7 resultados para Foraging strata

em Helda - Digital Repository of University of Helsinki


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The present dissertation analyses 36 local vernaculars of villages surrounding the northern Russian city of Vologda in relation to the system of the vowels in the stressed syllables and those preceding the stressed syllables by using the available dialectological researches. The system in question differs from the corresponding standard Russian system by that the palatalisation of the surrounding consonants affects the vowels much more significantly in the vernaculars, whereas the phonetic difference between the stressed and non-stressed vowels is less obvious in them. The detailed information on the local vernaculars is retrieved from the Dialektologičeskij Atlas Russkogo Jazyka dialect atlas, the data for which were collected, for the most part, in the 1940 s and 1950 s. The theoretical framework of the research consists of a brief cross-section of western sociolinguistic theory related to language change and that of historical linguistics related to the Slavonic vowel development, which includes some new theories concerning the development of the Russian vowel phonemes. The author has collected dialect data in one of the 36 villages and three villages surrounding it. During the fieldwork, speech of nine elderly persons and ten school children was recorded. The speech data were then transcribed with coded information on the corresponding etymological vowels, the phonetic position, and the factual pronunciation at each appearance of vowels in the phonetic positions named above. The data from both of the dialect strata were then systematised to two corresponding systems that were compared with the information retrievable from the dialect atlas and other dialectological literature on the vowel phoneme system of the traditional local vernacular. As a result, it was found out (as hypothesised) that the vernacular vowel phoneme system has approached that of the standard language but has nonetheless not become similar to it. The phoneme quantity of the traditional vernacular is by one greater than that of the standard language, whereas the vowel phoneme quantity in the speech of the school children coincides with that in the standard language, although the phonetic realisations differ to some extent. The analysis of the speech of the elderly people resulted in that it is quite difficult to define the exact phoneme quantity of this stratum due to the fluctuation and irregularities in the realisation of the old phoneme that has ceased to exist in the newest stratum. It was noticed that the effect of the quality of the surrounding consonants on the phonetic realisation of the vowel phonemes has diminished, and the dependence of the phonetic realisation of a vowel phoneme on its place in a word in relation to the word stress has become more and more obvious, which is the state of affairs in the standard language as well.

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Knowledge of the habitat requirements of bat species is needed in decision making in land use planning. Bats' hibernation requirements were studied both in Estonia and in southern Finland. In both countries, the northern bat and the brown long-eared bat hibernated in colder and drier locations, whereas Daubenton's bat and Brandt's/whiskered bats hibernated in warmer and more humid locations. In Estonia, the pond bat hibernated in the warmest and most humid conditions, whereas Natterer's bat hibernated in the coldest and driest conditions. Hibernacula were at their coldest in mid-season and became warmer towards the end of the season. The results suggest that bats made an active choice of colder hibernation temperatures at the seasons end. They minimised the negative effects of hibernation early in the hibernation season by hibernating in warmer locations and energy expenditure late in the hibernation season by hibernating in colder locations. The use of foraging habitats was studied in northern and southern Finland. The northern bat used foraging sites opportunistically. Daubenton's bat foraged mainly in water habitats, whereas Brandt's/whiskered bats and the brown long-eared bat foraged mainly in forest habitats. In northern Finland, Daubenton's bats foraged almost exclusively on rivers and typically together with the northern bat. Daubenton's bats and Brandt's/whiskered bats were found only where there were lower ambient light levels. One of the most important things in the management of foraging areas for them is to keep them shady. Hibernacula in Finland typically housed few bats, suggesting that hibernation sites used by even a small number of bats are important. Bats typically used natural stone for hibernation suggesting that natural underground sites in rocks or cliffs or man-made underground sites built using natural stone are important for them. The results suggest that appropriate timing of surveys may vary according to the species and latitude.

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Individual movement is very versatile and inevitable in ecology. In this thesis, I investigate two kinds of movement body condition dependent dispersal and small-range foraging movements resulting in quasi-local competition and their causes and consequences on the individual, population and metapopulation level. Body condition dependent dispersal is a widely evident but barely understood phenomenon. In nature, diverse relationships between body condition and dispersal are observed. I develop the first models that study the evolution of dispersal strategies that depend on individual body condition. In a patchy environment where patches differ in environmental conditions, individuals born in rich (e.g. nutritious) patches are on average stronger than their conspecifics that are born in poorer patches. Body condition (strength) determines competitive ability such that stronger individuals win competition with higher probability than weak individuals. Individuals compete for patches such that kin competition selects for dispersal. I determine the evolutionarily stable strategy (ESS) for different ecological scenarios. My models offer explanations for both dispersal of strong individuals and dispersal of weak individuals. Moreover, I find that within-family dispersal behaviour is not always reflected on the population level. This supports the fact that no consistent pattern is detected in data on body condition dependent dispersal. It also encourages the refining of empirical investigations. Quasi-local competition defines interactions between adjacent populations where one population negatively affects the growth of the other population. I model a metapopulation in a homogeneous environment where adults of different subpopulations compete for resources by spending part of their foraging time in the neighbouring patches, while their juveniles only feed on the resource in their natal patch. I show that spatial patterns (different population densities in the patches) are stable only if one age class depletes the resource very much but mainly the other age group depends on it.

