9 research outputs found
Advanced diagnostic technologies for Ascochyta blight detection in chickpea
No full textBackground: Early diagnosis of plant pathogens is of global interest due to the economic aspects of over-usage of fungicides, as well as their effect on overall grain quality. Consequently, there is a need to develop technology that can provide accurate and timely identification and quantification of plant pathogens. Currently, there are several biosensor applications that involve use of nanotechnology, imaging, mobile phone and even drones for detection of airborne pathogens. This PhD research demonstrates implementation of several proof-of-concept assays, which with further developments towards in-field application, may be useful use in farms, glasshouses and in agricultural nurseries.[...]Thesis (PhD Doctorate)Doctor of Philosophy (PhD)School of Environment and ScScience, Environment, Engineering and TechnologyFull Tex
Biosensor Technologies for Early Detection and Quantification of Plant Pathogens
No full textPlant pathogens are a major reason of reduced crop productivity and may lead to a shortage of food for both human and animal consumption. Although chemical control remains the main method to reduce foliar fungal disease incidence, frequent use can lead to loss of susceptibility in the fungal population. Furthermore, over-spraying can cause environmental contamination and poses a heavy financial burden on growers. To prevent or control disease epidemics, it is important for growers to be able to detect causal pathogen accurately, sensitively, and rapidly, so that the best practice disease management strategies can be chosen and enacted. To reach this goal, many culture-dependent, biochemical, and molecular methods have been developed for plant pathogen detection. However, these methods lack accuracy, specificity, reliability, and rapidity, and they are generally not suitable for in-situ analysis. Accordingly, there is strong interest in developing biosensing systems for early and accurate pathogen detection. There is also great scope to translate innovative nanoparticle-based biosensor approaches developed initially for human disease diagnostics for early detection of plant disease-causing pathogens. In this review, we compare conventional methods used in plant disease diagnostics with new sensing technologies in particular with deeper focus on electrochemical and optical biosensors that may be applied for plant pathogen detection and management. In addition, we discuss challenges facing biosensors and new capability the technology provides to informing disease management strategies.Full Tex
Calculation of Structures Lying On an Anisotropic Basis
No full textThe definition of the nucleus and the influence function of a transversally isotropic half-space is considered. Expressions of deflection and internal forces in an infinite base plate are obtained, taking into account their deepening into the rock mass, as well as the effect of the anisotropy of the base on the distribution of deflections and internal forces. The results obtained serve as a reference for the reconciliation of the results obtained by numerical and computer methods. This calculation algorithm allows us to estimate the bearing capacity of an anisotropic soil base
Виявлення впливу малоциклової втоми залізобетонних конструкцій на властивості знижуючого коефіцієнта за дії навантаження сейсмічного типу
No full textThe object of consideration is seismic design, and the subject of the study is the determination of the reduction coefficient. One of the important problems of earthquake-resistant design is to determine the effect of low-cycle fatigue of reinforced concrete on the reduction coefficient and determine its optimal value. This problem is not disclosed and is not specifically taken into account in the standards for earthquake engineering when determining the maximum bearing capacity of types of structures due to the lack of study of the issue. To solve the problem, a series of experimental studies were carried out on low-cycle fatigue of reinforced concrete bending elements and frame units. The range of results of the reduction coefficient values and the degree of influence of monocyclic fatigue on the properties of the reduction coefficient are obtained.
A feature and characteristic of the results obtained is that the reduction coefficient Rμ depends on the nature of the hysteresis deformation pattern and the plastic life of structural elements estimated by the plasticity coefficient μ, which is significantly influenced by low-cycle fatigue manifested at peak accelerations of strong seismic impacts. The above test algorithm, the feature and characteristics of the results obtained made it possible to solve the problem under study.
