62 resultados para GROUP-IV DONORS
Resumo:
The commodity plastics that are used in our everyday lives are based on polyolefin resins and they find wide variety of applications in several areas. Most of the production is carried out in catalyzed low pressure processes. As a consequence polymerization of ethene and α-olefins has been one of the focus areas for catalyst research both in industry and academia. Enormous amount of effort have been dedicated to fine tune the processes and to obtain better control of the polymerization and to produce tailored polymer structures The literature review of the thesis concentrates on the use of Group IV metal complexes as catalysts for polymerization of ethene and branched α-olefins. More precisely the review is focused on the use of complexes bearing [O,O] and [O,N] type ligands which have gained considerable interest. Effects of the ligand framework as well as mechanical and fluxional behaviour of the complexes are discussed. The experimental part consists mainly of development of new Group IV metal complexes bearing [O,O] and [O,N] ligands and their use as catalysts precursors in ethene polymerization. Part of the experimental work deals with usage of high-throughput techniques in tailoring properties of new polymer materials which are synthesized using Group IV complexes as catalysts. It is known that the by changing the steric and electronic properties of the ligand framework it is possible to fine tune the catalyst and to gain control over the polymerization reaction. This is why in this thesis the complex structures were designed so that the ligand frameworks could be fairly easily modified. All together 14 complexes were synthesised and used as catalysts in ethene polymerizations. It was found that the ligand framework did have an impact within the studied catalyst families. The activities of the catalysts were affected by the changes in complex structure and also effects on the produced polymers were observed: molecular weights and molecular weight distributions were depended on the used catalyst structure. Some catalysts also produced bi- or multi-modal polymers. During last decade high-throughput techniques developed in pharmaceutical industries have been adopted into polyolefin research in order to speed-up and optimize the catalyst candidates. These methods can now be regarded as established method suitable for both academia and industry alike. These high-throughput techniques were used in tailoring poly(4-methyl-1-pentene) polymers which were synthesized using Group IV metal complexes as catalysts. This work done in this thesis represents the first successful example where the high-throughput synthesis techniques are combined with high-throughput mechanical testing techniques to speed-up the discovery process for new polymer materials.
Resumo:
The range of consumer health and medicines information sources has diversified along with the increased use of the Internet. This has led to a drive to develop medicines information services and to better incorporate the Internet and e-mail into routine practice in health care and in community pharmacies. To support the development of such services more information is needed about the use of online information by consumers, particularly of those who may be the most likely to use and to benefit from the new sources and modes of medicines communication. This study explored the role and utilization of the Internet-based medicines information and information services in the context of a wider network of information sources accessible to the public in Finland. The overall aim was to gather information to develop better and more accessible sources of information for consumers and services to better meet the needs of consumers. Special focus was on the needs and information behavior among people with depression and using antidepressant medicines. This study applied both qualitative and quantitative methods. Consumer medicines information needs and sources were identified by analyzing the utilization of the University Pharmacy operated national drug information call center (Study I) and surveying Finnish adults (n=2348) use of the different medicines information sources (Study II). The utilization of the Internet as a source of antidepressant information among people with depression was explored by focus group discussions among people with depression and with current or past use of the antidepressant(s) (n=29, Studies III & IV). Pharmacy response to the needs of consumers in term of providing e-mail counseling was assessed by conducting a virtual pseudo customer study among the Finnish community pharmacies (n=161, Study V). Physicians and pharmacists were the primary sources of medicines information. People with mental disorders were more frequent users of telephone- and Internet-based medicines information sources and patient information leaflets than people without mental disorders. These sources were used to complement rather than replace information provided face-to-face by health professionals. People with depression used the Internet to seek facts about antidepressants, to share experiences with peers, and for the curiosity. They described that the access to online drug information was empowering. Some people reported lacking the skills necessary to assess the quality of online information. E-mail medication counseling services provided by community pharmacies were rare and varied in quality. Study results suggest that rather than discouraging the use of the Internet, health professionals should direct patients to use accurate and reliable sources of online medicines information. Health care providers, including community pharmacies should also seek to develop new ways of communicating information about medicines with consumers. This study determined that people with depression and using antidepressants need services enabling interactive communication not only with health care professionals, but also with peers. Further research should be focused on developing medicines information service facilitating communication among different patient and consumer groups.
