Rust has gained traction in the technical community as a safe system programming language. A unique feature of Rust is the memory ownership model, which enforces memory safety at compile-time. This project investigated how the memory model is used in practice. This report defines patterns that categorize the usage of variables with owned values in Rust. An automated analysis was used to scan over 3 million function bodies with over 7 million owned variables from 8 951 open-source projects. The analysis indicates that only 18% of all owned variables are borrowed at one point. In fact, only 61% of all analyzed function bodies contained at least one borrow. The data indicates that owned values are either mutable or immutably borrowed, only 0.6% of the analyzed variables had both borrow kinds in the same scope. Another interesting observation is that most values are moved instead of dropped at the end of their scope.

Doctor of Philosophy / Department of Agronomy / Allan K. Fritz / In this research, a recombinant inbred line (RIL) population derived from cross between a leaf rust- and stripe rust-susceptible spring wheat ‘Avocet S’ and a slow leaf- and stripe-rusting resistant spring wheat ‘Amadina’ was used to postulate and map leaf rust seedling resistance genes, identify quantitative trait loci (QTL) for slow-rusting resistance against leaf and stripe rust, and study slow leaf-rusting components, latent period and infection frequency. Two known Lr genes (Lr23, and Lr26) were identified to be present in ‘Amadina’ through gene postulation, pedigree, cytogenetic, and polymerase chain reaction analyses. One unknown gene associated with seedling resistance was also mapped on chromosome 1BL. In greenhouse experiment, it was estimated that at least five genes conditioning final disease severity (FS) and latent period (LP), and four genes conditioning infection frequency (IF), segregated in the population. Correlations between LP and FS, and LP and IF were moderately negative, and that between IF and FS was moderately positive, indicating inter-dependence of the traits. Two QTL on chromosomes 1BL and 6BL were associated with LP and FS, and three QTL on chromosomes 1BL, 6BL and 2DS were associated with IF. Segregation of the RIL population in field experiment indicated that there were at least four and three adult plant resistance (APR) genes involved in resistance for leaf and stripe rust. Six QTL on chromosomes 3AL, 4AL, 1BL, 5BL, and 7BL were associated with APR for leaf rust, and seven QTL on chromosome 4AL, 5AL, 1BL, 2BL, 4BL, 5BL, 2DL, and 4D were associated with APR for stripe rust. Our results indicated that the major portion of genetic variability for slow-rusting resistance was additive gene action, and, to some extent, epistasis. In this research, we also explored the utility of remote sensing and geographic information systems (GIS) and analytical operations to discriminate leaf rust pustules from other parts of leaf and to accurately determine pustule size in ‘Amadina’ and ‘Avocet S’.