The results obtained are accepted for practical use in the action of seismic loads: on the calculation of strength taking into account new low-cycle coefficients, reduction coefficients for determining the spectra of design reactions and seismic loads, taking into account energy absorption. New reduction coefficients are proposed for determining the spectra of calculated reactions and seismic loadsОб’єктом розгляду є сейсмічний проект, а предметом дослідження – визначення коефіцієнта зниження. Однією з важливих проблем сейсмостійкого проектування є визначення впливу малоциклової втоми залізобетону на коефіцієнт зниження та визначення його оптимального значення. Ця проблема не розкривається і спеціально не враховується в нормах сейсмотехніки при визначенні максимальної несучої здатності типів конструкцій через недостатню вивченість питання. Для вирішення поставленої задачі було проведено серію експериментальних досліджень малоциклової втоми залізобетонних згинальних елементів і каркасних вузлів. Отримано діапазон результатів значень коефіцієнта зниження та ступінь впливу моноциклічної втоми на властивості коефіцієнта зниження.
Особливістю та характеристикою отриманих результатів є те, що коефіцієнт зменшення Rμ залежить від характеру гістерезисної картини деформації та пластичної довговічності елементів конструкції, оціненої за коефіцієнтом пластичності μ, на який суттєво впливає малоциклова втома, що проявляється на піку. прискорення сильних сейсмічних впливів. Наведений вище алгоритм тестування, особливість і характеристики отриманих результатів дозволили вирішити досліджувану задачу.
Отримані результати прийняті для практичного використання при дії сейсмічних навантажень: з розрахунку міцності з урахуванням нових малоциклових коефіцієнтів, коефіцієнтів приведення для визначення спектрів розрахункових реакцій і сейсмічних навантажень з урахуванням поглинання енергії. Запропоновано нові коефіцієнти приведення для визначення спектрів розрахункових реакцій і сейсмічних навантажен
Виявлення впливу малоциклової втоми залізобетонних конструкцій на властивості знижуючого коефіцієнта за дії навантаження сейсмічного типу
No full textThe object of consideration is seismic design, and the subject of the study is the determination of the reduction coefficient. One of the important problems of earthquake-resistant design is to determine the effect of low-cycle fatigue of reinforced concrete on the reduction coefficient and determine its optimal value. This problem is not disclosed and is not specifically taken into account in the standards for earthquake engineering when determining the maximum bearing capacity of types of structures due to the lack of study of the issue. To solve the problem, a series of experimental studies were carried out on low-cycle fatigue of reinforced concrete bending elements and frame units. The range of results of the reduction coefficient values and the degree of influence of monocyclic fatigue on the properties of the reduction coefficient are obtained.
A feature and characteristic of the results obtained is that the reduction coefficient Rμ depends on the nature of the hysteresis deformation pattern and the plastic life of structural elements estimated by the plasticity coefficient μ, which is significantly influenced by low-cycle fatigue manifested at peak accelerations of strong seismic impacts. The above test algorithm, the feature and characteristics of the results obtained made it possible to solve the problem under study.
The results obtained are accepted for practical use in the action of seismic loads: on the calculation of strength taking into account new low-cycle coefficients, reduction coefficients for determining the spectra of design reactions and seismic loads, taking into account energy absorption. New reduction coefficients are proposed for determining the spectra of calculated reactions and seismic loadsОб’єктом розгляду є сейсмічний проект, а предметом дослідження – визначення коефіцієнта зниження. Однією з важливих проблем сейсмостійкого проектування є визначення впливу малоциклової втоми залізобетону на коефіцієнт зниження та визначення його оптимального значення. Ця проблема не розкривається і спеціально не враховується в нормах сейсмотехніки при визначенні максимальної несучої здатності типів конструкцій через недостатню вивченість питання. Для вирішення поставленої задачі було проведено серію експериментальних досліджень малоциклової втоми залізобетонних згинальних елементів і каркасних вузлів. Отримано діапазон результатів значень коефіцієнта зниження та ступінь впливу моноциклічної втоми на властивості коефіцієнта зниження.