Resumo:
The purpose of this study is to find a framework for a holistic approach to, and form a conceptual toolbox for, investigating changes in signs and in their interpretation. Charles S. Peirce s theory of signs in a communicative perspective is taken as a basis for the framework. The concern directing the study is the problem of a missing framework in analysing signs of visual artefacts from a holistic perspective as well as that of the missing conceptual tools. To discover the possibility of such a holistic approach to semiosic processes and to form a conceptual toolbox the following issues are discussed: i) how the many Objects with two aspects involved in Peirce s definition of sign-action, promote multiple semiosis arising from the same sign by the same Interpretant depending on the domination of the Objects; ii) in which way can the relation of the individual and society or group be made more apparent in the construction of the self since this construction is intertwined with the process of meaning-creation and interpretation; iii) how to account for the fundamental role of emotions in semiosis, and the relation of emotions with the often neglected topic of embodiment; iv) how to take into account the dynamic, mediating and processual nature of sign-action in analysing and understanding the changes in signs and in the interpretation of signs. An interdisciplinary approach is chosen for this dissertation. Concepts that developed within social psychology, developmental psychology, neurosciences and semiotics, are discussed. The common aspect of the approaches is that they in one way or another concentrate on mediation provided by signs in explaining human activity and cognition. The holistic approach and conceptual toolbox found are employed in a case study. This consists of an analysis of beer brands including a comparison of brands from two different cultures. It becomes clear that different theories and approaches have mutual affinities and do complement each other. In addition, the affinities in different disciplines somewhat provide credence to the various views. From the combined approach described, it becomes apparent that by the semiosic process, the emerging semiotic self intertwined with the Umwelt, including emotions, can be described. Seeing the interpretation and meaning-making through semiosis allows for the analysis of groups, taking into account the embodied and emotional component. It is concluded that emotions have a crucial role in all human activity, including so-called reflective thinking, and that emotions and embodiment should be consciously taken into account in analysing signs, the interpretation, and in changes of signs and interpretations from both the social and individual level. The analysis of the beer labels expresses well the intertwined nature of the relationship between signs, individual consumers and society. Many direct influences from society on the label design are found, and also some indirect attitude changes that become apparent from magazines, company reports, etc. In addition, the analysis brings up the issues of the unifying tendency of the visual artefacts of different cultures, but also demonstrates that the visual artefacts are able to hold the local signs and meanings, and sometimes are able to represent the local meanings although the signs have changed in the unifying process.
Resumo:
My PhD-thesis Body Images! Psychoanalytical Analysis of Finnish Performance and Body Art in the 1980s and 1990s considers Finnish performance and body art performed mainly by visual artists. In Part I, I chart the historical construction of performance art and its extension since the beginning of the 21st century. There are several wievs of the historical background of performance art. I introduce three different genealogies of performance art. One is Rose-Lee Goldberg s view. She connects performance art with the European avant-garde already at the beginning of the 20th century from futurists and dadaists to Russian avant-garde and the Bauhaus. I prefer to present performance art as contemporary art, which began to take shape in connection with visual arts in the 1950s and 1960s. The focus on the body is apparent in nearly all performance art. Nevertheless, throug the concept of body art I want to empasize the artist s body as the place of art. Body art (as part of performance art) functions as thematic and interpretive concept, which allows me to focus on performances where the questions of body image, narcissism, desire, language and pleasure are incorporated in particular intensive ways. In Part II, I explore the arrival of performance art in Finnish visual arts in the 1980s. I study the new generation s relation to earlier Finnish happenings (1960s) and performative actions in 1970 s. I briefly introduce performance groups of the 1980s art scene and consider their reception in media. The main focus is on the group Jack Helen Brut, in which I see many similarities to the so- called Theatre of Images. The goal of this part II is to provide historical context for the performance analysis that follows. In Part III, I develop the concept of body image which is my main theoretical term. The concept of body image is used according to Lacanian psychoanalytical theory, especially his considerations of mirror stages. My first mapping of body image, which I call imaginary body image, is based on Lacan s famous mirror stage article (1949). According to my reading, body image is narcistic and aggressive. The important concepts here are ego, imaginary, méconnaisance and alienation. In 1953 Lacan began to develop different version on mirror stage, in which he emphasized the primacy of symbolic dimension. It is not image, but language which constructs the foundations of body image. Central concepts in this chater are Other as language, ego-ideal, demand and desire. In