33 research outputs found
Anatomical, pathological and clinical study of donkey teeth
Eighty normal cheek teeth and 26 normal incisors extracted from 14 donkeys (median age 19
years) at post mortem were anatomically examined including grossly and by computerised axial
tomography (CAT) imaging. Decalcified histology was performed on 54 sections from 18 teeth
(8 donkeys), undeclacified histology on 16 sections from 7 donkeys and scanning electron
microscopy on 10 sections from 10 teeth (3 donkeys). The dental formulae and tooth number
was found to be the same as in horses with a higher prevalence (17 %) of canine teeth in female
donkeys. A decrease in tooth length, pulp horn length and pulp horn width with age was
illustrated, as was an increase in occlusal secondary dentine depth with age, although not all
these age changes were statistically significant. Normal histological and ultrastructural features
of donkey teeth were identified and found to be similar to equine findings. Enamel was found to
be thicker buccally in both maxillary and mandibular cheek teeth. Quantitative measurements of
transverse dentine thickness around pulp cavities, dentinal tubule diameters and densities, and
enamel prism diameters were made. Left lower incisors (301) were extracted from 7 donkeys
and 6 horses for micro-hardness determination of enamel, primary and secondary dentine using a
Knoop Hardness indenter. No significant difference between donkey and horse incisor
microhardness was demonstrated. Examination of 19 donkey skulls at post mortem examination
showed donkeys to have a higher degree of anisognathia (27%) compared to horses (23%).
Post mortem dental examination of 349 donkeys (median age 31) demonstrated a high
prevalence of dental disease (93%) and in particular cheek teeth diastemata (85%). Furthermore,
age was associated with increasing prevalence of dental disease and diastemata. Diastemata were
also associated with the presence of other dental disorders and with colic-related death in
affected donkeys. Quantitative measurements of 45 diastemata from 16 donkeys showed no
difference in the medial and lateral width of diastemata but periodontal pockets were deeper
laterally. The definition of valve and open diastemata were confirmed. Pulp exposure, dental
caries and periodontal disease were examined in detail (54 skulls) at post mortem. A total of 19
teeth were extracted for further detailed examination as performed in normal anatomy.
Clinical dental examinations were performed on 357 donkeys in the U.K. that were selected for
age distribution, and the prevalence of dental disease in different age groups was found to
increase from 28% in the youngest group (age 0-10 years) to 98% in the oldest group (age > 35
years). An increased prevalence of most dental disorders with age was demonstrated as was an
association between dental disease and weight loss, poor body condition score, supplemental
feeding and previous episodes of colic. Clinical dental examination of 203 working donkeys in
Mexico showed similar types of dental disorders as found in the U.K. study, with dental disease
present in 62%, of which 18% required urgent dental treatment. There was a significant
association between age groups and dental disease, and age groups and body condition score, but
there was no association between dental disease and body condition score. However, body
condition score was not associated with supplemental feeding or faecal egg counts either
Community Engagement newsletter, Faculty of Veterinary Science, Autumn, 2012
The 5th Annual Donkey Workshop at Onderstepoort, University of Pretoria, from 2 to 3 March 2012, funded by the Donkey Sanctuary, UK / Dr Nicole du Toit -- Rust de Winter excursion / Dr Fortune Sithole -- History and origin of the Makapanstad CVC / Dr Debbie PleanerOriginally published as HTML file, converted to PDF with Adobe Acrobat 9 Pro Version 9.0.0.The 5th Annual Donkey Workshop at Onderstepoort, University of Pretoria, from 2 to 3 March 2012, funded by the
Donkey Sanctuary, UK / Nicole du Toit -- Rust de Winter Excursion / Fortune Sithole -- History and origin of the
Makapanstad CVC / Debbie Pleaner.ab2012mn201
Community Engagement newsletter, Faculty of Veterinary Science, Spring 2013
Community Engagement Day for Public Health / Thandi Fourie ; photos by Nicole Epstein -- Some TLC for our canine friends / Alison Cook, Bevin Meyer, Tessa Morris, Kelsey Skinner and Olivia McMurray -- Dog bite awareness / Bob Maswanganye -- Performing to fight animal abuse / Nadine Strydom, Megan Naude, Lise-Marie Roux and Charney Sargent -- All eyes on ears / Carine du Toit.Originally published as HTML file, converted to PDF with Adobe Acrobat 9 Pro Version 9.0.0.News articles with colour photos about the various community engagement projects of the Faculty of Veterinary Science, University of Pretoria.ab201
Chronic pleuropulmonary fibrosis and elastosis of aged donkeys: similarities to human pleuroparenchymal fibroelastosis
Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis
BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London
Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study
Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world.
Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231.
Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001).
Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication
Barriers to multiple stakeholder value co-creation in JSE-listed companies
This study contributes to the recommended approach to innovative collaboration, which
supports value co-creation with multiple stakeholders. Identifying the barriers to
effective collaboration processes and the challenges when adopting collaborative
behaviours will enable organisations to proceed with a proactive rather than a reactive
approach to co-creation.
