The conservation of germplasm of indigenous plant species is vital not only to preserve valuable genotypes, but also the diversity represented by the gene pool. A complicating factor, however, is that a considerable number of species of tropical and sub-tropical origin produce recalcitrant or otherwise non-orthodox seeds. Such seeds are hydrated and metabolically active when shed and cannot be stored under conventional conditions of low temperature and low relative humidity. This poses major problems for the longterm conservation of the genetic resources of such species. Presently, the only strategy available for the long-term conservation of species that produce recalcitrant seeds is cryopreservation. Ekebergia capensis is one such indigenous species that produces recalcitrant seeds. The aim of the present study was to develop methods for the cryopreservation of germplasm of this species. Different explant types were investigated for this purpose, viz. embryonic axes (with attached cotyledonary segments) excised from seeds, and two in vitro-derived explants, i.e. ‘broken’ buds excised from in vitro-germinated seedlings and adventitious shoots generated from intact in vitro-germinated roots. Suitable micropropagation protocols were developed for all explant types prior to any other experimentation. Before explants could be cryopreserved it was necessary to reduce their water content in order to limit damaging ice crystallisation upon cooling. All explants tolerated dehydration (by flash drying) to 0.46 – 0.39 g gˉ¹ water content (dry mass basis) with survival ranging from 100 – 80%, depending on the explant. In addition, penetrating and non-penetrating cryoprotectants were used to improve cryo-tolerance of explants. The cryoprotectants tested were sucrose, glycerol, DMSO and a combination of sucrose and glycerol. Explant survival following cryoprotection and dehydration ranged from 100 – 20%. Cryoprotected and dehydrated explants were exposed to cryogenic temperatures by cooling at different rates, since this factor is also known to affect the success of a cryopreservation protocol. The results showed that ‘broken’ buds could not tolerate cryogen exposure. This was likely to have been a consequence of the large size of explants and their originally highly hydrated condition. Adventitious shoots tolerated cryogenic exposure slightly better with 7 – 20% survival after cooling in sub-cooled nitrogen. Limited shoot production (up to 10%) was obtained when axes with attached cotyledonary segments were exposed to cryogenic temperatures. In contrast, root production from axes cooled in sub-cooled nitrogen remained high (67 – 87%). Adventitious shoots were subsequently induced on roots generated from cryopreserved axes by applying a protocol developed to generate adventitious shoots on in vitrogerminated roots. In this manner, the goal of seedling establishment from cryopreserved axes was attained. Each stage of a cryopreservation protocol imposes stresses that may limit success. To gain a better understanding of these processes the basis of damage was investigated by assessing the extracellular production of the reactive oxygen species (superoxide) at each stage of the protocol, as current thinking is that this is a primary stress or injury response. The results suggested that superoxide could not be identified as the ROS responsible for lack of onwards development during the cryopreparative stages or following cryogen exposure. The stresses imposed by the various stages of a cryopreservation protocol may affect the integrity of germplasm. Since the aim of a conservation programme is to maintain genetic (and epigenetic) integrity of stored germplasm, it is essential to ascertain whether this has been achieved. Thus, explants (axes with cotyledonary segments and adventitious shoots) were subjected to each stage of the cryopreservation protocol and the epigenetic integrity was assessed by coupled restriction enzyme digestion and random amplification of DNA. The results revealed little, if any, DNA methylation changes in response to the cryopreparative stages or following cryogen exposure. Overall, the results of this study provided a better understanding of the responses of germplasm of E. capensis to the stresses of a cryopreservation protocol and two explant types were successfully cryopreserved. Future work can be directed towards elucidating the basis of damage incurred so that more effective protocols can be developed. Assessment of the integrity of DNA will give an indication as to the suitability of developed protocols, or where changes should be made to preserve the genetic (and epigenetic) integrity of germplasm. / Thesis (Ph.D.)-University of KwaZulu-Natal, Westville, 2011.

