °C in the sea surface temperatures of the tropical part of the Southern Indian Ocean in the winter of 1991. This may have been instrumented in causing an anomaly in the mean Walker circulation to develop, through which the inflow of warm, moist air from the Mozambique Channel to the eastern escarpment of Southern Africa was inhibited, with a concurrent reduction in rainfall. It is concluded that the pattern and cycles of summer rainfall over Southern Africa are now sufficiently well understood to venture tentative predictions, but that increased co-operation between the meteorological bodies of Southern Africa will be required to achieve this.
Sekresiemeganisme van atriale natriuretiese peptied (ANP)
Authors: Theron J. J. , Bosman H. , De Winter R. , Henning C. N.
Published: July 2013

Mechanical stretch of atrial muscle in vitro induces movement of ANP granules from central perinuclear areas to the periphery of the sarcoplasm at the sarcolemma. This centrifugal movement is associated with maximal secretion of ANP into the suspension medium, without morphological evidence of exocytosis. Since the addition of vinblastine suppresses the movement of granules and ANP secretion, microtubuli are probably involved in the intracellular movement of ANP granules.
Vruggroei van Macadamia integnfolia Maiden & Betche cv Keauhou in die Transvaalse Laeveld
Authors: Joubert A. J. , Holtzhausen L. C.
Published: July 2013

The morphological changes of the fruit of Macadamia integrifolia, from fruit set to fruit ripening, were studied and the growth phases of the fruit are described. The length of the fruit growth period, from full bloom to fruit ripening, was 31 weeks and the growth period is divided into three stages. During Stage I, which lasted 2 weeks, the zygote was dormant. Stage II is the seed development period, which lasted 12 weeks. Stage III is the ripening period, which occurred over 17 weeks.
Oksitosien: ’n kort oorsig
Authors: Levay P. F. , Viljoen M. , Meij H. S.
Published: July 2013

Oxytocin is traditionally associated with parturition and lactation. The similarity in oxytocin plasma levels in males and females implies a wider physiological role for the hormone. Oxytocin would now appear to be involved not only in milk ejection, but also in the production of milk. The hormone has further been shown to play a paracrine role in menstruation and to be of importance for normal fertilisation. Several endocrine modulatory as well as neurotransmitter effects have also been reported for oxytocin. The discovery of the role of oxytocin in central nervous system processes such as pain, anxiety, memory and learning has stimuluted a search for possible therapeutic applications of oxytocin in cases such as chronic pain and Alzheimer’s disease. A short review is presented of some of the biochemical and physiological aspects underlying the functions and possible therapeutic applications of oxytocin.
De preventie van diepe veneuze trombose
Authors: Verstraete M.
Published: July 2013

It is generally held that the clinical diagnosis of deep vein thrombosis constitutes a gross underestimate of the true incidence of the disease. Most cases of venous thrombosis occur after operation, during pregnancy and the puerperium, during prolonged immobilisation, in obese patients with varicose veins or in patients with solid tumours.
Die Nuwe Chemiewoordeboek
Authors: Office Editorial
Published: July 2013

As redakteur van Die Nuwe Chemiewoordeboek (1991) verwelkom ek selfs kritiek, want dit beteken dat daar minstens deur sommige chemici deeglik aandag aan die werk geskenk word. In hierdie moeilike tye, waarin daar selfs bedenkinge oor die voortbestaan van Afrikaans geopper word, is dit veral wenslik dat die Afrikaanssprekende vakman sy vaktaal sal ken en in ere sal hou.
Aspekte van mediumenergie-kernfisika in Suid-Afrika
Authors: Cowley A. A.
Published: July 2013

South Africa has participated in basic research on medium-energy nuclear physics for the past eight years since the completion of the cyclotron facility of the National Accelerator Centre. The research projects that have been conducted during this period have had a major influence on the development of the discipline of nuclear physics. This review of a selection of projects that have been completed to date illustrates the advance of knowledge and how this work has contributed towards a further understanding of the atomic nucleus. The possible impact of these studies on future application is alluded to by means of two important illustrative examples.
Die toksisiteit van Gladiolus dalenii van Geel
Authors: Van Dyk S. , Gerritsma- Van der Vijver L. M. , Van der Nest D. G.
Published: July 2013