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In aquatic systems, the ability of both the predator and prey to detect each other may be impaired by turbidity. This could lead to significant changes in the trophic interactions in the food web of lakes. Most fish use their vision for predation and the location of prey can be highly influenced by light level and clarity of the water environment. Turbidity is an optical property of water that causes light to be scattered and absorbed by particles and molecules. Turbidity is highly variable in lakes, due to seasonal changes in suspended sediments, algal blooms and wind-driven suspension of sediments especially in shallow waters. There is evidence that human activity has increased erosion leading to increased turbidity in aquatic systems. Turbidity could also play a significant role in distribution of fish. Turbidity could act as a cover for small fish and reduce predation risk. Diel horizontal migration by fish is common in shallow lakes and is considered as consequences of either optimal foraging behaviour for food or as a trade-off between foraging and predator avoidance. In turbid lakes, diel horizontal migration patterns could differ since turbidity can act as a refuge itself and affect the predator-prey interactions. Laboratory experiments were conducted with perch (Perca fluviatilis L.) and white bream (Abramis björkna (L.)) to clarify the effects of turbidity on their feeding. Additionally to clarify the effects of turbidity on predator preying on different types of prey, pikeperch larvae (Sander lucioperca (L.)), Daphnia pulex (Leydig), Sida crystallina (O.F. Müller), and Chaoborus flavicans (Meigen) were used as prey in different experiments. To clarify the role of turbidity in distribution and diel horizontal migration of perch, roach (Rutilus rutilus (L.)) and white bream, field studies were conducted in shallow turbid lakes. A clear and a turbid shallow lake were compared to investigate distribution of perch and roach in these two lakes in a 15-year study period. Feeding efficiency of perch and white bream was not significantly affected with increasing clay turbidity up to 50 NTU. The perch experiments with pikeperch larvae suggested that clay turbidity could act as a refuge especially at turbidity levels higher than 50 NTU. Perch experiments with different prey types suggested that pikeperch larvae probably use turbidity as a refuge better compared to Daphnia. Increase in turbidity probably has stronger affect on perch predating on plant-attached prey. The main findings of the thesis show that turbidity can play a significant role in distribution of fish. Perch and roach could use turbidity as refuge when macrophytes disappear while small perch may also use high turbidity as refuge when macrophytes are present. Floating-leaved macrophytes are probably good refuges for small fish in clay-turbid lakes and provide a certain level of turbidity and not too complex structure for refuge. The results give light to the predator-prey interactions in turbid environments. Turbidity of water should be taken in to account when studying the diel horizontal migrations and distribution of fish in shallow lakes.

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Ingarden (1962, 1964) postulates that artworks exist in an “Objective purely intentional” way. According to this view, objectivity and subjectivity are opposed forms of existence, parallel to the opposition between realism and idealism. Using arguments of cognitive science, experimental psychology, and semiotics, this lecture proposes that, particularly in the aesthetic phenomena, realism and idealism are not pure oppositions; rather they are aspects of a single process of cognition in different strata. Furthermore, the concept of realism can be conceived as an empirical extreme of idealism, and the concept of idealism can be conceived as a pre-operative extreme of realism. Both kind of systems of knowledge are mutually associated by a synecdoche, performing major tasks of mental order and categorisation. This contribution suggests that the supposed opposition between objectivity and subjectivity, raises, first of all, a problem of translatability, more than a problem of existential categories. Synecdoche seems to be a very basic transaction of the mind, establishing ontologies (in the more Ingardean way of the term). Wegrzecki (1994, 220) defines ontology as “the central domain of philosophy to which other its parts directly or indirectly refer”. Thus, ontology operates within philosophy as the synecdoche does within language, pointing the sense of the general into the particular and/or viceversa. The many affinities and similarities between different sign systems, like those found across the interrelationships of the arts, are embedded into a transversal, synecdochic intersemiosis. An important question, from this view, is whether Ingardean’s pure objectivities lie basically on the impossibility of translation, therefore being absolute self-referential constructions. In such a case, it would be impossible to translate pure intentionality into something else, like acts or products.

