56 resultados para Solanum lycopersicum Mill
Resumo:
The aim of this study is to describe and interpret discourses in Finnish national early childhood education and care (ECEC) documents concerning the child, childhood and family, including preschool education of six-year-old children. The study begins with preparation phase of the Act on Children s Day Care (1967) and concludes with the definition of ECEC policy (1999). The research data consists of committee memoranda and national ECEC curriculum guidelines. The total number of documents studied was 20, comprising some 1700 pages. The research data was examined with qualitative text analysis and employed a discursive approach. A semiotic square (Greimas rectangle) served as a tool for clarifying the discourses and constructions reflected in the research data. The theoretical framework of the study consists of the theories of childhood and family studies. The main concepts from childhood studies used in this study were childhood as a cultural construct and child-centred pedagogy in ECEC. The theoretical approaches from family studies used were the formation of modern and late-modern parenthood and family, as well as the concept of familism. Two main discursive lines were constructed from the ECEC documents. The notion of universalistic childhood suggests that early education and care aim to create the same good childhood for all children, regardless of their family background or living area. The second discursive line followed in the documents is the familistic discourse. This discourse contains emphasis on the priority of parental care. The construct of the competent child was found in the research data as early as in the mid-1970s. On the other hand, the construct of the weak family is distinguishable throughout almost the entire research period. This raises the question of whether Finnish ECEC system has been developed for the competent and self-sufficient child of a weak family which needs constant support and guidance of welfare experts. According to the study, it appears that within the Finnish ECEC system the relatively heavy emphasis on social work rather than on early education has been legitimised by the construct of the weak family. This study also shows that a more thorough analysis should be given to what we mean when we say that the main task of ECEC system is to support families in the upbringing of their children. The study was completed during the period when historical decisions concerning the administration in Finland were in the making (i.e. the potential transfer of ECEC services from the Ministry of Social Affairs and Health to the Ministry of Education). Also, over the past decade, a major reformation of the Act on Children s Daycare has been on the agenda, but no concrete measures have been implemented. Based on the findings of this study, we can ask for what kind of child and family we are preparing the ECEc reforms of the new millennium. Key words: ECEC policy Finland, childhood, family, familism, discourse analysis, semiotic square
Resumo:
Tutkimus käsittelee verkko-opetusinnovaation leviämistä perusasteen ja lukion maantieteeseen vuosina 1998–2004. Työssä sovellettiin opetusinnovaation leviämismallia ja innovaatioiden diffuusioteoriaa. Aineisto hankittiin seitsemänä vuotena kyselylomakkeilla maantieteen verkko-opetuksen edelläkävijäopettajilta, jotka palauttivat 326 lomaketta. Tutkimuksen pääongelmat olivat 1) Millaisia edellytyksiä edelläkävijäopettajilla on käyttää verkko-opetusta koulun maantieteessä? 2) Mitä sovelluksia ja millä tavoin edelläkävijäopettajat käyttävät maantieteen verkko-opetuksessa? 3) Millaisia käyttökokemuksia edelläkävijäopettajat ovat saaneet maantieteen verkko-opetuksesta? Tutkimuksessa havaittiin, että tietokoneiden riittämätön määrä ja puuttuminen aineluokasta vaikeuttivat maantieteen verkko-opetusta. Työssä kehitettiin opettajien digitaalisten mediataitojen kuutiomalli, johon kuuluvat tekniset taidot, informaation prosessointitaidot ja viestintätaidot. Opettajissa erotettiin kolme verkko-opetuksen käyttäjätyyppiä: informaatiohakuiset kevytkäyttäjät, viestintähakuiset peruskäyttäjät ja yhteistyöhakuiset tehokäyttäjät. Verkko-opetukseen liittyi intensiivisiä myönteisiä ja kielteisiä kokemuksia. Se toi iloa ja motivaatiota opiskeluun. Sitä pidettiin rikastuttavana lisänä, joka haluttiin integroida opetukseen hallitusti. Edelläkävijäopettajat ottivat käyttöön tietoverkoissa olevaa informaatiota ja sovelsivat työvälineohjelmia. He pääsivät alkuun todellisuutta jäljittelevien virtuaalimaailmojen: satelliittikuvien toistaman maapallon, digitaalikarttojen ja simulaatioiden käytössä. Opettajat kokeilivat verkon sosiaalisia tiloja reaaliaikaisen viestinnän, keskusteluryhmien ja ryhmätyöohjelmien avulla. Mielikuvitukseen perustuvat virtuaalimaailmat jäivät vähälle sillä opettajat eivät juuri pelanneet viihdepelejä. He omaksuivat virtuaalimaailmoista satunnaisia palasia käytettävissä olevan laite- ja ohjelmavarustuksen mukaan. Virtuaalimaailmojen valtaus eteni tutkimuksen aikana digitaalisen informaation hyödyntämisestä viestintäsovelluksiin ja aloittelevaan yhteistyöhön. Näin opettajat laajensivat virtuaalireviiriään tietoverkkojen dynaamisiksi toimijoiksi ja pääsivät uusin keinoin tyydyttämään ihmisen universaalia tarvetta yhteyteen muiden kanssa. Samalla opettajat valtautuivat informaation kuluttajista sen tuottajiksi, objekteista subjekteiksi. Verkko-opetus avaa koulun maantieteelle huomattavia mahdollisuuksia. Mobiililaitteiden avulla informaatiota voidaan kerätä ja tallentaa maasto-olosuhteissa, ohjelmilla sitä voidaan muuntaa muodosta toiseen. Internetin autenttiset ja ajantasaiset materiaalit tuovat opiskeluun konkretiaa ja kiinnostavuutta, mallit, simulaatiot ja paikkatieto havainnollistavat ilmiöitä. Viestintä- ja yhteistyövälineet sekä sosiaaliset informaatiotilat vahvistavat yhteistyötä. Avainsanat: verkko-opetus, internet, virtuaalimaailmat, maantiede, innovaatiot
Resumo:
The National Board of Education in Finland has defined school catering as a part of education in comprehensive schools. School catering is defined in Finnish law and is financed by the municipalities. The emphasis on supplementary education in the school curriculum obliges the whole staff to learn new professional roles and to co-operate in the school com-munity. An in-service training programme, Smart Catering Staff (SCS) was designed and put into practice among school catering staff. The aim of the one-year SCS programme was to add to and encourage the development of the know-how of catering personnel regarding new challenges in the school community as well as to enhance and empower their educator’s role in the school. The content of the programme consisted of four two-day intensive teaching sessions as well as assignments which were carried out between theese sessions. The main contents of the SCS programme were personal and organizational learning, school curriculum concerning school catering, school culture and co-operation, customer service, and the role of catering staff as educators. The data in this action research was gathered from 2000 to 2008. The results show that the SCS programme can change the work community culture in that the catering staff is more encouraged to participate in the development projects of the school, and can see themselves more as educators alongside the teaching staff. It is concluded that in school communities all adults can be educators, but to achieve this aim empowering in-service training is needed. The school catering staff’s commitment to participation in the education align with the educational goals of the school unite children’s and teens safety nets. This can affect for example the growth of communal responsibility and prevention of alienation. Key words: School Catering, Smart School Catering Staff, Expanded Education, School Community, Action Research
Resumo:
Motivation and personal goals play an important role in the ways in which people direct their behavior. Personal goals are closely connected with well-being but they also relate to how people perform in different achievement domains. Many studies show that evaluating study-related goals as important, easy to attain and non stressful, predict better academic achievements than evaluating them as non attainable and stressful (Salmela-Aro & Nurmi, 1997b). The aim of this study was to describe motivational factors among theology students. They form an interesting group in terms of exploring connections between motivation, spiritual goals and academic achievements. The average duration of graduation at the Faculty of Theology is among the highest at the University of Helsinki. On the other hand, it may be assumed that many theology students have spiritual goals which affect their studies. A special focus was paid on the different evaluations of study-related personal projects and how they are related to academic achievement. A methodology of personal projects (Little, 1983) was used to study what kind of personal goals theology students are engaged in during their studies. In the first part of the questionnaire the subjects (N=133) were asked to describe important personal projects. They were given four numbered lines for their written responses. In the second part the subjects were asked to rate projects concerning their studies according to 13 dimensions using a 7-point Likert-scale. Three subgroups were formed on a K-Means Cluster Analysis on the basis of evaluations of the study-related projects. The groups were named committed, self-fulfillers and non-committed according to their evaluations of their study related projects. Academic achievements among the different groups varied substantially. After two years of studying the students who were in the committed group had completed on an average twenty study credits more than those who were in the non-committed group. Self-fulfillers placed in the middle of the three groups. Committed and self-fulfiller students also reported higher levels of intrinsic reasons for striving towards study-related goals. The results indicate that goals reported at the beginning of studies predicted academic achievement later on. The results also showed that different evaluations of goals have long lasting connections to progress in studying. Implications for student well-being and how these results can be utilized for student counseling are discussed.
Resumo:
The aim of the study was to get acquainted with the activity of Näppärät Mummot, a Lahti-based crafts society, and its importance to the wellness of the members of the group. The selected aim, i.e., analyzing the wellness, largely affected the whole research process and its results. According to earlier studies in the field, different forms of craft and expressional activity promote one's wellness as well as support the work for one's identity. Based on my theoretical knowledge, my research was set out to: 1) form a general view of crafts culture within Näppärät Mummot and 2) find out how recollective craft that promotes wellness is perceived through communality, experiential activity, work for one's identity, and divided as well as undivided craft. Qualitative field work was governed by ethnographic research strategy, according to which I set out to get thoroughly familiar with the society I was studying. The methods I used to collect data were participant observation and thematic interview. I used a field diary for writing down all data I acquired through the observation. The interviewee group was formed by seven members of Näppärät Mummot. An mp3 recorder was used to record the interviews, which I transcribed later. The method for data analysis was qualitative content analysis, for which I used Weft QDA, a qualitative analysis software application. I formed themes that shed light on research tasks from the data using coding and theory-driven analysis. I kept literature and data I collected in cooperation through the whole analysis process. Lastly, drawing from the classes of meaning of therapeutic craft that I sketched by means of summarizing and classifying, I presented the central concepts that describe the main results of the study. The main results were six concepts that describe Näppärät Mummot's crafts culture and recollective craft with its wellness-beneficial effect: 1) autobiographical craft, 2) shared work for one's identity, 3) shared intention for craft, 4) craft as a partner, 5) individual manner of craft, and 6) shared improvement. Craft promoted wellness in many ways. It was used to promote inner life management in difficult times and it also provided sensations of empowerment through pleasure from craft. Expressional, shared craft also served as means of reinforcing one's identity in various ways. Expressional work for one's identity through autobiographical themes of craft represented rearranging one's life through holistic craft. A personal way of doing things also served as expressional action and work for one's identity even with divided craft. Shared work for identities meant reinforcing the identities of the members through discources of craft and interaction with their close ones. What proves the interconnection between communality and craft as well as their shared meaning is that communality motivated the members to work on their craft projects, while craft served as the means of communication between the members: communication through craft was easier than lingual communication. The results can not be generalized to apply to other groups: they are used to describe the versatile means of recollective craft to promote the well-being among the crafts society Näppärät Mummot. However, the results do introduce a new perspective to the social discussion on how cultural activities promote well-being.