The biological activity of Gladiolus dalenii van Geel (Iridaceae) corms (used in ethnomedicine) and leaves were evaluated in a few systems. A profile of acute toxicity in rats was compiled and it was found that both corms and leaves contained cytotoxic substances affecting mitotic active tissue. Acute deaths resulted from congestive heart failure. The toxicity of a fraction (coded as GDI) isolated from corms was qualitatively similar to that of corms and leaves. Estimated minimum lethal doses, given in mg/kg body weight, lie in the range 10-31 (i.p.) and 3 160 - 5 620 (p.o.) for corms, 100-316 (i.p.) and > 1 780 (p.o.) for leaves and 1-3 (i.p.) and > 1 000 (p.o.) for fraction GDI. Intact plant material showed no activity against a series of microbes. Fraction GDI was active against Candida albicans. Phototoxicity was not detected.
Kritiese evaluering van termodinamiese ontwerpsprosedures vir vuurpylontstekers
Authors: Knoetze J. H.
Published: July 2013

There are different methods that can be used for the thermodynamic design of igniters for solid rocket motors. These methods are mostly empirically based and can easily lead to an under-designed or over-designed igniter. The best-known methods are the free volume method, the surface area method, the critical pressure, the Bryan-Lawrence equation, the ignition delay-free volume method, the mass discharge coefficient method and the heat flux method.
Die verandering in totale opgeloste sout - konsentrasies in die Vaalrivier se water
Authors: Prinsloo J. F. , Pieterse A. J. H.
Published: July 2013

No abstract
Die invloed van blootstelling aan mirasidiums Schistosoma mansoni op mortaliteitskoerse van kohorte van vier geografiese stamme van Biomphalaria pfeifferi
Authors: De Kock K. N.
Published: July 2013

First generation cohorts of 25 specimens each of parental populations of Biomphalaria pfeifferi from four different localities, were each exposed to three Schistosoma mansoni miracidia per snail at an age of four weeks. The effect on survival was evaluated by calculating the weekly per capita mortality rates and the mean life-expectancy of the exposed snails. No significant differences could be demonstrated between the per capita mortality rates of F₁ cohorts of the two parental strains originating from localities in endemic bilharzia areas. Likewise there were no significant differences in this respect as far as F₁ cohorts of the two strains originating from localities in non-endemic bilharzia areas were concerned.
Die vleiplantegroei in die Grootvlei-Villiers - omgewing, Oos-Transvaal
Authors: Myburgh W. J.
Published: July 2013

The vegetation of the wetlands in the Grootvlei-Villiers area was investigated phytosociologically to distinguish plant communities. The results of a numerical classification (TWINSPAN) of 44 relevés, refined by Braun-Blanquet procedures, revealed ten plant communities which are classified hierarchically and which are presented in a phytosociological table. Although individual wetlands are poor in plant species, considerable variation in species composition exists among the different wetlands.
Die invloed van kompetisie op drie Namakwalandse efemeer-plantspesies
Authors: Oosthuizen M. A.
Published: July 2013

No abstract
Renale opruiming van melatonien
Authors: Office Editorial
Published: July 2013

Only two publications exist in which actual values for the renal clearance of intact melatonin in man is described. The melatonin clearance values were, however, obtained either after the oral intake of melatonin, or by applying different techniques for the determination of melatonin in urine and plasma. In this study, renal clearance of melatonin was determined during the hours where melatonin concentrations are relatively constant. Melatonin levels in plasma and urine respectively were each deter­mined by three analytical techniques, i.e. the Fraser, NID and WHB methods. The results show renal clearance of melatonin to be under 2 ml/min and that higher values are obtained with analytical techniques which bypass the extraction process.
Die plantegroeikomponent van ’n omgewings - bestuursprogram vir Bankfontein, Kendal
Authors: Myburgh W. J.
Published: July 2013

