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163 Uppsatser om Scent detection - Sida 2 av 11

Validation of realtime-PCR of Fusarium avenaceum for detection in wheat

Mould is a common contamination in cereals. The growth of mould can stimulate mycotoxins production andsome of which at critical concentrations cause health problems in humans and animals. Fusarium is one of thefungus species that has been found in crops and can cause major problems for farmers such as reduced harvestand economic losses. A group of Fusarium species, Fusarium avenaceum, Fusarium poae and Fusariumtricinctum express a mycotoxin, enniatin. The limited information available today about enniatin-forming fungiis that they grow out on fields of wheat in colder climates.

XRF-analys av förorenad mark : undersökning av felkällor och lämplig provbearbetning

X-ray fluorescence (XRF) detection of heavy metals is a cost- and time-effective method for investigation of polluted areas. Compared to laboratory analysis, XRF analysis is limited by high detection limits and uncertainties in some situations. Preparation of samples is known to affect the results of measurements.The purpose of this thesis is to bring a deeper understanding of how different factors affect the results of XRF-analysis. A large number of measurements have been made with the instruments Niton XLt 700 and Niton Xli 700. Results from measurements of lead, zinc and copper have been analysed.This study has shown that a greater moisture content will give a lower measured concentration for the same sample.

PLA som metod för detektion av bornavirusinfektion hos katt

A method for intra vitam detection of bornaviral infection and diagnosis of bornaviral dis-ease in the cat is currently lacking. The aim of this work was to explore the possibility of using the proximity ligation assay (PLA), with its capacity of recognizing femtomolar con-centrations of a protein, as a method for detection of the minute quantities of antigen and antibodies that are present in the tissues and body fluids of a bornaviraly infected cat. For this purpose reliable comparative assays, in the form of an ELISA and an IFA, had to be established. When this proved impossible within the time frame of the project, the aim of the study had to be abandoned, further underscoring the need for improved means of detec-tion of bornaviral antibodies and antigen..

Evaluation of a selective media for the detection of gram-positive bacteria in leg ulcers and pressure wounds

Hard-to-heal ulcers are resource intensive due to the fact that they are difficult to treat and especially vulnerable to bacterial invasion. The bacterial culture contaminating these wounds often consist of several different bacterial organisms that originate from endogenous sources. Necrotic material in ischemic ulcers provide nutrition which support bacterial reproduction, increasing the risk of infection. Determining causative pathogen in infected ulcers proves to be difficult when culturing swab samples, however Staphylococcus aureus and hemolytic streptococci generally act as primary pathogens.    The aim of the study was to investigate if the detection rate increased for S. aureus and hemolytic streptococci when culturing swab samples from ulcers on Columbia CNA; a media selective for gram-positive bacteria.

Evaluation of an automated multiplex real-time RT-PCR assay for rapid detection of Influenza A and B viruses

Influenza is a viral infection that affects global health and economy with its endemic and sometimes pandemic spread. Rapid detection of Influenza viruses enables antiviral use and can bring financial savings. It is also essential for the global surveillance of prevalent Influenza strains. RT-PCR is considered the most specific and sensitive method for detection of Influenza, but Influenza mutates at a high rate and it is therefore crucial that RT-PCR methods are updated regularly.In 2014, Cepheid released their Xpert Flu/RSV XC assay, which can detect Influenza A and B and RSV by multiplex RT-PCR in approximately one hour. The aim of this study was to evaluate this assay at Laboratoriemedicin Västernorrland by using the laboratory?s previous PCR assay for detection of Influenza viruses as reference method.Real-time RT-PCR was used to compare Xpert Flu/RSV XC to the reference method.

IPv6 - Gatewayredundans : Snabbt nog?

IPv6 har, till skillnad från tidigare versioner av protokollet, inbyggt stöd för redundans hos gatewayenheter. Vid nyttjande av ett flertal gatewayenheter kan det, med hjälp av Neighbor Unreachability Detection, ske automatisk övergång till en ny gatewayenhet utifall att den aktiva skulle gå ur funktion. Innan IPv6 har man varit tvungen att förlita sig på externa lösningar för att uppnå denna redundans. Den huvudsakliga fråga som ställs i rapporten är om det inbyggda stödet för gatewayredundans i IPv6 är tillräckligt snabbt för att kunna nyttjas självständigt, utan att förlita sig på externa lösningar. För att kunna ta fram ett värde om vad som var ?tillräckligt snabbt? har vi, genom att läsa tidigare forskning om användares upplevelse av fördröjningar, kommit fram till att en fördröjning ej får överstiga tio sekunder.

