Dissertations / Theses on the topic 'Diseases and injuries'

The construction and building industry is one of the most dangerous industries worldwide. A review of the literature indicates a direct correlation between lack of safety culture and the occurrence of accidents within this industry. As a result of this research, nine OHS management system models have been recommended which are formed from a cluster of factors and from many different disciplines to be used as an assessment tool, to prevent accidents in construction or related industries.

Following cervical or upper thoracic level spinal cord injury (SCI), motor, sensory and autonomic systems are disrupted. One form of this autonomic dysfunction is the condition autonomic dysreflexia (AD), which is characterised by episodes of high blood pressure in response to afferent input from regions below the injury level. An animal model of autonomic dysreflexia, the T4 transected rat, was used in this thesis to gain insight into the cardiovascular and temperature components of the disorder, possible peripheral mechanisms and interventions to prevent its development. Chapter 2 of the thesis includes the charaterisation of a T4 transection rat model of spinal cord injury. This characterisation includes confirmation of decreased baseline mean arterial pressure (MAP, 71 down from 117 mmHg) and elevated heart rate (HR, 431 bpm from 366 bpm) for 6 weeks post injury (p.i.). Documentation of the development of AD found that hypertensive responses were fully developed (+20 mmHg) by 4 weeks p.i. Further, during episodes of AD at Weeks 4 and 5 p.i., tail surface temperatures decreased significantly (mid-tail, -1.7oC), indicative of extensive vasoconstriction. Comparison of vascular responses of intact and SCI animals to adrenergic agonists (phenylephrine, PHE and methoxamine, METH) following ganglionic blockade in vivo found that SCI animals experienced prolonged vasoconstriction in blood vessels above and below injury level in response to PHE but not METH. Possible mechanisms of this change included decreased neuronal reuptake of PHE (METH is not a substrate for neuronal reuptake). The presence of prolonged vasoconstriction in blood vessels throughout the body, not just regions below injury level, suggests a widespread mechanism for the change, such as the decreased basal MAP, norepinephrine levels or neural activity present following injury. Thus, it was hypothesised that increased activity from an early stage post injury may prevent the peripheral adaptation and perhaps hinder development of AD. For this, the common rehabilitation technique, treadmill training, was used. Surprisingly, rather than preventing AD, the training actually accelerated its development, producing exaggerated hypertensive responses to colorectal distension (CRD) at Weeks 3 and 4 post-injury (Week 4, Trained: +38.5 ?? 1.5 mmHg; Sedentary: 23.4 ?? 3.1mmHg). Comparison of vascular responses of both groups to PHE injection found no significant difference indicating that the enhanced responses were not a result of peripheral vascular changes. Investigation of the central morphology following SCI, made via immunohistochemical processing of the post-mortem spinal cords, found that Treadmill Trained SCI animals had elevated calcitonin gene related peptide (CGRP) immunoreactivity within lamina III/IV of lumbar segments, compared to intact cords. It is possible that this finding indicates afferent sprouting that may have accelerated the development of AD in Treadmill Trained animals. The results within this thesis highlight the importance of awareness and examination of autonomic function in SCI patients, especially those undergoing rehabilitative training.

Volatile metabolites from headspace gas of mango cultivars Tommy Atkins and Keitt, wounded and inoculated with two pathogens, Colletotrichum gloeosporioides and Lasiodiplodia theobromae or non-inoculated controls were profiled using a GC/MS to develop a technology to discriminate diseases. Several disease discriminatory compounds were identified and classified into three groups: (i) compounds unique to only one treatment; (ii) compounds common to two or more treatments but not to all; and (iii) compounds common to all treatments but with varying in their abundance. 1-pentanol and boronic acid ethyl were detected in only Lasiodiplodia-inoculated mangoes while thujol was observed only in Colletotrichum-inoculated mangoes. Models based on significant mass ions classified up to 100% of the diseases/inoculations. The disease discriminatory compounds and discriminant analysis models developed here could be used in the early detection of postharvest diseases of mango fruit, after validation under commercial conditions.

Thesis (MPH) -- University of Limpopo, 2012.
SUMMARY OCCUPATIONAL INJURIES AND DISEASES AMONGST HEALTHCARE WORKERS OF THE DEPARTMENT OF HEALTH IN LIMPOPO PROVINCE AIM: To analyse and provide data on the incidence of occupational injuries and the prevalence of occupational diseases amongst healthcare workers of Department of Health in Limpopo Province. OBJECTIVES: The specific objectives of the study were as follows: 1. To determine the most common occupational types of injuries and/or diseases amongst healthcare workers with regard to the demographic profile (i.e. age, gender, occupation, workstation) of healthcare workers; 2. To establish outcomes of these injuries and diseases fatalities regard to the demographic profile (i.e. age, gender, occupation, workstation) of healthcare workers; and 3. To assess the association between the predominant injuries and diseases with the profile of the health care workers METHOD: The researcher sourced data electronically from Department of Health as quarterly reports, four (4) for each year of the financial years 2007/2008, 2008/2009 and 2009/2010 respectively. The data was consolidated into financial years, cleaned out part of 2007 and 2010 so at to remain with 3 calendar years (2007, 2008 &2009) prior analysis. RESULTS: There were 725 per 100 000 healthcare workers affected by injuries and diseases during the study period. These injuries/and diseases affected more males than females above 40 years with the mean age being 43 years. Of the 631 injuries and diseases reported, 89% were injuries whist 11 % were diseases with most employees from Mopani district. The most common injuries which affected HCWs thus included needle stick injuries (24%), slip/trip/fall (23%), motor vehicle accidents (14%), injuries by external objects (10%) and assaults (7%). The most common diseases which affected HCWs were found to be TB (69%), diseases by chemical agents (12%), cholera (9%) and poisoning (2%). The needle stick injury affected clinical nurses (59%) more than other professionals; moreover, TB affected 63.6% of nurses. The captured outcome of this injury/disease was 4 fatalities among EMS personnel. CONCLUSION: In conclusion, this study demonstrates that tuberculosis is the most common occupational disease acquired whilst needle stick injury is the commonest occupational injury sustained by healthcare workers of the Department of Health, Limpopo Province. The employees were therefore affected by preventable occupational injuries and diseases. RECOMMENDATIONS: Preventative programs need to be strengthened to reduce morbidity of tuberculosis and needle stick injuries amongst employees.

Magister Legum - LLM
This mini thesis provides a comparative study on two Member States of the ILO. These are, namely: South Africa and Zimbabwe. The purpose of this research is to find out whether Zimbabwe and South Africa are complying with the standards set by the ILO regarding the issue of compensation for occupational injuries and diseases. The terms workers compensation and employment injury benefits are frequently used interchangeably.¹³ Workers compensation is the older term, generally used originally to refer to schemes which provide benefits in the case of death and incapacity due to accidents at work and, later, due to prescribed occupational diseases as well. These benefits could be temporary or permanent, total or partial. In these ILO instruments, the term employment injury is used to cover both accidents at work and occupational diseases.¹⁴ This mini-thesis determines whether South Africa and Zimbabwe are complying with or failing to meet the standards set by the ILO. The research further provides recommendations regarding the shortfalls that South Africa and Zimbabwe are facing so that they will get in line with the standards of ILO, because this is essential to the lives of millions of workers working in these two countries.