The natural vegetation of the farm Bankfontein was ecologicaly investigated. Three terrestrial and three aquatic/semi-aquatic vegetation units were identified. These units were named and described. The study was carried out according to the guidelines provided by the "Aide-Mémoire”, obtainable from the Department of Mineral and Energy Affairs.
Optimering van die plasmaondersteunde chemiese dampdeponering van kwartsagtige lagies by lae temperature
Authors: Crouse P. L. , Bester J. A.
Published: July 2013

Results pertaining to the plasma-assisted chemical vapour deposition (PACVD) of SiOᵪCᵧ thin films at room temperature using a self-biasing radio-frequency plasma reactor are presented. Response surface analysis was used for experimental design. A simple technique is illustrated for the optimizing of any physical property, subject to the constraints imposed by the apparatus and by the required values of other physical properties.
Nuwe terme in chemie en verwante gebiede
Authors: De Villiers W. Van Z.
Published: July 2013

No abstract
Stikstofoksied en die senuweestelsel
Authors: Meij H. S.
Published: July 2013

It was discovered fairly recently that nitric oxide (NO), a poisonous gas molecule, can act as a cellular messenger in biological systems. In the human body it is produced and released by several types of cells in a number of different organs, and it appar­ently plays a fundamental part in the functions of almost all the body systems. Nitric oxide seems to be significantly involved in the cardiovascular system (especially in vasodilation), the defence systems of the body (destruction of pathogens) and in the nervous system as neurotransmitter and -modulator. In this short review aspects regarding the synthesis and possible actions of NO are described, and the importance of this gas molecule in the nervous system is summarised.
"Why bother to publish in Afrikaans?"
Authors: Office Editorial
Published: July 2013

No abstract
Fisiologie en patofisiologie van selorganelle
Authors: Theron J. J. , Panzer A. , Claasen N. , Lizamore N.
Published: July 2013

Peroxisomes are round or oval organelles with a finely granular matrix surrounded by a single membrane and are especially found in liver and kidney cells. Catalase-positive structures or microperoxisomes are, however, found in all eucaryotic cells except mature red blood cells. Enzyme proteins (approximately fifty) destined for peroxisomes are synthesized in free cytosolic ribosomes and are incorporated in the matrix of forming organelles with the aid of two signal peptides: a carboxy terminal SKL-tripeptide and possibly an aminoterminal undecapeptide. The functions of peroxisomes include, inter alia, extramitochondrial fi-oxidation (espe­cially very long chain fatty acids), synthesis of plasmalogens and other ether lipids and metabolism of hydrogen peroxide.
Statistiese terminologieprojek
Authors: Steyn H. S.
Published: July 2013

Daar bestaan die afgelope paar dekades ’n Afrikaans-Engelse Statistiekwoordeboek. Hierdie woordeboek is laas in 1984 hersien en ongeveer agt jaar later het die behoefte begin ontstaan om die woordeboek by te werk met byvoeging van nuwe terme en hersiening van die bestaande terme. Aan die einde van 1992 is ’n projek geloods om hierdie werk aan te pak. Die inisiatief is geneem deur die Suid-Afrikaanse Statistiese Vereniging (SASV) se Onderwyskomitee. Die Nasionale Terminologiediens (NTD) het hulp verskaf sover dit advies en infrastruktuur betref.
Wêreldmededingendheid en die landbou
Authors: Van Zyl J.
Published: July 2013

Against the background of a changing environment in which market factors and greater world trade and competitiveness are increasingly becoming the only criteria for success, a framework for the analysis of world competitiveness is initially developed. This is followed by a discussion on the growth of productivity in agriculture, as well as an exposition of the role of agricultural research. Thirdly, price factors and the terms of trade are discussed, followed by a summary of policy implications.
Die ontwikkeling van ’n opleidingsmikrobeheerder vir nie - elektroniese ingenieurs
Authors: Lubbe A. J.
Published: July 2013

During training of Industrial engineering students at the University of Pretoria it was realized that no suitable micro controller system for the training of non-electronic engineers in the application of micro controllers was locally available. A micro controller system which complies with the unique training requirements of non-electronic engineers was developed. The systems were made availcdyle to the students during training and after two years in use, the design was revised and the deficiencies corrected. A software control programme was developed that combines into one, all the different programmes needed to programme the micro controller Software was also written fo r the controller which handles the communication protocol between the personal computer and the micro controller.
Pseudotopologiese Rieszruimtes
Authors: Muller M. A.
Published: July 2013