Seeds remain the most convenient and successful way for storing the genetic diversity of plant species and for producing new plants routinely for agriculture and horticulture. The importance of seed storage and the ability to predict seed longevity must therefore not be underestimated. To be successful, storage conditions must maintain seed vigour and viability and ensure that normal seedlings are subsequently established under field conditions. Seed quality is best retained when deteriorative events are minimised, which is achieved by storage of low moisture-content seeds under cool to cold, or even sub-zero, temperatures. Such conditions are employed for 'orthodox' seeds, which are desiccation tolerant and able to survive at sub-zero temperatures in the dehydrated state for extended periods. It is seeds referred to as 'recalcitrant' that cannot be dehydrated and often not stored at low temperatures because they are desiccation sensitive and may not tolerate chilling. According to almost anecdotal records chilling temperatures for such seeds are those below 15°C down to 0°C, depending on the species. The limited storage lifespan of recalcitrant seeds presents a problem even for short-term storage, and as most research on chilling sensitivity has been conducted on vegetative tissue, relatively little data exist for seeds, especially recalcitrant types. The purpose of this study was to gain an understanding of the chilling response of recalcitrant seeds, as reduced temperature could have the potential to extend, rather than curtail, storage lifespan, depending on the species. Selected physiological, biochemical and ultrastructural responses of recalcitrant seeds of Avicennia marina and Ekebergia capensis were characterised. Seeds of the two species were stored at 25, 16 and 6°C. Germination, water content (determined gravimetrically), respiration (measured as CO2 production) and leachate conductivity (tissue electrolyte leakage over time) were assessed at regular intervals. Chilling response at the subcellular level was examined using transmission electron microscopy (TEM). Changes in sugar metabolism and activities of the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT) and glutathione reductase (GR) were assessed for A. marina seeds, which were severely affected by the chilling temperature of 6°C, losing viability after 1 week. In contrast, the seeds of E. capensis retained viability after 12 weeks of storage at 6°C, indicating the marked difference in chilling response between seeds of the two recalcitrant species, despite their common tropical provenance. However, when E. capensis seeds were stored at 3°C viability decreased significantly after 8 weeks, thus indicating how critically temperature must be controlled if such conditions are to be profitably employed. Ultrastructural studies revealed that in both E. capensis and A. marina seeds vacuole formation was initiated more rapidly at lower temperatures than at higher temperatures, indicating that this was a response specific to the chilling stress imposed. Once again, 'lower temperatures' differed relative to the species concerned. In the E. capensis seeds, nucleolar morphology was affected and the extent of chromatin patches in the nuclei increased as the storage temperature was reduced. Other ultrastructural findings could not be linked specifically to the chilling stress imposed on the E. capensis and A. marina seeds. Activity of the antioxidant enzymes SOD and GR was detected in the A. marina seeds. No measurable CAT activity was detected. Glutathione reductase activity increased in response to chilling stress, the rate of the increase depending upon the severity of the chilling stress imposed. Other than when the A. marina seeds were placed directly at 6°C, there were no notable increases in SOD activity. Interestingly, SOD and GR activity was not the same in the axes as in the cotyledons. Superoxide dismutase activity was found to be higher in the axes and GR activity higher in the cotyledons. It would have been beneficial to determine the extent of antioxidant enzyme activity in the E. capensis seeds as well if this had been possible. Generally, chilling of recalcitrant seeds seems to evoke a response similar to that of dehydration below a critical water content. This could lead to the conclusion that recalcitrant seeds do not possess the genetic ability to cope with dehydration or chilling stress, if it were not for the existence of recalcitrant seed species that are more chilling tolerant. / Thesis (M.Sc.)-University of Natal, Durban, 2002.

No description available.

In this research, three alternative approaches to chemical preservatives to extend the mold free shelf-life and quality of pita bread were investigated namely: Modified Atmosphere Packaging (MAP) involving gas packaging, oxygen absorbents technology and ethanol vapor generators, high pressures, and direct and indirect heating. / Gas packaging using 60%CO2 (balance N2) inhibited the growth of Aspergillus niger and Penicillium notatum from 3d (pita bread packaged in air) to 35d at ambient temperature. A longer extension in shelf-life (42d) was possible using an Ageless oxygen absorbent or a Freshmax oxygen absorbent label in conjunction with gas packaging. / Similar results were obtained with 2G--4G sachets of Ethicap, and 100--200S sachets of Negamold, a dual functional oxygen absorbent-ethanol vapor generator. / High pressures (30--400MPa) used to inhibit mold growth, resulted in delamination of the packaging film and textural changes to the pita bread. / Other alternatives, such as direct heating and microwave processing had a minimal effect in increasing the shelf-life of pita bread. (Abstract shortened by UMI.)

