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813 Uppsatser om Didactical indicator species - Sida 44 av 55

Begomovirus prevalence and diversity in the TYLCV resistant tomato cultivar Shanty in Nicaragua

Every year begomovirus infections cause severe constraints to the tomato production in Nicaragua. Extensive yield losses are followed by large economical losses, both for the country and the single farmer. During recent years the use of begomovirus resistant or tolerant tomato cultivars has increased in Nicaragua as an effort to improve yields. Still, begomovirus infection is a large threat to the tomato production. Therefore, ongoing work in Nicaragua is focusing on finding new, better, begomovirus tolerant or resistant tomato cultivars.

A literature study on Methicillin-resistant Staphylococcus pseudintermedius (MRSP) : classification, resistance mechanisms, risk factors and clonal distribution

The increased frequency of reported Methicillin-resistant Staphylococcus pseudintermedius (MRSP) is of great concern to small animal healthcare due to limited options of antimicrobial therapy. The aim of this literature study is to investigate 1) characteristics and classification of S. pseudintermedius, 2) resistance mechanisms and emergence of MRSP, 3) risk factors for selection of MRSP, and 4) clonal distribution around the world. S. pseudintermedius is a skin and mucosal commensal in healthy dogs and cats, but can cause infections, including pyoderma. Beta-lactam antibiotics inhibit bacterial growth by binding to the penicillin binding protein (PBP), a vital enzyme in the synthesis of the bacterial cell wall.

Metodjämförelse mellan instrumenten Vitros 5,1 FS och QuikRead CRP för analysen P-CRP

In studies of serum, in the early 1930s, from patients with pneumonia, a factor was found. It could agglutinate certain pneumococcal species. This factor, which later became known as C-reactive protein (CRP), increased sharply during the early and middle stages of the disease. CRP was identified as an acute phase protein and found especially in bacterial infections. CRP is synthesized in the liver by stimulation of interleukin 6 (IL-6), which is produced by the monocytes, and consists of five non-covalently bound subunits.The aim of this study was to compare two different analytical instruments (Vitros 5.1 FS Ortho-Clinical Diagnostics and QuikRead CRP Orion Diagnostica) for CRP analysis.

Akut mikrocystinförgiftning hos däggdjur

Förgiftningar hos däggdjur som druckit vatten kontaminerat med cyanotoxiner har observerats världen över, och riskerar att öka i takt med tilltagande övergödning och klimatförändringar. Denna litteraturstudie inriktar sig på mikrocystin (MC) som är det vanligaste och mest studerade cyanotoxinet. Studien avgränsar sig till akut intoxikation hos däggdjur och fokuserar på grundläggande mekanismer hos toxinet, såsom absorption, distribution, metabolism och elimination. Vidare beskrivs de toxiska mekanismerna och de akuta toxiska effekterna. MC orsakar utbredda nekroser och blödningar i levern. Den specifika distributionen till levern anses bero på det höga uttrycket av organiska anjontransportörer (OATP).

Selection of habitat and resources during migration by a large mammal : a case study of moose in northern Sweden

Migration is a worldwide phenomenon that has occurred for thousands of years in a vast variety of species. The general knowledge of migrating animals is poor even though billions of animals from a range of different groups migrate every year. The human impact on migrating ungulates is high and many populations are declining globally due to direct and indirect causes. Hence it becomes vital to study the migration phase and the habitat and resources selected during migration. The objective with this study was to identify the habitat characteristics and resource selection of moose during migration and compare the selection between different seasons and utilization distribution (relative frequency distribution for the points of location of an animal over a period of time) categories.

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.

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.

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.

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.

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.

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