Pseudo-topological spaces (i.e. limit spaces) were defined by Fischer in 1959. Properties of topological Riesz spaces are well-known. In this paper it is shown that if the topology on a Riesz space is replaced by a pseudo-topology more general results are obtained.
Fisiologie en patofisiologie van selorganelle
Authors: Theron J. J. , Claasen N. , Lizamore N.
Published: July 2013

Mitochondria are found in all eucaryotic cells except mature red blood cells. The structural components of these organelles are briefly described. The primary function of mitochondria, i.e. transduction of energy with formation of ATP through a process of oxidative phosphorylation (OXPHOS) occurs in six protein complexes arranged in sequence on the mitochondrial cristae formed by infoldings of the internal membrane. Mitochondrial DNA and ribosomes are found in mitochondria and protein synthesis can therefore occur in these organelles. However, most mitochondrial proteins and practically all lipids are imported from the cytoplasm.
Fotovoltaïese elektrisiteit
Authors: Swanepoel R.
Published: July 2013

PPhotovoltaic electricity (PV) is a free and clean source of renewable energy and presents a solution for many of the socio-economic problems of both first world and third world communities. Large-scale introduction of PV is currently hampered by the high cost of solar cells. At present crystalline silicon solar cells dominate the world market. These cells consist of flat wafers pure Si with a p-n junction and the technology is almost perfected with cell efficiencies of 24%. The efficiency of poly-crystalline wafers is somewhat lower but they are more cost effective.
Inleiding tot die toepassing van genetiese algoritmes in ingenieurswese
Authors: Shaw I. S.
Published: July 2013

Genetic algorithms constitute a new research area in the field of artificial intelligence. This work is aimed at their application in specific areas of engineering where good results have already been achieved. The purpose of this work is to provide a basic introduction for students as well as experienced engineers who wish to upgrade their knowledge. A distinctive feature of artificial intelligence is that instead of mathematical models, either direct human experience or certain functions of the human brain for the modelling of physical phenomena are used.
Epidemies in antieke Rome en ander Mediterreense lande
Authors: Retief F. P.
Published: July 2013

Epidemic diseases recorded in ancient Rome and surrounding Mediterranean countries from 53 BC to the onset of the Christian era are reviewed. With few exceptions historians omitted to record clinical details, which makes identification of diseases very difficult.
’n Vergelyking van die lipiedkomponente van springbokvleis met die van beesvleis en die verwante belangrikheid vir aspekte van die menslike gesondheid
Authors: Gouws J.
Published: July 2013

Coronary heart diseases are today considered an epidemic and dieticians suggest a drastically reduced intake of saturated fatty acids.
Die toepassing van peptiedblootlegging op fage in trombose en hemostase
Authors: Meiring S. M.
Published: July 2013

The scope and utility of phage display are reviewed with emphasis on application in the field of thrombosis and haemostasis and drug design. General principles of this technique are described.
Terminologie met betrekking tot kernmateriaalwaarborge
Authors: Von Wielligh N. , Maritz J. S. , De Villiers W. Van Z.
Published: July 2013

No abstract
Die ontwikkeling van ’n prototipe - borduurmasjien vanaf ’n huishoudelike naaimasjien
Authors: Lubbe A. J.
Published: July 2013

The prototype embroidery machine was developed by building a computer-controlled XY-table which is connected to a normal household sewing machine and a personal computer.
Vergiftiging in antieke Rome
Authors: Retief F. P. , Cilliers L.
Published: July 2013

Recorded instances of poisoning in ancient Rome were studied. The firs t such event was in 33l BC when, concurrent with a serious epidemic, 170 women were formed guilty of mass poisoning. Historians reported a subsequent increase in deliberate poisoning, which appeared to reach an alarming peak during the Julio-Claudian dynasty and the reign of Nero in particular.
Die familie Asteraceae: ’n Algemene oorsig
Authors: Herman P. P. J.
Published: July 2013