the last chapter I connect the third version of the mirror stage to concepts of gaze, phantasy, real, jouissance and object a. In previous chapters I had considered body image in relation to ego. Now I explore it in relation to subject. In my reading the body image is fragile phenomen, which oscillates between yearning for coherence and phantasies of fragmented images. Part IV of the thesis begins with an introduction to the central concepts and debates in performace studies over the last few decades. Important concepts are presence, performativity and theatricality. The main substance of my thesis, however, is the performance analysis, which focuses on works by three Finnish artists and one Finnish group. The first analysis concerns the performance (1992) of Kimmo Schroderus. I discuss the relationship between narcissism and body art and the changes in demands projected on body images of men in recent decades in a Euro-American context. I also explore this performance in relation to the myth of Narcissus, which I reinterpret through Narcissus s aggression against his own body. The group Homo S is the main subject of the next analysis. I discuss the relationship between feminist art and performance art, especially in the United States in the 1960s and 1970s. Homo S is different from this early performance art because of its anarchism, humor and rejection of all ideals. Homo S characterizes its performance Body Body (1983) as liberating vulgar feminism . Sociality and performance of erotic relations between women are central in Body Body. Pia Lindman s performances are the subjects of my third analysis. I study three of her performances: Olen muoto (1993), 17 and in love (1994) and Arranged views (1995). I interpret these performances as efforts to disperse the imaginary and symbolic structures of the body image. She constructs the peculiar object a and phantasy space of her own. In the last analysis I move from questions of image and gaze to a study of language, sound and jouissance. I discuss at a general level the performance of orality and helplesness (Hilflosigkeit) in body art. The central elements in Pentti Otto Koskinen s performances are the ear, listening and receptive gestures and postions. Perseveraatio (1998) can be understood representing as submission to the super-ego s power, which compels one to enjoy. I examine particularly closely the performance Maissi on hyvää ei missään nimessä maissia (1995), which I interpret as the return of a baby s body image to the liminal site of choice: language or jouissance?
Resumo:
Aptitude-based student selection: A study concerning the admission processes of some technically oriented healthcare degree programmes in Finland (Orthotics and Prosthetics, Dental Technology and Optometry). The data studied consisted of conveniencesamples of preadmission information and the results of the admission processes of three technically oriented healthcare degree programmes (Orthotics and Prosthetics, Dental Technology and Optometry) in Finland during the years 1977-1986 and 2003. The number of the subjects tested and interviewed in the first samples was 191, 615 and 606, and in the second 67, 64 and 89, respectively. The questions of the six studies were: I. How were different kinds of preadmission data related to each other? II. Which were the major determinants of the admission decisions? III. Did the graduated students and those who dropped out differ from each other? IV. Was it possible to predict how well students would perform in the programmes? V. How was the student selection executed in the year 2003? VI. Should clinical vs. statistical prediction or both be used? (Some remarks are presented on Meehl's argument: "Always, we might as well face it, the shadow of the statistician hovers in the background; always the actuary will have the final word.") The main results of the study were as follows: Ability tests, dexterity tests and judgements of personality traits (communication skills, initiative, stress tolerance and motivation) provided unique, non-redundant information about the applicants. Available demographic variables did not bias the judgements of personality traits. In all three programme settings, four-factor solutions (personality, reasoning, gender-technical and age-vocational with factor scores) could be extracted by the Maximum Likelihood method with graphical Varimax rotation. The personality factor dominated the final aptitude judgements and very strongly affected the selection decisions. There were no clear differences between graduated students and those who had dropped out in regard to the four factors. In addition, the factor scores did not predict how well the students performed in the programmes. Meehl's argument on the uncertainty of clinical prediction was supported by the results, which on the other hand did not provide any relevant data for rules on statistical prediction. No clear arguments for or against the aptitude-based student selection was presented. However, the structure of the aptitude measures and their impact on the admission process are now better known. The concept of "personal aptitude" is not necessarily included in the values and preferences of those in charge of organizing the schooling. Thus, obviously the most well-founded and cost-effective way to execute student selection is to rely on e.g. the grade point averages of the matriculation examination and/or written entrance exams. This procedure, according to the present study, would result in a student group which has a quite different makeup (60%) from the group selected on the basis of aptitude tests. For the recruiting organizations, instead, "personal aptitude" may be a matter of great importance. The employers, of course, decide on personnel selection. The psychologists, if consulted, are responsible for the proper use of psychological measures.
