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1038 Uppsatser om Signal species - Sida 46 av 70
The effects of Gotland pony grazing on forest composition and structure in Lojsta hed, south eastern Sweden
Livestock animals affect their environment in a number of different ways, mostly through grazing and trampling. This study focused on the effects of Gotland pony grazing on forest structure and diversity, and the impact on ground cover. To compare the fenced and grazed area with a reference area outside the enclosure a number of transects were used. The study showed that there was no significant difference in height structure and diversity between the compared sites; however, there were a significantly higher proportion of damaged trees inside the enclosure. The ground cover variables showed a higher amount of bare soil, plant litter and wood-rush (Luzula sp.) inside the enclosure whilst grass was more frequent in the reference area.
Skånska trähägnader : en studie i konstruktion och historisk utbredning
The Scanian woodfences has been determined by two mainly elements: Scania's composition of tree species, with a large element of deciduous forest, and the local building tradition which has more in common with the European continent than the Swedish tradition. By examining responses from ethnological question lists deriving from the first half of the 1900s, combined with literature studies, I have been able to deepen and broaden the knowledge behind the various fencing design. In addition I ?ve constructed maps which could illustrate their historical geographic distribution.I have come to the conclusion that there was three main types of woodfences that was most common until the barbed wire was introduced in the early 1900s and later on replaced the elderly woodfences. Common for the three main types is that the base material was made out of Juniperus communis, this largely because of its durability against rot.
Antipredator behavior by the red-tailed guenon, Cercopithecus ascanius
This master thesis was conducted in order to investigate the effects of the browsing
species Yeheb on animal tissues in Swedish landrace goats and to make a literature
review in order to increase the knowledge of the importance of this plant for livestock
production in Somalia. The evergreen Yeheb bush is a very important feeding source for
grazing and browsing animals in Somalia during the dry period. Yeheb contains
cordeauxiaquinone that stains the bones of the animals red/pink, which has been an
increasing problem when exporting meat to foreign countries. In an experiment, two
goats were fed dry and fresh leaves from the Yeheb bush for one and two months,
respectively. The goats did not feed the intended amount of dry leaves, since the supply
and palatability was not as high as estimated.
Djur inom vården : sett från djurens perspektiv
Animal-assisted therapy had its large breakthrough in the 1960-ties when a psychiatrist named Boris Levinson discovered the great advantages of involving animals in the treatment of patients. Therapy with animals involves that animals are used in a systematic way, in a person's process of treatment. The most distinguished companion animal used within this area is the dog, but horses, cats, rabbits, birds, dolphins and the most common farm animals are used in animal-assisted therapy. Most animals that are to be used for this specific purpose need to be trained in order to maintain their physical and mental health, but also to minimize the risks for the people that are involved. Most studies within this research area are focused on the positive effects on the patients and less on the effects on the animals.
Kisel som växtstärkande medel : en litteraturstudie
Sammanfattning
Kisel (Si) är det näst vanligaste ämnet (drygt 25 %) i berggrunden. Bara en del av detta är tillgängligt som monokiselsyra, den form i vilken kisel är upptagbart för växter. Jordens kiselinnehåll är beroende av bergets vittring. Mycket höga halter av kisel återfinns i naturen i vulkaniska substrat (pimpsten innehåller drygt 66 % Si och scoria närmare 47 % Si), i diatomit (ett mineral bestående av resterna från encelliga kiselhaltiga alger, s.k. diatoméer) innehållande 66 % Si, scoria approximatly 47% Si), in diatomite (a mineral consisting of the remainings of single celled algae, diatoms containing < 40 % Si) and in some clays (30-60% Si).
