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1100 Uppsatser om Mixed species enclosures - Sida 60 av 74
Den globala uppvärmningen : vad kommer att hända med morgondagens värld?
Mankind faces a serious threat. Its activities, for example the burning of fossil fuels, have led to an enhancement of the greenhouse effect - something that has given rise to a global warming. The climate is becoming warmer, a change that has important effects on the nature as well as for humans and their society. Sea level rising, extreme temperatures are becoming more common, glaciers and other ice caps melt and storms becomes more intense when they appear. The main cause is the emission of greenhouse gases into the atmosphere - carbon dioxide in particular.
Nitrogen fixation among boreal feather mosses along a clear-cut chronosequence
The Swedish boreal forests are limited by nitrogen (N) availability. While biological N2 fixation by cyanobacteria hosted by pleurocarpous feather mosses are important sources of N input to natural boreal forest ecosystems, little is known about the patterns of N2 fixation in silvicultural systems. This study investigates the biological N2 fixation rates of two boreal feather moss species (Pleurozium schreberi and Hylocomium splendens) along a chronosequence from clear-cut to mature forest, as well as the vegetation characteristics along the chronosequence. Measurements and samples were collected from 32 forest sites that were classified into four age classes (clear-cut, pre-commercially thinned, thinned and mature forest). The sites were located near the city of Arvidsjaur in northern Sweden.
Francisella tularensis subspecies holarctica : the curious case of a water- and mosquito associated bacterium in Sweden
Francisella tularensis, the causative agent of the zoonotic disease tularaemia, is highly contagious and potentially fatal for a wide range of wildlife species of the northern
hemisphere, also humans. Although recognized as a pathogen for over 100 years, much still remains to be elucidated concerning the ecology and transmission of the bacterium, hence this literature overview aims at compiling data regarding the aquatic association and the role of
mosquitoes in transmission of Francisella tularensis subspecies holartica, the sole subspecies in Sweden. While a linkage between the bacterium and natural waters stands beyond dispute, there is no consensus in the literature concerning its potential as a reservoir. However, two
prevailing theories can be distinguished; one proposes the water association being mammaldependent and thus merely the result of contamination from semi-aquatic mammals living in
close vicinity to the water source. The other, quite contrary, suggests mammal-independence and hence that water, possibly in association with protozoa, serves as an environmental reservoir for the bacterium.
Herrelösa katter i Skåne : problem och hantering
The large number of surrendered and feral cats is a big animal welfare problem all over the world. Populations of feral cats arise through a large number of unwanted cats which can lead to surrender of these, through cats allowed to roam free outside which can lead to the owner losing these and through the reproduction that occurs amongst these surrendered or lost cats. One aim of this study is to give an account of this problem. It is however difficult to draw general conclusions about these populations of cats since studies all over the world has been carried out on different types of populations, during different conditions and different periods of time. The welfare of many of these cats is presumably low because they are exposed to risks as disease, starvation, climate, traffic, other animals and humans.
Hur upplevs en främre korsbandsskada som ådragits för mer än 10 år sedan påverka den skadade idag?
Aim: The aim of this study was to investigate how women who have incurred ACL injury for more than 10 years ago, feel that the injury affects them today.Method: A qualitative semi-structured interview survey with five women who 10- 28 years ago incurred the anterior cruciate ligament injuries when playing handball or soccer has been performed. The study has been inspired by a phenomenological concept of science, mainly by life-world concept. Data were analyzed using qualitative content analysis.Main result: Some informants have experienced severe loss of physical ability in both daily living situations and in training, while others did not appreciably felt impacted in daily living and experienced great opportunities for physical activity. Limitations which emerged were restrictions in movement, joint stiffness, pain, swelling, and crepitations that led to the loss of physical ability. One respondent had been diagnosed with advanced osteoarthritis.
Skillnader i kungsörnens (Aquila chrysaetos) flyttningsmönster beroende på ålder och klimatfaktorer : En studie för skyddet av kungsörn
This study examines the factors that influence the seasonal movements of Golden Eagles (Aquila chrysaetos), and can thus provide important information that helps to improve the protection of the species. There were two main purposes of this study. First, I wanted to analyze the difference between preferences of juvenile and adult Golden Eagles in their choice of southern or northern hibernation areas. Do younger eagles prefer moving longer distance to southern areas of Sweden? Second, I wanted to investigate how the climate influenced the choice of date of migration in the fall.
Naturvårdsrestriktioners effekter på brukandet av ädellövskogen i Skåne :
Restrictions in nature conservations are increasing the influence of forest management. Nobel broadleaved forests are more influenced than other forests, because they are considered to be more valuable than other forest types in Skåne. There has been a lack of knowledge about the amount that is set-aside for nature conservation and what types of forest that is concerned.
These are the main questions to be answered in this thesis. Moreover has the timber quality been compared between set-aside and non-set-aside areas since it affect the financial conditions for the forestry in nobel broadleved forests. The last asked question deals with the financial consequences of set-aside.
Molecular analysis of insecticide resistance in pollen beetle (Meligethes aeneus)
The escalating usage of pyrethroids has resulted in an increased awareness about resistance towards pyrethroids in insects. Pyrethroids inhibit voltage-sensitive sodium channels (VSSC) in nerve cell membranes and are composed of synthetic molecules based on pyrethrins present in pyrethrum extracts from Chrysanthemum species. VSSC are transmembrane proteins that are important for electric signalling over the membrane in insects. Mutations in the gene encoding the sodium channel have proved to be a common reason for resistance against pyrethroids. Pyrethroid resistance among pollen beetles is spread all over Sweden and also abroad and is increasing.