Resumo:
The aim of this dissertation was to adapt a questionnaire for assessing students’ approaches to learning and their experiences of the teaching-learning environment. The aim was to explore the validity of the modified Experiences of Teaching and Learning Questionnaire (ETLQ) by examining how the instruments measure the underlying dimensions of student experiences and their learning. The focus was on the relation between students’ experiences of their teaching-learning environment and their approaches to learning. Moreover, the relation between students’ experiences and students’ and teachers’ conceptions of good teaching was examined. In Study I the focus was on the use of the ETLQ in two different contexts: Finnish and British. The study aimed to explore the similarities and differences between the factor structures that emerged from both data sets. The results showed that the factor structures concerning students’ experiences of their teaching-learning environment and their approaches to learning were highly similar in the two contexts. Study I also examined how students’ experiences of the teaching-learning environment are related to their approaches to learning in the two contexts. The results showed that students’ positive experiences of their teaching-learning environment were positively related to their deep approach to learning and negatively to the surface approach to learning in both the Finnish and British data sets. This result was replicated in Study II, which examined the relation between approaches to learning and experiences of the teaching-learning environment on a group level. Furthermore, Study II aimed to explore students’ approaches to learning and their experiences of the teaching-learning environment in different disciplines. The results showed that the deep approach to learning was more common in the soft sciences than in the hard sciences. In Study III, students’ conceptions of good teaching were explored by using qualitative methods, more precisely, by open-ended questions. The aim was to examine students’ conceptions, disciplinary differences and their relation to students’ approaches to learning. The focus was on three disciplines, which differed in terms of students’ experiences of their teaching-learning environment. The results showed that students’ conceptions of good teaching were in line with the theory of good teaching and there were disciplinary differences in their conceptions. Study IV examined university teachers’ conceptions of good teaching, which corresponded to the learning-focused approach to teaching. Furthermore, another aim in this doctoral dissertation was to compare the students’ and teachers’ conceptions of good teaching, the results of which showed that these conceptions appear to have similarities. The four studies indicated that the ETLQ appears to be a sufficiently robust measurement instrument in different contexts. Moreover, its strength is its ability to be at the same time a valid research instrument and a practical tool for enhancing the quality of students’ learning. In addition, the four studies emphasise that in order to enhance teaching and learning in higher education, various perspectives have to be taken into account. This study sheds light on the interaction between students’ approaches to learning, their conceptions of good teaching, their experiences of the teaching-learning environment, and finally, the disciplinary culture.