The family Asteraceae (the daisy family) is probably the largest plant family in the world. It is cosmopolitan in distribution and is economically important as many members are used for food, medicinal purposes, grazing for stock, or ornamentals, while some are troublesome weeds or poisonous to animals. The ‘flower ’is actually a collection of flowers grouped together to form a capitulum.
Optieseveselkommunikasie: verlede, hede en toekoms
Authors: Lacquet B. M.
Published: July 2013

The exponential increase in the use of the Internet and the consequent growing need for higher bandwidth demand that the telecommu­nications industry expand the laid networks at a much faster rate. Optical fibre is the only transmission medium that has the potential of unlimited bandwidth and the ability to handle very high data rates.
Die omvang van die oorsake van laat voltooiing van bouprojekte in die Republiek van Suid-Afrika
Authors: Klopper C. H.
Published: July 2013

The extent of delays on building projects in the Republic of South Africa caused by individual factors (each considered separately), are investigated. Where possible, the research results are quantified and presented in various tabular formats.
Entropic entanglement criteria for fermion systems
Authors: Zander Claudia
Published: July 2013

Entanglement criteria for general (pure or mixed) states of systems consisting of N identical fermions are introduced. These criteria are based on appropriate inequalities involving the entropy of the global density matrix describing the total system and the entropy of the one-particle, reduced density matrix.
Ortogonale voorstelling van drywing deur middel van kwaternione
Authors: Enslin J. H. R.
Published: July 2013

The increased use of power control equipment resulted in the distortion of the excitation and response functions in power systems from simple sinusoids. These systems resulted in discrepancies in the general definition of power. This distortion has a negative effect on the accurate definition and representation of power in a contaminated power system. The mathe­matical representation of power with the aid of the theory of quaternions in vector calculus is investigated to obtain a generalized definition of power in all power systems, especially in power systems where the excitation and response functions show non-sinusoidal characteristics. The general description of power is illustrated with the aid of electrical power systems, but is however proposed to be beneficial in all power systems, being mechanical, thermal or chemical. Power is divided into different orthogonal components which describes the energy transfer through a system. The quaterni­on theory has orthogonal properties which can be used together with the Cauchy-Schwarz inequality to describe the power components using the excitation and respective response functions.
Bornologiese pseudotopologiese vektorruimtes
Authors: Muller M. A.
Published: July 2013

Homological spaces were defined by Hogbe-Nlend in 1971 and pseudo-topological spaces by Fischer in 1959. In this paper properties of bornological pseudo-topological vector spaces are investigated. A characterization of such spaces is obtained and it is shown that quotient spaces and direct sums o f boruological pseudo-topological vector spaces are bornological. Every bornological locally convex pseudo-topological vector space is shown to be the inductive limit in the category of pseudo-topological vector spaces of a family of locally convex topological vector spaces.
Energieverlies deur nie-fekale en fekale uitskeiding van die mariene elasmobranch Rhinobatos annulatus (Muller & Henle, 1841)
Authors: Du Preez H. H.
Published: July 2013

The nonfaecal and faecal excretion of the sandshark Rhinobatos annulatus were investigated at 15° C and 20° C. Nonfaecal nitrogen excreted by starved and fed sandsharks consisted mainly of ammonia-N (60%) and urea-N (36%). Ammonia-N ex­cretion rates were temperature independent with the excretion rate of fed sandsharks significantly higher than those of starved sandsharks.
Mechanisms leading to enhanced soil nitrous oxide fluxes induced by freeze–thaw cycles
Authors: Risk Neil , Snider David , Wagner-Riddle Claudia
Published: July 2013