Thesis (PhD(Agric))--University of Stellenbosch, 2001.
ENGLISH ABSTRACT: Postharvest decay of stone fruit in the Western Cape province of South Africa is caused primarily by Botrytis cinerea (grey mould) and Monilinia laxa (brown rot). Little is known about the relative importance and seasonal occurrence of the two pathogens in nectarine and plum orchards, the mode of penetration of fruits by M laxa, latency and subsequent disease expression by the latter pathogen. These aspects were investigated in this study. By sampling from the Unifruco Quality Evaluation Scheme and from 11 stone fruit orchards, observations were made over a 3-year period of the occurrence of grey mould and brown rot in the major stone fruit regions. Botrytis cinerea was found to be the most important pathogen causing blossom blight and postharvest decay on stone fruit. The pathogen was most prominent on early- and mid-season culti~ars. Brown rot was exclusively caused by M laxa and no evidence was found that M fructicoZa had been introduced into the region. Monilina laxa was most prominent on the later maturing cultivars. Botrytis cinerea blossom infection did not contribute directly to postharvest decay. Both surface inoculum and latent infection consistently occurred on fruit in each orchard, although at fluctuating levels. Disease expression on developing fruit was not governed by the amount of B. cinerea occurring on fruit surfaces, but by the ability of fruit to resist disease expression. The amount of B. cinerea on fruits was generally higher during spring than during summer. Monilinia laxa occurred sporadically on the blossoms of late-maturing cultivars. Immature fruit were generally pathogen-free and disease expression occurred on maturing fruit only. These findings suggest that conidia of M laxa are generally produced in orchards when fruits are approaching maturity and can penetrate and infect maturing fruit only. The behaviour of airborne M laxa conidia was subsequently studied on nectarine (cultivar Flamekist) and plum (cultivar Laetitia) fruit. For these studies, an inoculation method that simulates natural infection by airborne conidia was used. Fruit at pit hardening, 2 wk before harvest, harvest stage and after cold storage (nectarines 4 wk at -o.soC followed by 1 wk at 23°C at ±56% RH; plums 10 days at .....().5°C,18 days at 7.5°C followed by 1 wk at 23°C at ±56% RH) were dusted with dry conidia of M laxa in a settling tower. The fruits were incubated for periods ranging from 3 to 48 h at high relative humidity (2':93%, humid fruit) or covered with a film of water (wet fruit). Behaviour of the solitary conidia was examined with an epifluorescence microscope on skin segments stained in a differential stain containing fluorescein diacetate, aniline blue and blankophor. The ability of solitary conidia to colonise the fruit surface, penetrate fruit skins and to induce disease expression was determined by using a differential set of tests. For these tests, fruit were surface-sterilised (30 s in 70% ethanol) or left Unsterile. From each group, fruit were selected for isolation (skin segment test), immersed in a 3% paraquat solution (paraquat-treated fruit test) or left untreated (sound fruit test). 1be findings demonstrated that solitary conidia of M laxa behaved consistently on plum and nectarine fruit surfaces: appressorium formation and direct penetration was not observed on any of the fruit surfaces and germ tubes penetrated fruit predominantly through stomata, lenticels and microfissures in the fruit skin. The monitoring of airborne conidia revealed subtle effects of the fruits on the behaviour of solitary germlings, which could not be seen when using conidial suspensions. On both fruit types, no deleterious effect was seen on conidial and germling survival when fruit were kept humid at pit hardening, 2 wk before harvest and harvest. However, conidial and germling survival were drastically reduced by prolonged wet incubation of fruits. The findings on disease expression in the skin segment, paraquat-treated fruit and sound fruit tests clearly showed that the skin of both nectarine and plum fruits were not penetrated at the pit hardening stage, latent infections were not established and fruitsreacted resistant to disease expression. These facets on both fruit types were furthermore unaffected by wetness. The barrier capacity of the fruit skin of the two stone fruit types however differed drastically later in the season. On nectarine, fruit skins were more readily penetrated and disease expression became more pronounced when fruit approached maturity. Penetration and disease expression on ripening nectarine fruit were furthermore greatly influenced by wetness. Maturing plum fruit, on the other hand, did not display the drastic change in the barrier capacity of fruit skins as observed on nectarine. The influence of wetness on infection and disease expression was also less pronounced than on nectarine. In fact, plum fruit remained asymptomatic in the sound fruit test after inoculation and humid incubation at the 2 wk before harvest stage, harvest stage and after cold storage. Plum fruit at these stages only developed disease after a prolonged period (~12 h) of wet incubation. The paraquat fruit test revealed that these fruits became more susceptible to latent infection, but they were not as susceptible as nectarine. Collectively, these findings indicate that M. laxa fruit rot epidemics on plum and nectarine are driven by inoculum levels on fruit approaching maturity and by weather conditions prevailing during the preharvest and harvest period. However, the barrier capacity of plum skins is considerably more effective than that of nectarine fruit. Wounds would therefore play an important role in the epidemiology of M. laxa on plum fruit. Infection of fresh wounds by airborne M. laxa conidia, and by conidia and germlings that have established on fruits, was therefore investigated. Plum fruit (cultivar Laetitia) at pit hardening, 2 wk before harvest, harvest stage and after cold storage were dusted with dry conidia of M. laxa in a settling tower.- Infection of rionwounded fruit and of fresh wounds by \ the airborne conidia on dry, humid and wet plum fruit surfaces, and by conidia and germlings that have been established on fruits under the wetness regimes was then investigated. Nonwounded immature and mature fruit remained mostly asymptomatic, whereas nonwounded cold stored fruit decayed readily. Wounding drastically increased infection by airborne conidia. Immature fruits were less susceptible to wound infection by the airborne conidia than mature fruits. Conidia dispersed freshly were more successful in infecting fresh wounds than conidia that were deposited, or germlings that established, on fruit surfaces 4 days prior to wounding. This decrease in infectivity was especially pronounced on humid and even more on wet incubated fruit. This study clearly showed that in order to reduce. the incidence of brown rot, inoculum levels on fruit approaching maturity should be reduced by sanitation practices and fungicide applications. Furthermore, it is essential to protect fruits, especially. near-mature fruits, from being wounded.
AFRIKAANSE OPSOMMING: EPIDEMIOLOGIE VAN MONILINIA LAXA OP NEKTARIEN EN PRUIM: INFEKSIE VAN VRUGTE DEUR KONIDIA OPSOMMING Naoesverrotting van steenvrugte in die Wes-Kaap provinsie van Suid-Afrika word hoofsaaklik veroorsaak deur Botrytis cinerea (vaalvrot) en Monilinia laxa (bruinvrot). Min is bekend oor die relatiewe belang en seisoenale voorkoms van hierdie patogene in nektarienen pruimboorde, asook oor die infeksieweg, latensie en daaropvolgende siekte-uitdrukking van M laxa. Hierdie aspekte is in dié studie nagevors. \ \ Monsters IS oor 'n 3-jaar periode van die Unifruco Kwaliteitsevalueringskema, en ook van 11 steenvrugboorde verkry. Die voorkoms van vaalvrot en bruinvrot in die hoof steenvrugareas is so bepaal. Botrytis cinerea was die belangrikste patogeen wat betref bloeiselversenging en naoesverrotting. Verder was hierdie patogeen ook meer prominent op die vroeë- en middel-seisoen kultivars. Bruinvrot is uitsluitlik deur M Iaxa veroorsaak en geen aanduiding omtrent die moontlike voorkoms van M fructicola in Suid-Afrika is waargeneem nie. Monilinia laxa was meer prominent op die laat-seisoen kultivars. Botrytis cinerea bloeiselinfeksie het nie direk bygedra tot naoesverrotting nie. Beide oppervlakkige inokulum en latente infeksie het deurgaans, maar wel teen wisselende hoeveelhede, op vrugte in die onderskeie boorde voorgekom. Siekte-uitdrukking op ontwikkelende vrugte is egter nie beinvloed deur die hoeveelheid B. cinerea op die vrug nie, maar eerder deur die vermoë van die vrug om siekte-uitdrukking te onderdruk. Die hoeveelheid B. cinerea op vrugte was verder hoër gedurende lente as gedurende somer. Monilinia laxa het slegs sporadies op die bloeisels van laat-seisoen kultivars voorgekom. Groen vrugte was in die algemeen vry van die patogeen en siekte-uitdrukking het slegs op ryp vrugte plaasgevind. Hierdie bevindinge dui daarop dat M laxa in boorde hoofsaaklik op ryper vrugte geproduseer word. Hierdie swam infekteer ook net ryp vrugte. Die gedrag van luggedraagde M laxa conidia is bestudeer op nektarien- (kultivar Flamekist) en pruimvrugte (kultivar Laetitia). 'n Inokulasie-metode wat natuurlike infeksie deur luggedraagde konidia simuleer, is vir hierdie studies gebruik. Vrugte van die pitverharding-, twee weke voor oes-, oesstadium, asook koud-opgebergde vrugte (nektariene, 4 weke by -o.soe gevolg met 1 week by 23°C en ±56% RH; pruime, 10 dae by -O.5°e, 18 dae by 7.Soe gevolg deur 1 week by 23°C en ±56% RH), is met droë konidia in 'n inokulasietoring geïnokuleer. Die vrugte is vir periodes wat gewissel het van 3 tot 48 h geïnkubeer by hoë relatiewe humiditeit (~93% RH, vogtige vrugte), of dit is bedek met'n film water (nat vrugte). Die gedrag van die enkelspore (konidia) op die vrugoppervlak is met 'n epifluorisensiemikroskoop bestudeer. Skilsegmente is gekleur in 'n kleurstof, bevattende fluorisein diasetaat, analien-blou en blankofor. Die vermoë van die enkelspore om die vrugoppervlak te koloniseer, te penetreer en om siekte-uitdrukking te induseer, is met 'n differensiële stel toetse bepaal. Vir hierdie toetse is die vrugte oppervlakkig gesteriliseer (30 s in 70% etanol), of nie-steriel gelaat. In elke groep is vrugte geneem vir isolasie (skilsegment-to\~ts), of gedoop in "n 3% parakwat-oplossing (parakwat vrugtoets), of\, onbehandeld gelaat (onbehandelde vrugtoets ). Die. bevindinge het op die soortgelyke gedrag van M laxa enkelspore op die verskillende vrugsoorte gedui: appressoria en direkte penetrasie is nie waargeneem nie, en kiembuise het die vrugte hoofsaaklik deur huidmondjies, lentiselle en mikro-krakies .in die vrugskil gepenetreer. Deur luggedraagde spore te bestudeer, is sekere subtiele effekte van die vrug op die gedrag van enkelspore op die vrugoppervlak waargeneem. Op beide vrugtipes is geen nadelige effek op konidiurn- en kiembuisoorlewing opgemerk wanneer die vrugte onder hoë vogtoestande geïnkubeer is. Konidiurn- en kiembuisoorlewing is egter drasties verlaag hoe langer die vrugte onder nat toestande geïnkubeer is. Die bevindinge van die skilsegment-, parakwat en onbehandelde vrugtoetse het duidelik daarop gewys dat die vrugskil van nektarien en pruim nie gepenetreer is tydens die pitverhardingstadium nie, latente infeksies is nie gevorm nie, en die vrugte was bestand teen siekte-uitdrukking. Hierdie fasette op beide vrugtipes is ook nie beinvloed deur inkubasie-natheid nie. Die beskermingskapasiteit van die vrugskil van hierdie steenvrugtipes het egter drasties verskil later in die seisoen. Nektarien-vrugskille is meer geredelik gepenetreer en siekte-uitdrukking het toegeneem met rypwording. Penetrasie en siekteuitdrukking is verder in 'n groot mate deur inkubasie-natheid bevoordeel. Rypwordende pruime het egter nie so In drasties verandering in die beskermingskapasiteit van die vrugskil getoon nie. Die invloed van inkubasie-natheid op infeksie en siekte-uitdrukking was ook minder opsigtelik as op nektarien. Pruimvrugte van die twee weke voor oes-, oesstadium, en , koud-opgebergde pruime, wat onder hoë vog geïnkubeer is, het simptoomloos in die onbehandelde vrugtoets gebly. Vrugte van hierdie stadia het slegs simptome ontwikkel na periodes van langer as 12 h onder nat toestande. Die parakwat-behandelde vrugtoets het egter gewys dat die pruimvrugte meer vatbaar vir latente infeksies raak, maar steeds nie so vatbaar soos die nektarienvrugte nie. Gesamentlik dui hierdie bevindinge daarop <41tM laxa bruinvrot epidemies op pruim en nektarien afhanklik is van inokulumvlakke op rypwordende vrugte, asook die weerstoestande gedurende die vooroes- en oesstadia. Die beskermingskapasiteit van pruim vrugskille was egter aansienlik meer effektief as dié van nektarien vrugte. Wonde op vrugte sal dus 'n groter rol speel in die epidemiologic van M laxa op pruim. Infeksie van vars wonde deur luggedraagde M laxa konidia, en deur konidia en kiembuise wat reeds op die vrugoppervlak gevestig is, is gevolglik bestudeer. Pruimvrugte (kultivar Laetitia) van die pitverharding-, twee weke voor oes-, oesstadium, asook koud- \ \ opgebergde vrugte is in 'n inokulasie-toring geïnokuleer met droë M laxa konidia. .Infeksie , , van nie-gewonde vrugte en van vars wonde deur luggedraagde konidia op droë, vogtige en nat pruim vrugoppervlaktes, asook deur konidia en kiembuise wat reeds op die vrugoppervlak onder hierdie toestande gevestig is, is bepaal. Nie-gewonde groen tot ryp vrugte het meestal simptoomloos gebly, terwyl koud-opgebergde ryp vrugte wel verrot het. Wonde .het die hoeveelheid infeksie deur luggedraagde spore drasties vermeerder. Konidia wat geïnokuleer is op vrugte met vars wonde, was meer in staat om hierdie wonde te infekteer as konidia en kiembuise wat 4 dae voor wonding gevestig is. Hierdie afname in infektiwiteit was meer sigbaar op die vogtige, maar veral die nat vrugte. Hierdie studie het duidelik gewys dat inokulumvlakke op rypwordende vrugte verlaag moet word deur sanitasie-praktyke en fungisiedtoedienings. Dit is verder belangrik om vrugte, veral rypwordende vrugte, teen wonding te beskerm.