A ferrugem alaranjada da cana-de-açúcar, causada pelo fungo Puccinia kuehnii, é atualmente a doença que mais preocupa o setor sucroenergético brasileiro, devido a sua introdução recente no país e aos prejuízos causados em indústrias canavieiras ao redor do mundo. A doença é controlada com variedades resistentes e por isso há a necessidade de maiores informações sobre a reação das cultivares mais importantes no Brasil. Os objetivos deste trabalho foram: (i) avaliar a reação de variedades de cana-de-açúcar à ferrugem alaranjada, em condições de infecção natural no campo; (ii) determinar a melhor época para avaliação da doença; (iii) estabelecer um método, em casa de vegetação e com inoculação artificial do patógeno, para seleção rápida de variedades com resistência no campo. Dezessete variedades foram avaliadas quanto às suas reações a P. kuehnii em dois experimentos de campo, plantados em abril e julho de 2011; neste último, após a colheita em maio de 2012, a cana-soca também foi avaliada. Para multiplicar e uniformizar a distribuição do inóculo, a variedade suscetível SP89-1115 foi usada como bordadura e plantada entre os blocos e em duas linhas, dividindo cada experimento ao meio. Avaliou-se a severidade da doença a cada 15 dias e, a partir destes dados, calculou-se a área abaixo da curva de progresso da doença (AACPD) e obteve-se a severidade máxima da doença. Para identificar o melhor período de avaliação, realizou-se análise de correlação entre a AACPD e cada levantamento de severidade. Em casa de vegetação, seis variedades com reações distintas à doença, com base nos resultados obtidos no campo, foram inoculadas com uma suspensão de 104 urediniósporos viáveis mL-1 de P. kuehnii, com auxílio de pulverizador manual, 60 dias após o plantio. As plantas foram mantidas por 24 horas em câmara de orvalho e, posteriormente, transferidas para casa de vegetação. Foram determinados os períodos de incubação e latência, o número de pústulas por cm2 e a severidade da doença. Oito das 17 variedades avaliadas no campo mostraram alta resistência à doença. As cultivares RB72454 e SP89-1115 foram as mais suscetíveis, seguidas da SP79-2233; por isso, o cultivo das mesmas não é recomendado. As variedades RB925211, SP81-3250, RB855156 e RB92579 tiveram reação intermediária, sendo que as duas primeiras apresentaram maiores níveis da doença. Avaliações realizadas no mês de março foram as que mais se correlacionaram com a AACPD, portanto este é o melhor período para determinar a reação de variedades de cana-de-açúcar à ferrugem alaranjada. O comportamento das variedades em casa de vegetação foi semelhante ao observado no campo, especialmente em relação às cultivares suscetíveis e resistentes. Assim, o método aplicado em casa de vegetação mostrou potencial para selecionar, em poucos dias, cultivares com resistência à doença no campo, além de economizar espaço, mão de obra e de ser facilmente executado. / Currently, sugarcane orange rust, caused by Puccinia kuehnii, is the disease that most concerns the Brazilian sugarcane industry, due to its recent introduction in the country and the damage caused to sugarcane industries all over the world. The disease is controlled with resistant varieties; hence there is a need for more information about the reaction of the major cultivars in Brazil. The objectives of this work were: (i) to evaluate the reaction of sugarcane varieties to orange rust in field, under natural infection conditions; (ii) to determine the best time for disease assessment; (iii) to establish a method in greenhouse, based on artificial inoculation, for rapid selection of field resistant varieties. Seventeen varieties were studied in two field experiments, planted in April and July 2011; in the latter, after the harvest in May 2012, the ratoon was also evaluated. The susceptible variety SP89-1115 was used as border and planted between the blocks in two lines, dividing each experiment in two halves in order to multiply and standardize the inoculum in the area. Disease severity was evaluated every 15 days and the area under disease progress curve (AUDPC) was calculated and the maximum disease severity was obtained. To identify the best time for disease assessment, a correlation analysis between the AUDPC and each disease severity assessment was done. In greenhouse, six varieties with different reactions to the disease based on results obtained in field were inoculated with a suspension of 104 viable urediniospores mL-1 of P. kuehnii with a manual sprayer 60 days after planting. Plants were maintained in dew chamber for 24 hours and afterwards they were transferred to the greenhouse. The incubation and latent period were determined as well as the number of pustules cm-2 and disease severity. Eight out of 17 varieties evaluated in field showed high disease resistance. The varieties RB72454 and SP89-1115 were the most susceptible, followed by SP79-2233; therefore, their commercial cultivation is not recommended. The varieties RB925211, SP81-3250, RB855156 and RB92579 had intermediate reaction, with the first two showing higher disease levels. Evaluations performed in March showed the highest correlation with AUDPC, thus this period is the best for determining sugarcane reaction to orange rust. The varieties reaction in greenhouse was similar to that observed in the field, particularly in relation to susceptible and resistant cultivars. So, the method applied in greenhouse showed potential to select, in a few days, field disease-resistant varieties, besides saving space and labor and being easily implemented.

Wheat diseases such as rusts and powdery mildews are among the most important and ancient diseases that affect wheat cultivation worldwide. The pathogen race specific resistance genes cannot maintain long lasting resistance. On the other hand, the presence of genes confers the non-race specific resistance last much longer. The durable resistance phenotypes in wheat against various rust and powdery mildew diseases were reported as Lr34, Yr18, and Pm38 separately / nevertheless, they were known to locate very close to each other based on linkage analysis. Recently, it was shown that all of these resistance phenotypes are indeed conferred by the same gene, encoding Adenosine triphosphate&ndash / binding cassette transporter (ABC-transporter) type protein. The way with which this transporter is functioning to maintain the durable resistance against different types of pathogens is still unknown. v The presence of LR34 (or ABC-transporter) gene resistant allele can be detected by specially designed markers. In spite of the few DNA sequence differences between the resistant and the susceptible alleles, the easily applicable PCR based markers allow the detection of the presence of this durable resistant allele on any given variety or cultivar. In our study, 62 different Turkish bread wheat varieties were screened by the gene specific molecular markers, developed from those LR34 gene mutation sites. The 11 cultivars determined to contain the resistant allele. This study is the first screening of Turkish cultivars for the presence of LR34 gene.