Tiriamojo darbo tikslas – nustatyti Lietuvos architektūros paveldo objektų, konkrečiai Lietuvos Didžiosios Kunigaikštystės valdovų rūmų Vilniaus Žemutinėje pilyje, Labanoro bažnyčios statinių komplekso ir Vilniaus dominikonų vienuolyno statinių ansamblio, atkūrimo darbų atitikimą tarptautinių paveldosaugos dokumentų nuostatoms. Darbe ištirta tarptautinės paveldosaugos pradžios (stilistinio restauravimo) bruožų ir pagrindinių tarptautinių paveldosaugos dokumentų (Atėnų, Venecijos ir Rygos chartijų bei Nara dokumento) nuostatų, susijusių su architektūros paveldo objektų išsaugojimu, raida. Taip pat išnagrinėtas Prancūzijos ir Vokietijos valstybių skirtingų laikotarpių architektūros paveldo objektų atkūrimo darbų ir to meto nuostatų, įteisintų tarptautiniuose paveldosaugos dokumentuose, atitikimas. Pagrindinė darbo dalis yra Lietuvos architektūros paveldo objektų (Lietuvos Didžiosios Kunigaikštystės valdovų rūmai Vilniaus Žemutinėje pilyje, Labanoro bažnyčios statinių komplekso, Vilniaus dominikonų vienuolyno statinių ansamblio) atkūrimo darbų atitikimas tarptautiniams paveldosaugos dokumentams. Tyrimui pritaikyta kokybinė dokumentų, literatūros, archyvinės medžiagos ir kitų informacijos šaltinių analizė. Be to, lyginama architektūros paveldo objektams vykdoma atkūrimo veikla su tarptautinių paveldosaugos rekomenduojama paveldo saugojimo veikla ir pateikiamos išvados, kuriose išskiriami gerosios praktikos ir prieštaravimų rekomendacijoms pavyzdžiai. / The aim of this paper is to determine the preservation compliance of Lithuanian architectural heritage objects, in particular the Royal Palace of Lietuvos Didžioji Kunigaikštytė, the Labanoras church buildings complex and the Vilnius Dominican Monastery buildings complex, in terms of international rebuilding regulations. The study is aimed towards the evolution of primary attitudes of architectural heritage preservation, from early stylistic restoration to currently valid international heritage documents. There are conclusions drawn for French and German rebuilding works’ compliance to statements of international heritage documents, applicable for certain periods. Main body of the paper is dedicated to aforementioned Lithuanian architectural heritage objects and recent rebuilding works done in context of international heritage documents, such as The Nara Document on Authenticity, The Athens Charter, The Venice Charter, and The Riga Charter. Research was driven by available documents, literature, archives and other sources of information in qualitative approach. Rebuilding works were also compared to statements of valid international heritage documents in order to provide conclusions, where examples of best practices and inadequacies are distinguished.

This dissertation is a study of the values and meanings people attach to places and why exploring those values is important in trails and historic preservation planning. From a foundation in critical humanistic geography and values based preservation literatures, the dissertation examines three rails to trails projects as case studies. Primary research questions include: how does a landscape become valued, devalued, and/or revalued through time? In what ways do different values of different people or groups intersect in rails to trails landscapes and how do they shape the landscape? How do historic values intersect with economic, social, political, and other values as these relate to landscape preservation? A subset of questions deals with the interactions between trails, historic preservation, and geography. What common ground do these three areas already share and what is the potential for further connections between and through them? The project contributes to the geographical tradition of interpreting ordinary landscapes but also works towards bringing together the common ground of three disparate endeavors: cultural geography, historic preservation, and trails planning around the theme of “values in place.”