Thesis (MSc Food Sc)--Stellenbosch University, 2003.
ENGLISH ABSTRACT: Post-storage quality of the stone fruit, apricots and peaches, is the major factor determining their suitability for canning after cold storage in South Africa. Short harvesting periods and the limited capacity of the factory to process the large quantities of fruit within two days after delivery, necessitates cold storage until canning. Apricots develop internal breakdown, whereas peaches develop internal breakdown accompanied by loosening of the skin and adhesion of the flesh to the stone. The deterioration takes place within the fruit during a cold storage period of one to two weeks. The tendency of the fruit to develop internal defects can, to date, not be identified prior to storage and are only discovered after destoning during canning. Near infrared spectroscopy (NIRS) combined with chemometrics were investigated as a non-destructive method to predict post-storage quality in Bulida apricots and clingstone peach cultivars. Near infrared (NIR) spectra (645-1201 nm), measured on the intact fruit just after harvesting, were correlated with subjective quality evaluations performed on the cut and destoned fruit after cold storage. The cold storage periods for apricots were four weeks (2002 season) and three and two weeks for peach cultivars for the 2002 and 2003 seasons, respectively. Soft independent modelling by class analogy (SIMCA) and multivariate adaptive regression splines (MARS) were applied to the spectral and reference data to develop models for good and poor post-storage quality. The ability of these models to predict post-storage quality was evaluated in terms of recognition (sensitivity) and rejection (specificity) of the samples in independent validation sets. Total correct classification rates of 50.00% and 69.00% were obtained with Bulida apricots, using SIMCA and MARS, respectively. Classification results with apricots showed that MARS performed better than SIMCA and is thus recommended for this application. Total correct classification rates of 53.00% to 60.00% (SIMCA) and 57.65% to 65.12% (MARS) were obtained for data sets of combined peach cultivars within seasons and over both seasons. Additional aspects of fruit quality were investigated to identify possible indices of post-storage quality. Classification trees were used to find correlations between the post-storage quality and the fruit mass, diameter, firmness and soluble solids content (SSC). Among these, fruit diameter and firmness were the major indices of post-storage quality. Accurate predictions of firmness could not be achieved by near infrared spectroscopy (NlRS), making the combination of NIRS and classification trees not yet suitable for predicting post-storage quality. NIRS was further used to predict poststorage SSC within seasons in Bulida apricots and intact peach cultivars. This confirmed sufficient NIR light penetration into the intact fruit and also provided a further application of NIRS for ripeness evaluation in the canning industry. Validations on peach samples obtained correlation coefficients (r) of 0.77-0.85 and SEP-values of 1.35-1.60 °Brix using partial least squares (PLS) regression. MARS obtained r = 0.77-0.82 and SEP = 1.42-1.55 °Brix. Predictions of sse in apricots were less accurate, with r = 0.39-0.88, SEP = 1.24-2.21 °Brix (PLS) and r = 0.51-0.82, SEP = 1.54-2.19 °Brix (MARS). It is suggested that the accuracy of sse measurements, and the subsequent predictions, were affected by the cold storage periods as well as internal variation within the fruit. This study showed that a combination of NIRS and chemometrics can be used to predict post-storage quality in intact peaches and apricots. A small scale feasibility study showed that 4% (R117 720) (apricot industry) and 3% (R610 740) (peach industry) of production losses can be saved if this method is implemented in the South African canning industry. Although it was difficult to assign specific chemical components or quality attributes to the formulation of the storage potential models, important hidden information in the spectra could be revealed by chemometric classification methods. NIRS promises to be a useful and unique quality evaluation tool for the South African fruit canning industry. Several recommendations are made for the canning practices to reduce losses and for future research to improve the current prediction models.
AFRIKAANSE OPSOMMING: Die kwaliteit van die steenvrugte, appelkose en perskes, is die hoof bepalende faktor vir hul geskiktheid vir inmaakdoeleindes na koelopberging in Suid-Afrika. Die vrugte moet opgeberg word by lae temperature vir een tot twee weke, aangesien die oestydperk kort is en die kapasiteit van die fabriek te beperk is om die groot hoeveeheid vrugte dadelik in te maak. Tydens hierdie opbergingstydperk vind agteruitgang in die vrugte plaas. Dit word in appelkose gekenmerk deur interne verval en in perskes gekenmerk aan interne verval, tesame met enlos skil en die vaskleef van die vrugvlees aan die pit. Tot dusver, bestaan daar geen metode om hierdie tipe agteruitgang in vrugte voor opberging te identifiseer nie. Dit word eers na opberging opgemerk wanneer die vrugte ontpit word. Naby-infrarooi spektroskopie (NIRS), gekombineerd met chemometriese metodes is gebruik om opbergingspotensiaal in Bulida appelkose en taaipitperske kultivars te bepaal. enKorrelasie is gemaak tussen naby-infrarooi (NIR) spektra, gemeet op die heel vrugte voor opberging en subjektiewe evaluering van kwaliteit, geïdentifiseer op die gesnyde vrugte na opberging. Die opbergingstydperke vir perskes was vir drie en twee weke vir die 2002 en die 2003 seisoene, onderskeldeflk, terwyl die appelkose vir vier weke opgeberg is. Twee chemometriese metodes, "soft independent modelling by class analogy" (SIMCA) en "multivariate adaptive regression splines" (MARS) is gebruik om die spektra en ooreenstemmende subjektiewe data te kombineer en modelle is ontwikkel vir goeie en swak opbergingspotensiaal. Die vermoë van die modelle om die vrugkwaliteit na die opbergingstydperk te voorspel, is geêvalueer in terme van herkenning en verwerping van vrugtemonsters in onafhanklike toetsstelle. Totale korrekte klassifikasies van 50.00% and 69.00% is verkry vir Bulida appelkose, met SIMCA en MARS, onderskeidelik. Die klassifikasie resultate het gewys dat MARS beter gevaar het as SIMCA en word dus sterk aanbeveel vir hierdie toepassing. Totale korrekte klassifikasies van 53.00% tot 60.00% (SIMCA) and 57.65% tot 65.12% (MARS) is verkry vir gekombineerde perskekultivars tussen seisoene en oor seisoene. Verdere aspekte van vrugkwaliteit is geêvalueer om enmoontlike indeks van opbergingspotensiaal te verkry. Klassifikasiebome is gebruik om en korrelasie te vind tussen kwaliteit na opberging en vrugmassa, deursnee, fermheid en totale oplosbare vastestowwe (TOV). Diameter en fermheid het die meeste gekorreleer met die kwaliteit na opberging. Voorspellings van fermheid deur die gebruik van naby infrarooi spektroskopie (NIRS) was ~gter nie akkuraat nie. Dus word die kombinasie van klassifikasiebome en NIRS om opbergingspotensiaal te voorspel nie tans aanbeveel nie. NIRS is verder gebruik om TOV te voorspel binne seisoene in heel Bulida appelkose en perskekultivars. Dit is uitgevoer om voldoende NIR ligpenitrasie in die vrugte te bevestig en ook om 'n verdere toepassing van kwaliteitsbepaling (as indeks van soetheid en rypheid) vir die inmaakindustrie te verskaf. Validasies is op perskemonsters uitgevoer en korrelasiekoêffisiente (r) van 0.77-0.85 en voorspellingsfoute van 1.35-1.60 °Brix is verkry met "partial least squares" (PLS) regressie. MARS het r = 0.77-0.82 and voorspellingsfoute = 1.42-1.55 °Brix verkry. Die akkuraatheid van die TOV meetings en gevolglike voorspellings is waarskynlik beïnvloed deur interne variasie binne die vrugte sowel as die opbergings tydperke wat verloop het tussen metings. Hierdie studie wys dat NIRS en chemometriese metodes wel gebruik kan word om opbergingspotensiaal in heel perskes in appelkose te voorspel. 'n Kosteberekening het gewys dat besparings van 4% (R117 720) (appelkoos industrie) en 3% (R610 740) (perske industrie) moontlik is indien NIRS en MARS geïmplementeer word. Alhoewel dit moeilik was om spesifieke chemiese komponente en .sekere kwaliteitsaspekte aan die ontwikkeling van die modelle te koppel, is belangrike verborge informasie in die spectra uitgebring deur chemornetriese metodes. NIRS beloof om 'n bruikbare en unieke kwaliteitskontrole maatstaf te wees vir die Suid-Afrikaanse inmaakindustrie. Verskeie aanbevelings is gemaak vir die inmaakpraktyke om verliese te voorkom en ook vir toekomstige navorsing om die huidige klassifikasiemodelle te verbeter.

Thesis (MScAgric)--University of Stellenbosch, 2005.
ENGLISH ABSTRACT: Shrivelling and friction discolouration (FD), as postharvest disorders, negatively influence the marketability and potential shelf life of pears. By investigating the contributing factors in each of the disorders, the potential involvement of handling and storage variables were determined. This allowed for a better understanding of the responsible factors that create susceptible environments for these disorders to occur. From the moment that pears are harvested they lose weight by means of transpiration and, to a lesser extent, respiration. When excessive losses are experienced, the fruit will appear shrivelled and the marketability and shelf life are negatively influenced. By minimizing the rates of weight loss, the occurrence of shrivelling among pears during the postharvest handling can be lessened. The periods that proved to be most conducive to shrivelling (during a simulated postharvest handling duration) were where temperatures above 0 °C were experienced. These short periods proved more perilous for shrivelling than lengthy storage durations at low temperatures. This influenced the transpiration rate in such a way that the driving force accelerated the rate of weight loss in all the cultivars that were studied. Removing field heat from fresh produce and maintaining the cold chain reduces the driving force behind the transpiration of the pears. In all the cultivars studied, ‘Packham’s Triumph’, ‘Beurrè Bosc’ and ‘Forelle’, smaller and less mature fruit were more inclined to appear shrivelled. The surface area to volume ratio is fundamental in determining the rate of weight loss. This was most evident in ‘Beurrè Bosc’. Although no reproducible results could be obtained from the morphological studies, literature has attributed this phenomenon to the composition and quantity of the cuticle layer. Reduction of weight loss was obtained by sealing of the fruit stem. This obstructed water movement from the fruit through the xylem conducting tissue to the surrounding atmosphere. Not only did the stem appear greener and fresher, but less weight loss and subsequent shrivel was noticeable in the treated fruit. This effect was most evident in ‘Packham’s Triumph’ and ‘Beurrè Bosc’, but not in ‘Forelle’. ‘Forelle’ typically has a very short, thin stem in comparison to the other two cultivars.All the cultivars showed visual shrivel symptoms after 11 days at 18 °C. Rate of weight loss was the lowest in ‘Packham’s Triumph’, but due to its prominent dimensions, it appeared shrivelled before any of the other cultivars. ‘Beurrè Bosc’ lost weight at the highest rate (0.42%.day-1). As fruit injury, in the presence of oxygen, is inevitable, the oxidative enzymatic browning of pears will always be troublesome. This defensive mechanism partially prevents the infection of the fruit where epidermal cells are injured. To minimize FD, impact and frictional forces need to be lower during both harvesting and handling practices. A laboratory scale method was developed through which reproduceable treatments could be performed, thereby subjecting the fruit to industry related friction, rather than impact, injury. By assessing the discolouration in terms of both extent and intensity, the influence of variables could be determined on both ‘Packham’s Triumph’ and ‘Doyenne du Comice’ pears. As also found in practice, ‘Doyenne du Comice’ proved to be far more susceptible to FD than ‘Packham’s Triumph’, although the activity of the enzyme, polyphenol oxidase (PPO) was found to be higher in the latter. Although no significant difference was found between the FD encountered at fruit temperature of 3 °C and 15 °C, discolouration was greater at the higher temperature. This might be attributed to a greater degree of water loss, lower cell turgidity or higher enzyme activity. Thus, fruit taken from storage and sorted directly thereafter will exhibit less FD. The contribution of condensation forming on the fruit, acting as lubrication, cannot be ignored. Such fruit, with high turgor pressure, might again be more susceptible to bruising which will only be revealed well after the injury. Since enzymes, which include PPO, catalyse biochemical reactions, the availability of sufficient substrate most probably regulates the extent of this biochemical discolouration. Harvesting at optimum maturity and preventing any unnecessary friction will most definitely reduce the occurrence of FD. The ultimate challenge remains to optimize sorting and packing conditions without compromising on fruit quality.
AFRIKAANSE OPSOMMING: Verrimpeling en friksie verbruining (FV), as na-oes defekte, het ’n negatiewe invloed op die bemarkbaarheid en potensiële raklewe van pere. Hierdie studie het die bydraende faktore vir elkeen van die defekte ondersoek. Daar is gepoog om die effek van verskillende hanteringsen opbergingsmetodes op bogenoemde defekte te bepaal. ‘n Beter begrip is verkry van die oorsaaklike faktore wat bydra tot die ontstaan van die betrokke defekte. Direk na die oes van pere, begin die vrug gewig verloor as gevolg van veral transpirasie. Oormatige verliese sal lei tot ’n vrug wat verrimpeld voorkom, met ‘n negatiewe invloed op die bemarkbaarheid en raklewe daarvan. Die voorkoms van die verrimpeling van pere tydens die na-oes hantering van die vrugte, kan verminder word deur vermindering van die tempo van gewigsverlies. Die periodes waartydens die verrimpeling veral voorgekom het, (soos gevind in ’n gesimuleerde na-oes hanteringsmodel) was wanneer temperature bo 0 °C ondervind is. Sulke kort periodes was meer geneig om aanleiding te gee tot verrimpeling as die verlengde periodes van opberging by lae temperature. Sulke periodes van hoër temperature het gelei tot versnelde transpirasie en ’n versnelde tempo van gewigsverlies in al die kultivars wat ondersoek is. Die transpirasietempo van pere kan verlaag word deur die verwydering van veld-hitte en deur die streng behoud van die koue-ketting. In al die kultivars wat ondersoek is, ‘Packham’s Triumph’, ‘Beurrè Bosc’ en ‘Forelle’, is gevind dat die kleiner en minder volwasse vrugte meer geneig was tot verrimpeling. Die oppervlak area tot volume verhouding is krities in die bepaling van die tempo van gewigsverlies. Hierdie bevinding was die prominentste in ‘Beurrè Bosc’. Alhoewel geen beduidende resultate verkry kon word van die morfologiese studies nie, is daar verskeie verwysings in die literatuur wat hierdie verskynsel toeskryf aan die samestelling en hoeveelheid van die kutikula laag. Vermindering van gewigsverlies is verkry deur verseëling van die vrugtestingel. Hierdie tegniek het gelei tot ’n blokkering van die watervloei van die vrug na die omgewing deur die xileem weefsel. Verseëling van die stingel het dit groener en varser laat voorkom, en het ook ’n merkbare vermindering in gewigsverlies en die daaropvolgende verrimpeling tot gevolg gehad. Die effek van stingel-verseëling was die prominentste in ‘Packham’s Triumph’ en‘Beurrè Bosc’. Dit was minder duidelik in ‘Forelle’ wat tipies gekenmerk word deur ‘n baie korter, dun stingel in vergelyking met die ander twee kultivars. Al die kultivars het makroskopiese verrimpeling getoon na ‘n opbergingperiode van 11 dae by 18 °C. Die tempo van gewigsverlies was die laagste in ‘Packham’s Triumph’ alhoewel dit eerste verrimpeld voorgekom het. Dit kan toegeskryf word aan die spesifieke afmetings van hierdie betrokke kultivar. ‘Beurrè Bosc’ het vinnigste gewig verloor (0.42%.dag-1). Aangesien die besering van vrugte, in die aanwesigheid van suurstof, onvermydelik is, sal oksidatiewe, ensiematiese verbruining van pere altyd problematies wees. Hierdie verdedigingsmeganisme voorkom tot ’n mate die infeksie van die vrug wanneer epidermale selle beskadig word. FV kan beperk word deur die vrugte tydens oes en hanteringsprosedures so min as moontlik bloot te stel aan impak en friksie kragte. ’n Laboratorium-model is ontwikkel ter nabootsing van die omstandighede in die industrie. Die vrugte is aan friksie, eerder as impak, onderwerp, soos ondervind in die industrie. Die omvang asook die intensiteit van die verbruining is gemeet in beide ‘Packham’s Triumph’ en ‘Doyenne du Comice’ pere. Op hierdie wyse kon die invloed van die onderskeie veranderlikes in elke kultivar bepaal word. Alhoewel die ensiematiese aktiwiteit van die polifenol oksidase ensiem (PFO) die hoogste in ‘Packham’s Triumph’ was, is gevind dat ‘Doyenne du Comice’ veel meer geneig was tot FV as ‘Packham’s Triumph’. Hierdie bevinding bevestig die verskynsel soos in die praktyk gevind. Alhoewel geen betekenisvolle verskil gevind is tussen FV by vrug temperatuur van 3 °C en 15 °C nie, was daar meer verbruining by die hoër temperatuur. Hierdie verskynsel kan toegeskryf word aan ’n groter mate van waterverlies, laer sel turgiditeit en hoër ensiem aktiwiteit. Dus sal vrugte wat direk na opberging gesorteer word, minder FV toon. Die bydrae van die kondensasie wat op die vrug vorm, en as ’n smeermiddel dien, kan nie geïgnoreer word nie. Sulke vrugte met hoër turgiditeit, mag egter meer vatbaar wees vir kneusing, wat egter eers ’n geruime tyd na die kneusing tevoorverskyn mag kom. Aangesien ensieme, wat PFO insluit, as katalis dien in biochemiese reaksies, sal die beskikbaarheid van voldoende substraat, na alle waarskynlikheid die omvang van die biochemiese verkleuring reguleer.Die oes van pere tydens optimum volwassenheid, en die voorkoming van onnodige friksie sal definitief die voorkoms van FV verminder. Die uitdaging is steeds om sortering- en verpakkingstegnieke verder te verfyn sonder om ’n negatiewe invloed op vrugtekwaliteit te hê.