This study made use of exploratory qualitative research and semi-structured interviews
with managers of selected industries listed on the Johannesburg Stock Exchange. The
research questions aimed at analysing why and how value is collaboratively created
with stakeholders and identified what inhibits the process of evolving co-creation with
stakeholders.
The findings of this research contributed to the understanding of co-creation with
stakeholders, the tools, approaches and impediments were identified. Additionally, the
diverse barriers and challenges that impede co-creation were identified and an
awareness of the impediments can support an organisation to engage in a more
predictable and satisfactory process of co-creation. Finally it was found that the
barriers uncovered could be categorised as barriers and challenges and were more
numerous and profound than was initially identified in the literature supporting this
study.Mini Dissertation (MBA)--University of Pretoria, 2017.nk2017Gordon Institute of Business Science (GIBS)MBAUnrestricte
Molecular phylogenetics of Cyclopia Vent.and its position within Podalyrieae (Fabaceae).
The tribe Podalyrieae is a diverse and interesting group with most of its species found in the Cape Floristic Region (120 out of 128 species), the smallest floral kingdom and the subject of intense conservation interest. DNA sequence data from nuclear ribosomal internal transcribed spacer, including the 5.8s coding region, were used to reconstruct the phylogeny of this Cape Floral Clade. Results support a transfer of Cadia (Sophoreae) to Podalyrieae. Cyclopia is well imbedded in a paraphyletic Podalyriinae and not sister to the tribe as previously suggested. A broader concept of Podalyrieae, which include Podalyriinae, Xiphothecinae and Cadia is suggested. Dating the nodes of the phylogenetic tree using non-parametric rate smoothing with a fossil calibration point indicates that the root node of Podalyrieae (+ Cadia) is 34.35MYA.Dr. M. van der Ban
Concrete and symbolic linearisability checking of non-blocking concurrent data structures
Thesis (MSc)--Stellenbosch University, 2021ENGLISH ABSTRACT: Non-blocking concurrent data structures are developed as a more efficient solution to concurrent
data structures; in non-blocking concurrent data structures hardware-level atomic instructions are
used instead of higher-level, expensive locking mechanisms. Lock-free algorithms, however, are
notoriously hard to design and prone to subtle concurrency errors that are difficult to pick up.
Linearisability Checking is the standard correctness condition for non-blocking concurrent data
structures; a data structure is linearisable if each concurrent execution of the data structure corresponds
to the execution of its correct sequential specification.
In this thesis, the focus is on the linearisability checking of non-blocking data structures using a
model checker. The approaches for checking linearisability using a model checker can be broadly
categorised into linearisation point and automatic linearisability checking. The state-of-the-art
strategies were implemented using the Java PathFinder Model Checker as basis. The linearisation
point linearisability checking strategy of Vechev et al. was extended to include data structures with
operations that act generically on the data structure, and not just on one element in the data structure.
An improved version of Doolan et al.’s external automatic checker was implemented and the
idea of an external checker was extended to the improved linearisation point checking strategy. The
lazy read optimisation, proposed by Long et al., and a hash optimisation, proposed in this thesis,
for the automatic checker was implemented and the effectiveness and benefit of the optimisations
determined. The performance-limiting factor of the automatic checker was investigated and the
claims made by Vechev et al., Liu et al., and Doolan et al. confirmed/falsified.
The concrete checker’s usefulness in finding linearisability errors is constrained by the user’s ability
to hand-craft test cases in which errors are present. A new Symbolic Linearisability Checker
was developed, the major novel contribution in this thesis, that integrates linearisability checking
into Symbolic PathFinder, a symbolic model checker. The symbolic checker performs linearisability
checking on all possible test cases and program paths; it verifies the linearisability of a data structure
in general, constrained only by a user-defined number of operations to be executed by each thread.
Finally, extensive evaluations and comparisons of all checkers were performed, on the same model
checking framework and hardware, considering their manual input required, resource usage, scalability,
and ability to find errors.AFRIKAANSE OPSOMMING: Nie-blokkerende gelyklopende data strukture is ’n meer effektiewe oplossing as data strukture
wat blokkeringsmeganismes gebruik; in nie-blokkerende data strukture word atomiese hardewareinstruksies
gebruik in plaas van duur, ho¨er vlak, blokkeringsmeganismes. Nie-blokkerende gelyklopende
data strukture is egter ingewikkeld, en is geneig om subtiele gelyklopende foute in te hˆe
wat moeilik is om op te spoor. Lineˆeriseerbaarheid is die standaard korrektheidskondisie vir nieblokkerende
gelyklopende data strukture; ’n data struktuur is lineˆeriseerbaar as elke uitvoering van
die data struktuur ooreenstem met die uitvoering van sy korrekte sekwensi¨ele spesifikasie.