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The Lucianic text of the Septuagint of the Historical Books witnessed primarily by the manuscript group L (19, 82, 93, 108, and 127) consists of at least two strata: the recensional elements, which date back to about 300 C.E., and the substratum under these recensional elements, the proto-Lucianic text. Some distinctive readings in L seem to be supported by witnesses that antedate the supposed time of the recension. These witnesses include the biblical quotations of Josephus, Hippolytus, Irenaeus, Tertullian, and Cyprian, and the Old Latin translation of the Septuagint. It has also been posited that some Lucianic readings might go back to Hebrew readings that are not found in the Masoretic text but appear in the Qumran biblical texts. This phenomenon constitutes the proto-Lucianic problem. In chapter 1 the proto-Lucianic problem and its research history are introduced. Josephus references to 1 Samuel are analyzed in chapter 2. His agreements with L are few and are mostly only apparent or, at best, coincidental. In chapters 3 6 the quotations by four early Church Fathers are analyzed. Hippolytus Septuagint text is extremely hard to establish since his quotations from 1 Samuel have only been preserved in Armenian and Georgian translations. Most of the suggested agreements between Hippolytus and L are only apparent or coincidental. Irenaeus is the most trustworthy textual witness of the four early Church Fathers. His quotations from 1 Samuel agree with L several times against codex Vaticanus (B) and all or most of the other witnesses in preserving the original text. Tertullian and Cyprian agree with L in attesting some Hebraizing approximations that do not seem to be of Hexaplaric origin. The question is more likely of early Hebraizing readings of the same tradition as the kaige recension. In chapter 7 it is noted that Origen, although a pre-Lucianic Father, does not qualify as a proto-Lucianic witness. General observations about the Old Latin witnesses as well as an analysis of the manuscript La115 are given in chapter 8. In chapter 9 the theory of the proto-Lucianic recension is discussed. In order to demonstrate the existence of the proto-Lucianic recension one should find instances of indisputable agreement between the Qumran biblical manuscripts and L in readings that are secondary in Greek. No such case can be found in the Qumran material in 1 Samuel. In the text-historical conclusions (chapter 10) it is noted that of all the suggested proto-Lucianic agreements in 1 Samuel (about 75 plus 70 in La115) more than half are only apparent or, at best, coincidental. Of the indisputable agreements, however, 26 are agreements in the original reading. In about 20 instances the agreement is in a secondary reading. These agreements are early variants; mostly minor changes that happen all the time in the course of transmission. Four of the agreements, however, are in a pre-Hexaplaric Hebraizing approximation that has found its way independently into the pre-Lucianic witnesses and the Lucianic recension. The study aims at demonstrating the value of the Lucianic text as a textual witness: under the recensional layer(s) there is an ancient text that preserves very old, even original readings which have not been preserved in B and most of the other witnesses. The study also confirms the value of the early Church Fathers as textual witnesses.

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Hyönteispölytys lisää monien ristipölytteisten viljelykasvien siemensatoa sekä parantaa sadon laatua. Marjakasveilla, kuten mansikalla ja vadelmalla marjojen koko suurenee sekä niiden laatu paranee onnistuneen pölytyksen seurauksena. Aiempien havaintojen mukaan mansikan kukat eivät pääsääntöisesti houkuttele mehiläisiä, kun taas vadelma on yksi mehiläisten pääsatokasveista. Tutkimuksen tarkoituksena oli selvittää, miten tehokkaasti mehiläiset vierailevat mansikalla sekä vadelmalla, keskittyen kukkakohtaisiin käynteihin tuntia kohti. Mehiläisiä voidaan käyttää Gliocladium catenulatum-vektoreina torjuttaessa mansikan ja vadelman harmaahometta (Botrytis cinerea). Kukkavierailujen perusteella arvioidaan, onko vektorilevitys riittävän tehokas torjumaan harmaahometta ja miten hyvin mehiläisiä voidaan käyttää pölytyspalveluihin, etenkin mansikalla. Havainnot kerättiin kuudelta eri tilalta Sisä-Savosta kesällä 2007. Kukkavierailuja laskettiin mansikan ja vadelman kukinnan aikana erilaisissa sääolosuhteissa, eri kellonaikoina ja eri etäisyyksillä mehiläispesistä. Kukat valittiin satunnaisesti, ja valintaperusteena oli kukan avonaisuus. Tarkkailuaika riippui mehiläisten lentoaktiivisuudesta. Mansikan koko havaintojakson keskiarvoksi tuli 1,75 käyntiä kukkaa kohti tunnissa. Vadelmalla vastaava luku oli 4,27, joten keskiarvojen perusteella vadelma oli houkuttelevampi kuin mansikka. Kasvukauden vaiheella ei ollut eroja vierailuihin kummallakaan kasvilla, mutta vuorokaudenajan suhteen vierailuja oli enemmän aamupäivällä kuin iltapäivällä. Lämpötila korreloi positiivisesti vierailutiheyden kanssa kummallakin kasvilla. Sääolosuhteet rajoittivat havaintojen keräämistä ja kesä oli erittäin sateinen. Mehiläiset vierailivat kukissa riittävästi haastavissakin sääolosuhteissa niin, että harmaahometorjunta onnistui. Vektorilevitystä suunnitellessa, etenkin mansikalla, tulee ottaa huomioon pesien sijoittelu sekä riittävä lukumäärä. Pesien ravinnontarpeen tulee olla suuri, jotta mehiläiset keräisivät ravintoa kukista mahdollisimman tehokkaasti. Pesiin voidaan lisätä tarvittaessa avosikiöitä tai poistaa siitepölyvarastoja ravinnonkeruuaktiivisuuden lisäämiseksi. Lisätutkimusta tarvitaan pesien sijoittelun, kilpailevien kasvien sekä mansikkalajikkeiden houkuttelevuuden vaikutuksesta vierailutiheyteen. Suomalaisten mansikkalajikkeiden meden sekä siitepölyneritystä olisi myös hyvä selvittää.