973 resultados para exercise of discretion to fix costs - applicable principles
Resumo:
The inheritance of resistance to powdery mildew in the pea cultivar MK-10 and some histological aspects of infection were assessed. For the inheritance study, F1, F2, backcrosses and F3 generations of MK-10 crossed with two susceptible populations were evaluated. Histological evaluations included percentage of germinated conidia, percentage of conidia that formed appresoria, percentage of conidia that established colonies, and number of haustoria per colony. Segregation ratios obtained in the resistance inheritance study were compared by Chi-square (ײ) test and the histological data were analyzed by Tukey's test at 5% probability. It was concluded that resistance of MK-10 to powdery mildew is due to a pair of recessive alleles since it is expressed in the pre-penetration stage and completed by post-penetration localized cellular death, characteristic of the presence of the pair of recessive alleles er1er1.
Resumo:
Rapid identification and resistance determination of pathogens in clinical specimens is vital for accurate treatment and monitoring of infectious diseases. Antimicrobial drug resistance is increasing globally and healthcare settings are facing this cost-intensive and even life-threatening problem. The incidence of resistant pathogens in Finland has remained relatively steady and manageable at least for the time being. DNA sequencing is the gold standard method for genotyping, mutation analysis, and identification of bacteria. Due to significant cost decrease in recent years, this technique is available to many research and clinical laboratories. Pyrosequencing technique, a rapid real-time DNA sequencing method especially suitable for analyzing fairly short stretches of DNA, was used in this study. Due to its robustness and versatility, pyrosequencing was applied in this study for identification of streptococci and detection of certain mutations causing antimicrobial resistance in different bacteria. Certain streptococcal species such as S. pneumoniae and S. pyogenes are significantly important clinical pathogens. S. pneumoniae causes e.g. pneumonia and otitis media and is one of the most important community-acquired pathogens. S. pyogenes, also known as group A streptococcus, causes e.g. angina and erysipelas. In contrast, the socalled alpha-haemolytic streptococci, such as S. mitis and S. oralis, belong to the normal microbiota, which are regarded to be non-pathogenic and are nearly impossible to identify by phenotypic methods. In this thesis, a pyrosequencing method was developed for identification of streptococcal species based on the 16S rRNA sequences. Almost all streptococcal species could be differentiated from one another by the developed method, including S. pneumoniae from its close relatives S. mitis and S. oralis . New resistance genes and their variants are constantly discovered and reported. In this study, new methods for detecting certain mutations causing macrolide resistance or extended spectrum beta-lactamase (ESBL) phenotype were developed. These resistance detection approaches are not only suitable for surveillance of mechanisms causing antimicrobial resistance but also for routine analysis of clinical samples particularly in epidemic settings. In conclusion, pyrosequencing was found to be an accurate, versatile, cost-effective, and rapid DNA sequencing method that is especially suitable for mutation analysis of short DNA fragments and identification of certain bacteria.
Resumo:
Weed control is commonly performed by the inter-row mechanical weeding associated to intrarow glyphosate directed spraying, causing a risk for drift or accidental herbicide application, that can affect the crop of interest. The objective was to evaluate the response of clones C219, GG100, I144, and I224 of eucalypt (Eucalyptus grandis x E. urophylla) to glyphosate doses of 0, 18, 36, 72, 180, 360, and 720 g of acid equivalent per hectare. The clones showed different growth patterns with regard to height, leaf number, stem dry weight, relative growth rate, net assimilation rate, and relative leaf growth rate. The clones I144 and GG100 were more susceptible to glyphosate, showing the doses required to reduce dry weight by 50% of 113.4 and 119.6 g acid equivalent per hectare, respectively. The clones C219 and I224 were less susceptible to glyphosate, showing the doses required to reduce dry weight by 50% of 237.5 and 313.5 g acid equivalent per hectare, respectively. Eucalyptus clones respond differently to glyphosate exposure, so that among I224, C219, GG100, and I144, the susceptibility to the herbicide is increasing.