Häckar för Norrland
I have observed that hedges are not as prevalent in gardens in the north of Sweden as in the south despite a number of beneficial qualities attached to their use. Consequently, the primary purpose of this essay is to examine the potential for the use of ligneous or woody plants as hedges in a cold climate. The aim of this study is to provide information about the various varieties of ligneous plants that can be used for both pruned and unclipped hedges in the north of Sweden. Because the hardiness of the ligneous plants is a vital factor here, only plants that are hardy enough to survive in the Swedish hardiness zones V to VIII are included in this study. Roses, dwarf shrubs, conifers, bushes with a final height of less than 1 metre and plants that ?bleed? have been excluded.
Jätteuttrar och deras beteende när de tilldelas musslor i hägn
The giant otter (Pteronura brasiliensis) is listed as an endangered species and scientific litterature concerning its biology and behaviour is scarce. The current study observed a group of three giant otters in a Swedish zoo. First the otters normal behaviour was recorded. Then the aim of the study was to see if the otters behaviour changed when given blue mussels (Mytilus edulis). Furthermore the aim was to see if the otters displayed any tool-using behaviour when given mussels.
Evighetsträd
FSC (Forest Stewardship Council) is the major form of certification system in Swedish forestry today and its more than 11 million hectares are covering almost half of the total productive forest area in the country. Its regulations prescribe that at least 10 wind firm trees should be left behind after every clear cutting operation.
This study have taken place on 30 recently clearcut objects in Bergslagen, Sweden, were an inventory of the standing stock have been made. The research shows that, with 90 % security, the retained trees together contain 9-13 m3sk per hectare. Pine is the dominant tree and it covers more than half the numbers of retained trees and its volume cover 65 % of the retained trees total volume. Spruce is on second place with 30 % of the retained trees, but only 21 % of the standing stock.
Förslag till kväverening i Forsåsystemet genom våtmarksetablering
The last hundred years humans have drastically changed the amount of available nitrogen in nature. Today human activities release twice as much available nitrogen as all natural processes are doing together. We also have degraded nature´s possibilities to take care of nitrogen through the draining of wetlands and straightening of rivers. In order to regain the potential of nitrogen retention in the water systems there now requires a reshape of the landscape we live in. A planned expansion of the mining activities in Garpenberg, Dalarna, would double the content of nitrogen in the waters below the mine.
Svampar associerade med raps : betydelse för uppkomst och grödetablering
Oilseed rape is an important crop in Sweden and is grown on about 90000 ha today. The interest in oil seed pro-duction is increasing because of growing demand and high prices for oil seed both in Sweden and Europe. However, an increased intensity in the oil seed production can bring higher risk of yield losses due to fungal diseases. The purpose of this study was to investigate what different fungi are associated with oilseed rape under field conditions and if their incidence is correlated to crop establishment problems.
This study was carried out in three parts: 1) investigations on fungal community structure in roots and rhizosphere soils from young spring- and winter rape plants sampled in failed respectively good establishment patches in four fields, 2) investigations on the pathogenicity of fungi isolated from oilseed rape in controlled environment and 3) investigations on the effect of different fungicide seed treatments on germination and early plant development in a field soil naturally infested with damping off- and Verticillium wilt pathogens.
The studies on community structure using a combined approach of standard fungal isolation techniques and DNA based methods revealed a high fungal diversity in three out of four studied fields of spring rape and winter rape. For some unknown reason, very few fungal species were identified from the fourth field.
Personlighetstyper och stressrespons hos djur ? med fokus på hund och häst
Animals living in captivity are often subjected to various kinds of stress. Individuals within species can respond differently to the same stressor depending on differences in coping style and physiology. Active and passive coping is a common way to describe different coping styles in animals and it is likely that these strategies have a high heritability. Individuals with an active coping style are characterized by an urge of control and a higher level of aggression than individuals with passive coping style, who in general are more flexible and respond to stress by immobilisation to a greater extent. The aim of this bachelor?s thesis is to investigate the presence of different coping styles and personality types in dogs (Canis lupus familiaris) and horses (Equus ferus caballus) and to find fields of application for this information.