Tubers of Russet Burbank were surface disinfested and 3 mm diameter by 3 mm deep wounds were made with cork borer. The holes were inoculated with 20muL of 104 macroconidia/ml suspension of (Fusarium sambucinum) or 20muL of 104 sporangia/ml suspension (Pythium ultimum) and incubated under mist. For infection studies, the inoculated tubers were exposed to 0--48 h of mist at 4--20ºC, dried and stored at 16ºC and 95% RH in growth chamber with forced air for 15 d (F. sambucinum), whereas stored at 12ºC and 95% RH for 30 d (P. ultimum). For lesion expansion studies tubers exposed to 24 h wet at 16ºC were stored in growth chambers at 4, 8, 12, and 16ºC for 15--90 d. At the end of storage tubers were cut and the volume of diseased area was measured. Models explained 94.2% of the variation in infection and 99.7% in lesion expansion for F. sambucinum . Whereas, models explained 96.7% of the variation in infection and 99.6% lesion expansion for P. ultimum. (Abstract shortened by UMI.)

Across the world, physical inactivity was found to be associated with cardiovascular and chronic diseases of lifestyle which often leads to an increased rate of various physical disabilities andpremature death. To combat these high incidences of chronic diseases of lifestyle, WHO strongly encourages people to become physically active on a daily basis to reduce the risk of 
premature death. Running has thus become the preferred choice of physical activity by thousands of people to help improve their overall health and wellbeing. Apart from the health benefits 
that running provides, it can also predispose the runner to potential injury especially when runners follow an inappropriate training programme and have inadequate knowledge about factors causing injury. Therefore, baseline data about the prevalence, incidence of injury and the identification of the aetiological factors associated with running injuries are needed to develop and 
implement preventative programmes to allow runners to optimally perform in training and races without injury. In South Africa, there is limited research available on the incidence of injury in runners yet there is an annual increase in participation in races such as Two Oceans and Comrades marathon which could lead to an increase in the number of running injuries.Thus, the purpose of this study was to determine the incidence of injuries and identify the various risk factors that are associated with injuries in road runners at a local athletic club. Methods: A prospective cohort study design over a 16 week period using quantitative research methods was used. A sample of 50 runners had consented to participate in the study. The participants had to complete a self-administered questionnaire and clinical measurements of BMI, Q-angle, leglength, muscle strength of lower leg and ROM of hip and knee were recorded. The participants had 
to complete an injury report form to record any new injuries sustained over the 16 week period of the study. Statistical Package for Social Sciences (SPSS) version 18 and software SAS v9 (SAS Institute Inc., Cary, NC, USA) was used for data capturing and analysis. Descriptive and inferential statistics were done to summarize the data and was expressed as frequencies, percentages, means and standard deviations. Injury prevalence and cumulative incidence was calculated as a proportion rate along with 95% confidence interval. The Poisson regression model was used to analyse the association between running injury and the independent variables of interest such as demographics, anthropometric measurements, training methods, running experience and 
previous injury. The alpha level was set as p<
0.05. Results: The study found that the majority (92%) of the participants (n=46) sustained running injuries in the past prior to the study. A total of 16 participants sustained a number of 50 new injuries over the 16 week study period. Thus the prevalence rate of injuries was 32%. The incidence rate of injuries for this study was 0.67 per 
1000km run at a 95% confidence interval of 0.41, 1.08. Furthermore, the most common location of new injuries reported were the calf (20%) and the second most common location was the 
knee (18%). PFPS was the most common type of knee injury diagnosed, followed by lumbar joint sprain. The results showed that none of the identified factors (running distance, stretching, age, Q-angle, BMI, running experience, leg-length discrepancy and previous running injuries) were directly associated with running injuries. However, a marginal significance was found for 
running distance (p = 0.08) and leg length discrepancy (p = 0.06). Conclusions: The study found a high prevalence and incidence rate of injury thus the need for preventative programmes have been highlighted. There was no statistical significance found between the identified factors and risk of injury however, there was clinical relevance found between factors identified. One major 
limitation was the small sample of participants and the short duration of study period. Thus, future research is needed to further determine possible factors associated with running injuries over a longer period and including a larger sample. The results of the study will be made available to all the stakeholders (runners, coaches and medical team) to implement in athletic club.

Thesis (MBA)--Stellenbosch University, 2001.
ENGLISH ABSTRACT: Daily more than 300 000 health care workers in South Africa are to a lesser or greater extent exposed to the risk of deadly viruses which can be transferred through neediestick injuries. It is estimated that currently 9,8 million people in South Africa are HIV positive. This high incidence of HIV has a great impact on the danger of infection from neediestick injuries. It is estimated that 44 000 neediestick injuries takes place annually in South Africa. Despite such a high risk there are currently few safety regulations or official efforts to prevent or determine the true impact and incidence of needlesticks in South Africa. This study project investigated the number of neediestick injuries that could potentially be prevented by the use of needles with safety features and estimated the ranges of benefits and costs of using such safety devices. With the financial constraints that are imposed on South African hospitals, infection control through the use of safety syringes makes economic sense. Prevention of infections is clearly far cheaper than cure.
AFRIKAANSE OPSOMMING: Daagliks word meer as 300 000 gesondheids personeel in Suid Afrika in 'n mindere of meerdere mate blootgestel aan die risiko van lewens gevaarlike viruse wat deur middel van naaldprik ongelukke oorgedra kan word. Hierdie risiko word spesifiek in Suid Afrika verhoog deur die hoë insidensie van HIV. Dit word beraam dat daar tans 9,8 miljoen mense in Suid Afrika is wat HIV positief is. Daar word beraam dat daar tans 44 000 naaldprik ongelukke per jaar in Suid Afrika plaasvind. Ten spyte van die hierdie hoë risko is daar tans min veiligheids regulasies of amptelike pogings om die omvang en voorkoming van naaldprik insidente te bepaal nie. Hierdie studie het die getal naaldprikke wat voorkom kan word deur die gebruik van veiligheids inspuitnaalde ondersoek en het die voordele en kostes van sulke veiligheidsmaatreëls beraam. Gegewe die finasiële druk wat ons tans in Suid Afrikaanse hospitale ondervind, is bewys dat die gebruik van veiligheids inspuitnaalde ekonomiese sin maak. Voorkoming op hierdie manier is bewys as 'n ver goedkoper opsie as nasorg.

Ten caucasian male quadriplegics were compared with eight sedentary caucasian male controls in regards to left ventricular dimensions and mass obtained from echocardiograrns. The interventricular septum (IVS), left ventricular posterior wall (LVPW) and left ventricular internal diameter (LVII) were within normal limits for both groups. However, the INS in the SCI were significantly thicker than controls (p <0.05). Myocardial thickness was larger in SCI subjects (p <0.05). Absolute left ventricular mass (LVM) and total left ventricular volume was not different ( p > 0.05), but SCI subjects had significantly greater LVM to lean body mass ratios. Echocardiographically, SCI patients demonstrate concentric hypertrophy. This suggests adaptive response to chronic increase in afterload pressure secondary to their daily activities and muscle spasticity.