The purpose of this study was to determine the knowledge of college students with regard to blood donation in order to be able to create an education program to recruit new donors. After creating a table of specifications, a questionnaire was designed and reviewed by a jury of experts, and then tested in a pilot study. In the final study, 782 usable questionnaires were completed; the majority of students from the convenience sample were female (60.9%), under the age of 21 (93.1%), white (86.2%), non-Hispanic (95.8%), and had earned some college credits (61.4%).The data were analyzed using mean, t-tests, and ANOVA to test five null hypotheses. The overall knowledge (60%) of the subjects was less (M = 13.11 out of a possible 22) than anticipated. Statistically significant differences in knowledge of blood donation was found between college males and females (p < 0 .028), among students by education level (p < 0.047), and among students who were frequent, occasional, and nondonors (p < 0.000). No difference was found in the knowledge of blood donation among students by age. / Department of Physiology and Health Science

This senior thesis is a study of the change over time of American perceptions of how natural public lands are to be utilized. American interactions with nature are analyzed and synthesized into the role of the conqueror, conservationist, and preservationist. These competing ideologies have shaped our nation and public lands. Looking specifically at the Eastern Sierra Nevada of California, the thesis investigates how the federal land management agency of the United States Forest Service has incorporated these competing roles into one management plan. The thesis analyzes a visitor guide to the area from 1925 and 2014 to see how different ideals were incorporated into the management and promotion of the area to tourists. Additionally, the thesis investigates how the environmental preservation ideology has limited access to public land and how the resort model of tourism has grown while primitive recreation opportunities have been diminished.

Initial challenge studies with spores of proteolytic Clostridium botulinum types A and B (~104 spores/g) showed that while air- and gas-packaged English-style crumpets (aw 0.990) and pizza crust (aw 0.960) were toxic after 42-days storage at ambient temperature (25°C), no neurotoxin was detected in bagels (a w 0.944). Further challenge studies with similarly packaged crumpets inoculated with C. botulinum (~102 spores/g), pre- or post-baking, demonstrated that all crumpets were toxic within 4 to 6 days at 25°C and that toxigenesis preceded spoilage. Furthermore, reformulating crumpets to pH 8.3 and packaging in 100% CO2 had little effect in delaying the growth of C. botulinum compared to crumpets formulated to pH 6.5 and packaged in 60% CO2. / Subsequent studies were directed at determining the levels of additional barriers that could be used to ensure the safety of high-moisture MAP crumpets. While ethanol vapour proved to be an effective additional barrier in crumpets (100-g, [aw 0.990, pH 6.5]) challenged with ~102 spores/g of C. botulinum, spoilage preceded toxigenesis due to absorption of ethanol from the package headspace by crumpets. Modelling studies in Trypticase Peptone Glucose Yeast (TPGY) broth confirmed the anti-botulinal nature of ethanol and showed that a level of ~4% (vol/vol) could be used for complete inhibition of this pathogen, depending on the aw and pH of the growth medium. However, while ethanol vapour could be used to inhibit the growth of C. botulinum in high-moisture crumpets, its anti-botulinal efficacy was influenced by the method of crumpet leavening (yeast v chemical). / Preliminary studies were also done to assess the potential of mastic oil, a novel inhibitor, against C. botulinum. While direct and indirect application of ethanolic extracts of mastic oil inhibited the growth of C. botulinum in vivo, they failed to do so in crumpets.

The fish processing industry is actively seeking for alternative methods of shelf life preservation and marketability of fresh fish, while at the same time economizing on energy costs. Two methods which fulfill both objectives are modified atmosphere packaging (MAP) and glucose oxidase (GOX)/Glucose dipping solutions. MAP is the packaging of perishable products in an atmosphere other than that of air and is used for the shelf life extension of beef, pork, fruits, vegetables and bakery products. GOX, either alone or in conjunction with MAP has the potential for shelf life extension of fresh fish. / The objectives of this study were to determine the combined effect of glucose oxidase/glucose or gluconic acid dipping solutions and modified atmosphere packaging in conjunction with refrigeration on the shelf life extension of mackerel and cod. / This study has shown that the shelf life of fresh fish can be extended through the combined use of MAP/dipping solutions and refrigeration. This novel process of "dipping" in GOX solution in conjunction with modified atmosphere packaging (MAP) will have a significant effect in the area of fish hygiene and will minimize fish losses incurred through spoilage.