27 research outputs found
Cultura e lingue classiche. Convegno di aggiornamento e di didattica. Roma, 1-2 novembre 1985, a cura di Biagio Amata. 2 tomes, 1986-1988 ; Pavanetto (Clelus),Litterarum graecarum classicarum lineamenla potiora,1984 ; Elementa linguae et grammaticae latinae, 1987
No full textDu Plessis Brigitte. Cultura e lingue classiche. Convegno di aggiornamento e di didattica. Roma, 1-2 novembre 1985, a cura di Biagio Amata. 2 tomes, 1986-1988 ; Pavanetto (Clelus),Litterarum graecarum classicarum lineamenla potiora,1984 ; Elementa linguae et grammaticae latinae, 1987. In: Revue des Études Anciennes. Tome 91, 1989, n°3-4. pp. 132-133
Thèses françaises de patristique et d'Antiquité tardive à la Faculté des Lettres de l'Université de Paris de 1870 à 1930
No full textThis article, which gives in appendix the list of the thesis upholded in Patristic and in Late Antiquity between 1870 and 1930 by fifty-six scholars, study some of these thesis to emphazise their relations with foreign works, in most cases german. The author shows also that certain great controversies which they reflect are still existing today.Cet article, qui donne en annexe la liste des thèses soutenues en patristique et en Antiquité tardive entre 1870 et 1930 par cinquante-six savants, étudie quelques-unes d'entre elles pour souligner leurs rapports avec des travaux étrangers, en très grande majorité allemands. L'auteur montre aussi que certaines grandes controverses dont ces thèses se font l'écho ont encore de l'actualité aujourd'hui.Du Plessis Brigitte. Thèses françaises de patristique et d'Antiquité tardive à la Faculté des Lettres de l'Université de Paris de 1870 à 1930. In: Revue des Études Anciennes. Tome 95, 1993, n°3-4. pp. 537-551
Evaluation of the microbial safety of commercially produced tomatoes in South Africa and the development of a novel enrichment broth for the identification of Escherichia coli O157:H7
No full textDissertation (MSc)--University of Pretoria, 2015.Since the discovery of Escherichia coli O157:H7 in the early 1980s and the increased
association of foodborne outbreaks linked to fresh produce, a growing number of research
articles relating to this subject have been published. Although leaps in our understanding of
foodborne pathogen association with fresh produce have been made, our knowledge regarding
this subject remains limited, with many research findings being contradictory. The microbial
safety of commercially produced tomatoes in South Africa was investigated during 2012-
2014. Although no tomatoes tested were contaminated with either Salmonella enterica or
Escherichia coli O157:H7, the presence of Salmonella enterica in the packinghouse of the
first farm investigated in 2012 does indicate a potential risk associated with fresh tomatoes.
Rapid, sensitive, and accurate detection of foodborne pathogens is vital to ensure produce
safety. Conventional culturing techniques should be improved to reduce the analysis time,
increase the efficiency of recovery, improve the resurrection and growth of injured cells, and
to exclude other microorganisms present in the samples. The part of this dissertation therefore
aimed to investigate the application of EnBase® technology for the enhanced recovery of sublethally
injured E. coli O157:H7 from the environment and particularly surface water.
Limiting fermentable carbohydrate availability through enzymatic glucose release would
hypothetically prevent metabolic overload during enrichment cultivation, allowing enhanced
resuscitation and growth of target organisms. This was found to be the case when E. coli
O157:H7 was grown axenically under pristine conditions. EnPresso® B and variations thereof
performed sub-optimally compared to buffered peptone water when used for the enrichment
of E. coli O157:H7-spiked surface water in the presence of naturally occurring coliforms. The utilization of EnBase® technology for the selective and differential isolation and enumeration
of sub-lethally injured E. coli O157:H7 from spiked surface water on solid media were not
effective due to interference of the buffering capacity of EnPresso® B with the pH indicator
neutral red.