Особливістю та характеристикою отриманих результатів є те, що коефіцієнт зменшення Rμ залежить від характеру гістерезисної картини деформації та пластичної довговічності елементів конструкції, оціненої за коефіцієнтом пластичності μ, на який суттєво впливає малоциклова втома, що проявляється на піку. прискорення сильних сейсмічних впливів. Наведений вище алгоритм тестування, особливість і характеристики отриманих результатів дозволили вирішити досліджувану задачу.
Отримані результати прийняті для практичного використання при дії сейсмічних навантажень: з розрахунку міцності з урахуванням нових малоциклових коефіцієнтів, коефіцієнтів приведення для визначення спектрів розрахункових реакцій і сейсмічних навантажень з урахуванням поглинання енергії. Запропоновано нові коефіцієнти приведення для визначення спектрів розрахункових реакцій і сейсмічних навантажен
Analysis of heavy metals content in domestic and imported poultry meat
No full textBackground and Aim. Heavy metal contamination of the environment and food has attracted intense public attention as it poses a serious threat to the ecological system and human health. Heavy metals are chemical elements that have a toxic effect on the human body. The expansion of various industries has led to a significant increase in levels of these components within envi ronment.Materials and Methods. Current work represents diagnostics and comparison of the content of heavy metals in poultry meat of domestic production and imported origin studied in 2023 using inductively coupled plasma mass spectrometry (ICP-MS).Results. Large concentrations of arsenic and lead were found in the samples, not exceeding the maximum permissible concentrations, while the cоntent of mercury and cadmium was at trace levels. The obtained data allows to assess the level of heavy metal contamination and compare the safety of poultry meat produced in the Republic of Kazakhstan and abroad.
Conclusion. A clear understanding of the ways and mechanisms by which heavy metals pose a risk to human health when consuming contaminated food products makes it possible to adopt appropriate strategies for managing and mitigating their negative effects. In addition, development of hand-held portable devices is needed for timely on-site diagnostics of HMs to ensure quality of meat products is sufficient for human consumption.Background and Aim. Heavy metal contamination of the environment and food has attracted intense public attention as it poses a serious threat to the ecological system and human health. Heavy metals are chemical elements that have a toxic effect on the human body. The expansion of various industries has led to a significant increase in levels of these components within envi ronment.Materials and Methods. Current work represents diagnostics and comparison of the content of heavy metals in poultry meat of domestic production and imported origin studied in 2023 using inductively coupled plasma mass spectrometry (ICP-MS).Results. Large concentrations of arsenic and lead were found in the samples, not exceeding the maximum permissible concentrations, while the cоntent of mercury and cadmium was at trace levels. The obtained data allows to assess the level of heavy metal contamination and compare the safety of poultry meat produced in the Republic of Kazakhstan and abroad.
Conclusion. A clear understanding of the ways and mechanisms by which heavy metals pose a risk to human health when consuming contaminated food products makes it possible to adopt appropriate strategies for managing and mitigating their negative effects. In addition, development of hand-held portable devices is needed for timely on-site diagnostics of HMs to ensure quality of meat products is sufficient for human consumption.Background and Aim. Heavy metal contamination of the environment and food has attracted intense public attention as it poses a serious threat to the ecological system and human health. Heavy metals are chemical elements that have a toxic effect on the human body. The expansion of various industries has led to a significant increase in levels of these components within envi ronment.Materials and Methods. Current work represents diagnostics and comparison of the content of heavy metals in poultry meat of domestic production and imported origin studied in 2023 using inductively coupled plasma mass spectrometry (ICP-MS).Results. Large concentrations of arsenic and lead were found in the samples, not exceeding the maximum permissible concentrations, while the cоntent of mercury and cadmium was at trace levels. The obtained data allows to assess the level of heavy metal contamination and compare the safety of poultry meat produced in the Republic of Kazakhstan and abroad.