Die tesis fokus op die verifikasie van lineˆeriseerbaarheid van nie-blokkerende data strukture deur
gebruik te maak van ’n modeltoetser. Die metodes vir die verifikosie van lineˆeriseerbaarheid deur
gebruik te maak van ’n modeltoetser kan breedweg gekattegoriseer word in lineˆerisasie-punt en outomatiese
lineˆerisasie toetsing. Die jongste tegnieke is implementeer deur gebruik te maak van die
Java PathFinder modeltoetser as basis. Die lineˆerisasie-punt lineˆeriseerbaarheids toetsstrategie¨e van
Vechev et alis uitgebrei om data strukture wat generiese operasies op die data struktuur uitvoer in
plaas van op ’n spesifieke element in die data struktuur, in te sluit. ’n Gevorderde weergawe van
Doolan et al. se eksterne outomatiese toetser is ge¨ımplementeer en die idee van ’n eksterne implementasie
is gebruik om ook ’n eksterne weergawe van die verbeterde lineˆerisasie-punt toetsstrategie
te implementeer. Die lui-lees optimering wat deur Long et al. voorgestel is, en ’n hutsstrategie
optimering wat in die tesis voorgestel word, is vir die outomatiese toetser ge¨ımplementeer en die
effektiwiteit en voordele van die optimerings is bepaal. Die faktore wat die effektiwiteit van die
outomatiese toetser beperk is ondersoek en die stellings wat deur Vechev et al., Liu et al., en Doolan
et al. gemaak is, is verifieer.
Die konkrete toetser se bruikbaarheid vir die vind van lineˆeriseringsfoute word beperk deur die
gebruiker se vermo¨e om toevoergevalle wat foute sal uitwys, op te stel. ’n Nuwe simboliese
lineˆerisasie toetser is ontwikkel, ’n groot bydrae van die tesis, wat lineˆerisasie toetsing in die simboliese
PathFinder, ’n simboliese modeltoetser, integreer. Die simboliese toetser voer toetsing uit
op al die moontlike toevoergevalle en al die moontlike paaie; dit verifieer dus die lineˆeriseerbaarheid
van ’n data struktuur vir algemene gevalle, en word slegs beperk deur die gebruikersgespesifiseerde
aantal operasies per liggewigproses.Master
Anatomical, pathological and clinical study of donkey teeth
Eighty normal cheek teeth and 26 normal incisors extracted from 14 donkeys (median age 19 years) at post mortem were anatomically examined including grossly and by computerised axial tomography (CAT) imaging. Decalcified histology was performed on 54 sections from 18 teeth (8 donkeys), undeclacified histology on 16 sections from 7 donkeys and scanning electron microscopy on 10 sections from 10 teeth (3 donkeys). The dental formulae and tooth number was found to be the same as in horses with a higher prevalence (17 %) of canine teeth in female donkeys. A decrease in tooth length, pulp horn length and pulp horn width with age was illustrated, as was an increase in occlusal secondary dentine depth with age, although not all these age changes were statistically significant. Normal histological and ultrastructural features of donkey teeth were identified and found to be similar to equine findings. Enamel was found to be thicker buccally in both maxillary and mandibular cheek teeth. Quantitative measurements of transverse dentine thickness around pulp cavities, dentinal tubule diameters and densities, and enamel prism diameters were made. Left lower incisors (301) were extracted from 7 donkeys and 6 horses for micro-hardness determination of enamel, primary and secondary dentine using a Knoop Hardness indenter. No significant difference between donkey and horse incisor microhardness was demonstrated. Examination of 19 donkey skulls at post mortem examination showed donkeys to have a higher degree of anisognathia (27%) compared to horses (23%). Post mortem dental examination of 349 donkeys (median age 31) demonstrated a high prevalence of dental disease (93%) and in particular cheek teeth diastemata (85%). Furthermore, age was associated with increasing prevalence of dental disease and diastemata. Diastemata were also associated with the presence of other dental disorders and with colic-related death in affected donkeys. Quantitative measurements of 45 diastemata from 16 donkeys showed no difference in the medial and lateral width of diastemata but periodontal pockets were deeper laterally. The definition of valve and open diastemata were confirmed. Pulp exposure, dental caries and periodontal disease were examined in detail (54 skulls) at post mortem. A total of 19 teeth were extracted for further detailed examination as performed in normal anatomy. Clinical dental examinations were performed on 357 donkeys in the U.K. that were selected for age distribution, and the prevalence of dental disease in different age groups was found to increase from 28% in the youngest group (age 0-10 years) to 98% in the oldest group (age > 35 years). An increased prevalence of most dental disorders with age was demonstrated as was an association between dental disease and weight loss, poor body condition score, supplemental feeding and previous episodes of colic. Clinical dental examination of 203 working donkeys in Mexico showed similar types of dental disorders as found in the U.K. study, with dental disease present in 62%, of which 18% required urgent dental treatment. There was a significant association between age groups and dental disease, and age groups and body condition score, but there was no association between dental disease and body condition score. However, body condition score was not associated with supplemental feeding or faecal egg counts either.EThOS - Electronic Theses Online ServiceGBUnited Kingdo