Dexametasons effekt på trombocytaggregering och syreradikalproduktion
Platelets are important for the healing of damaged blood vessels since they have an importantpart to play in the coagulation process. At the same time, the blood must be kept fluid and notcoagulate at the wrong time. Therefore there are factors that effect the aggregation of plateletsin a positive or a negative way.Previous investigations have shown that platelets during stirring conditions produce reactiveoxygen species (ROS) that weaken the inhibiting effect of nitric oxides (NO) on platelets andthat the drug Dexamethasone (Dex) can reduce the ROS-production.The aim of this project was to investigate if glucocorticoids, in this case Dexamethasone,could restore the inhibiting effect of NO on platelets and if there was any decrease in ROS-production.The result of the ROS-measurements showed a great variance and it was difficult to draw anyconclusions from them, but a clear decrease in ROS, as previous reported, was not shown. In the aggregation experiments the inhibiting effect of NO was observed through the drug S-nitroso-N-acetylpenicillamine (SNAP), a NO-donator.From the aggregation experiments, the result seemed to be that SNAP during longerincubation time lost its inhibiting effect, probably because the cells become desensitized.With superoxid dismutase (SOD), the effect of SNAP increased, both in the experiment withlonger and shorter incubation times. Dex seemed to reinforce the aggregation in relation toboth SOD and SNAP.
Smarttelefon-sensorernas möjligheter - En studie om barometer-, GPS- och accelerometersensorer. The smartphone sensor possibilities - A case study featuring the barometer, GPS and accelerometer sensors
Denna rapport sammanfattar resultat av ett examensarbete på en högskoleingenjörsutbildning
som utfördes av två studenter på Malmö högskola.
Arbetets syfte var att genomföra en mängd olika experiment med accelerometer, barometer
och GPS i en modern smarttelefon. Ett antal scenarier för en tänkbar sensoranvändning i applikationer
formulerades för att vägleda olika experiment. Experimentdata dokumenterades noggrant
och analyserades med avsikten att skapa en databank med information för framtida studier.
Analys av data inkluderar höjdbestämning i naturen och i byggnader med hjälp av barometersensor,
geografisk position med hjälp av GPS, hastighet och acceleration under en hissfärd
med hjälp av accelerometer.
Rapporten innehåller en omfattande litteraturstudie om användning av sensorer vid inomhuspositionering.
Från analys av mätdata, kom vi fram till slutsatsen att är möjligt att beräkna höjden
från barometerdata med bra noggrannhet under optimala omständigheter. GPS höjden
från mätningarna har stor felmarginal jämfört med den verkliga höjden samt när den jämförs
med den beräknade höjden från barometern.
Genom att utföra en numerisk integration på accelerometer-data kom vi fram till att det är möjligt
att beräkna ungefär hur långt man har färdats med en hiss, dock att vissa detaljer måste tas
i beaktning..
Adaptiv varvtalsstyrning vid användning av en lastbils kraftuttag
Med ett växande fokus på ett långsiktigt hållbart samhälle som tar ansvar för miljönsträvar fordonstillverkare efter att sänka energiförbrukningen på sina fordon. Dettaarbete behandlar hur man kan sänka bränsleförbrukningen för lastbilar medpåbyggnader. En påbyggnad kan t.ex. vara en kran, en lastväxlare eller enbetongpump. En metod för att sänka energiförbrukningen är att sänka det varvtal somlastbilens dieselmotor arbetar vid.
Effekten av Bisfenol A (BPA) på hanråttors (Rattus norvegicus) reproduktion
Today evidence exist that environmental chemicals deteriorate male sperm quality and that testicular cancer is increasing. Bisphenol A (BPA) is a chemical with estrogenic effects used in the manufacture of polycarbonate plastic and are found in, for instance, plastic boxes, feeding bottles and food containers. Much of the research on how men's reproductive ability is influenced are performed on rats. This review article complies how male rat reproduction is affected by BPA as a model for humans. Studies have investigated how sperm are affected, hormonal changes during reproduction and how reactive oxygen species (ROS) affects sperm.