Resumo:
Cognitive impairments of attention, memory and executive functions are a fundamental feature of the pathophysiology of schizophrenia. The neurophysiological and neurochemical changes in the auditory cortex are shown to underlie cognitive impairmentsin schizophrenia patients. Functional state of the neural substrate of auditory information processing could be objectively and non-invasively probed with auditory event-related potentials (ERPs) and event- related fields (ERFs). In the current work, we explored the neurochemical effect on the neural origins of auditory information processing in relation to schizophrenia. By means of ERPs/ERFs we aimed to determine how neural substrates of auditory information processing are modulated by antipsychotic medication in schizophrenia spectrum patients (Studies I, II) and by neuropharmacological challenges in healthy human subjects (Studies III, IV). First, with auditory ERPs we investigated the effects of olanzapine (Study I) and risperidone (Study II) in a group of patients with schizophrenia spectrum disorders. After 2 and 4 weeks of treatment, olanzapine has no significant effects on mismatch negativity(MMN) and P300, which, as it has been suggested, respectively reflect preattentive and attention-dependent information processing. After 2 weeks of treatment, risperidone has no significant effect on P300, however risperidone reduces P200 amplitude. This latter effect of risperidone on neural resources responsible for P200 generation could be partly explained through the action of dopamine. Subsequently, we used simultaneous EEG/MEG to investigate the effects of memantine (Study III) and methylphenidate (Study IV) in healthy subjects. We found that memantine modulates MMN response without changing other ERP components. This could be interpreted as being due to the possible influence of memantine through the NMDA receptors on auditory change- detection mechanism, with processing of auditory stimuli remaining otherwise unchanged. Further, we found that methylphenidate does not modulate the MMN response. This finding could indicate no association between catecholaminergic activities and electrophysiological measures of preattentive auditory discrimination processes reflected in the MMN. However, methylphenidate decreases the P200 amplitudes. This could be interpreted as a modulation of auditory information processing reflected in P200 by dopaminergic and noradrenergic systems. Taken together, our set of studies indicates a complex pattern of neurochemical influences produced by the antipsychotic drugs in the neural substrate of auditory information processing in patients with schizophrenia spectrum disorders and by the pharmacological challenges in healthy subjects studied with ERPs and ERFs.
Resumo:
The study is part of a research project of 269 psychiatric patients with major depression, Vantaa Depression Study, in the Department of Mental Health and Alcohol Research of the National Public Health Institute and the Department of Psychiatry of the Peijas Medical Care District. The aim was to study at the onset of MDE psychosocial differences in subgroups of patients and clustering of events into time before depression and its prodromal phase, to study whether more severe life events and less social support predict poorer outcome in all patients, but most among those currently in partial remission, whether social support declines as a consequence of time spent in MDE, is sensitive to improvement, and whether social support is influenced by neuroticism and extraversion. After screening, a semistructured interview (SCAN, version 2.0) was used for the presence of DSM-IV MDE, and other psychiatric diagnoses. Life events and social support were studied with semistructured methods (IRLE, Paykel 1983; IMSR, Brugha et al. 1987), perceived social support and neuroticism/extraversion with questionnaires (PSSS-R, Blumenthal et al. 1987; EPI, Eysenck and Eysenck 1964) at baseline, 6 and 18 months. At the onset of depression life events were common. No major differences between subgroups of patients were found; the younger had more events, whereas those with comorbid alcoholism and personality disorders perceived less support. Although events were distributed evenly between the time before depression, the prodromal phase and the index MDE, two thirds of the patients attributed their depression to some life event. Adversities and poor perceived support influenced the outcome of all psychiatric patients, most in the subgroup of full remission. In the partial remission group, the impact of severe events and in the MDE, perceived support was important. Low objective and subjective support were predicted by longer time spent in MDE. Along with improvement subjective support improved. Neuroticism and extraversion were associated with the size of social network and perceived support and predicted change of perceived support. In conclusion, adversities were common in all phases of depression. They may thus have many roles; before depression they may precipitate it, in the prodromal phase worsen symptoms, and during the MDE, the outcome of depression. Patients often attributed their depression to a life event. Psychosocial subgroup differences were quite small. Perceived support predicted the outcome of depression, and time spent in MDE objective and subjective support. Neuroticism and extraversion may modify the level and change particularly in perceived support, thereby indirectly effecting vulnerability to depression.