Resumo:
The central nervous system (CNS) is the most cholesterol-rich organ in the body. Cholesterol is essential to CNS functions such as synaptogenesis and formation of myelin. Significant differences exist in cholesterol metabolism between the CNS and the peripheral organs. However, the regulation of cholesterol metabolism in the CNS is poorly understood compared to our knowledge of the regulation of cholesterol homeostasis in organs reached by cholesterol-carrying lipoprotein particles in the circulation. Defects in CNS cholesterol homeostasis have been linked to a variety of neurodegenerative diseases, including common diseases with complex pathogenetic mechanisms such as Alzheimer s disease. In spite of intense effort, the mechanisms which link disturbed cholesterol homeostasis to these diseases remain elusive. We used three inherited recessive neurodegenerative disorders as models in the studies included in this thesis: Niemann-Pick type C (NPC), infantile neuronal ceroid lipofuscinosis and cathepsin D deficiency. Of these three, NPC has previously been linked to disturbed intracellular cholesterol metabolism. Elucidating the mechanisms with which disturbances of cholesterol homeostasis link to neurodegeneration in recessive inherited disorders with known genetic lesions should shed light on how cholesterol is handled in the healthy CNS and help to understand how these and more complex diseases develop. In the first study we analyzed the synthesis of sterols and the assembly and secretion of lipoprotein particles in Npc1 deficient primary astrocytes. We found that both wild type and Npc1 deficient astrocytes retain significant amounts of desmosterol and other cholesterol precursor sterols as membrane constituents. No difference was observed in the synthesis of sterols and the secretion of newly synthesized sterols between Npc1 wild type, heterozygote or knockout astrocytes. We found that the incorporation of newly synthesized sterols into secreted lipoprotein particles was not inhibited by Npc1 mutation, and the lipoprotein particles were similar to those excreted by wild type astrocytes in shape and size. The bulk of cholesterol was found to be secreted independently of secreted NPC2. These observations demonstrate the ability of Npc1 deficient astrocytes to handle de novo sterols, and highlight the unique sterol composition in the developing brain. Infantile neuronal ceroid lipofuscinosis is caused by the deficiency of a functional Ppt1 enzyme in the cells. In the second study, global gene expression studies of approximately 14000 mouse genes showed significant changes in the expression of 135 genes in Ppt1 deficient neurons compared to wild type. Several genes encoding for enzymes of the mevalonate pathway of cholesterol biosynthesis showed increased expression. As predicted by the expression data, sterol biosynthesis was found to be upregulated in the knockout neurons. These data link Ppt1 deficiency to disturbed cholesterol metabolism in CNS neurons. In the third study we investigated the effect of cathepsin D deficiency on the structure of myelin and lipid homeostasis in the brain. Our proteomics data, immunohistochemistry and western blotting data showed altered levels of the myelin protein components myelin basic protein, proteolipid protein and 2 , 3 -cyclic nucleotide 3 phosphodiesterase in the brains of cathepsin D deficient mice. Electron microscopy revealed altered myelin structure in cathepsin D deficient brains. Additionally, plasmalogen-derived alkenyl chains and 20- and 24-carbon saturated and monounsaturated fatty acids typical for glycosphingolipids were found to be significantly reduced, but polyunsaturated species were significantly increased in the knockout brains, pointing to a decrease in white matter. The levels of ApoE and ABCA1 proteins linked to cholesterol efflux in the CNS were found to be altered in the brains of cathepsin D deficient mice, along with an accumulation of cholesteryl esters and a decrease in triglycerols. Together these data demonstrate altered myelin architecture in cathepsin D deficient mice and link cathepsin D deficiency to aberrant cholesterol metabolism and trafficking. Basic research into rare monogenic diseases sheds light on the underlying biological processes which are perturbed in these conditions and contributes to our understanding of the physiological function of healthy cells. Eventually, understanding gained from the study of disease models may contribute towards establishing treatment for these disorders and further our understanding of the pathogenesis of other, more complex and common diseases.
Resumo:
The main targets of human immunodeficiency virus (HIV) are CD4 receptors of CD4+ lymphocytes and many other cells such as monocytes/macrophages, megakaryocytes, peripheral blood dendritic cells, follicular dendritic cells (DC), epidermal Langerhans cells, and astrocytes. Infection and killing of CD4+ lymphocytes or false reaction of the body to HIV infection and the spontaneous apoptosis of CD4+ lymphocytes decrease CD4+ lymphocyte counts leading to immunosuppression, further disease progression, and appearance of opportunistic infections and malignancies. Oral manifestations are considered to be among the first signs of HIV infection. Enhanced degradation of extracellular matrix and basement membrane components in oral diseases including periodontitis is caused by Zn-dependent enzymes called matrix metalloproteinases (MMPs). The levels and degrees of activation of MMP-1, -2, -3, -7, -8, -9, -25, -26, tissue inhibitors of MMPs (TIMP)-1 and -2, and myeloperoxidase (MPO) and collagenolytic/gelatinolytic activities, and also Ig A, -G, and -M, total protein, and albumin levels in a two-year follow-up were studied from salivary samples. The expression of MMP-7, -8, -9, -25, and -26 immunoreactivities in gingival tissue specimens were studied. Healthy HIV-negative subjects served as controls. All studied clinical periodontal parameters and microbiological evaluation of the periodontopathogens showed that periodontal health of the HIV-positive patients was moderately decreased in comparison to the healthy controls. The levels of Candida in the periodontal pockets and salivary MPO increased with the severity of HIV infection. Immunoreactivities and levels of MMPs and TIMPs, and MMP activities (collagenase, gelatinase) were enhanced in the HIV-positive patient salivary samples relative to the healthy controls regardless of the phase of HIV infection. However, these parameters did not reflect periodontal status in a similar way as in the generally healthy periodontitis patients. Salivary total protein, albumin, IgA, -G, and -M levels were significantly higher in all phases of HIV infection compared to the controls, and salivary total protein, IgG and IgM levels remained higher after two years follow-up, partly correlating with the disease progression and which may reflect the leakage of serum components into the mouth and thus a decreased mucosal barrier. Salivary analyses of MMPs and TIMPs with immunohistochemical analyses showed that HIV infection could predispose to periodontal destruction when compared with healthy controls or the body s defence reactions associated with HIV infection may have been reflected or mediated by MMPs.