Field studies of a population of Arisaema triphyllum affected by the systemic rust Uromyces ari-triphylli were conducted to examine dynamics of disease transmission and to identify factors influencing plant susceptibility to rust infection. Of undiseased plants that developed foliar infections during the growing season, 55% possessed active resistance to the rust disease, and were able to prevent the foliar infection from becoming a systemic one. Flowering increased the susceptibility of plants to both Mar and systemic infections. A phenotypic selection study was carried out to estimate selection on five plant traits and to determine the role of foliar infections of U. ari-triphylli in mediating selection. Multivariate path analysis suggests that both leaf diameter and a general size factor are under positive directional selection. Pathogen-mediated selection coefficients are small, but comparable in magnitude to overall selection coefficients (15%, on average), indicating the potential importance of diseases as selective agents in nature.

Thèse (M.Sc)--Université Laval, 1998. / Bibliogr. Publié aussi en version électronique.

The aim of this work is the accurate diagnosis of the Puccinia species of the selected turf grass species under field and laboratory conditions and evaluate influences on the intensity of occurrence. The laboratory tests will be recommended for the best stage of plants to artificial infection. The experiment was carried out in collaboration with SŠ Větrov. In the two-year follow-up (in 2011 and 2012) were at particular times of samples of infected plants, which were then evaluated microscopically. And at the same time experimental work was carried out in laboratory conditions (artificial infection) in plant material of the same origin and assessed degree assault with a precise diagnosis of the type of pathogen. Between 2011 and 2012, was higher occurence stem rust than crown rust.. From a total of 514 tests was stem rust in 379 cases, while crown rust in only 40 cases. In 95 samples was observed incidence of both simultaneously rust and mildew spores remaining plants were discovered. Greenhouse resistance tests were performed on younger plants (3 sheets) and older (6 sheets) in 16 variants, of which 4 were control. Infected leaves were spray uredispor with talc and injected with an aqueous suspension followed by looking drops and were then sealed under insulators at 23 ° C for 24 - 48 hours.