Resumo:
Background: Malnutrition is a common problem for residents of nursing homes and long-term care hospitals. It has a negative influence on elderly residents and patients health and quality of life. Nutritional care seems to have a positive effect on elderly individuals nutritional status and well-being. Studies of Finnish elderly people s nutrition and nutritional care in institutions are scarce. Objectives: The primary aim was to investigate the nutritional status and its associated factors of elderly nursing home residents and long-term care patients in Finland. In particular, to find out, if the nursing or nutritional care factors are associated with the nutritional status, and how do carers and nurses recognize malnutrition. A further aim was to assess the energy and nutrient intake of the residents of dementia wards. A final objective was to find out, if the nutrition training of professionals leads to changes in their knowledge and further translate into better nutrition for the aged residents of dementia wards. Subjects and methods: The residents (n=2114) and patients (n=1043) nutritional status was assessed in all studies using the Mini Nutritional Assessment test (MNA). Information was gathered in a questionnaire on residents and patients daily routines providing nutritional care. Residents energy and nutrient intake (n=23; n=21) in dementia wards were determined over three days by the precise weighing method. Constructive learning theory was the basis for educating the professionals (n=28). A half-structured questionnaire was used to assess professionals learning. Studies I-IV were cross-sectional studies whereas study V was an intervention study. Results: Malnutrition was common among elderly residents and patients living in nursing homes and hospitals in Finland. According to the MNA, 11% to 57% of the studied elderly people suffered from malnutrition, and 40-89% were at risk of malnutrition, whereas only 0-16% had a good nutritional status. Resident- and patient-related factors such as dementia, impaired ADL (Activities of Daily Living), swallowing difficulties and constipation mainly explained the malnutrition, but also some nutritional care related factors, such as eating less than half of the offered food portion and not receiving snacks were also related to malnutrition. The intake of energy and some nutrients by the residents of dementia wards were lower than those recommended, although the offered food contained enough energy and nutrients. The proportion of residents receiving vitamin D supplementation was low, although there is a recommendation and known benefits for the adequate intake of vitamin D. Nurses recognized malnutrition poorly, only one in four (26.7%) of the actual cases. Keeping and analysing food diaries and reflecting on nutritional issues in small group discussions were effective training methods for professionals. The nutrition education of professionals had a positive impact on the energy and protein intake, BMIs, and the MNA scores of some residents in dementia wards. Conclusions: Malnutrition was common among elderly residents and patients living in nursing homes and hospitals in Finland. Although residents- and patient related factors mainly explained malnutrition, nurses recognized malnutrition poorly and nutritional care possibilities were in minor use. Professionals nutrition education had a positive impact on the nutrition of elderly residents. Further studies describing successful nutritional care and nutrition education of professionals are needed.
Resumo:
B. cereus is one of the most frequent occurring bacteria in foods . It produces several heat-labile enterotoxins and one stable non-protein toxin, cereulide (emetic), which may be pre-formed in food. Cereulide is a heat stable peptide whose structure and mechanism of action were in the past decade elucidated. Until this work, the detection of cereulide was done by biological assays. With my mentors, I developed the first quantitative chemical assay for cereulide. The assay is based on liquid chromatography (HPLC) combined with ion trap mass spectrometry and the calibration is done with valinomycin and purified cereulide. To detect and quantitate valinomycin and cereulide, their [NH4+] adducts, m/z 1128.9 and m/z 1171 respectively, were used. This was a breakthrough in the cereulide research and became a very powerful tool of investigation. This tool made it possible to prove for the first time that the toxin produced by B. cereus in heat-treated food caused human illness. Until this thesis work (Paper II), cereulide producing B. cereus strains were believed to represent a homogenous group of clonal strains. The cereulide producing strains investigated in those studies originated mostly from food poisoning incidents. We used strains of many origins and analyzed them using a polyphasic approach. We found that the cereulide producing B. cereus strains are genetically and biologically more diverse than assumed in earlier studies. The