Design and testing of stand-specific bucking instructions for use on modern cut-to-length harvesters
Resumo:
This study addresses three important issues in tree bucking optimization in the context of cut-to-length harvesting. (1) Would the fit between the log demand and log output distributions be better if the price and/or demand matrices controlling the bucking decisions on modern cut-to-length harvesters were adjusted to the unique conditions of each individual stand? (2) In what ways can we generate stand and product specific price and demand matrices? (3) What alternatives do we have to measure the fit between the log demand and log output distributions, and what would be an ideal goodness-of-fit measure? Three iterative search systems were developed for seeking stand-specific price and demand matrix sets: (1) A fuzzy logic control system for calibrating the price matrix of one log product for one stand at a time (the stand-level one-product approach); (2) a genetic algorithm system for adjusting the price matrices of one log product in parallel for several stands (the forest-level one-product approach); and (3) a genetic algorithm system for dividing the overall demand matrix of each of the several log products into stand-specific sub-demands simultaneously for several stands and products (the forest-level multi-product approach). The stem material used for testing the performance of the stand-specific price and demand matrices against that of the reference matrices was comprised of 9 155 Norway spruce (Picea abies (L.) Karst.) sawlog stems gathered by harvesters from 15 mature spruce-dominated stands in southern Finland. The reference price and demand matrices were either direct copies or slightly modified versions of those used by two Finnish sawmilling companies. Two types of stand-specific bucking matrices were compiled for each log product. One was from the harvester-collected stem profiles and the other was from the pre-harvest inventory data. Four goodness-of-fit measures were analyzed for their appropriateness in determining the similarity between the log demand and log output distributions: (1) the apportionment degree (index), (2) the chi-square statistic, (3) Laspeyres quantity index, and (4) the price-weighted apportionment degree. The study confirmed that any improvement in the fit between the log demand and log output distributions can only be realized at the expense of log volumes produced. Stand-level pre-control of price matrices was found to be advantageous, provided the control is done with perfect stem data. Forest-level pre-control of price matrices resulted in no improvement in the cumulative apportionment degree. Cutting stands under the control of stand-specific demand matrices yielded a better total fit between the demand and output matrices at the forest level than was obtained by cutting each stand with non-stand-specific reference matrices. The theoretical and experimental analyses suggest that none of the three alternative goodness-of-fit measures clearly outperforms the traditional apportionment degree measure. Keywords: harvesting, tree bucking optimization, simulation, fuzzy control, genetic algorithms, goodness-of-fit
Resumo:
Tutkimuksen tavoitteena on historiantutkimuksen menetelmiä käyttäen selvittää metsänhoidon teorian sekä käytännön metsänhoidon kehitysvaiheet ja näihin vaikuttaneet tekijät, keskiajalta lähtien 1870-luvulla tapahtuneeseen metsäteollisuuden läpimurtoon saakka. Tutkimus tarkastelee Suomen metsiä, niiden käyttöä ja metsänhoidon alkuvaiheita Ruotsin ja Venäjän vallan aikoina. Vastauksia haetaan erityisesti seuraaviin pääkysymyksiin: - miten eri metsänkäyttömuodot ja -käyttäjät vaikuttivat metsiin ja metsänhoidon edistymiseen? - millä tavoin maanomistuksen kehitys vaikutti metsien käyttöön ja hoitoon? - millaisiin päämääriin ja yhteiskunnallisiin taustatekijöihin metsien käytön julkinen ohjaus perustui? - mitä käytännön vaikutuksia valtion metsäpolitiikalla ja ohjauksella oli metsänhoidon kehitykseen? - missä ja miten kehittyivät Suomessa sovellettu metsänhoidon teoria ja käytännön menetelmät? - mitkä tekijät säätelivät metsänhoidon teorioiden soveltamista käytäntöön? - mikä oli naapurimaiden metsänhoidon sekä kansainvälisten yhteyksien merkitys metsänhoidon kehitykselle Suomessa? - miten vuosisatainen pelko metsien ja puun loppumisesta vaikutti metsänhoidon kehitykseen? - millainen merkitys puun arvon kehityksellä oli metsänhoidon alkuun saattamiselle ja edistymiselle? Suomessa harjoitettiin 1870-luvulle saakka pääasiassa talonpoikaista metsänkäyttöä. Maaseudun väestö hankki toimeentulonsa metsistä eränkäynnin, kaskiviljelyn, laiduntamisen, rakennushirsien valmistamisen, tervantuotannon ja paikoin myös potaskan tai sysien valmistamisen avulla. Erityisesti rannikkoseuduilla tuotettiin "isorakennuksen puita", lehtereitä, mastopuita ja muuta erikoispuutavaraa. Lautojen ja lankkujen sahaus laajeni vähitellen, saavuttaen 1800-luvun lopulla hallitsevan aseman myyntiin tarkoitettujen metsäntuotteiden tuotannossa. Polttopuun sekä muun kotitarvepuun kulutus säilyi suurimpana puunkäytön ryhmänä pitkälle 1900-luvulle saakka. Mainituista metsänkäyttömuodoista erityisesti kaskeaminen ja sitä seuraava laiduntamisvaihe sekä tervaspuiden koloaminen "autioittivat" laajoja metsäalueita. Tiheimmin asutuilla seuduilla esiintyi pulaa poltto- ja rakennuspuusta myöhäiskeskiajalta alkaen. Nämä ongelmat sekä laivanrakennuksen ja vuoriteollisuuden puunsaannin turvaamisen tarve johtivat 1600-luvun puolivälissä pysyvään metsänkäytön julkiseen ohjaukseen. Tuolloin Ruotsin valtakunnan metsälainsäädännön kivijalaksi tuli kestävyyden periaate, josta kruunu kylläkin joutui tinkimään moneen otteeseen. Valtion jatkuva rahantarve oli käytännössä metsäpolitiikan tärkein taustavoima sekä Ruotsin vallan että autonomian aikana. Jo 1600-luvulla ruvettiin vaatimaan talonpoikien yhteismaiden jakamista omistajilleen vastuullisemman metsänkäytön nimissä. Isoajakoa saatiin Suomessa odottaa 1770-luvulle saakka. Etelä-Suomessa se valmistui melko nopeasti, 1800-luvun puoliväliin mennessä. Sillä olikin myönteinen, metsien säästävämpään käsittelyyn johtava vaikutus. Valtiosta tuli isonjaon myötä erityisesti Pohjois-Suomessa merkittävä metsänomistaja 1800-luvun jälkipuoliskolla. Valtion metsähallinto, jota maaherrat ja sivistyneistö vaativat perustettavaksi jo 