Resumo:
The reduction of pesticide spraying drift is still one of the major challenges in Brazilian agriculture. The aim of this study was to evaluate the potential of different adjuvant products, such as surfactants, drift retardants, mineral oil and vegetable oil for reducing drift in agricultural spraying. The experiment consisted of quantifying drift of sprayings of 18 adjuvants dissolved in water under controlled conditions in a wind tunnel. Tests were performed in triplicates with spraying nozzles type Teejet XR8003 VK, pressure of 200kPa and medium drops. Solutions sprayed were marked with Brilliant Blue dye at 0.6% (m v-1). The drift was collected using polyethylene strips transversally fixed along the tunnel at different distances from the nozzle and different heights from the bottom part of the tunnel. Drift deposits were evaluated by spectrophotometry in order to quantify deposits. The adjuvants from chemical groups of mineral oil and drift retardant resulted in lower values of drift in comparison with surfactants and water. The results obtained in laboratory show that the selection of appropriate class and concentration of adjuvants can significantly decrease the risk of drift in agricultural spraying. However, the best results obtained in laboratory should be validated with pesticide under field conditions in the future.
Resumo:
The increasing demand for lightweight components has led to a huge exploitation of non-metallic materials such as polymers, fibers and elastomers in industrial and manufacturing processes. Recent trends towards cost effectiveness, weight reduction and production flexibility in industrial production and manufacturing processes has led to a growing interest in hybrid components where two or more dissimilar materials coexist to achieving specifically optimized characteristics. The importance of this research is to serve as a bridge to understanding the theories behind various joining techniques and the adaptation of the process for metal to polymer hybrid joints. Moreso, it helps companies to select the most productive and yet economical joining process for realization of lightweight metal to polymer hybrid components. This thesis is a literature review analyzing various materials that has been published on various joining methods for metal to polymer hybrid joints on the feasibility and eventual realization of the joint between these dissimilar materials. This study is aimed at theoretically evaluating the feasibility of joining processes between metal and plastic components by exploiting exhaustively joining and welding sources.
Resumo:
The modern business development of China began during 1978 and during the last decades Chinese have created one of the most dynamic and strongest economies in the world. China is now second largest trading power calculated in dollars. The special characteristic of this economic development is that it is not copy of any existing economy, instead the developments have been strongly influenced by the Chinese cultural characteristics. One cultural characteristic, guanxi, which is a “network of services and counter- services” is argued to be major component of successful business in China where these changes of services happen between people but also between companies. Obtaining introductions and the guanxi when doing business in China will give attentive audience and security for companies business. Despite the evidenced importance of guanxi, China´s business environment is rapidly changing towards Western economies, which might then reduce the importance of guanxi. Therefore the current impact of guanxi is a important topic to study. The main purpose of this study is to explore the impact of guanxi for Western big and small sized multinational companies´ business processes when doing business in China. This study looks What is the impact of guanxi in contemporary Chinese business environment for foreign companies doing business in China. Sub-questions in this research focus on what is the impact of guanxi on corporate reputation, management and negotiations. Findings present a mixed view where the importance of guanxi is not anymore critical, especially among younger people in the cities, however guanxi was clearly important outside the cities and when dealing with government officials. Efficient use of guanxi can be extremely profitable especially during early stages of business operations and guanxi plays role when bargaining prices and ensuring product quality from the factories. Therefore guanxi should be considered as essential element for successful business in China.