Understanding the biological and ecological factors enabling survival and persistence of
human enteric bacteria in fresh produce, as well as better detection and monitoring
techniques, are crucial in developing pre- and postharvest strategies to ensure safe produce in
the future.Microbiology and Plant PathologyMScUnrestricte
Communication as a strategic monetary policy tool : an evaluation of the effectiveness of the South African Reserve Bank's communication
No full textThesis (PhD)--Stellenbosch University, 2011.ENGLISH ABSTRACT: The effectiveness of monetary policy depends importantly on the expectations of the private sector, as it is largely through this channel of the transmission mechanism that policy changes are transmitted to long-term interest rates. This has increased the emphasis on the role of central bank communication as a monetary policy tool. Successful communication is essential both to enhance the effectiveness of monetary policy and to build support for the institutional framework within which monetary policy is implemented. While the large and growing literature on central bank communication over the past decade has delivered strong support for the important role of central bank communication, there is less agreement about what the optimal communication strategy is. Furthermore, research has been limited mainly to studies of communication between central banks and the financial markets. In an evaluation of progress in the literature, Blinder et al. (2008) highlight the need to examine the interaction between central banks and the rest of the private sector (the general public) as well. The objective of this PhD dissertation is to evaluate the South African Reserve Bank’s (SARB’s) use of communication as a monetary policy tool. Special focus is given to communication with the inattentive general public, who set prices in the labour market and the market for goods and services. Different aspects of the SARB’s communication were studied, including the consistency of the South African Reserve Bank’s communication, the transmission of this communication via the media to the general public, and the process by which the general public gathers and processes the information on inflation.
An evaluation of the SARB’s communications (its original messages) provided some evidence that the SARB has succeeded in communicating consistently over the inflation targeting period. This was followed by an assessment of the role of the media in transmitting the original communications to the general public. The results suggest that South African media reports generally show a lack of critical assessment of monetary policy decisions and that the inter-meeting communication by the SARB is ineffective at influencing these. An important challenge is for the SARB to consider how it can participate more actively in the economic discussion at this level and how it can build productive strategic relationships with the media. The final section of this dissertation explores the process by which the general public forms its inflation expectations, relying on epidemiological models to describe the spread of inflation information and to estimate the speed at which the general public, in aggregate, updates their inflation expectations. This estimate of the speed of adjustment will be valuable to future research that aims to build a Phillips curve in a new way for South Africa. A well-modelled Phillips curve will both improve the monitoring of the impact of monetary policy and inform future policy design and implementation.AFRIKAANSE OPSOMMING: Die doeltreffendheid van die monetêre beleid is beduidend afhanklik van die verwagtinge in die privaat sektor, aangesien beleid hoofsaaklik deur hierdie kanaal langtermyn rentekoerse beïnvloed. Hierdie bewustheid het die klem op die rol van sentrale bank kommunikasie as ‘n monetêre instrument versterk. Suksesvolle kommunikasie is noodsaaklik om beide die effektiwiteit van monetêre beleid te verseker sowel as om ondersteuning vir die institusionele raamwerk waarbinne die monetêre beleid geïmplimenteer word, te bou. Hoewel daar ‘n groot en groeiende literatuur is wat die belangrikheid van sentrale bank kommunikasie oor die afgelope dekade beklemtoon, is daar nie eenstemmigheid oor wat die optimale kommunikasie strategie behels nie. Daarbenewens is meeste studies beperk tot die kommunikasie tussen monetêre owerhede en die finansiële sektor. In ‘n evaluering van die literatuur het Blinder et al. (2008) die noodsaaklikheid beklemtoon