1700-luvun puolivälissä, aloitti toimintansa maanlaajuisesti 1860-luvulla. Se oli ensimmäinen merkittävä metsänhoidon organisaatio, ja vasta sen myötä metsänkäyttöä ohjaavilla säädöksillä ja ohjeilla alkoi olla käytännön merkitystä. Yksityismetsiä varten ei tällaista organisaatiota vielä perustettu, niitä rasittivat pahoin nousevan sahateollisuuden määrämittahakkuut pitkälle 1900-luvun puolelle. Turun Akatemiassa tehtiin mittavaa metsänhoidon menetelmiä koskevaa sekä myös metsäpoliittista tutkimustyötä 1700-luvun jälkipuoliskolla. Tulokset eivät vielä sanottavasti siirtyneet käytäntöön, lähinnä puun alhaisen arvon ja tarvittavien organisaatioiden puuttumisen takia. Kun valtion metsähallintoa ja Suomen omaa metsäopetusta ryhdyttiin perustamaan 1800-luvun puolivälissä, haettiin metsänhoidon mallia alan johtavaksi maaksi kehittyneestä Saksasta. Tultaessa 1870-luvulle, oli Evolla jo käynnissä voimakas kehitystyö maamme olosuhteisiin soveltuvien menetelmien luomiseksi saksalaisen teorian pohjalta. Metsänhoidon tiedot ja taidot olisivat jo tässä vaiheessa riittäneet kestävän metsätalouden harjoittamiseen kaikkien omistajaryhmien metsissä, jos tarvittavat organisaatiot olisi kyetty perustamaan ja metsäammattilaisia olisi koulutettu tarpeeksi. Metsänhoidon kehitystä hidastivat 1800-luvun lopulla lähinnä valtion heikko talous ja poliittiset näkemyserot. Metsäteollisuuden 1870-luvulta alkanut voimakas kasvu ja lisääntyvä puuntarve pakottivat kuitenkin valtiovallan pitämään huolta puuntuotannon jatkuvuudesta. Metsäteollisuuden kasvavan viennin kautta lisääntyvät verotulot ja kan-santalouden myönteinen kehitys antoivat vähitellen mahdollisuuden metsänhoidon edistämiseen ammattilaisten koulutuksen, kansalaisten neuvonnan, lainsäädännön ja viranomaisten toiminnan kautta. Tämä tutkimus lähestyy aihettaan metsähistorian, taloushistorian, yhteiskuntahistorian ja ympäristöhistorian näkökulmista. Ajankohtaista merkitystä sillä on kehitysmaiden sekä Itä-Euroopan siirtymätalouksien metsänhoidon edistämiselle, missä suomalaiset metsäammattilaiset ovat mukana lukuisten kehityshankkeiden asiantuntijoina. Kymmenissä maissa metsätalous kamppailee samanlaisten ongelmien kanssa kuin Suomessa ja naapurimaissa 100 - 300 vuotta sitten. Meidän kokemuksistamme on näille kansantalouksille hyötyä valtion- ja yksityismetsätalouden metsänhoito-organisaatioita sekä metsälainsäädäntöä kehitettäessä.
Resumo:
Selenium (Se) has been demonstrated to be an essential trace element for maintenance of animal and human health. Although it has not been confirmed to be an essential micronutrient in higher plants, there is increasing evidence that Se functions as an antioxidant in plants. Selenium has been shown to exert a beneficial effect on crop growth and promotes stress tolerance at low concentrations. However, the specific physiological mechanisms that underlie the positive effects of Se in plants have not been clearly elucidated. The aims of this study were to determine the Se concentration in potato (Solanum tuberosum L.) and the effects of Se on the accumulation of carbohydrates, growth and yield in potato plants. An additional aim was to study the impact of Se on the total glycoalkaloid concentration in immature potato tubers. The distribution of Se in different biochemical Se fractions and the effect of storage on the Se concentration were studied in Se-enriched tubers. Furthermore, the effect of Se on raw darkening and translocation of Se from seed tubers to the next tuber generation was investigated. Due to the established anti-ageing properties of Se, it was of interest to study if Se affects physiological age and growth vigour of seed tubers. The Se concentrations in the upper leaves, roots, stolons and tubers of potato increased with increasing Se supplementation. The highest Se concentration was reached in young upper leaves, roots and stolons, indicating that added selenate was efficiently utilized and taken up at an early stage. During the growing period the Se concentration declined in the aerial parts, roots and stolons of potato plants whereas an intensive accumulation took place in immature and mature tubers. Selenium increased carbohydrate accumulation in the young upper leaves and in stolons, roots and tubers at maturity. This could not be explained by increased production of photoassimilates as net photosynthesis did not differ among Se treatments. The Se treated plants produced higher tuber yields than control plants, and at the highest Se concentration (0.3 mg kg-1) lower numbers of larger tubers were harvested. Increased yield of Se treated plants suggested that Se may enhance the allocation of photoassimilates for tuber growth, acting as a strong sink for both Se and for carbohydrates. Similarly as for other plant species, the positive impact of Se on the yield of potato plants could be related to its antioxidative effect in delaying senescence. The highest Se supplementation (0.9 mg kg-1) slightly decreased the glycoalkaloid concentration of immature tubers. However, at this level the Se concentration in tubers was about 20 µg g-1 DW. A 100 g consumption of potato would provide about 500 mg of Se, which exceeds the upper safe intake level of 400 µg per day for human dietary. The low Se applications (0.0035 and 0.1 mg kg-1) diminished and retarded the degree of raw darkening in tubers stored for one and eight months, which can be attributed to the antioxidative properties of Se. The storage for 1 to 12 months did not affect the Se concentrations of tubers. In the Se enriched tubers Se was allocated to the organic Se fraction, indicating that it was incorporated into organic compounds in tubers. Elevated Se concentration in the next-generation tubers produced by the Se enriched seed tubers indicated that Se could be translocated from the seed tubers to the progeny. In the seed tubers stored for 8 months, at high levels, Se had some positive effects on the growth vigour of sprouts, but Se had no consistent effect on the growth vigour of seed tubers of optimal physiological age. These results indicate that Se is a beneficial trace element in potato plants that exerts a positive effect on yield formation and improves the processing and storage quality of table potato tubers. These positive effects of Se are, however, dependent on the Se concentration and the age of the potato plant and tuber.