Contortatallens odlingsvärde i Götaland
The third most common conifer in Sweden is Pinus contorta (lodgepole pine). It originates from the western part of North America and was brought here in the end of the 1920s. The lodgepole pine is today allowed for commercial plantations in central and northern Sweden, excluding high altitude locations. Since 1979 only plantations with scientific purpose are allowed in south-central and south Sweden.
This document is focused on how lodgepole pine manage perform compared with Pinus sylvestris (Scots pine) in the southernmost part of Sweden, Götaland. The idea came from the fact that the Swedish government is evaluating a notification from the National Forest Agency that suggests lodgepole pine to be allowed for commercial plantation even in southern Sweden.
Införande av GY2011 på ett yrkesprogram
Reaktionskrafter från monteringsverktyg är troligen en bidragande orsak till mångabelastningsskador i tillverkningsindustrin och monteringsarbete ligger också i topp istatistiken över arbetssjukdomar i Sverige.Idag används i stor utsträckning avancerat styrda verktyg, som kan programmeras så att dekänns bekväma, men det finns ingen utvärderingsmetod för reaktionsmoment som premierardessa funktioner. Dessutom tar dagens utvärderingsmetoder hänsyn till att människor är olikastarka i olika arbetsställningar.En utvärderingsmetods främsta syfte är att hjälpa till vid val av verktyg och vid bedömningom reaktionskraften kan tas upp för hand eller om mothåll bör användas. Tas inte operatörensstyrka beroende på arbetsställning med blir denna bedömning i många fall felaktig.Syftet med det här arbetet är att ta fram en bättre bedömningsmodell för reaktionsmomentfrån monteringsverktyg. Några krav som sätts på den förbättrade metoden är att den ska varaenkel att använda, mätningar ska inte behöva göras på verktyget och den ska ta hänsyn tillvariation i styrka beroende arbetsställning.En grupp om sju testpersoner sattes samman och de utvärderade reaktionsmomentet från envinkelmutterdragare i tre olika positioner. I varje position testades 6 olika typer avreaktionsmoment.
Skiljer sig hundvalpars lekbeteende åt mellan raser och kön? :
There are many theories why animals play but none have jet been proven. During observation on Canids, play seems to be important when they learn to control the intensity of the bite and to facilitate the social structure within a group. When dogs play they perform behaviours that otherwise are used during hunting, reproduction and aggression that in another context would be for example hostile. The dog is one of the species that we humans have domesticated and they have been exposed to an intense and concentrated breeding so they can function in different areas, for example herding and hunting. This breeding has resulted in that the pure bred dogs can be very different between the breeds.
Är direktägda bostadsfastigheter en bättre investering än aktier? : En studie över riskjusterad avkastning
Background:Investments in different forms have always been popular to every human being. For the most common investments, such as stocks and bonds, there are loads of information to gather for the investor. Historical data like risk, return, dividends and fundamental data like annual reports are often very easy to find, regarding these kinds of investments. The background of this thesis is the lack of market information in residential real estate investments. A problem with this investment is that there is lack of information regarding risk adjusted return for real estates, which this thesis intends to present.Objective:The objective with this thesis is to study which alternative, directly-owned residential estates or stocks, who generates the highest risk adjusted return.
Naturvårdshänsyn i boreal bruksskog : En studie om avverkningar och avverkare i skogarna runt Saxdalen i södra Dalarna
As the past century?s technological development has progressed the Swedish boreal forests have transformed into dense, highly productive, homogenous and coniferous forests. The area around Saxdalen in Ludvika municipality has long been dominated forests which have been heavily worked since the 18th century. There are in Ludvika 119 000 hectares of productive forest land. Around 70 percent are owned by forest companies and 20 by private forest owners.
Controlled traffic for grass silage production : an economic evaluation for dairy farmers
The farm management system controlled traffic farming (CTF) aims to reduce soil compaction by restricting the field traffic from agricultural machinery to permanent traffic
lanes. Literature and empirical findings show that soil compaction and field traffic from heavy machinery may affect crop growth negatively, reducing crop yields. If grass-clover leys are subject to heavy field traffic the botanic composition might be altered, providing a lower
clover content in the forage. Clover as a silage feed is rich in protein providing good conditions for high yielding dairy cows. Grass-clover silage production is generally associated with intensive field traffic.
Development of green space in Dar es Salaam, Tanzania
In Dar es Salaam, as in many cities in developing countries, green areas are decreasing due to the fact that the growth of buildings, infrastructure and services has become a priority. As the population increases more buildings and infrastructure are needed and much of the building activity takes the form of uncontrolled settlements, which encroaches the public green space. Dar es Salaam has approximately three million inhabitants, of which about 70 percent are living in informal settlements.
The aim with this study is to make a design proposal for a park and recreation area where the Msimbazi river basin in the centre of Dar es Salaam is today.
The basin consist of a few playing fields, footpaths and some urban farming, but apart from this it mostly consists of unused grasslands, swamps and forests. Because it is an unsafe place and badly connected to the rest of the city infrastructure, it has become a barrier. The annual flood combined with the constant still shallow water creates a good breading ground for malaria mosquitoes.