The number of lesions increased with increasing temperatures over the range of wet periods except at 30$ sp circ$C, where their number decreased with increasing wetness duration. Cultivars were evaluated for partial resistance under field and greenhouse conditions. In the field ranking was based on cluster analysis of the standard area under the disease progress curve (SAUDPC) for intervals between sampling dates. In the greenhouse, the cultivars were evaluated on the basis of their response relative to five components of partial resistance: the SAUDPC, mean lesion area (MLA), pycnidial density (PCD), spore density (SPD), and the latency period defined as the time from inoculation to 50% and 75% disease (T$ sb{50}$ and T$ sb{75}$). In the greenhouse, overall ranking was based on cluster and principal component analysis of responses to SAUDPC, MLA, PCD and SPD. T$ sb{50}$ and T$ sb{75}$ were not significant. Three cultivars, Golden Plume, Superdora and Summit, were rated as moderately resistant in both field and greenhouse trials. The others ranged from moderately susceptible to very susceptible. (Abstract shortened by UMI.)

Venturia inaequalis, the causal agent of apple scab, overwinters in apple leaves on the orchard floor. To develop a control strategy based on the prevention of the maturation of overwintering pseudothecia, a sampling of fungi colonizing dead apple leaves was conducted from different orchard floors in Quebec during the spring and fall of 1993. A total of 345 different isolates were obtained, from which fifteen genera have never been previously recorded as colonizers of apple leaves in North America. Small differences were detected in genera richness among orchards but the fungal composition of each orchard was fairly unique. Different tests on growth on amended media and leaf decomposition demonstrated that leaf degradation is not a reliable parameter alone to screen antagonist against V. inaequalis. No significant relation between growth on amended media, leaf rheology and ascospore inhibition was detected. However, 40 fungi reduced significantly ascospore production more than 87% compared to the control (V. inaequalis only). Of these antagonists, 30% decomposed apple leaves, suggesting that competition for the substrate is involved in the mode of action of at least one third of the antagonits detected. Other possible modes of antagonism are discussed.

No description available.

The purpose of the study is to determine whether absenteeism is a real concern amongst the educators in South African schools. Although there are sufficient and appropriate policies in place, the rate of absenteeism is on the increase on a daily basis. Through the literature and investigations, the study tries to unravel the causes of absenteeism and the solutions thereof. The study revealed that 66% of the educators abused the current leave policy. Great majority (64%) of the educators were in favour of the introduction of some form of incentives and seventy eight percent of the educators wanted the re-introduction of the accumulation of leave policy. Eighty four percent of the respondents also agreed that teacher absenteeism contributes to poor learner performance. Workload of educators was not a major contributing factor in the high rate of teacher absenteeism. Some of the reasons attributed to absenteeism are depression, redeployment, ill health, lack of motivation and self esteem, low salary, demoralizing learners and poor working conditions. All levels of educators suggested solutions to this ever-increasing problem, which is becoming difficult to manage. Recognition of least absenteeism, effective implementation of the policy, strong management team, motivating the staff, offering fringe benefits, organizing workshops to manage absenteeism and to equip educators and building team work are some of the noticeable and common solutions suggested by all levels of educators. The study recommends the re-introduction of accumulation of leave policy and linking the school database of educators with departmental database so that on a daily basis the leave statistics can be l:Jpdated and appropriate actions effected with out delay. / (MBA) North-West University, Mafikeng Campus, 2006