A ferrugem alaranjada da cana-de-açúcar, causada pelo fungo Puccinia kuehnii, é atualmente a doença que mais preocupa o setor sucroenergético brasileiro, devido a sua introdução recente no país e aos prejuízos causados em indústrias canavieiras ao redor do mundo. A doença é controlada com variedades resistentes e por isso há a necessidade de maiores informações sobre a reação das cultivares mais importantes no Brasil. Os objetivos deste trabalho foram: (i) avaliar a reação de variedades de cana-de-açúcar à ferrugem alaranjada, em condições de infecção natural no campo; (ii) determinar a melhor época para avaliação da doença; (iii) estabelecer um método, em casa de vegetação e com inoculação artificial do patógeno, para seleção rápida de variedades com resistência no campo. Dezessete variedades foram avaliadas quanto às suas reações a P. kuehnii em dois experimentos de campo, plantados em abril e julho de 2011; neste último, após a colheita em maio de 2012, a cana-soca também foi avaliada. Para multiplicar e uniformizar a distribuição do inóculo, a variedade suscetível SP89-1115 foi usada como bordadura e plantada entre os blocos e em duas linhas, dividindo cada experimento ao meio. Avaliou-se a severidade da doença a cada 15 dias e, a partir destes dados, calculou-se a área abaixo da curva de progresso da doença (AACPD) e obteve-se a severidade máxima da doença. Para identificar o melhor período de avaliação, realizou-se análise de correlação entre a AACPD e cada levantamento de severidade. Em casa de vegetação, seis variedades com reações distintas à doença, com base nos resultados obtidos no campo, foram inoculadas com uma suspensão de 104 urediniósporos viáveis mL-1 de P. kuehnii, com auxílio de pulverizador manual, 60 dias após o plantio. As plantas foram mantidas por 24 horas em câmara de orvalho e, posteriormente, transferidas para casa de vegetação. Foram determinados os períodos de incubação e latência, o número de pústulas por cm2 e a severidade da doença. Oito das 17 variedades avaliadas no campo mostraram alta resistência à doença. As cultivares RB72454 e SP89-1115 foram as mais suscetíveis, seguidas da SP79-2233; por isso, o cultivo das mesmas não é recomendado. As variedades RB925211, SP81-3250, RB855156 e RB92579 tiveram reação intermediária, sendo que as duas primeiras apresentaram maiores níveis da doença. Avaliações realizadas no mês de março foram as que mais se correlacionaram com a AACPD, portanto este é o melhor período para determinar a reação de variedades de cana-de-açúcar à ferrugem alaranjada. O comportamento das variedades em casa de vegetação foi semelhante ao observado no campo, especialmente em relação às cultivares suscetíveis e resistentes. Assim, o método aplicado em casa de vegetação mostrou potencial para selecionar, em poucos dias, cultivares com resistência à doença no campo, além de economizar espaço, mão de obra e de ser facilmente executado. / Currently, sugarcane orange rust, caused by Puccinia kuehnii, is the disease that most concerns the Brazilian sugarcane industry, due to its recent introduction in the country and the damage caused to sugarcane industries all over the world. The disease is controlled with resistant varieties; hence there is a need for more information about the reaction of the major cultivars in Brazil. The objectives of this work were: (i) to evaluate the reaction of sugarcane varieties to orange rust in field, under natural infection conditions; (ii) to determine the best time for disease assessment; (iii) to establish a method in greenhouse, based on artificial inoculation, for rapid selection of field resistant varieties. Seventeen varieties were studied in two field experiments, planted in April and July 2011; in the latter, after the harvest in May 2012, the ratoon was also evaluated. The susceptible variety SP89-1115 was used as border and planted between the blocks in two lines, dividing each experiment in two halves in order to multiply and standardize the inoculum in the area. Disease severity was evaluated every 15 days and the area under disease progress curve (AUDPC) was calculated and the maximum disease severity was obtained. To identify the best time for disease assessment, a correlation analysis between the AUDPC and each disease severity assessment was done. In greenhouse, six varieties with different reactions to the disease based on results obtained in field were inoculated with a suspension of 104 viable urediniospores mL-1 of P. kuehnii with a manual sprayer 60 days after planting. Plants were maintained in dew chamber for 24 hours and afterwards they were transferred to the greenhouse. The incubation and latent period were determined as well as the number of pustules cm-2 and disease severity. Eight out of 17 varieties evaluated in field showed high disease resistance. The varieties RB72454 and SP89-1115 were the most susceptible, followed by SP79-2233; therefore, their commercial cultivation is not recommended. The varieties RB925211, SP81-3250, RB855156 and RB92579 had intermediate reaction, with the first two showing higher disease levels. Evaluations performed in March showed the highest correlation with AUDPC, thus this period is the best for determining sugarcane reaction to orange rust. The varieties reaction in greenhouse was similar to that observed in the field, particularly in relation to susceptible and resistant cultivars. So, the method applied in greenhouse showed potential to select, in a few days, field disease-resistant varieties, besides saving space and labor and being easily implemented.

Most of the software stack is built upon C today. C is a very flexible language, but the flexibility also brings some safety risks, particularly when handling memory through pointers. Rust is a new programming language which can guarantee memory safety without performance-heavy runtime services such as garbage collection. In this article, two partial file systems are implemented based on the design of EXT2. One system is implemented in C — Nafs — and one system is implemented in Rust — Rufs. A number of benchmarks are also developed, with the purpose of testing the most common features of a file system. After running the benchmarks, the results showed that Nafs provided better performance for all but one feature. There could be many reasons for this, and some hypotheses are discussed. Aspects like different compiler optimizations, the use of pointer dereferencing vs. data structure representation, using dynamic memory, and using system calls are considered. Some optimizations to Rufs are also implemented, and their impact analyzed. Earlier research has shown that Rust can guarantee memory safety while still providing good performance. It has also shown that Rust can be used to implement system programs, such as operating system kernels. Over the course of this article, it is shown that safe Rust can be used to implement a file system — thereby guaranteeing a memory safe program. It is also shown that a file system implemented in safe Rust provides worse performance than a similar system written in C. Future work will have to tell whether a file system can be as performant in Rust as in C, by using different implementation methods or unsafe Rust for some of the most performance critical parts of the system.

No description available.