The market life of many fruits and vegetables can be extended through storage at low temperatures. Chilling injury (CI) is a major postharvest storage problem for tropical commodities. Storing these products at temperatures below their critical temperature may result in severe physiological disorders known as CI symptoms. Mangoes (Mangifera indica. L) are susceptible to CI when stored below 12 °C. Visual CI symptoms include uneven ripening, surface pitting, discoloration, shriveling and scalding. Research has been conducted to overcome these serious problems using various postharvest treatments such as hot water, methyl jasmonate (MJ) or diphenylamine (DPA) with some reduction of the incidence of CI symptoms in fruits and vegetables.
Experiments were performed to assess and compare the potential of the above-mentioned postharvest treatments to reduce the CI symptoms on mango cv. Kent. The obtained results indicated that MJ- and DPA-treatments gave significantly greater percentage of marketable fruits.
Experiments were also conducted with mangoes cv. Tommy Atkins treated with MJ and DPA before storing at low temperatures (1, 4, 7 and 10°C). The chemical treatments were successful at reducing CI symptoms of mangoes. Fruit decay was reduced during subsequent ripening. MJ-treated fruits had lower mass loss and higher total soluble solids (TSS) than the control treatment. The overall quality of MJ- and DPA-treated fruits was good with lower surface pitting and scalding compared with the control treatment. The best results were obtained at storage temperatures of 7 and 10°C. Both MJ and DPA postharvest treatments can reduce CI symptoms in mangoes cvs. Kent and Tommy Atkins when the mangoes are stored at below critical temperature.

Over 260,000 Americans are living with a traumatic spinal cord injury (SCI). Medical advances have increased the longevity of individuals living with SCI into middle age and beyond. The majority of these individuals are living with an incomplete SCI (NSCISC, 2012), and the proportion of incomplete injuries is rising (DeVivo, 2012). There is little research that specifically examines the changes in physical function experienced by individuals aging with a traumatic incomplete SCI. The purpose of this qualitative descriptive study was to describe the changes in physical function experienced by participants with a traumatic incomplete SCI aging through middle age. Data were collected through moderately structured individual interviews (N=17), in either a face-to-face (n=6) or an email (n=11) format. The seventeen participants ranged in age from 35 to 65 years, with a 16 to 36 year duration of injury. Participants described changes in various body systems and recalled the timing of those changes as they transitioned through their middle years. Qualitative content analysis revealed that participants described primarily gradual changes including decreased muscle strength, decreased endurance, weight gain, and wear and tear changes. When asked to identify sources of information about physical changes, participants predominantly emphasized their lack of knowledge about anticipated changes. Further content analysis revealed three themes related to this transition. Participants likened their experience to travelling through uncharted territory. They described strategies for living in uncharted territory that help them to prevent or manage changes in physical function, with sub-themes of being vigilant in their self-assessment and self-management practices, investing time in figuring out what changes they experienced and why those changes happened, and staying positive. They also described the importance of recognizing the impact of changes. These findings provide a foundation for understanding this age-related transition, and identify the need for further research to support effective self-management strategies and efficient mechanisms for disseminating this knowledge to people with SCI, their caregivers and families. In acute and chronic patient care settings, nurses are well-positioned to be a valuable support and information source for individuals living with an incomplete SCI.

This study investigates respiration rate of potatoes (Solanum tuberosum L.) under real and experimental storage conditions. Real storage conditions were obtained by building a small-scale storage facility equipped with two independent storage bins including all controls. Each bin was filled with 2.5 metric tons of potatoes and these were stored for five months. Temperature, relative humidity, air flowrate and other operational parameters were collected. Also, mass loss and CO2 analyses were performed.
A heat and moisture balance was applied to quantify heat and moisture rates produced by potatoes and were converted to respiration rates as CO 2 produced (ml.kg-1.h-1). Evaporation rates were also determined (g.kg-1.h -1). The balance was mainly applied on data collected from specific periods in which steady conditions were imposed; heaters and humidifiers were turned off and fans were operated to circulate air at a given flowrate for more than 8 h/day over a two month period. Respiration rates were determined as rates of heat produced (W) with stability and acceptable accuracy for a relatively large facility. Respiration rates were converted to CO2 production (ml.kg-1.h-1), and these agreed fairly with ranges reported in the literature. Simultaneously, respiration rates were measured by in-store CO2 analysis, and later they were measured under laboratory conditions using a closed gas analysis system. Comparing these with rates obtained by the heat and moisture balance, the later were slightly higher. Mass losses were also obtained by both weight losses and moisture balance; results from the two methods were quite similar and comparable with those reported in the literature.
Under experimental conditions, respiration rates were measured for healthy, diseased and sprouted tubers using a gas analysis method. This experiment demonstrated the need for a more extensive investigation of disease development and its relation to respiration rates, and the need for a faster and more convenient gas analysis system. (Abstract shortened by UMI.)

Thesis (Ph.D.)--University of Florida, 2004.
Typescript. Title from title page of source document. Document formatted into pages; contains 97 pages. Includes Vita. Includes bibliographical references.

The influence of uniformity of heat transfer with respect to the effect of heat treatment was investigated by correlating engineering parameters with the quantified heat treatment effects. Differences in treatment effect in terms of quality, anti-pathogen and chilling injury (CI) control properties among commodities was studied by exposing them to different target temperatures. Similar effects were also evaluated and quantified within an individual commodity by a custom-designed device. This device, whose design parameters were based on a heat transfer simulation, insured that one hemisphere of a tomato was exposed to air at 39°C and 0.24 m s-1; while the other hemisphere was exposed to air at a lower temperature with a velocity of0.24 m s-1 or 0.12 m s-1.
Single-temperature heat treatment was most effective in limiting pathogen development and varied according to the parameter measured: 38°C for hypersensitive response (HR), 36°C for tissue breakdown, 36°C, 38°C or 39°C for mycelium abundance, and 38°C or 39°C for lesion size. Bilateral differences in temperature across the fruit significantly affected disease control: decreasing temperature differences significantly improved the uniformity of disease control.
Some of the effects of heat treatment on tomato quality, such as color development and resistance to CI, appear to be localized. A significant difference in redness was identified between heated parts and unheated parts of tomato fruits immediately after treatment; and the differences persisted during storage. Differences in lightness and chroma were noted on day 4. Delay in ripening caused by heat treatment was confirmed through the higher TA and TSS values of heated tomatoes or heated portion of partially heated tomatoes.
The heated parts of tomatoes showed a stronger resistance to chilling injury. The effective temperature control range for CI was wide, but temperatures higher than 39.5°C for 23 h hot air treatment could lead to adverse effects.
Differences in physiological effects between hemispheres in two chambers was reduced by directly decreasing the temperature difference between upper and lower chambers or relatively increasing the heating air flow rate, highlighting the importance of improving the uniformity of air flow around each individual treated fruit.

Background As mortality rates decline, life expectancy increases, and populations age, non-fatal outcomes of diseases and injuries are becoming a larger component of the global burden of disease. The Global Burden of Diseases, Injuries, and Risk Factors Study 2016 (GBD 2016) provides a comprehensive assessment of prevalence, incidence, and years lived with disability (YLDs) for 328 causes in 195 countries and territories from 1990 to 2016. Methods We estimated prevalence and incidence for 328 diseases and injuries and 2982 sequelae, their non-fatal consequences. We used DisMod-MR 2.1, a Bayesian meta-regression tool, as the main method of estimation, ensuring consistency between incidence, prevalence, remission, and cause of death rates for each condition. For some causes, we used alternative modelling strategies if incidence or prevalence needed to be derived from other data. YLDs were estimated as the product of prevalence and a disability weight for all mutually exclusive sequelae, corrected for comorbidity and aggregated to cause level. We updated the Socio-demographic Index (SDI), a summary indicator of income per capita, years of schooling, and total fertility rate. GBD 2016 complies with the Guidelines for Accurate and Transparent Health Estimates Reporting (GATHER). Findings Globally, low back pain, migraine, age-related and other hearing loss, iron-deficiency anaemia, and major depressive disorder were the five leading causes of YLDs in 2016, contributing 57.6 million (95% uncertainty interval [UI] 40.8-75.9 million [7.2%, 6.0-8.3]), 45.1 million (29.0-62.8 million [5.6%, 4.0-7.2]), 36.3 million (25.3-50.9 million [4.5%, 3.8-5.3]), 34.7 million (23.0-49.6 million [4.3%, 3.5-5.2]), and 34.1 million (23.5-46.0 million [4.2%, 3.2-5.3]) of total YLDs, respectively. Age-standardised rates of YLDs for all causes combined decreased between 1990 and 2016 by 2.7% (95% UI 2.3-3.1). Despite mostly stagnant age-standardised rates, the absolute number of YLDs from non-communicable diseases has been growing rapidly across all SDI quintiles, partly because of population growth, but also the ageing of populations. The largest absolute increases in total numbers of YLDs globally were between the ages of 40 and 69 years. Age-standardised YLD rates for all conditions combined were 10.4% (95% UI 9.0-11.8) higher in women than in men. Iron-deficiency anaemia, migraine, Alzheimer's disease and other dementias, major depressive disorder, anxiety, and all musculoskeletal disorders apart from gout were the main conditions contributing to higher YLD rates in women. Men had higher age-standardised rates of substance use disorders, diabetes, cardiovascular diseases, cancers, and all injuries apart from sexual violence. Globally, we noted much less geographical variation in disability than has been documented for premature mortality. In 2016, there was a less than two times difference in age-standardised YLD rates for all causes between the location with the lowest rate (China, 9201 YLDs per 100 000, 95% UI 6862-11943) and highest rate (Yemen, 14 774 YLDs per 100 000, 11 018-19 228). Interpretation The decrease in death rates since 1990 for most causes has not been matched by a similar decline in age-standardised YLD rates. For many large causes, YLD rates have either been stagnant or have increased for some causes, such as diabetes. As populations are ageing, and the prevalence of disabling disease generally increases steeply with age, health systems will face increasing demand for services that are generally costlier than the interventions that have led to declines in mortality in childhood or for the major causes of mortality in adults. Up-todate information about the trends of disease and how this varies between countries is essential to plan for an adequate health-system response. Copyright (C) The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license.

The potential of hot water dipping, vapour heating or ultraviolet irradiation to eliminate the use of chemicals for control of sprouting and post-harvest diseases of the potato (Solanum tuberosum L.) was examined. The microorganisms on which these treatments were tested were the fungal dry rot (Fusarium solani) and the bacterial soft rot (Erwinia carotovora pv. carotovora), two major post-harvest pathogens of potatoes. The study focused on short-term storage (three months) at 8$ sp circ$C or 18$ sp circ$C, which are representative of storage temperatures used by producers in northern temperate and semi-arid tropical regions, respectively.
Response surface methodology was used in experimentation to facilitate analysis of data and identification of optimal operating conditions for the treatments. The following parameters were used to assess tuber quality after the treatments and 3-month storage: firmness, color and structure.
It was found possible to obtain 100% control of sprouting and diseases for the three-month storage without resorting to the use of chemicals. This was achieved without significantly altering the quality attributes of the tubers under certain conditions of hot water, ultraviolet radiation or combinations of these two with storage at 8$ sp circ$C for three months. Although 100% control was not possible for the storage at 18$ sp circ$C, treated tubers performed much better than the controls. Vapour heat (50-70$ sp circ$C) was much less effective at controlling sprouting and was therefore not tested on the pathogens.
A numerical model of the heat transfer phenomenon in the tuber was also developed. It was used to predict the transient temperature distribution in the tuber. The model was solved using the line-by-line technique and model simulations were validated against experimental data.