Resumo:
Prerequisites and effects of proactive and preventive psycho-social student welfare activities in Finnish preschool and elementary school were of interest in the present thesis. So far, Finnish student welfare work has mainly focused on interventions and individuals, and the voluminous possibilities to enhance well-being of all students as a part of everyday school work have not been fully exploited. Consequently, in this thesis three goals were set: (1) To present concrete examples of proactive and preventive psycho-social student welfare activities in Finnish basic education; (2) To investigate measurable positive effects of proactive and preventive activities; and (3) To investigate implementation of proactive and preventive activities in ecological contexts. Two prominent phenomena in preschool and elementary school years—transition to formal schooling and school bullying—were chosen as examples of critical situations that are appropriate targets for proactive and preventive psycho-social student welfare activities. Until lately, the procedures concerning both school transitions and school bullying have been rather problem-focused and reactive in nature. Theoretically, we lean on the bioecological model of development by Bronfenbrenner and Morris with concentric micro-, meso-, exo- and macrosystems. Data were drawn from two large-scale research projects, the longitudinal First Steps Study: Interactive Learning in the Child–Parent– Teacher Triangle, and the Evaluation Study of the National Antibullying Program KiVa. In Study I, we found that the academic skills of children from preschool–elementary school pairs that implemented several supportive activities during the preschool year developed more quickly from preschool to Grade 1 compared with the skills of children from pairs that used fewer practices. In Study II, we focused on possible effects of proactive and preventive actions on teachers and found that participation in the KiVa antibullying program influenced teachers‘ self-evaluated competence to tackle bullying. In Studies III and IV, we investigated factors that affect implementation rate of these proactive and preventive actions. In Study III, we found that principal‘s commitment and support for antibullying work has a clear-cut positive effect on implementation adherence of student lessons of the KiVa antibullying program. The more teachers experience support for and commitment to anti-bullying work from their principal, the more they report having covered KiVa student lessons and topics. In Study IV, we wanted to find out why some schools implement several useful and inexpensive transition practices, whereas other schools use only a few of them. We were interested in broadening the scope and looking at local-level (exosystem) qualities, and, in fact, the local-level activities and guidelines, along with teacherreported importance of the transition practices, were the only factors significantly associated with the implementation rate of transition practices between elementary schools and partner preschools. Teacher- and school-level factors available in this study turned out to be mostly not significant. To summarize, the results confirm that school-based promotion and prevention activities may have beneficial effects not only on students but also on teachers. Second, various top-down processes, such as engagement at the level of elementary school principals or local administration may enhance implementation of these beneficial activities. The main message is that when aiming to support the lives of children the primary focus should be on adults. In future, promotion of psychosocial well-being and the intrinsic value of inter- and intrapersonal skills need to be strengthened in the Finnish educational systems. Future research efforts in student welfare and school psychology, as well as focused training for psychologists in educational contexts, should be encouraged in the departments of psychology and education in Finnish universities. Moreover, a specific research centre for school health and well-being should be established.
Resumo:
Toxoplasmosis is caused by the obligate intracellular protozoan parasite Toxoplasma gondii and affects warm-blooded vertebrates, including pets and man. Dogs are epidemio-logically important since they act as sentinels for the infection in humans. The present study aimed to determine the presence of antibodies to T. gondii in 205 serum samples from dogs in Ubatuba, Sao Paulo state, Brazil, through indirect immunofluorescence reaction (IFAT), as well as the risk factors related to toxoplasmosis in the animals such as breed, age, sex, access to outdoors, homemade food ingestion, access to untreated water, and contact with rodents. Toxoplasmosis-positive samples accounted for 52/205 (25.4%), with titers ranging from 16 to 256. The serological results presented significant association (P<0.05) with homemade food ingestion (45/118; 38.1%; CI95% 29.9%-47.2%) (OR=7.0; CI95% 3.0-16.6), and with access to outdoors where those that do not have access to the street were prevalent (37/121; 30.6%; CI95% 23.1%-39.3%) (OR=0.5; CI95% 0.2-1.0). These results show that toxoplasmosis in this region is related to problems of sanitary education, mainly concerning the appropriate cooking of foods, since most positive animals did not show significant association with the presence of rodents or untreated water consumption but showed, instead association with ingestion of homemade food. Thus, toxoplasmosis is a public health problem in the studied region, and sanitary measures are needed to control the infection due to the strict relationship between man and dog and the presented risk factors