Risk, N., Snider, D. and Wagner-Riddle, C. 2013. Mechanisms leading to enhanced soil nitrous oxide fluxes induced by freeze–thaw cycles. Can. J. Soil Sci. 93: 401–414. The freezing and thawing of soil in cold climates often produces large emissions of nitrous oxide (N2O) that may contribute significantly to a soil's annual greenhouse gas emission budget. This review summarizes the state of knowledge of the physical and biological mechanisms that drive heightened N2O emissions at spring melt. Most studies of freeze–thaw N2O emissions have concluded that denitrification is the dominant process responsible for the large thaw fluxes. Soil moisture, availability of carbon and nitrogen substrates, and freeze temperature and duration are the major factors identified as controlling freeze–thaw cycle (FTC) N2O emissions. Two mechanisms are proposed to lead to enhanced N2O emissions at thaw: (1) the physical release of N2O that is produced throughout the winter and trapped under frozen surface layers and/or within nutrient-rich water films in the frozen layers, and (2) the emission of newly produced (de novo) N2O at the onset of thaw, which is stimulated by increased biological activity and changes in physical and chemical soil conditions. Early studies implicated the physical release of N2O from subsurface soil layers as the main mechanism contributing to spring thaw emissions, but most current studies do not support this hypothesis. Mounting evidence suggests that most of the emitted N2O is produced de novo. This may be fueled by newly available denitrification substrates that are liberated from dead microbes, fine roots, and/or the disintegration of soil aggregates. The release of N2O trapped in shallow surface layers may represent a small, but important contribution of the total emissions. Application of new techniques to study microbial communities in their natural environments, such as metagenomics and stable isotope studies, have the potential to enhance our understanding of the soil N cycle and its linkages to FTC N2O emissions. Future field studies of N2O emissions ought to quantify both overwinter accumulation/release and the de novo production of N2O so that the contribution of each mechanism to the annual emission budget is known.
Growing season N2O emissions from two-year potato rotations in a humid environment in New Brunswick, Canada
Authors: Snowdon Emily , Zebarth Bernie J. , Burton David L. , Goyer Claudia , Rochette Philippe
Published: July 2013

Snowdon, E., Zebarth, B. J., Burton, D. L., Goyer, C. and Rochette, P. 2013. Growing season N2O emissions from two-year potato rotations in a humid environment in New Brunswick, Canada. Can. J. Soil Sci. 93: 279–294. Few studies have examined the effects of crop rotation on N2O emissions. This study quantified N2O emissions from seven 2-yr potato rotations over a 3-yr period, 2008–2010, where the potato phase was present in 2008 and 2010. In addition, the potential to predict variation in cumulative growing season N2O emissions was examined using indices of nitrate availability [nitrate exposure (NE), a time integrated measure of soil nitrate concentrations in the surface soil], carbon availability (cumulative growing season CO2emissions) and aeration [time-weighted average water-filled pore space (WFPS)]. In the potato phase of the rotations, even for treatments receiving the same fertilizer N rate (193 kg N ha−1), a wide range in cumulative growing season N2O emissions was measured in both 2008 and 2010 (0.39–1.49 and 0.81–2.03 kg N ha−1, respectively). The NE explained 52 and 70% of the variation in growing season N2O emissions under potato production in 2008 and 2010, respectively. Carbon availability also had a significant effect on N2O emissions, as indicated by increased N2O emissions in rotations where residues of the preceding crop resulted in increased CO2emissions early in the growing season. A large proportion (67%) of the variation in cumulative N2O emissions among rotation crops was also explained by NE. Choice of rotation crop resulted in an almost twofold difference (0.9–1.7 kg N ha−1) in N2O emissions over the 2-yr rotation cycle. Greater N2O emissions over the 2-yr rotation cycle were measured for rotation crops of soybean, Italian ryegrass, red clover and potato than for rotation crops of corn, canola and barley. However, the fertilizer N management in both the potato and rotation crop phases may be as or more important than the choice of rotation crop in influencing the risk of N2O emissions.
Phosphorus and trace metals in serpentine-affected soils of the Sumas Basin, British Columbia
Authors: Baugé S. M. Y. , Lavkulich L. M. , Schreier H. E.
Published: July 2013