Injury now surpasses disease as the leading global cause of premature death and disability, claiming over 5.8 millions lives each year. However, unlike disease, which has been subjected to a rigorous epidemiologic approach, the field of injury prevention and control has been a relative newcomer to scientific investigation. With the distribution of injury now well described (i.e. ???who???, ???what???, ???where??? and ???when???), the underlying hypothesis is that progress in understanding ???how??? and ???why??? lies in classifying injury occurrences aetiologically. The advancement of a means of classifying injury aetiology has so far been inhibited by two related limitations: 1. Structural limitation: The absence of a cohesive and validated aetiological taxonomy for injury, and; 2. Methodological limitation: The need to manually classify large numbers of injury cases to determine aetiological patterns. This work is directed at overcoming these impediments to injury research. An aetiological taxonomy for injury was developed consistent with epidemiologic principles, along with clear conventions and a defined three-tier hierarchical structure. Validation testing revealed that the taxonomy could be applied with a high degree of accuracy (coder/gold standard agreement was 92.5-95.0%), and with high inter- and intra- coder reliability (93.0-96.3% and 93.5-96.3%). Practical application demonstrated the emergence of strong aetiological patterns which provided insight into causative sequences leading to injury, and led to the identification of effective control measures to reduce injury frequency and severity. However, limitations related to the inefficient and error-prone manual classification process (i.e. average 4.75 minute/case processing time and 5.0-7.5% error rate), revealed the need for an automated approach. To overcome these limitations, a knowledge acquisition (KA) software tool was developed, tested and applied, based on an expertsystems technique known as ripple down rules (RDR). It was found that the KA system was able acquire tacit knowledge from a human expert and apply learned rules to efficiently and accurately classify large numbers of injury cases. Ultimately, coding error rates dropped to 3.1%, which, along with an average 2.50 minute processing time, compared favourably with results from manual classification. As such, the developed taxonomy and KA tool offer significant advantages to injury researchers who have a need to deduce useful patterns from injury data and test hypotheses regarding causation and prevention.

The purpose of this study was to investigate if the systematic management of the work environment at four departments at Umeå university lives up to the demands in the legislation, identify deficiencies and develop proposals for improvement. The methods that were used for completing this study were a literature study about work environment and related legislation and a then a practical study. The practical study consisted of two parts, interviews with head of department and work environment representatives and a questionnaire among the employees. The results show a number of deficiencies in the systematic management of the work environment. In order to live up to the demands in the legislation the departments have to implement risk assessments at changes in the organization, implement annual follow-ups of the systematic management of the work environment, start to control completed measures and include psychological and social factors. To get a more effective systematic management of the work environment the departments have to prioritize the work environment higher and enhance the employees commitment and knowledge. The conclusions of this study is that the systematic management of the work environment at this four departments at Umeå university partly lives up to the demands in the legislation, but they have a number of deficiencies that must be corrected.

У статті показано стан професійних захворювань. Наведенo статистичні дані в Україні за 2015 рік за найбільш небезпечними регіонами та галузями економіки. Висвітлено домінуючи причини формування несприятливих умов праці.
The status of occupational diseases are presented in this article. Statistics of the most traumatic regions and industries are shown in Ukraine in 2015. Also the dominant reasons for formation of injury are described.

The need to develop therapies for neurodegenerative diseases and spinal cord injuries has led researchers to study the primary olfactory system, as it continuously renews itself throughout life, and completely regenerates after injury. A pool of cells that line the basal surface of the olfactory epithelium gives rise to new olfactory neurons both during normal olfactory nervous system turnover and to a greater extent following injury. The unique, growth promoting olfactory system environment is crucial for this neurogenesis and regeneration. Significantly glial scarring (as is typically seen in neurodegeneration and neural damage elsewhere in the nervous system) is largely absent following injury to the olfactory tract. Thus replicating the favourable condition in the olfactory nervous system would be invaluable for developing these successful therapies. If we can mimic the cellular and molecular mechanisms responsible for maintenance andregeneration of the olfactory neurons, we can promote regeneration and facilitate the reestablishment of connectivity in damaged neural tracts. To model neural regeneratio n strategies in the olfactory nervous system we need to understand the normal olfactory system biology.
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Natural Sciences
Science, Environment, Engineering and Technology
Full Text

BACKGROUND Cardiac surgery patients have some of the highest reported incidence and prevalence of pressure injuries (PI). A growing subset of cardiac surgery include patients with end-stage heart failure who undergo ventricular assist device (VAD) or total artificial heart (TAH) surgery. The risk of PI and their natural history of development in this population are unknown and the specific risk factors for PI development remain unexplored. OBJECTIVES To perform a systematic review of the literature to identify the incidence and risk factors of PI development in patients undergoing VAD-TAH surgery and thereby inform study design and variables in an eight-year retrospective study of all patients undergoing VAD-TAH surgery at a large academic university medical center. METHODS The preferred reporting items for systematic reviews and meta-analyses or PRISMA statement guided this systematic review. Quality of evidence was determined using the Johns Hopkins Nursing Evidence-Based Practice Rating Scale. Two reviewers independently appraised manuscripts matching the eligibility criteria for study inclusion. Four databases including PubMed, CINAHL, Web of Science, Google Scholar, and hand searches of journals based on reference lists from included studies were utilized. Initial results of this primary search revealed zero studies that met inclusion and this search methodology was confirmed by medical librarian consultation. Therefore, a follow up retrospective study was necessary to identify incidence of PI in the VAD-TAH population. However, a secondary search, dropping keywords of VAD-TAH and instead focusing on studies of on-pump cardiac surgery and mixed surgical studies where cardiac surgery patients were included, was conducted to establish variables to guide a retrospective study of all VAD-TAH surgeries between 2010-2018. The retrospective study evaluated the incidence of pressure ulcers by case, patient and incidence density for each of the respective 1000 patient days during the study period. Univariate statistics are reported by four different VAD-TAH devices. Variables significant in bivariate analysis were entered in a stepwise logistic regression model. RESULTS In the systematic review, 312 articles were identified from the databases with eight additional articles from hand searches. Following abstract review, 208 were excluded for not meeting inclusion criteria or study quality metrics. 77 articles were read in full, with 61 excluded, leaving 16 articles for inclusion. 31 risk factors were identified for PI development in on-pump cardiac surgery patients with 11 risk factors which were identified as significant in multivariate analysis for inclusion in the retrospective study.

Thesis (Master of Applied Sciences in Chemistry)--Cape Peninsula University of Technology, 2018.
Maintenance of optimum wound chemistry is important to ensure timely healing of a wound. Bacterial infections impair the process of wound healing by producing toxins that alter the chemical environment in and around the wound. The imbalance in the wound chemistry prolongs healing and opens doors to opportunistic infections. Bacteria have developed resistance to conventional bactericides hence, there is need for search of new bactericides that can control bacteria in and around the wound. Therefore, new chemical or biochemical bactericides, which are not resisted by the bacteria, can be explored to control bacterial life around the wound in a bid to maintain optimum wound healing chemistry. Materials such as chitosan, zinc oxide, copper oxide and silver have showed remarkable potential as both bactericidal and wound healing agents. In this work silver, zinc oxide, and copper oxide nanoparticles (NPs) and their chitosan composites (CH-NPs) were synthesized using the chemical reduction method and simple chelation respectively to produce nanoparticles of Ag, ZnO, and CuO as well as composites of CH-ZnO, CH-Ag, CH-CuO, and CH-ZnO-Ag-CuO. Formation of the NPs was confirmed by the exhibition of characteristic peaks in UV-Visible and Fourier Transform Infrared Resonance (FTIR) spectroscopy as well as X-ray diffraction. The nanoparticles (NPs) had optical and electronic band gaps in the range 1 to 5eV indicating their semi-conductive nature. X-ray diffraction (XRD) investigations depicted the crystalline structures of the NPs to be base-centred, face-centred, and hexagonal for Ag, CuO, and ZnO respectively. Transmission electron microscopy (TEM) studies exhibited spherical, hexagonal, and rod-shaped shapes for silver, copper oxide, zinc oxide NPs respectively. Electrochemical investigations of the pure NPs indicated the existence of both the adsorption and the diffusion controlled electron transfer processes at electrode surfaces as well as fast electron transfer rate as depicted by the charge transfer coefficient and standard rate constant parameter values. FTIR spectra of CH-NPs composites depicted new excitation bands absent in spectra of both chitosan and the NPs. The spectra also indicated the deformation and absence of the amine (-NH2) and hydroxyl bands (-OH) within the CH-NPs composites. UV-Visible spectroscopy investigations of the CH-NPs composites exhibited blue-shifts of the λmax with respect to the NPs. The FTIR and UV-Visible spectra confirmed the existence of bonding between the chitosan and the NPs. The optical band gap energies of all the CH-NPs composites fell within the range of 2.0 to 4.5 eV indicating that the CH-NPs fell in the category of the semi-conducting materials after chelating with the chitosan.

"Back injuries have consistently been the most common types of injuries suffered by people at work. They have been a significant worker injury problem in most, if not all, industrialised countries for many years and manual handling has long been established as a significant task related back injury causal factor.[...] This research project established that the manufacturers of the jet airlines used by the airlines in this study had not previously been acquainted with the issue of baggage handler back injuries.[...] This study also canvassed the opinion of airline safety professionals and airline baggage handlers concerning baggage handling tasks and working environment related causal factors. [...] A major focus of this research project was also to measure the effect of ACE and Sliding Carpet, two commercially available retro-fit baggage systems, on the risk of back injuries to baggage handlers stacking baggage within Boeing B737 narrow-body aircraft."
Doctor of Philosophy

"Back injuries have consistently been the most common types of injuries suffered by people at work. They have been a significant worker injury problem in most, if not all, industrialised countries for many years and manual handling has long been established as a significant task related back injury causal factor.[...] This research project established that the manufacturers of the jet airlines used by the airlines in this study had not previously been acquainted with the issue of baggage handler back injuries.[...] This study also canvassed the opinion of airline safety professionals and airline baggage handlers concerning baggage handling tasks and working environment related causal factors. [...] A major focus of this research project was also to measure the effect of ACE and Sliding Carpet, two commercially available retro-fit baggage systems, on the risk of back injuries to baggage handlers stacking baggage within Boeing B737 narrow-body aircraft."
Doctor of Philosophy

"Back injuries have consistently been the most common types of injuries suffered by people at work. They have been a significant worker injury problem in most, if not all, industrialised countries for many years and manual handling has long been established as a significant task related back injury causal factor.[...] This research project established that the manufacturers of the jet airlines used by the airlines in this study had not previously been acquainted with the issue of baggage handler back injuries.[...] This study also canvassed the opinion of airline safety professionals and airline baggage handlers concerning baggage handling tasks and working environment related causal factors. [...] A major focus of this research project was also to measure the effect of ACE and Sliding Carpet, two commercially available retro-fit baggage systems, on the risk of back injuries to baggage handlers stacking baggage within Boeing B737 narrow-body aircraft."
Doctor of Philosophy