Resumo:
Thousands of tons of pharmaceuticals are consumed yearly worldwide. Due to the continuous and increasing consumption and their incomplete elimination in wastewater treatment plants (WWTP), pharmaceuticals and their metabolites can be detected in receiving waters, although at low concentrations (ng to low μg/L). As bioactive molecules the presence of pharmaceuticals in the aquatic environment must be considered potentially hazardous for the aquatic organisms. In this thesis, the biotransformation and excretion of pharmaceuticals in fish was studied. The main biotransformation pathways of three anti‐inflammatory drugs, diclofenac, naproxen and ibuprofen, in rainbow trout were glucuronidation and taurine conjugation of the parent compounds and their phase I metabolites. The same metabolites were present in fish bile in aquatic exposures as in fish dosed with intraperitoneal injection. Higher bioconcentration factor in bile (BCFbile) was found for ibuprofen when compared to diclofenac and naproxen. Laboratory exposure studies were followed by a study of uptake of pharmaceuticals in a wild fish population living in lake contaminated with WWTP effluents. Of the analyzed 17 pharmaceuticals and six phase I metabolites, only diclofenac, naproxen and ibuprofen was present in bream and roach bile. It was shown, that diclofenac, naproxen and ibuprofen excreted by the liver can be found in rainbow trout and in two native fish species living in the receiving waters. In the bream and roach bile, the concentrations of diclofenac, naproxen and ibuprofen were roughly 1000 times higher than those found in the lake water, while in the laboratory exposures, the bioconcentration of the compounds and their metabolites in rainbow trout bile were at the same level as in wild fish or an order of magnitude higher. Thus, the parent compounds and their metabolites in fish bile can be used as a reliable biomarker to monitor the exposure of fish to environmental pharmaceuticals present in water receiving discharges from WWTPs.
Resumo:
Experiments were designed to study in-vivo effects of sodium cyanide on biochemical endpoints in the freshwater fish Labeo rohita. Fish were exposed to two sublethal concentrations (0.106 and 0.064mg/L) for a period of 15 days. Levels of glycogen, pyruvate, lactate and the enzymatic activities of lactate dehydrogenase (LDH), succinate dehydrogenase (SDH), glucose-6-phosphate dehydrogenase (G6PDH), phosphorylase, alkaline phosphatase (ALP), acid phosphatase (AcP) were assessed in different tissues (liver, muscle and gills). Result indicated a steady decrease in glycogen, pyruvate, SDH, ALP and AcP activity with a concomitant increase in the lactate, phosphorylase, LDH and G6PD activity in all selected tissues. The alterations in all the above biochemical parameters were significantly (p<0.05) time and dose dependent. In all the above parameters, liver pointing out the intensity of cyanide intoxication compare to muscle and gills. Study revealed change in the metabolic energy by means of altered metabolic profile of the fish. Further, these observations indicated that even sublethal concentrations of sodium cyanide might not be fully devoid of deleterious influence on metabolism in L. rohita.
Resumo:
This study aims at standardizing the pre-incubation and incubation pH and temperature used in the metachromatic staining method of myofibrillar ATPase activity of myosin (mATPase) used for asses and mules. Twenty four donkeys and 10 mules, seven females and three males, were used in the study. From each animal, fragments from the Gluteus medius muscle were collected and percutaneous muscle biopsy was performed using a 6.0-mm Bergström-type needle. In addition to the metachromatic staining method of mATPase, the technique of nicotinamide adenine dinucleotide tetrazolium reductase (NADH-TR) was also performed to confirm the histochemical data. The histochemical result of mATPase for acidic pre-incubation (pH=4.50) and alkaline incubation (pH=10.50), at a temperature of 37ºC, yielded the best differentiation of fibers stained with toluidine blue. Muscle fibers were identified according to the following colors: type I (oxidative, light blue), type IIA (oxidative-glycolytic, intermediate blue) and type IIX (glycolytic, dark blue). There are no reports in the literature regarding the characterization and distribution of different types of muscle fibers used by donkeys and mules when performing traction work, cargo transportation, endurance sports (horseback riding) and marching competitions. Therefore, this study is the first report on the standardization of the mATPase technique for donkeys and mules.