strains diverge in the adenylate kinase (adk) gene (two sequence types), in ribopatterns obtained with EcoRI and PvuII (three patterns), tyrosin decomposition, haemolysis and lecithine hydrolysis (two phenotypes). Our study was the first demonstration of diversity within the cereulide producing strains of B. cereus. To manage the risk for cereulide production in food, understanding is needed on factors that may upregulate cereulide production in a given food matrix and the environmental factors affecting it. As a contribution towards this direction, we adjusted the growth environment and measured the cereulide production by strains selected for diversity. The temperature range where cereulide is produced was narrower than that for growth for most of the producer strains. Most cereulide was by most strains produced at room temperature (20 - 23ºC). Exceptions to this were two faecal isolates which produced the same amount of cereulide from 23 ºC up until 39ºC. We also found that at 37º C the choice of growth media for cereulide production differed from that at the room temperature. The food composition and temperature may thus be a key for understanding cereulide production in foods as well as in the gut. We investigated the contents of [K+], [Na+] and amino acids of six growth media. Statistical evaluation indicated a significant positive correlation between the ratio [K+]:[Na+] and the production of cereulide, but only when the concentrations of glycine and [Na+] were constant. Of the amino acids only glycine correlated positively with high cereulide production. Glycine is used worldwide as food additive (E 640), flavor modifier, humectant, acidity regulator, and is permitted in the European Union countries, with no regulatory quantitative limitation, in most types of foods. B. subtilis group members are endospore-forming bacteria ubiquitous in the environment, similar to B. cereus in this respect. Bacillus species other than B. cereus have only sporadically been identified as causative agents of food-borne illnesses. We found (Paper IV) that food-borne isolates of B. subtilis and B. mojavensis produced amylosin. It is possible that amylosin was the agent responsible for the food-borne illness, since no other toxic substance was found in the strains. This is the first report on amylosin production by strains isolated from food. We found that the temperature requirement for amylosin production was higher for the B. subtilis strain F 2564/96, a mesophilic producer, than for B. mojavensis strains eela 2293 and B 31, psychrotolerant producers. We also found that an atmosphere with low oxygen did not prevent the production of amylosin. Ready-to-eat foods packaged in micro-aerophilic atmosphere and/or stored at temperatures above 10 °C, may thus pose a risk when toxigenic strains of B. subtilis or B. mojavensis are present.
Resumo:
This thesis examines the mythology in and social reality behind a group of texts from the Nag Hammadi and related literature, to which certain leaders of the early church attached the label, Ophite, i.e., snake people. In the mythology, which essentially draws upon and rewrites the Genesis paradise story, the snake's advice to eat from the tree of knowledge is positive, the creator and his angels are demonic beasts and the true godhead is depicted as an androgynous heavenly projection of Adam and Eve. It will be argued that this unique mythology is attested in certain Coptic texts from the Nag Hammadi and Berlin 8502 Codices (On the Origin of the World, Hypostasis of the Archons, Apocryphon of John, Eugnostos, Sophia of Jesus Christ), as well as in reports by Irenaeus (Adversus Haereses 1.30), Origen (Contra Celsum 6.24-38) and Epiphanius (Panarion 26). It will also be argued that this so-called Ophite evidence is essential for a proper understanding of Sethian Gnosticism, often today considered one of the earliest forms of Gnosticism; there seems to have occurred a Sethianization of Ophite mythology. I propose that we replace the current Sethian Gnostic category by a new one that not only adds texts that draw upon the Ophite mythology alongside these Sethian texts, but also arranges the material in smaller typological units. I also propose we rename this remodelled and expanded Sethian corpus "Classic Gnostic." I have divided the thesis into four parts: (I) Introduction; (II) Myth and Innovation; (III) Ritual; and (IV) Conclusion. In Part I, the sources and previous research on Ophites and Sethians will be examined, and the new Classic Gnostic category will be introduced to provide a framework for the study of the Ophite evidence. Chapters in Part II explore key themes in the mythology of our texts, first by text comparison (to show that certain texts represent the Ophite mythology and that this mythology is different from Sethianism), and then by attempting to unveil social circumstances that may have given rise to such myths. Part III assesses heresiological claims of Ophite rituals, and Part IV is the conclusion.