Background Measurement of changes in health across locations is useful to compare and contrast changing epidemiological patterns against health system performance and identify specific needs for resource allocation in research, policy development, and programme decision making. Using the Global Burden of Diseases, Injuries, and Risk Factors Study 2016, we drew from two widely used summary measures to monitor such changes in population health: disability-adjusted life-years (DALYs) and healthy life expectancy (HALE). We used these measures to track trends and benchmark progress compared with expected trends on the basis of the Socio-demographic Index (SDI). Methods We used results from the Global Burden of Diseases, Injuries, and Risk Factors Study 2016 for all-cause mortality, cause-specific mortality, and non-fatal disease burden to derive HALE and DALYs by sex for 195 countries and territories from 1990 to 2016. We calculated DALYs by summing years of life lost and years of life lived with disability for each location, age group, sex, and year. We estimated HALE using age-specific death rates and years of life lived with disability per capita. We explored how DALYs and HALE differed from expected trends when compared with the SDI: the geometric mean of income per person, educational attainment in the population older than age 15 years, and total fertility rate. Findings The highest globally observed HALE at birth for both women and men was in Singapore, at 75.2 years (95% uncertainty interval 71.9-78.6) for females and 72.0 years (68.8-75.1) for males. The lowest for females was in the Central African Republic (45.6 years [42.0-49.5]) and for males was in Lesotho (41.5 years [39.0-44.0]). From 1990 to 2016, global HALE increased by an average of 6.24 years (5.97-6.48) for both sexes combined. Global HALE increased by 6.04 years (5.74-6.27) for males and 6.49 years (6.08-6.77) for females, whereas HALE at age 65 years increased by 1.78 years (1.61-1.93) for males and 1.96 years (1.69-2.13) for females. Total global DALYs remained largely unchanged from 1990 to 2016 (-2.3% [-5.9 to 0.9]), with decreases in communicable, maternal, neonatal, and nutritional (CMNN) disease DALYs offset by increased DALYs due to non-communicable diseases (NCDs). The exemplars, calculated as the five lowest ratios of observed to expected age-standardised DALY rates in 2016, were Nicaragua, Costa Rica, the Maldives, Peru, and Israel. The leading three causes of DALYs globally were ischaemic heart disease, cerebrovascular disease, and lower respiratory infections, comprising 16.1% of all DALYs. Total DALYs and age-standardised DALY rates due to most CMNN causes decreased from 1990 to 2016. Conversely, the total DALY burden rose for most NCDs; however, age-standardised DALY rates due to NCDs declined globally. Interpretation At a global level, DALYs and HALE continue to show improvements. At the same time, we observe that many populations are facing growing functional health loss. Rising SDI was associated with increases in cumulative years of life lived with disability and decreases in CMNN DALYs offset by increased NCD DALYs. Relative compression of morbidity highlights the importance of continued health interventions, which has changed in most locations in pace with the gross domestic product per person, education, and family planning. The analysis of DALYs and HALE and their relationship to SDI represents a robust framework with which to benchmark location-specific health performance. Country-specific drivers of disease burden, particularly for causes with higher-than-expected DALYs, should inform health policies, health system improvement initiatives, targeted prevention efforts, and development assistance for health, including financial and research investments for all countries, regardless of their level of sociodemographic development. The presence of countries that substantially outperform others suggests the need for increased scrutiny for proven examples of best practices, which can help to extend gains, whereas the presence of underperforming countries suggests the need for devotion of extra attention to health systems that need more robust support. Copyright (C) The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license.

Dissertation (PhD (Agric))--University of Stellenbosch, 2003.
ENGLISH ABSTRACT: Leaf blackening is a particular problem limiting vase life and marketability of Protea cut flowers. This research investigated suppression of Protea leaf blackening with a specific focus on Protea cv. Sylvia (P. eximia x P. susannae) cut flowers. Leaf blackening decreased significantly with decreasing storage temperatures m 'Sylvia' proteas and this was attributed to lower respiration rate and conservation of carbohydrate. Low storage temperatures were beneficial in short term handling procedures encountered during airfreight. However, use of low temperatures alone during the longer sea freight period was unsatisfactory in either maintaining or extending 'Sylvia' protea vase life. Cooling of 'Sylvia' proteas under vacuum significantly suppressed leaf blackening and was of greater benefit than forced air cooling. Although removal of the uppermost leaves delayed leaf blackening in short term storage no significant benefit was found for longer storage periods. Girdling directly beneath the 'Sylvia' protea flowerhead significantly reduced leaf blackening and in combination with low storage temperatures (O°C) enabled a significant extension in both storage and vase life of 'Sylvia' proteas. 'Sylvia' proteas did not exhibit a climacteric respiration peak during 96 h storage at O°C. Exposure to ethylene did not increase Protea leaf blackening or have a detrimental effect on vase life of either proteas or pincushions evaluated. No beneficial response to sucrose supplementation was found in 'Sylvia' proteas. Analysis of the sugar content of both flowerhead and leaves indicated that glucose supplementation might be of benefit and was investigated. Holding solutions of 2.5 % glucose significantly extended vase life due to a significant reduction in leaf blackening. Vase life was terminated due to flowerhead collapse instead of leaf blackening for the first time in 'Sylvia' protea cut flowers. Vase life was significantly extended by 2:3% glucose pulse solutions and leaf blackening significantly suppressed with increasing glucose pulse concentration. Solution uptake was facilitated by use of high intensity PAR lights in the early morning and was attributed to increased stomata opening and a consequent increase in both transpiration and glucose solution uptake. The faster uptake of glucose solutions in shoots harvested in the afternoon was attributed to higher shoot temperatures and consequent transpiration rate to those harvested in the morning. There was a significant reduction in uptake time with increasing pulse temperature, which enabled vacuum cooling to be performed earlier further benefiting storage and vase life extension. Enclosure of 'Sylvia' proteas in polyethylene (PE) lined cartons did suppress leaf blackening in non-pulsed shoots. However, this had no practical significance on useful vase life, which was terminated at this point due to excessive leaf blackening. Water loss appears to have a minimal influence on 'Sylvia' protea leaf blackening. Shading at four and three weeks prior to harvest coincided with a period of significant flowerhead dry mass increase. It is thought that shading at this point, concurrent with an increased carbohydrate demand by the developing flower head resulted in a temporary limitation in carbohydrate supply resulting in the appearance of preharvest leaf blackening. It would appear that proteas do not store large quantities of carbohydrate. Although accentuating winter light conditions by shading did result in a decrease in carbohydrate content the fact that carbohydrate content was already low precluded shading from having a significant impact on postharvest leaf blackening. The finding that glucose was beneficial in extension of both storage and vase life of 'Sylvia' proteas directed research into its use for other Protea and Leucospermum cut flowers. Significant differences in the response to glucose supplementation were found in both Protea and Leucospermum (pincushions). The significant difference in sensitivity to glucose concentration in 'Pink Ice' proteas (phytotoxic at 2:4%) and 'Susara' proteas (no apparent toxicity), in conjunction with a lack of response in 'Cardinal' proteas, a hybrid from the same parents as 'Sylvia' indicates the need to direct future research to individual cultivars. Glucose supplementation had no beneficial effect on vase life of 'Scarlet Ribbon' and 'Tango' pincushions, whilst significantly extending vase life of 'Cordi', 'Gold Dust', 'High Gold' and 'Succession' pincushions.
AFRIKAANSE OPSOMMING: Blaarverswarting is 'n spesifieke probleem wat die vaasleeftyd en die bemarkbaarheid van Protea snyblomme beperk. In hierdie navorsing is ondersoek ingestel na die onderdrukking van Protea blaarverswarting met spesifieke fokus op die snyblomme van die kv. Sylvia (P. eximia x P. susannae). Die voorkoms van blaarverswarting by 'Sylvia' het merkbaar afgeneem tydens die verlaging van bergingstemperature. Hierdie afname is toegeskryf aan 'n laer respirasietempo en die behoud van koolhidrate. Lae bergingstemperature in die korttermyn hantering van die produk tydens lugvrag was voordelig. Die gebruik van lae temperature, slegs tydens die langer verskeepingsperiode, was egter onbevredigend vir vaasleeftyd verlenging en onderhoud van 'Sylvia' protea. Die afkoeling van 'Sylvia' proteas onder vakuum het blaarverswarting in 'n groot mate onderdruk en het beter resultate gelewer as geforseerde lugverkoeling. Alhoewel die verwydering van die heel boonste blare blaarverswarting by korttermynopberging vertraag het, het dit geen merkbare voordele vir langer bergingsperiodes ingehou nie. Ringelering direk onder die blomkop van die 'Sylvia' protea het blaarverswarting aansienlik verminder, en saam met lae bergingstemperature (O°C) het dit 'n merkbare verlenging in beide die bergingstyd en die vaasleeftyd van 'Sylvia' proteas teweeggebring. 'Sylvia' proteas het geen klimakteriese respirasiekruin tydens 'n bergingsperiode van 96 uur teen O°C getoon nie. Blootstelling aan etileen het nie die Protea blaarverswarting laat toeneem of 'n nadelige effek op die vaasleeftyd van die proteas of speldekussings wat geevalueer is, gehad nie. Geen voordelige reaksie op sukrose-byvoeging is in 'Sylvia' proteas gevind nie. 'n Analise van die suikerinhoud van beide die blomkoppe en die blare het aangetoon dat 'n glukose-byvoeging moontlik voordelig kon wees, en hierdie aspek is ondersoek. Met stooroplossings van 2,5 % glukose is die vaasleeftyd aansienlik verleng omdat daar 'n merkbare afname in blaarverswarting was. Vir die eerste keer in die geval van die 'Sylvia' protea, het die vaasleeftyd van die snyblomrne tot 'n einde gekom omdat die blornkoppe uitmekaar gebreek het en nie omdat blaarverswarting ingetree het nie. Die vaasleeftyd is aansienlik verleng met ~ 3% glukose-pulsoplossings, en blaarverswarting is merkbaar onderdruk met die verhoging van hierdie oplossings se glukosekonsentrasie. Die opname van die oplossings is gefasiliteer deur hoe intensiteit PAR (fotosinteties-aktiewe radiasie) ligte vroeg in die oggend, en is toegeskryf daaraan dat meer huidmondjies oopgegaan het. Dit het gelei tot 'n toename in transpirasie en 'n toename in die opname van die glukose-oplossing. Die feit dat glukose-oplossings vinniger opgeneem is deur lote wat in die middag geoes is, is toegeskryf daaraan dat loottemperature dan hoer is as soggens en gevolglik lei tot 'n vinniger transpirasietempo. Daar was 'n merkbare afname in die opnametyd wanneer die temperatuur van die pulsoplossings verhoog is. Vakuumafkoeling kon dus vroeer toegepas word, wat 'n verlenging in bergingstyd en vaasleeftyd tot gevolg gehad het. Verpakking van 'Sylvia' proteas in kartonne wat met poli-etileen uitgevoer is, het blaarverswarting van lote wat nie aan pulsering onderwerp is nie, onderdruk. Hierdie maatreel het egter geen praktiese waarde met betrekking tot vaasleeftyd nie; die vaasleeftyd het tot 'n einde gekom as gevolg van omvangryke blaarverswarting. Dit lyk asof waterverlies weinig invloed het op die blaarverswarting van' Sylvia' proteas. Die vermoede bestaan dat lae koolhidraatvlakke proteas ontvanklik maak vir blaarverswarting. Alhoewel die beklemtoning van winterligtoestande deur beskaduwing gelei het tot 'n afname in koolhidraatinhoud, was hierdie inhoud reeds laag en blaarverswarting na die oes is nie beinvloed nie. Beskaduwing tydens die vier en drie weke voor oestyd het saamgeval met 'n tydperk van aansienlike toename in die droe massa van die blomkop. Die vermoede bestaan dat beskaduwing tydens hierdie fase, saam met die toename in die ontwikkelende blomkop se behoefte aan koolhidrate, aanleiding gegee het tot 'n tydelike beperking in koolhidraatvoorraad wat die voorkoms van blaarverswarting voor die oes tot gevolg gehad het. Die bevinding dat glukose voordelig is vir die verlenging van beide die bergingstyd en die vaasleeftyd van 'Sylvia' proteas het die navorsing gerig om ook ondersoek in te stel na die gebruik daarvan vir ander Protea en Leucospermum snyblomme. Merkbare veranderinge is gevind in die reaksie op glukosebyvoegings in beide Protea en Leucospermum (speldekussings). Die opmerklike verskil in sensitiwiteit vir glukosekonsentrasie in 'Pink Ice' proteas (fitotoksies by ~ 4%) en 'Susara' proteas (geen klaarblyklike toksisiteit), saam met 'n gebrek aan reaksie by 'Cardinal' proteas, 'n hibried van dieselfde ouers as 'Sylvia', dui aan dat verdere navorsing op individuele kultivars toegespits sal rnoet word. Glukosebyvoegings het geen voordelige uitwerking op die vaasleeftyd van 'Scarlet Ribbon' en 'Tango' speldekussings gehad nie, terwyl dit die vaasleeftyd van 'Cordi', 'Gold Dust', 'High Gold' en 'Succession' speldekussingkultivars merkbaar verIeng het.