om die wisselwerking tussen monetêre owerhede en die res van die privaat sektor (die publiek) te bestudeer. Die doel van hierdie proefskrif is om die Suid-Afrikaanse Reserwebank (SARB) se gebruik van hierdie kommunikasie instrument te evalueer. Spesiale aandag word geskenk aan kommunikasie met die onoplettende publiek wat pryse bepaal in die arbeidsmark en markte vir goedere en dienste. Verskillende aspekte van die SARB se kommunikasie strategie word bestudeer, insluitende die konsekwentheid van kommunikasie, die oordrag van hierdie kommunikasie via die media aan die publiek, asook die proses waarmee die publiek informasie rakende inflasie versamel en verwerk. ‘n Evaluering van die SARB se kommunikasie (die oorspronklike boodskappe) lewer bewys dat die SARB daarin geslaag het om konsekwent te kommunikeer tydens die inflasie teikeningsperiode. Dit word gevolg deur ‘n evaluering van die rol van die media om oorspronklike informasie suskesvol aan die publiek oor te dra. Die resultate dui daarop dat berigte in die Suid Afrikaanse media oor die algemeen aan kritiese evaluering van die monet.re beleidsbesluite ontbreek en die SARB se kommunikasie tussen monetêre beleidsvergaderings is ook oneffektief gevind. ‘n Belangrike uitdaging vir die SARB is dus om te bepaal hoe dit op hierdie vlak tot die ekonomiese debat kan toetree en hoe dit produktiewe strategiese verhoudings met die media kan bou. Die laaste afdeling van die proefskrif bestudeer die proses waarvolgens die publiek hul inflasieverwagtinge formuleer deur gebruik te maak van epidemiologiese modelle wat die verspreiding van inflasie verwagtinge, asook die spoed waarteen die publiek oor die algemeen hul inflasieverwagtinge opdateer, beskryf. Die snelheid waarmee die publiek hul verwagtinge opdateer behoort veral van waarde te wees vir toekomstige studies wat poog om ‘n Phillips kurwe met ‘n nuwe aanslag vir Suid Afrika te skort. ‘n Goed geformuleerde Phillips kurwe sal monitering van monetêre beleide se impak verbeter, en sal ook as ‘n goeie riglyn vir toekomstige beleidsontwerp en -implimentering dien.Doctora
Second-round effects on inflation, and underlying inflation
No full textThesis (PhD)--Stellenbosch University, 2016.ENGLISH SUMMARY : Supply shocks, especially food and energy price shocks, play a significant role in the evolution
and dynamics of headline consumer price inflation in South Africa. Although headline
inflation is the price index officially targeted by the South African Reserve Bank, monetary
policy can neither control the relative price movements, nor would it be desirable for the central
bank to do so. It is only when these relative price shocks affect the underlying trend rate of inflation
– core inflation – through second-round effects that monetary policy has a critical role to
play. The presence of second-round effects change how a central bank needs to respond to relative
price shocks. Generally, a central bank can look through shocks to food and energy prices,
in the absence of second-round effects, communicating clearly the reason for its inaction. However,
when second-round effects are present, the central bank has to respond appropriately to
ensure that inflation expectations remain anchored around the target.
Second-round effects emanate from the ability of price-setting firms and wage-setting labour
to increase prices (whether through mark-ups or higher marginal costs) and wages, and therefore
general prices of goods and services, in response to relative price shocks. In order for monetary
policy to adequately respond to second-round effects, these effects need to be identified and
quantified. Such identification depends on the definition of core inflation, the underlying trend
in overall inflation, and the consequent measurement of this core inflation. This PhD dissertation
contributes to the academic literature and policy discussion of second-round effects and
underlying, or core, inflation in South Africa.
First, the impact of second-round effects on inflation following supply shocks will be quantified
using a Structural Bayesian vector autoregressive model, with sensible zero and sign restrictions.
This identification relies on a conventional exclusion-based measure of core inflation – headline CPI less food and energy – that is often used in policy discussions and decisionmaking.
The results of this model confirm the impact of wage-setters in South Africa, that
changes in the prices of food, petrol and energy are accommodated and lead to strong secondround
effects.