Resumo:
The studies presented in this thesis contribute to the understanding of evolutionary ecology of three major viruses threatening cultivated sweetpotato (Ipomoea batatas Lam) in East Africa: Sweet potato feathery mottle virus (SPFMV; genus Potyvirus; Potyviridae), Sweet potato chlorotic stunt virus (SPCSV; genus Crinivirus; Closteroviridae) and Sweet potato mild mottle virus (SPMMV; genus Ipomovirus; Potyviridae). The viruses were serologically detected and the positive results confirmed by RT-PCR and sequencing. SPFMV was detected in 24 wild plant species of family Convolvulacea (genera Ipomoea, Lepistemon and Hewittia), of which 19 species were new natural hosts for SPFMV. SPMMV and SPCSV were detected in wild plants belonging to 21 and 12 species (genera Ipomoea, Lepistemon and Hewittia), respectively, all of which were previously unknown to be natural hosts of these viruses. SPFMV was the most abundant virus being detected in 17% of the plants, while SPMMV and SPCSV were detected in 9.8% and 5.4% of the assessed plants, respectively. Wild plants in Uganda were infected with the East African (EA), common (C), and the ordinary (O) strains, or co-infected with the EA and the C strain of SPFMV. The viruses and virus-like diseases were more frequent in the eastern agro-ecological zone than the western and central zones, which contrasted with known incidences of these viruses in sweetpotato crops, except for northern zone where incidences were lowest in wild plants as in sweetpotato. The NIb/CP junction in SPMMV was determined experimentally which facilitated CP-based phylogenetic and evolutionary analyses of SPMMV. Isolates of all the three viruses from wild plants were genetically similar to those found in cultivated sweetpotatoes in East Africa. There was no evidence of host-driven population genetic structures suggesting frequent transmission of these viruses between their wild and cultivated hosts. The p22 RNA silencing suppressor-encoding sequence was absent in a few SPCSV isolates, but regardless of this, SPCSV isolates incited sweet potato virus disease (SPVD) in sweetpotato plants co-infected with SPFMV, indicating that p22 is redundant for synergism between SCSV and SPFMV. Molecular evolutionary analysis revealed that isolates of strain EA of SPFMV that is largely restricted geographically in East Africa experience frequent recombination in comparison to isolates of strain C that is globally distributed. Moreover, non-homologous recombination events between strains EA and C were rare, despite frequent co-infections of these strains in wild plants, suggesting purifying selection against non-homologous recombinants between these strains or that such recombinants are mostly not infectious. Recombination was detected also in the 5 - and 3 -proximal regions of the SPMMV genome providing the first evidence of recombination in genus Ipomovirus, but no recombination events were detected in the characterized genomic regions of SPCSV. Strong purifying selection was implicated on evolution of majority of amino acids of the proteins encoded by the analyzed genomic regions of SPFMV, SPMMV and SPCSV. However, positive selection was predicted on 17 amino acids distributed over the whole the coat protein (CP) in the globally distributed strain C, as compared to only 4 amino acids in the multifunctional CP N-terminus (CP-NT) of strain EA largely restricted geographically to East Africa. A few amino acid sites in the N-terminus of SPMMV P1, the p7 protein and RNA silencing suppressor proteins p22 and RNase3 of SPCSV were also submitted to positive selection. Positively selected amino acids may constitute ligand-binding domains that determine interactions with plant host and/or insect vector factors. The P1 proteinase of SPMMV (genus Ipomovirus) seems to respond to needs of adaptation, which was not observed with the helper component proteinase (HC-Pro) of SPMMV, although the HC-Pro is responsible for many important molecular interactions in genus Potyvirus. Because the centre of origin of cultivated sweetpotato is in the Americas from where the crop was dispersed to other continents in recent history (except for the Australasia and South Pacific region), it would be expected that identical viruses and their strains occur worldwide, presuming virus dispersal with the host. Apparently, this seems not to be the case with SPMMV, the strain EA of SPFMV and the strain EA of SPCSV that are largely geographically confined in East Africa where they are predominant and occur both in natural and agro-ecosystems. The geographical distribution of plant viruses is constrained more by virus-vector relations than by virus-host interactions, which in accordance of the wide range of natural host species and the geographical confinement to East Africa suggest that these viruses existed in East African wild plants before the introduction of sweetpotato. Subsequently, these studies provide compelling evidence that East Africa constitutes a cradle of SPFMV strain EA, SPCSV strain EA, and SPMMV. Therefore, sweet potato virus disease (SPVD) in East Africa may be one of the examples of damaging virus diseases resulting from exchange of viruses between introduced crops and indigenous wild plant species. Keywords: Convolvulaceae, East Africa, epidemiology, evolution, genetic variability, Ipomoea, recombination, SPCSV, SPFMV, SPMMV, selection pressure, sweetpotato, wild plant species Author s Address: Arthur K. Tugume, Department of Agricultural Sciences, Faculty of Agriculture and Forestry, University of Helsinki, Latokartanonkaari 7, P.O Box 27, FIN-00014, Helsinki, Finland. Email: tugume.arthur@helsinki.fi Author s Present Address: Arthur K. Tugume, Department of Botany, Faculty of Science, Makerere University, P.O. Box 7062, Kampala, Uganda. Email: aktugume@botany.mak.ac.ug, tugumeka@yahoo.com
Resumo:
In Finland, suckler cow production is carried out in circumstances characterized by a long winter period and a short grazing period. The traditional winter housing system for suckler cows has been insulated or uninsulated buildings, but there is a demand for developing less expensive housing systems. In addition, more information is needed on new winter feeding strategies, carried out in inexpensive winter facilities with conventional (hay, grass silage, straw) or alternative (treated straw, industrial by-product, whole-crop silage) feeds. The new feeding techniques should not have any detrimental effects on animal welfare in order to be acceptable to both farmers and consumers. Furthermore, no official feeding recommendations for suckler cows are available in Finland and, thus, recommendations for dairy cows have been used. However, this may lead to over- or underfeeding of suckler cows and, finally, to decreased economic output. In Experiment I, second-calf beef-dairy suckler cows were used to compare the effects of diets based on hay (H) or urea-treated straw (US) at two feeding levels (Moderate; M vs. Low; L) on the performance of cows and calves. Live weight (LW) gain during the indoor feeding was lower for cows on level L than on level M. Cows on diet US lost more LW indoors than those on diet H. The cows replenished the LW losses on good pasture. Calf LW gain and cow milk production were unaffected by the treatments. Conception rate was unaffected by the treatments but was only 69%. Urea-treated straw proved to be a suitable winter feed for spring-calving suckler cows. Experiment II studied