ABSTRACT: Formation of organ shape is an intriguing yet largely unanswered question in developmental biology. Shapes arise as a result of tightly controlled spatial variation in the rates and directions of tissue expansion over the course of development; therefore, quantifying these growth patterns could provide information about the underlying mechanisms of morphogenesis. Here we present a novel technique and computational tools for quantifying growth and shape changes in developing leaves, with a few unique capabilities. This includes the ability to compute growth from three-dimensional (3D) coordinates, which makes this the first method suitable for studying leaf growth in species or mutants with non-flat leaves, as well as small leaves at early stages of development, and allows us to simultaneously capture 3D shape changes. In the following, we apply these methods to study growth and shape changes in the first rosette leaf of Arabidopsis thaliana. Results reveal clear spatiotemporal patterns in growth rates and directionality, and tissue deformation maps illustrate an intricate balance involved in maintaining a relatively flat leaf surface in wild type leaves. Semi-automated tools presented make a high throughput of data possible with this method, and algorithms for generating mean maps of growth will make it possible to perform standardized comparative analyses of growth patterns between wild type and mutants and/or between species. The methods presented in this thesis will therefore be useful for studying leaf growth and shape, to further investigate the mechanisms of morphogenesis.   RÉSUMÉ: Comment un organe acquiert sa forme particulière au cours du développement est une question intéressante mais largement non résolue. La forme d’un organe résulte de la façon dont les taux et directions de croissance de ses tissues varient dans l’espace et dans le temps. Quantifier les motifs de croissance est donc nécessaire pout élucider les mécanismes sous-jacents de la morphogenèse. Nous présentons ici une nouvelle méthodologie pour quantifier la croissance et les changements de forme dans les feuilles en développement. Cette méthodologie s’appuie sur le développement de nouvelles techniques expérimentales et de programmes informatiques, et présente des avantages uniques : la croissance de la surface des feuilles et le changement de forme peuvent être analysés en trois dimensions (3D), pour une longue période et de large déformations. De plus l’analyse de multiples échantillons permet de générer une cartographie moyenne des motifs de croissance à la surface des feuilles au cours de leur développement, ainsi qu’une description quantitative de la déformation des tissus sous l’effet de leur croissance. Dans cette thèse, nous présentons les résultats de croissance et de changements de forme de la première feuille de rosette d'Arabidopsis thaliana au cours de son développement. Les cartes moyennes de croissance révèlent des motifs spatio-temporels évidents tant pour les taux que pour les directions de croissance. De plus, la description de la déformation des tissus démontre l'équilibre complexe impliqué dans le maintien d'une surface relativement plane dans les feuilles. La méthode proposée et les logiciels associés permettra d’effectuer des analyses comparative de la croissance entre feuilles de type sauvage et feuilles de mutants aux formes altérées, afin d’élucider les mécanismes de la morphogenèse foliaire.

Fenoliniai junginiai yra vieni iš daugelio obelų lapuose sutinkamų junginių. Dažniausiai sutinkami fenoliniai junginiai yra flavonoidai (floridzinas, epikatechinas, katechinas ir kiti) ir fenolinės rūgštys (kavos rūgštis, chlorogeno rūgštis). Fenoliniai junginiai apsaugoaugalus nuo oksidacinės pažaidos ir kitų nepalankių aplinkos sąlygų. Medicinoje vienas iš svarbiausių flavonoidų pritaikymo būdas, paremtas jų antioksidantiniu poveikiu. Jie vartojami mažinant oksidacinį stresą. Kiti naudingi poveikiai: antiuždegiminis, antivėžinis, antimikrobinis bei teigiamas poveikis širdies ir kraujagyslių sistemai. Tyrimo tikslas: Lietuvoje auginamų skirtingų veislių obelų lapuose nustatyti bendrą fenolinių junginių ir flavonoidų kiekius bei jų antioksidantinį aktyvumą spektrofotometriniu ir ESC metodais. Metodai:liofilizuoti obelų lapai ekstrahuoti ultragarso vonelėje. Ekstrahentas- 70proc. etanolis, ekstrakcijos laikas – 40min, ekstrakcijos temperatūra – 60˚C. Nustatant bendrą fenolinių junginių kiekį tiriamuosiuose ekstraktuose taikytas spektrofotometrinis Folin-Ciocalteu metodas, o rezultatai išreikšti galo rūgšties ekvivalentu (mg/g). Nustatant bendrą flavonoidų kiekį ekstraktuose buvo taikyta reakcija su AlCl3, rezultatai išreikšti rutino ekvivalentu (mg/g).Spektrofotometriniai metodai (DPPH ir FRAP) naudoti nustatant ekstraktų antioksidantinį aktyvumą, kuris išreikštas trolokso ekvivalentu (TEAC μmol/g). ESC metodas taikytas identifikuoti fenolinius junginius ir nustatyti jų... [toliau žr. visą tekstą] / Phenolic compounds are commonly found in apple leaves as secondary plant metabolites. Most common phenolic compounds are flavonoids (phloridzin, epicatechin, catechin and others) and phenolic acids (caffeic acid, chlorogenic acid). For plants phenolics act as antioxidants, protective agents against harsh conditions. For human use phenolics are used as natural antioxidants due to their ability to scavenge free radicals, inhibit their formation processes and induce response to oxidative stress. Other beneficial effects are antimicrobial, anti-cancerogenic, anti-inflammatory and cardiovascular protective effect. The aim of this research was to evaluate total content of phenolic compounds, total content of flavonoid compounds and antioxidant activity of different apple cultivars (Ligol, Aldas, Lodel, Auksis) using spectrophotometry and HPLC. Methods: Apple leaf samples were lyophilised and extracted using ultrasonic sound assisted extraction. 70% ethanol was used as extractant, extraction time was 40 min and temperature – 60˚C. To determine total content of phenolic compounds expressed as gallic acid equivalent (mg/g) for absolutely dried lyophilisate in apple leaf extracts spectrophotometric Folin-Ciocalteu method was used. To identify total content of flavonoids expressed as rutin equivalent (mg/g) for absolutely dried lyophilisate more specific reaction with AlCl3 was used. Two spectrophotometric methods FRAP and DPPH were used to determine total antioxidant activity expressed... [to full text]