Second, monetary policy in South Africa is forward-looking and requires forecasts of inflation
to set policy. To ensure the best possible estimates of core inflation are available to
the central bank, we look at a host of possible models that existing literature shows to have
some success in forecasting, and that cover a wide variety of new techniques. These include
models that take account of large datasets of information, that address possible breaks in the
inflation series as monetary policy regimes change, that address the changing relationship between
variables and inflation or the structure of the economy, and that provide mechanisms to
look at the importance of volatility. The myriad of forecasting techniques reveal that accounting
for changing relationships improve forecasts of core inflation, while exploiting more economic
information does not necessarily produce better forecasts compared with smaller models.
Last, it may be that a conventional definition of core inflation currently used by central banks
– headline CPI less food, non-alcoholic beverages and energy, the exclusion-based measure
most quoted by the South African Reserve Bank – is not the most appropriate, or theoretically
consistent, to ensure best policy outcomes. To address this, a novel approach to the definition
and calculation of core inflation will be followed using micro-price-level data. We study the
underlying dynamics of 5;200;466 individual price quotes of goods to determine the frequency
of price changes at a product level. This is used to construct a sticky-price goods inflation
measure. Sticky-price goods inflation is more persistent, less volatile and correlates well with
future goods inflation. The advantage of sticky-price inflation is that it grounds the concept
of underlying inflation into the theoretical framework currently used by central banks to make
policy decisions, and what is considered optimal policy by monetary theorists, making it an
ideal core inflation candidate for the central bank.AFRIKAANSE OPSOMMING : Geen opsomming beskikbaar.Doctora
Saving and wealth in the context of extreme inequality
No full textThesis (DCom)--Stellenbosch University, 2017.ENGLISH SUMMARY : Saving and wealth are important determinants for the wellbeing of individual households and the development of whole economies. Unlike flow variables like income and consumption, however, balance sheet data on wealth have been collected only recently. Among the developing countries, South Africa has been the rst to publish ocial household sector balance sheets, one of the rst to conduct large-scale household wealth surveys, and one of the first to give researchers access to anonymised tax records. In this dissertation, I use these new data to study saving and wealth in the context of a developing country with extreme inequality. The rst chapter focuses on saving and studies how the balance sheet concept of saving (the change in wealth between two periods of time) differs from the flow concept (the residual between income and expenditure). It finds that household wealth has grown much more strongly over the last decades than would have been implied by the flow measure of saving alone, owing to sizeable capital gains on existing asset holdings. The second chapter puts this nding into an international perspective, tying it to the literature that developed from Thomas Piketty's influential Capital in the Twenty-First Century (2014). While Piketty nds that capital gains contributed to a strong increase in rich-world wealth-income ratios between 1970 and 2010, I find that a similar trend started only in the late 1990s in South Africa. I also nd that this trend was generated almost entirely through corporate savings and the strong performance of the stock market, which contrasts with the importance of household savings and house price developments in Piketty's sample of advanced economies. Since a large share of stocks are held through domestic pension and retirement funds, the appreciation of nancial assets has beneted millions of South Africans. Yet, it is very likely that the boom has enriched a small number of individual shareholders disproportionately. The third chapter thus takes a distributional perspective on wealth, using two distinct data sources to estimate the degree of inequality in the country. I compare a survey with 18,820 respondents in 6,450 households to a novel dataset of almost 