the effects of feeding accuracy on the performance of first- and second-calf beef-dairy cows and calves. In II-1, the day-to-day variation in the roughage offered ranged up to ± 40%. In II-2, the same variation was used in two-week periods. Variation of the roughages offered had minor effects on cow performance. Reproduction was unaffected by the feeding accuracy. Accurate feeding is not necessary for young beef-dairy crosses, if the total amount of energy offered over a period of a few weeks fulfills the energy requirements. Effects of feeding strategies with alternative feeds on the performance of mature beef-dairy and beef cows and calves were evaluated in Experiment III. Two studies consisted of two feeding strategies (Step-up vs. Flat-rate) and two diets (Control vs. Alternative). There were no differences between treatments in the cow LW, body condition score (BCS), calf pre-weaning LW gain and cow reproduction. A flat-rate strategy can be practised in the nutrition of mature suckler cows. Oat hull based flour-mill by product can partly replace grass silage and straw in the winter diet. Whole-crop barley silage can be offered as a sole feed to suckler cows. Experiment IV evaluated during the winter feeding period the effects of replacing grass silage with whole-crop barley or oat silage on mature beef cow and calf performance. Both whole-crop silages were suitable winter feeds for suckler cows in cold outdoor winter conditions. Experiment V aimed at assessing the effects of daily feeding vs. feeding every third day on the performance of mature beef cows and calves. No differences between the treatments were observed in cow LW, BCS, milk production and calf LW. The serum concentrations of urea and long-chain fatty acids were increased on the third day after feeding in the cows fed every third day. Despite of that the feeding every third day is an acceptable feeding strategy for mature suckler cows. Experiment VI studied the effects of feeding levels and long-term cold climatic conditions on mature beef cows and calves. The cows were overwintered in outdoor facilities or in an uninsulated indoor facility. Whole-crop barley silage was offered either ad libitum or restricted. All the facilities offered adequate shelter for the cows. The restricted offering of whole-crop barley silage provided enough energy for the cows. The Finnish energy recommendations for dairy cows were too high for mature beef breed suckler cows in good body condition at housing, even in cold conditions. Therefore, there is need to determine feeding recommendations for suckler cows in Finland. The results showed that the required amount of energy can be offered to the cows using conventional or alternative feeds provided at a lower feeding level, with an inaccurate feeding, flat-rate feeding or feeding every third day strategy. The cows must have an opportunity to replenish the LW and BCS losses at pasture before the next winter. Production in cold conditions can be practised in inexpensive facilities when shelter against rain and wind, a dry resting place, adequate amounts of feed suitable for cold conditions and water are provided for the animals as was done in the present study.
Resumo:
This thesis reports on investigations into the influence of heat treatment on the manufacturing of oat flakes. Sources of variation in the oat flake quality are reviewed, including the whole chain from the farm to the consumer. The most important quality parameters of oat flakes are the absence of lipid hydrolysing enzymes, specific weight, thickness, breakage (fines), water absorption. Flavour, colour and pasting properties are also important, but were not included in the experimental part of this study. Of particular interest was the role of heat processing. The first possible heat treatment may occur already during grain drying, which in Finland generally happens at the farm. At the mill, oats are often kilned to stabilise the product by inactivating lipid hydrolysing enzymes. Almost invariably steaming is used during flaking, to soften the groats and reduce flake breakage. This thesis presents the use of a material science approach to investigating a complex system, typical of food processes. A combination of fundamental and empirical rheological measurements was used together with a laboratory scale process to simulate industrial processing. The results were verified by means of industrial trials. Industrially produced flakes at three thickness levels (nominally 0.75, 0.85 and 0.90 mm) were produced from kilned and unkilned oat groats, and the flake strength was measured at different moisture contents. Kilning was not found to significantly affect the force required to puncture a flake with a 2mm cylindrical probe, which was taken as a measure of flake strength. To further investigate how heat processing contributes to flake quality, dynamic mechanical analysis was used to characterise the effect of heat on the mechanical properties of oats. A marked stiffening of the groat, of up to about 50% increase in storage modulus, was observed during first heating at around 36 to 57°C. This was also observed in tablets prepared from ground groats and extracted oat starch. This stiffening was thus attributed to increased adhesion between starch granules. Groats were steamed in a laboratory steamer and were tempered in an oven at 80 110°C for 30 90 min. The maximum force required to compress the steamed groats to 50% strain increased from 50.7 N to 57.5 N as the tempering temperature was increased from 80 to 110°C. Tempering conditions also affected water absorption. A significantly higher moisture content was observed for kilned (18.9%) compared to unkilned (17.1%) groats, but otherwise had no effect on groat height, maximum force or final force after a 5 s relaxation time. Flakes were produced from the tempered groats using a laboratory flaking machine, using a roll gap of 0.4 mm. Apart from specific weight, flake properties were not influenced by kilning. Tempering conditions however had significant effects on the specific weight, thickness and water absorption of the flakes, as well as on the amount of fine material (<2 mm) produced during flaking. Flake strength correlated significantly with groat strength and flake thickness. Trial flaking at a commercial mill confirmed that groat temperature after tempering influenced water absorption. Variation in flake strength was observed , but at the groat temperatures required to inactivate lipase, it was rather small. Cold flaking of groats resulted in soft, floury flakes. The results presented in this thesis suggest that heating increased the adhesion between starch granules. This resulted in an increase in the stiffness and brittleness of the groat. Brittle fracture, rather than plastic flow, during flaking could result in flaws and cracks in the flake. These would be expected to increase water absorption. This was indeed observed as tempering temperature increased. Industrial trials, conducted with different groat temperatures, confirmed the main findings of the laboratory experiments. The approach used in the present study allowed the systematic study of the effect of interacting process parameters on product quality. There have been few scientific studies of oat processing, and these results can be used to understand the complex effects of process variables on flake quality. They also offer an insight into what happens as the oat groat is deformed into a flake.