Baugé, S. M. Y., Lavkulich, L. M. and Schreier, H. E. 2013. Phosphorus and trace metals in serpentine-affected soils of the Sumas Basin, British Columbia. Can. J. Soil Sci. 93: 359–367. Soils of the Sumas watershed in the Lower Fraser Valley of British Columbia have contrasting P, Mg and trace elements contents arising from two major sources, periodic deposition of serpentine-rich sediments and intensive agricultural activities. Four study sites were examined for soil P by several extractants commonly used for P availability assessments. The results were compared with aqua regia to determine best estimates of extractable P. In addition, these extractants were evaluated as indices of associated trace metal amounts. Aqua regia, acid ammonium oxalate and 1 M HCl extracted similar amounts of P and trace metals. Acid ammonium oxalate was found to be closely related to the estimates of total P and recoverable elements, followed by 1 M HCl. There was clear separation of the sites by both P values and trace elements associated with serpentine (Cr and Ni) and those from agricultural activities (Cu and Zn). Results suggest that a single extraction, 1 M HCl, can be an effective measure of both available P and trace elements in serpentinitic soils.
Artificially induced migration of redox layers in a coastal sediment from the Northern Adriatic
Authors: Metzger E. , Langlet D. , Viollier E. , Koron N. , Riedel B. , Stachowitsch M. , Faganeli J. , Tharaud M. , Geslin E. , Jorissen F.
Published: July 2013

Abstract. Long term experimental studies suggest that, under anoxic transient conditions, redox fronts within the sediment shift upwards causing sequential rise and fall of benthic fluxes of reduced species (Mn(II), Fe(II) than S(−II)). Infaunal benthic organisms are associated to different redox fronts as micro-habitats and must be affected by such changes during natural hypoxia events. In order to document geochemical evolution of the sediment during prolonged anoxia in a realistic system, benthic chambers were deployed on the seafloor of the Northern Adriatic and sampled after 9, 30 and 315 days of incubation. Oxygen and sulfide were measured continuously in the early stages of the experiment (during 9 days). High-resolution porewater profiles were sampled by DET probes and redox sensitive species were analysed (alkalinity, SO42–, Mn2+, Fe2+). After 7 days, anoxia was reached within the chambers. Mn and Fe started diffusing towards the water column giving a rusty color to the seafloor. Infaunal species appeared at the surface. After 20 days, all macro-organisms were dead. Macro-organisms decomposition laying on the seafloor generated important production of sulfides within the chamber generating a downward flux of sulfide towards the sediment where sulfides were quickly oxidized by metallic oxides or precipitated as FeS. Sulfide was no more detectable in the water column and porewaters at the end of the experiment. Therefore, our results suggest that sulfide enrichment in the water column in coastal systems is strongly controlled by the biomass of benthic macrofauna and its decay during hypoxia while its residence time in water column is controlled by iron content (as solid oxides or as dissolved reduced cation) within the sediment, even without water circulation.
Foraminiferal species responses to in situ experimentally induced anoxia in the Adriatic Sea
Authors: Langlet D. , Baal C. , Geslin E. , Metzger E. , Zuschin M. , Riedel B. , Risgaard-Petersen N. , Stachowitsch M. , Jorissen F. J.
Published: July 2013

Abstract. Anoxia was successfully induced in four benthic chambers installed at 24 m depth in the northern Adriatic Sea, for periods varying from 9 days to 10 months. During the 10 months period, species richness significantly decreased. Although no significant change in Shannon diversity and Evenness is observed, the composition of the foraminiferal assemblages changes with time. This change is due to interspecific differences in tolerance with respect to anoxia and free sulphides. Leptohalysis scottii, Textularia agglutinans and Quinqueloculina cf. stelligera all showed a significant decrease with time, strongly suggesting they are sensitive to the anoxia and sulphides. Conversely, Eggerella scabra, Bulimina marginata, Lagenammina atlantica, Hopkinsina pacifica and Bolivina pseudoplicata appear to be resistant to the experimental conditions. Quinqueloculina seminula also appears to be sensitive to anoxia but shows a clear standing stock increase during the first month of the experiment, which we interpret as an opportunistic response to increasing organic matter availability due to the degradation of the dead macrofaunal organisms. It appears that none of the anoxia sensitive species is capable to accumulate intracellular nitrates. Such a capacity could be shown for some tested specimens of the dominant anoxia tolerant species E. scabra and B. marginata. However, tests on the denitrification capacity of these taxa yielded negative results, suggesting that their resistance to long-term anoxia is not due to a capacity to denitrify.