1.2 million personal income tax records. Despite the differences in the coverage of each source, I nd robust evidence that wealth is much more unequally distributed than income. Ten percent of the population own more than 50-95 percent of all wealth, compared to a top labour income share of “only” 45 percent. While an income or consumption perspective thus allows us to speak of a South African middle class, the balance sheet data suggest that a propertied middle class is still largely non-existent.AFRIKAANSE OPSOMMING : Besparing en rykdom is belangrike bepalers van die welstand van individuele huishoudings sowel as die ontwikkeling van ekonomieë in die geheel. Tog, in teenstelling met vloeiveranderlikes soos inkomste en verbruik, word balansstaatdata oor rykdom eers sedert betreklik onlangs ingesamel. Suid-Afrika was een van die eerste ontwikkelende lande wat amptelike balansstate vir die huishoudelike sektor gepubliseer, grootskaalse huishoudelike welvaartopnames gedoen, en navorsers toegang tot naamlose belastingrekords gegee het. In hierdie tesis gebruik ek hierdie nuwe data om besparing en rykdom in die konteks van ‘n ontwikkelende land met uiterste ongelykheid te bestudeer. Die eerste hoofstuk konsentreer op besparing, en bestudeer die verskille tussen die balansstaatkonsep van besparing (die verandering in rykdom van een tydperk tot ‘n volgende) en die vloeikonsep (die verskil tussen inkomste en uitgawes). Dit bring aan die lig dat huishoudelike rykdom oor die afgelope dekades veel sterker gegroei het as wat die vloeimaatstaf van besparing op sy eie sou aandui, as gevolg van beduidende kapitaalwinste op bestaande bates. Die tweede hoofstuk beskou hierdie bevinding uit ‘n internasionale hoek deur dit te koppel aan die literatuur wat uit Thomas Piketty se gesaghebbende Capital in the Twenty-First Century (2014) ontwikkel het. Terwyl Piketty vasgestel het dat kapitaalwinste tussen 1970 en 2010 tot ‘n sterk toename in rykdom-inkomsteverhoudings in die welvarende wreld gelei het, bevind ek dat ‘n soortgelyke tendens eers laat in die 1990's in Suid-Afrika posgevat het. Ek bevind ook dat hierdie tendens byna geheel en al deur korporatiewe besparing en die sterk prestasie van die aandelemark tot stand gekom het, in teenstelling met die belang van huishoudelike besparing en huisprysontwikkelings in Piketty se steekproef van gevorderde ekonomieë. Aangesien binnelandse pensioen- en aftreefondse oor ‘n groot aandeelhouding beskik, het miljoene Suid-Afrikaners baat gevind by die waardevermeerdering van finansiële bates. Tog het di voorspoedgolf heel waarskynlik ‘n klein getal individuele aandeelhouers buite verhouding verryk. Die derde hoofstuk beskou rykdom dus uit ‘n verdelingsoogpunt deur van twee verskillende databronne gebruik te maak om die mate van ongelykheid in die land te bepaal. Ek vergelyk ‘n opname van ongeveer 18 820 respondente in 6 450 huishoudings met ‘n nuwe datastel van bykans 1,2 miljoen persoonlike inkomstebelastingrekords. Hoewel die omvang en dekking van die databronne verskil, kom ek af op robuuste bewyse dat rykdom ongelyker verdeel is as inkomste. Tien persent van die bevolking besit meer as 90-95 persent van alle rykdom, vergeleke met ‘n topinkomste-aandeel van “slegs” 45 persent. Hoewel ‘n mens dus volgens ‘n inkomste- of verbruiksperspektief van ‘n Suid-Afrikaanse middelklas kan praat, dui die balansstaatdata daarop dat ‘n middelklas van eiendomsbesitters steeds grotendeels ontbreek.Doctora
Advancing paternal age at birth is associated with poorer social functioning earlier and later in life of schizophrenia patients in a founder population
No full textConsistent associations have been found between advanced paternal age and an increased
risk of psychiatric disorders, such as schizophrenia in their offspring. This increase appears
to be linear as paternal age increases. The present study investigates the relationship
between early deviant behaviour in the first 10 years of life of patients as well as longer
term functional outcome and paternal age in sporadic Afrikaner founder population cases of
schizophrenia. This might improve our understanding of Paternal Age-Related
Schizophrenia (PARS). Follow up psychiatric diagnosis was confirmed by the Diagnostic
Interview for Genetic Studies (DIGS). An early deviant childhood behaviour semi-structured
questionnaire and the Specific Level of Functioning Assessment (SLOF) were completed.