Resumo:
The resistance of barnyardgrass (Echinochloa crus-galli) to imidazolinone herbicides is a worldwide problem in paddy fields. A rapid diagnosis is required for the selection of adequate prevention and control practices. The objectives of this study were to develop expedite bioassays to identify the resistance to imidazolinone herbicides in barnyardgrass and to evaluate the efficacy of alternative herbicides for the post-emergence control of resistant biotypes. Three experiments were conducted to develop methods for diagnosis of resistance to imazethapyr and imazapyr + imazapic in barnyardgrass at the seed, seedling and tiller stages, and to carry out a pot experiment to determine the efficacy of six herbicides applied at post-emergence in 13 biotypes of barnyardgrass resistant to imidazolinones. The seed soaking bioassay was not able to differentiate the resistant and susceptible biotypes. The resistance of barnyardgrass to imidazolinones was effectively discriminated in the seedlings and tiller bioassays seven days after incubation at the concentrations of 0.001 and 0.0001 mM, respectively, for both imazethapyr and imazapyr + imazapic. The biotypes identified as resistant to imidazolinones showed different patterns of susceptibility to penoxsulam, bispyribac-sodium and pyrazosulfuron-ethyl, and were all controlled with profoxydim and cyhalofop-butyl. The seedling and tiller bioassays are effective in the diagnosis of barnyardgrass resistance to imidazolinone herbicides, providing an on-season opportunity to identify the need to use alternative herbicides to be applied at post-emergence for the control of the resistant biotypes.
Resumo:
Parasitic weed species of the genus Orobanche are serious threat for the production of several crops in Europe, Africa and Asia. Research on resistant host plant varieties is one of the most effective management strategies for this parasitic weed. In this study, the susceptibility of twenty-nine tomato varieties to broomrape infection (Orobanche aegyptiaca) under greenhouse conditions was investigated. The employed experimental design was completely randomized with three replications. Differences in susceptibility to infection were monitored among tomato varieties based on their difference in the number of emerged shoots of broomrape and broomrape dry weight (shoots and tubercles). Date of Orobanche emergence varied over a period of 3 to 30 days between varieties. Very late infection was monitored for varieties of Cal-jN3, Viva, Caligen 86, Packmor, CSX 5013, Hyb. PS 6515 and Hyb Petopride5. Differences in the growth and fruit yield among tomato varieties were also found in response to broomrape infestation. Moderate levels of resistance were obtained in Viva, Caligen 86, Hyb. PS 6515, Hyb.Firenze (PS 8094) and Cal-jN3 among other tomato varieties. In contrast, varieties of Kimia-Falat, Hyb. Petopride II and Hyb.AP865 were the most susceptible hosts to Orobanche aegyptiaca.
Resumo:
ABSTRACT The aim of this work was to evaluate the selectivity of fomesafen alone or in a tank mixture with other preemergent herbicides, with or without S-metolachlor application in early postemergence in cotton plant, cultivar DP 555 BG RR(r). The design utilized was a randomized complete block, organized in a split-plot arrangement, with four replications. For that, 24 herbicides were evaluated with fomesafen (0.45 and 0.625 kg ha-1), prometryn (1.25 kg ha-1), diuron (1.25 kg ha-1), trifluralin (1.8 kg ha-1), and S-metolachlor (0.77 kg ha-1), applied as preemergent, with or without S-metolachlor (0.77 kg ha-1) applied in early postemergence. The variables evaluated were: phytotoxicity, insertion height of the first reproductive branch, plant height, stand, number of reproductive branches per plant, number of bolls per plant, bolls weight, and productivity of cotton seed. Fomesafen alone or in a tank mixture with preemergent prometryn, diuron, trifluralin and S-metolachlor was selective to cotton plant. Preemergent fomesafen isolated application followed by the application of S-metolachlor in early postemergence was also selective. However, on average, preemergent tank mixtures applied in association with preemergent S-metolachlor early application was not selective to cotton crop.