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Screening of wastewater effluents from municipal and industrial wastewater treatment plants with biotests showed that the treated wastewater effluents possess only minor acute toxic properties towards whole organisms (e.g. bacteria, algae, daphnia), if any. In vitro tests (sub-mitochondrial membranes and fish hepatocytes) were generally more susceptible to the effluents. Most of the effluents indicated the presence of hormonally active compounds, as the production of vitellogenin, an egg yolk precursor protein, was induced in fish hepatocytes exposed to wastewater. In addition, indications of slight genotoxic potential was found in one effluent concentrate with a recombinant bacteria test. Reverse electron transport (RET) of mitochondrial membranes was used as a model test to conduct effluent assessment followed by toxicant characterisations and identifications. Using a modified U.S. EPA Toxicity Identification Evaluation Phase I scheme and additional case-specific methods, the main compound in a pulp and paper mill effluent causing RET inhibition was characterised to be an organic, relatively hydrophilic high molecular weight (HMW) compound. The toxicant could be verified as HMW lignin by structural analyses using nuclear magnetic resonance. In the confirmation step commercial and in-house extracted lignin products were used. The possible toxicity related structures were characterised by statistical analysis of the chemical breakdown structures of laboratory-scale pulping and bleaching effluents and the toxicities of these effluents. Finally, the biological degradation of the identified toxicant and other wastewater constituents was evaluated using bioassays in combination with chemical analyses. Biological methods have not been used routinely in establishing effluent discharge limits in Finland. However, the biological effects observed in this study could not have been predicted using only routine physical and chemical effluent monitoring parameters. Therefore chemical parameters cannot be considered to be sufficient in controlling effluent discharges especially in case of unknown, possibly bioaccumulative, compounds that may be present in small concentrations and may cause chronic effects.
Resumo:
Cereal kernels are known to contain a number of minor components that possess beneficial health attributes. In this thesis rye and wheat were studied as sources of steryl ferulates and steryl glycosides and their behaviour in processing were evaluated. Further, enzymatic hydrolysis of these conjugates was studied, as well as the capacity of steryl ferulates to inhibit lipid oxidation at different temperatures. Steryl ferulates were shown to have a strong positive correlation with dietary fibre contents in milling fractions from the outer parts of the kernels obtained from a commercial scale mill. Highest contents of steryl ferulates were found in the bran in both cereals, with the content decreasing once moving towards the inner parts of the kernel. Variation in the contents of steryl ferulates was higher in wheat fractions than rye fractions. Steryl glycosides, on the other hand, had either negative or no correlation with dietary fibre, and the range of the steryl glycoside contents was much narrower than that of steryl ferulates in both cereals. There were significant differences in the sterol compositions of these steryl conjugates when compared with each other or with the total plant sterols in the corresponding fractions. Properties of steryl ferulates and steryl glycosides were evaluated after common processing methods and in enzymatic hydrolysis. Thermal and mechanical processing had only minor or no effects on the contents of steryl conjugates from rye and wheat bran. Enzymatic treatments on the other hand caused some changes, especially in the contents of glycosylated sterols. When steryl ferulates extracted from rye or wheat bran were subjected to enzymatic treatments by steryl esterase, significant differences in the rates of hydrolysis were observed between steryl ferulates from different sources with differing sterol compositions. Further, differences were also observed between enzymes from different sources. Steryl glycosides were shown to be hydrolysed by β-glucosidase (cellobiase) from A. niger, but less with β-glucosidases from other sources. Steryl ferulates showed good antioxidant activity at both moderate and high temperatures. In bulk and emulsion systems of methyl linoleate at 40°C steryl ferulates extracted from rye and wheat bran inhibited hydroperoxide formation much more effectively than synthetic steryl ferulates or those extracted from rice (γ-oryzanol), demonstrating that the sterol composition has an effect on the activity. At cooking (100°C) and frying temperatures (180°C) sitostanyl ferulate was shown to inhibit polymer formation significantly and, especially at 100°C, comparably to α-tocopherol. The rate of antioxidant degradation was slower for sitostanyl ferulate, showing higher heat stability than α-tocopherol. When evaluated as a mixture, no synergistic effect was observed between these two antioxidants. The data presented in this thesis provides information that may henceforth be applied when evaluating the intakes of steryl conjugates from cereal sources, as well as their possible influences as minor bioactive components. Wheat and rye both are good sources of steryl ferulates and steryl glycosides and, especially with steryl ferulates, what may be lost out to some other cereals on quantity is compensated with quality of the sterol composition.