Conclusion. A clear understanding of the ways and mechanisms by which heavy metals pose a risk to human health when consuming contaminated food products makes it possible to adopt appropriate strategies for managing and mitigating their negative effects. In addition, development of hand-held portable devices is needed for timely on-site diagnostics of HMs to ensure quality of meat products is sufficient for human consumption
Amplification-free detection of Ascochyta blight in chickpea using a simple molecular beacon assay
No full textAbstract Ascochyta blight is a major biotic stress that limits chickpea production globally. Fungicide application remains one of the effective control measures for the endemic spread. Due to the serious threat that synthetic fungicides pose to crop quality, early diagnosis of the pathogen is imperative. Whilst there have previously been several conventional lab-based diagnostic methods developed for early detection of Ascochyta rabiei, they require long assay times, specialised equipment and facilities, and trained personnel to process the samples. To overcome this challenge, a rapid amplification-free detection assay using a molecular beacon probe was developed. The method consists of a simple assembly assay that accurately detects pathogen within 30 min. The developed assay is species-specific and has a similar sensitivity level as conventional amplification-based methods. Although it is still a lab-based technique, considering the simplicity of the assay, it has a great potential to be developed further as a reliable in-field diagnostic device for early detection and quantification of fungal pathogen spores
Comparative Analysis of Surgical Methods for Distal, Mid-, and Proximal Shaft Hypospadias in Young Males: A Prospective Study on Postoperative Outcomes
No full textBackground and Objectives: The purpose of this study is to report on the results of hypospadias surgery in boys using newly developed methods compared with traditional methods of urethroplasty. Materials and Methods: A total of 136 patients were divided into two groups. Fifty patients with coronal, subcoronal, and distal penile types of hypospadias were allocated to Group I. These patients were treated with a new method of SMU I and urethroplasty according to the Snodgrass procedure and MAGPI. Group II consisted of 86 patients with mid- and proximal shaft penile types of hypospadias who underwent urethroplasty using the new SMU II method and urethroplasty according to the Snodgraft and Bracka procedures. The outcomes were assessed according to the level of postoperative wound healing and the presence of complications. Results: The mean age of the patients was 41 to 60 months. After urethroplasty using the SMU I and SMU II methods, recovery was noted in 92.9% of the patients, and repeated surgery was performed in 7.1%. In the patients undergoing operations utilizing the SMU I and SMU II methods, neomeatus dystopia was not detected and postoperative fistulas were observed in 16.7% of incidence. With the standard urethroplasty method, the rate of complications was higher (p < 0.05). Even though the duration of surgery in the group undergoing a procedure using the standard urethroplasty method was lower (p < 0.001), the frequency of primary wound healing was higher in the SMU I and SMU II groups (p < 0.001). Conclusions: The proposed new methods of distal and shaft hypospadias surgery, in comparison with traditional surgical techniques, have the following advantages: good cosmetic appearance of the penis, complete straightening of the shaft, and right outflow of urine through the slit-like neomeatus at the apex of the glans penis
Identification and Pathogenicity of Causal Agents of Apple Canker Disease in Kazakhstan
No full textApples are widely consumed by people all over the world due to their taste and nutritional value. However, apple trees are prone to various environmental stresses, including fungal diseases. Among them, Cytospora canker (or Valsa canker) can cause dieback of branches and twigs. Although Kazakhstan is well known as an origin of apples, very little is known about canker diseases that spread across all commercial orchards. Therefore, an accurate identification of the causal agents of those diseases is needed for further application of informed disease management strategies. In this study, eleven isolates belonging to four Cytospora species were isolated from multiple cultivars, grown in six different orchards within the Almaty region, Kazakhstan. As a result of a multilocus phylogenetic analysis using ITS, LSU and tef1-α marker genes and morphological characterization, these isolates were described as Cytospora parasitica, Cytospora sorbina, Cytospora pruinopsis and Cytospora chrysosperma. Moreover, a pathogenicity test was conducted on detached twigs, and it demonstrated that two of these fungi were highly virulent. Overall, this paper is a first report of the causal agents of apple canker disease in Kazakhstan and could be a trigger for conducting future studies to better understand the disease epidemiology, as well as build management strategies