Thesis (MScFoodSc)--Stellenbosch University, 2012.
ENGLISH ABSTRACT: Postharvest fruit loss is a major challenge in addressing food security, sustainable management of resources and profitability of agribusiness. The incidence of postharvest loss and changes in physico-chemical properties of three types of fruit (peaches, pears and oranges) were evaluated at retail and during post-purchase storage. The amount of physical loss at the three retail outlets studied ranged from 3.61% to 18.09% among the fruit types, with the highest incidence occurring in peaches. The estimated annual national physical loss at retail was 418 tons for pears, 1000 tons for oranges, and 7 240 tons for peaches. Based on the WHO recommended 146 kg per capita per year consumption of fruit, the total loss of the three types of fruit was sufficient to meet the dietary fruit requirements of 50 000 people per annum. Similarly, based on the recommended daily allowance of 50 mg of ascorbic acid, these losses could meet the annual vitamin C needs of 82 000 people. The estimated monetary value of the losses at retail ranged from R2.2 million to R96.87 million per annum depending on fruit type and retail outlet. The land wasted to produce lost fruits was 1965 ha while energy wasted was 32.77 x 106 MJ. Greenhouse gas emission of the losses was 2870 tons CO2eq and total water footprint 68 0000 m3. Losses were mainly due to the presence of severe physical damage, rots and physiological disorders. There were significant variations in physico-chemical properties of fruit of the same type from different retail outlet. Although ambient temperature storage improved fruit colour and some chemical constituents responsible for palatability, it was associated with high physical and nutritional (vitamin C) losses. Results from this study show that appropriate harvesting maturity, packaging and maximum care in fruit handling is essential in reducing postharvest losses. Efficient cold chain management and fruit inspection for rots and damages could help to reduce subsequent spoilage at retail and during post-purchase storage. Given that the incidence of postharvest fruit loss observed at retail is the result of cumulative effects along the supply chain, further studies are warranted to map fruit history and magnitude of losses along the value chain.
AFRIKAANSE OPSOMMING: Naoesvrugteverlies is ‟n groot uitdaging in die strewe na voedselsekerheid, volhoubare hulpbronbestuur en winsgewende landbousake. Die voorkoms van naoesverlies sowel as fisiko-chemiese naoesveranderinge by drie vrugtesoorte (perskes, pere en lemoene) is gevolglik by kleinhandelsafsetpunte én gedurende berging ná aankoop beoordeel. Die graad van fisiese verlies by die drie betrokke kleinhandelspunte het gewissel van 3,61% tot 18,09% tussen die vrugtesoorte, met die hoogste verlies by perskes. Die geraamde jaarlikse nasionale fisiese verlies by die kleinhandelspunte was 418 ton pere, 1 000 ton lemoene en 7 240 ton perskes. Op grond van die Wêreldgesondheidsorganisasie se aanbevole jaarlikse vrugte-inname van 146 kg per persoon, was die totale verlies van die drie vrugtesoorte genoeg om aan die vrugtedieetvereistes van 50 000 mense per jaar te voldoen. Op grond van die aanbevole daaglikse inname van 50 mg askorbiensuur, kan hierdie verlies eweneens in die jaarlikse vitamien C-behoeftes van 82 000 mense voorsien. Die geraamde geldwaarde van die verlies by die kleinhandelspunte strek van R2,2 miljoen tot R96,87 miljoen per jaar, na gelang van die vrugtesoort en bepaalde kleinhandelspunt. Die vermorste grond om die verlore vrugte te produseer, was 1 965 ha, terwyl energievermorsing op 32,77 x 106 MJ te staan gekom het. Kweekhuisgasvrystellings met betrekking tot die verlies was 2 870 ton CO2e, en die totale watervoetspoor 68 0000 m3. Vrugteverlies kon hoofsaaklik aan ernstige fisiese skade, verrotting en fisiologiese afwykings toegeskryf word. Daar was beduidende variasies in die fisiko-chemiese eienskappe van dieselfde vrugtesoort by verskillende kleinhandelaars. Hoewel berging by omgewingstemperatuur vrugtekleur en bepaalde chemiese komponente vir smaaklikheid verbeter, word dit ook met groot fisiese en voedingstof- (vitamien C-) verliese verbind. Die resultate van hierdie studie toon dat toepaslike oesrypheid, die regte verpakking en maksimum sorg in vrugtehantering noodsaaklik is om naoesverlies te verminder. Doeltreffende koelkettingbestuur en vrugte-inspeksie vir verrotting en skade kan latere bederf by kleinhandelsafsetpunte sowel as gedurende berging ná aankoop help beperk. Aangesien die naoesvrugteverlies wat by die kleinhandelspunte waargeneem is uit kumulatiewe faktore in die verskaffingsketting spruit, is verdere studies nodig om vrugtegeskiedenis na te spoor en die omvang van die verlies in die algehele waardeketting te bepaal.

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Dissertação (Mestrado em Tecnologia Nuclear)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Thesis (MSc)--Stellenbosch University, 2015.
ENGLISH ABSTRACT: In order to export South African plums to overseas markets strict quality standards must be maintained. Among these quality classifications are specifications about the presence of cavities and pieces of broken stone/pit within the flesh of the fruit. If more than 10% of the fruit in a carton are affected by severely broken stones or large flesh cavities, the fruit have to be marketed as Class 2. A substantial amount of plums destined for export from South Africa is affected by broken stones and thus have to be marketed as Class 2. Lower prices are attained for Class 2 fruit, therefore, the presence of broken stones has a detrimental effect on the income generated from these fruit. The main aim of this study was to gain a better understanding of broken stone development and compare the growth characteristics of Japanese plum cultivars differing in their susceptibility to broken stones. Stone breakage in ‘Laetitia’ was observed as soon as stone hardening was initiated. At the start of stone hardening the parts of the stone that are still ‘soft’ are not strong enough to resist the pulling forces of the growing mesocarp and the stone is subsequently pulled apart. Regression analysis indicated that lengthwise growth of the fruit, fresh weight of the endo- and mesocarp, minimum orchard temperature and orchard night temperature, and relative humidity (RH) early in the growing season could possibly be used to predict the incidence of broken stones at harvest. Differences in the incidence of broken stones were observed between ‘Laetitia’, ‘Sapphire’ and ‘Songold’ plums and between seasons. Furthermore, significant differences were observed in the density of the endocarp in different parts of the stone. For ‘Laetitia’ and ‘Songold’, stone breakage was observed when rapid increases in stone density coincided with rapid increases in fruit growth. The stones broke in positions where an interface exists between high and low density parts in the stone and when rapid radial growth takes place in the direction where the stone is least dense. In contrast, in ‘Sapphire’, stone breakage was observed before the stones had started to lignify, indicating that the endocarp was pulled apart by the expanding flesh because it was too soft to withstand the strong pulling forces created by the flesh. The incidence of broken stones was influenced by environmental factors, as higher temperatures during the stone development and hardening period could lead to more complete endocarp formation (more stone cells are formed under such conditions). Such fruit would thus have higher endocarp density, which, if coupled with rapid radial growth, could lead to a higher incidence of broken stones. Foliar and/or root applications of calcium nitrate and potassium silicate were applied to ‘Laetitia’ plums to determine whether the incidence of broken stones could be reduced by increasing the strength of the endocarp cell walls. However, no such effect was observed. Hence, neither calcium nor silicate treatments can be recommended for reducing broken stones in plums.
AFRIKAANSE OPSOMMING: Om Suid-Afrikaanse pruime na oorsese markte uit te voer moet vrugte aan streng kwaliteitstandaarde voldoen. Daar is ondermeer spesifikasies in verband met die teenwoordigheid van holtes en stukkies gebreekte pit binne die vrug. Indien meer as 10% van die vrugte in ʼn karton deur ernstige gebreekte pit of groot vrugholtes geaffekteer word, moet die vrugte as Klas 2 bemark word. Aangesien ʼn groot hoeveelheid van die pruime wat vir uitvoer bestem is, geaffekteer word deur gebreekte pit en gevolglik as Klas 2 bemark moet word, word aansienlike finansiële verliese gelei. Laer pryse word behaal vir Klas 2 vrugte, en dus het die teenwoordigheid van gebreekte pitte ʼn negatiewe effek op die wins wat deur die uitvoer van hierdie vrugte gegenereer kan word. Die hoofdoel van hierdie studie was om die ontwikkeling van gebreekte pit in Japannese pruime te ondersoek en om die groei-patrone van kultivars wat geneig is tot gebreekte pit te vergelyk met ʼn nie-sensitiewe kultivar. Gebreekte pit in ‘Laetitia’ is opgemerk sodra die pit begin verhard het. Met die aanvangs van pit- verharding is die gedeeltes van die pit wat nog nie volkome verhard het nie, nie sterk genoeg om die sterk trekkragte van die groeiende mesokarp te weerstaan nie en die pit word gevolglik uitmekaar- getrek. Regressie-analise het gewys dat lengtegroei van die vrugte, vars massa van die endo- en mesokarp, minimum boordtemperatuur en boord-nagtemperatuur, asook relatiewe humiditeit gedurende die vruggroei-periode moontlik gebruik kan word om die voorkoms van gebreekte pit by oes te voorspel. Verskille in die voorkoms van gebreekte pit is opgemerk tussen ‘Laetitia’, ‘Sapphire’ en ‘Songold’ pruime, en ook tussen seisoene. Verder is beduidende verskille opgemerk in die digtheid van die endokarp in verskillende dele van die pit. By beide ‘Laetitia’ en ‘Songold’ is gebreekte pit opgemerk wanneer vinnige toename in pit-digtheid saamgeval het met ʼn vinnige toename in vruggroei. Die pitte breek veral in die oorgang tussen dele van die pit met hoë en lae digtheid en as dit gekombineer is met vinnige radiale vruggroei in die rigting waar die pit die minste dig is. In teenstelling hiermee is gebreekte pit in ‘Sapphire’ opgemerk selfs voordat die pitte begin verhard het. Dit dui daarop dat die endokarp uitmekaargetrek is deur die vinnig groeiende mesokarp, omdat dit te sag was om die trekkragte van die groeiende vrugvlees te weerstaan. Die voorkoms van gebreekte pit word ook deur weerstoestande beïnvloed, want hoër temperature gedurende die pit-ontwikkeling en verhardingsperiode, kan lei tot die ontwikkeling van endokarpe met meer steenselle. Hierdie vrugte sal dus ʼn hoër digtheid hê, en as dit saamval met vinnige radiale groei, kan dit lei tot ʼn groter voorkoms van gebreekte pit. Blaar- en/of worteltoedienings van kalsiumnitraat en kaliumsilikaat is gemaak om te bepaal of die voorkoms van gebreekte pit in ‘Laetitia’ verminder kon word deur die versterking van die endokarp-selwande. Geen van hierdie behandelings het tot ʼn vermindering in gebreekte pit gelei nie en nie kalsiumnitraat of kaliumsilikaat kan dus aanbeveel word om gebreekte pit in pruime te verminder nie.