The last works of Jane Austen and Barbara Pym, written while each was knowingly dying, both continue and transform a discourse of illness and cure traceable through their canon. Illness figures both literally and metaphorically in their narratives; in Austen as failures in wholeness and in Pym as failures in love. After undergoing the metaphorically medical treatments of purging and vivifying in Austen and inoculating in Pym, their female protagonists achieve conditions of health and wholeness by closure of the narrative. In the dying works, individual metaphorical illnesses become a general societal condition of fragmentation, and cure becomes more elusive. The shared use of a village undergoing profound change reflects each writer's own bodily transformation as certain death approaches, and the restoration of health to the village-as-body becomes one of achieving balance or homeostasis. This is effected in the narrative by the hinted-at curative powers of nature in Sanditon and of restored faith in A Few Green Leaves. On a theoretical level, both texts reflect their narratives of dis-ease and cure. Pym's last text remained unpublished before her death and therefore "ill" because not functioning, but second opinions and faith in her reputation confirmed its public health. Austen's Sanditon as a fragment embodies its own discourse of dis-ease, or failure of wholeness, and requires a curative act on the part of the reader to restore it to some sense of ideal wholeness or health.

No description available.

Typescript / Copies of two papers co-authored by the author, in back cover pocket / Bibliography: leaves 128-143 / 143 leaves, [60] leaves : ill., maps ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Botany, 1987

[Truncated abstract] Currently, one of the active areas of research in computer graphics is related to creating realistic images and animations that mimic the world we see around us. There has been significant work in modeling and simulating natural phenomena such as fire, clouds, water, and vegetation. Some of these works are employed in the entertainment industry, especially as special effects in cinematic films. Of particular interest is the area of vegetation, given the possible structural complexity and variation in different types of plants. This provides a challenge to develop methods and techniques that effectively and realistically model the movement and behavior of plants. In response to this challenge, there has been significant work in the area of modeling plant structure, as well as modeling of the dynamics and wind interaction of tree branches. However, there is a distinct lack of approaches involved with modeling the dynamics and behavior of individual leaves. Most of the previous approaches focus on the modeling of the branches of a tree, and rarely consider the movement of the leaves in detail. This makes it particularly hard to model the interactions of plants with relatively large leaves, where the dynamics of the leaves are important. In other words, there is no method that could effectively simulate the lower canopy of a forest or jungle, where there are many ferns, saplings, and other broad-leafed plants. Therefore, I present in this thesis a leaf animation system that is designed specifically for simulating and animating plants with relatively large leaves with realistic dynamics in real-time. .... These interactions illustrate the flexibility and robustness of the leaf movement model. In particular, I present a novel approach in modeling volumetric wind through the wind cube that approximates wind behavior such as obstruction by leaves, and constructive and destructive interference. This unique approach is based on modeling wind as a spatial collection of wind vectors and the interaction of the vectors is governed by the rules of each cube-shaped cell of the wind cube. In the end, this wind cube allows for convincing behavior of wind and the subsequent interaction with the leaves of a plant. The leaf animation system is also suitable for simulating a number of plants in a landscape. This is possible through another novel method of reducing the rendering time to allow for more plants to be simulated. This method involves using an animated texture in place of plants that are far from the camera, when the difference visually is not blatantly noticeable. This is a form of the commonly used levels of detail to reduce the complexity of the landscape, but my method is novel in that it has not been implemented in a way where the texture itself is animated in place of the plant. I investigate the strengths and limitations of this approach in reducing rendering time for a landscape of plants. Thus, the leaf animation system is suitable for realistic and interactive virtual reality environments. These virtual environments feature heavily in current video games that involve realistic and believable worlds. In addition to the film and video game industry, these virtual environments are also integral in the application of virtual reality as psychological therapies.