From the logistic regression models fitted, a significant negative relationship was found between paternal age at birth and social dysfunction as early deviant behaviour.Additionally, regression analysis revealed a significant negative relationship between paternal age at birth and the SLOF for interpersonal relationships later in life. Early social dysfunction may represent a phenotypic trait for PARS. Further research is required to understand the relationship between early social dysfunction and deficits in interpersonal
relationships later in life.http://www.elsevier.com/locate/psychres2017-09-30hb2016PsychiatryStatistic
The SIB Swiss Institute of Bioinformatics' resources: focus on curated databases
No full textThe SIB Swiss Institute of Bioinformatics (www.isb-sib.ch) provides world-class bioinformatics databases, software tools, services and training to the international life science community in academia and industry. These solutions allow life scientists to turn the exponentially growing amount of data into knowledge. Here, we provide an overview of SIB's resources and competence areas, with a strong focus on curated databases and SIB's most popular and widely used resources. In particular, SIB's Bioinformatics resource portal ExPASy features over 150 resources, including UniProtKB/Swiss-Prot, ENZYME, PROSITE, neXtProt, STRING, UniCarbKB, SugarBindDB, SwissRegulon, EPD, arrayMap, Bgee, SWISS-MODEL Repository, OMA, OrthoDB and other databases, which are briefly described in this article
Cytotoxicity of syringin and 4-methoxycinnamyl alcohol isolated from <i>Foeniculum vulgare</i> on selected human cell lines
No full text<div><p>This study was carried out to determine the cytotoxic effect of seven plant extracts and the isolated compounds – syringin and 4-methoxycinnamyl alcohol – on cancerous and non-cancerous cells. The ethanol extract of <i>Foeniculum vulgare</i> was found to exhibit the most significant toxicity with an IC<sub>50</sub> value of 19.97 μg/mL on HeLa cells. Bioassay-guided fractionation led to the isolation of two compounds, syringin (<b>1</b>) and 4-methoxycinnamyl alcohol (<b>2</b>). Both compounds showed toxicity against MCF-7, HeLa and DU145 cancer cell line. The results showed that compound <b>2</b> showed high toxicity against all the cancer cell lines with IC<sub>50</sub> values of 14.24, 7.82 and 22.10 μg/mL, respectively. 4-Methoxycinnamyl alcohol also showed no apoptotic effect in cell cycle analysis after 48 h at a concentration of 10 μg/mL. However, DNA fragmentation study revealed that necrosis took place at a concentration of 10 μg/mL after 48 h exposure.</p></div
Cytotoxicity of syringin and 4-methoxycinnamyl alcohol isolated from Foeniculum vulgare on selected human cell lines
No full textThe present study was carried out to determine the cytotoxic effect of seven plant
extracts and the isolated compounds; syringin and 4-methoxycinnamyl alcohol on
cancerous and non-cancerous cells. The ethanol extract of F. vulgare was found to
exhibit the most significant toxicity with an IC50 value of 19.97 μg/mL on HeLa
cells. Bioassay guided fractionation lead to the isolation of two compounds,
syringin (1) and 4-methoxycinnamyl alcohol (2). Both compounds showed
toxicity against MCF-7, HeLa, and DU145 cancer cell line. The results showed
that compound 2 showed high toxicity against all the cancer cell lines with IC50
values of 14.24, 7.82 and 22.10 μg/mL, respectively. 4-Methoxycinnamyl alcohol
also showed no apoptotic effect in cell cycle analysis after 48 hours at a
concentration of 10 μg/mL. However DNA fragmentation study revealed that,
necrosis took place at a concentration of 10 μg/mL after 48 h exposure.http://www.tandfonline.com/loi/gnpl202016-09-15hb201