Algoritmer för objektdetektering i SAR och IR-bilder

The first part of the thesis consists of a brief introduction to the general principles of target detection and the sensor-systems used. In the following part there is a theoretical description of the algorithms this thesis focuses on. The detection algorithms described in this paper are called Cell Average, Ordered Statistics, 2parameter and Gammadetector. Two different discriminators called Extended Fractal Features and Quadratic Gamma Discriminator are also described. The algorithms are tested on three different types of data, simulated SAR-pictures, authentic SAR-targets and IR-pictures.

Optimering av informationsinsamlingvid prototyptillverkning

This report discusses a method to detect divers in harbour environments usingpassive acoustic detection. The goal was to achieve as high detection as possiblewithout having too high false alarm rate. A short execution time was also desirable.By using the characteristic of an inhalation a band-pass filter was applied to the signalto improve the signal to noise ratio. After the filtering an energy estimation of thesignal was made. This energy estimation was later used in a frequency analysis, whichcould tell us if there were enough energy in the frequencies that correspond to adivers breathing frequency.

Validering av metoder för analys av Cu, Fe och Na i processvatten med AAS-grafitugn

Södra Cell Mörrum is one of the five paper pulp plants that are included in Södra Cell, and the paper pulp that is produced here is not only sold to Swedish paper mills. Most of the paper pulp is exported to different countries in Europe. In the manufacturing process the plant needs different kind of process water and there are guideline values for how much copper, iron and sodium this water is allowed to contain. Analyzes of this water is in the current situation done with an atomic absorption spectrometric instrument (AAS-instrument) with a flame. Measurements done with flame-AAS of samples that have concentrations near the guideline values for copper, iron and sodium, are not reliable. The reason for not being reliable is that the quantitation limits of these metals are higher than the limit values.

Wildlife Detection Network

Traffic accidents where wild animals are involved represents between 60 and 80 percent of all reported accidents, depending on location in Sweden. In a country like Sweden, with a lot of forest, there is always risk of a collision with a wild animal. Imagine if you, as a road user, had the possibility to receive warnings when the risk of an accident according to statistics is extra high.Wildlife Detection Network is a wildlife warning system with an information service, which makes the whole concept unique. When an animal is approaching the road, it is registered by sensors, and warning lights along the road are lit to inform drivers of the potential danger. In conclusion, this is a direct warning to all drivers on the road where the system is placed.When an animal is registered by the sensors, information containing time, date, weather circumstances and coordinates are sent to a database.

Police Science - expansionen av ett kunskapsfält : En studie om vetenskapligt gränsdragningsarbete i 1930-talets Chicago

In 1929, the Scientific Crime Detection Laboratory was established in Chicago?the first of its kind in the United States. The purpose was to engage in practical use of scientific methods in the detection of crime. In 1930, the institute published its own periodical called The American Journal of Police Science. Applying the theory of boundary-work, this essay analyses how the novelty institute argued its legitimacy as a scientific establishment through the expansion of Police Science as a collective field of knowledge.

Implementering av Constant Fraction Detection vid avståndsmätning

This thesis is performed at Saab Bofors Dynamics in Karlskoga and investigates a technique for ranging with laser pulses. The investigated technique is called Constant Fraction Detection (CFD). Described briefly, the received laser pulse is split into two equal parts, where one part is delayed half the pulse width and inverted. This signal is added to the original pulse. The resulting curve has the shape of a laying S and the detection of the zero level is used to stop the time measurement.

detection and quantification of almond (Prunus dulcis) in food with ELISA

Reliable methods to analyze food for the presence of almond are important ? not only for those allergic to almond, but also for monitoring the compliance with labelling regulations (EG directive 2003/89). Until now the Swedish National Food Administration has used methods like rocket immunoelectrophoresis and real-time PCR to detect almond in food. These methods are, however, not sensitive enough for protecting the most sensitive individuals. Therefore, the performance of a commercial ELISA kit was tested with regard to specificity/cross reactivity and limit of detection for almond both in solution and in different matrixes.The limit of quantitation was at least 3,1 ppm (mg/kg) in solution and similar concentrations were measured in bisquits and chocolate.

Metabolit- och hormonnivåer som tidiga markörer för fruktsamhet och produktionsstörningar hos mjölkkor

During the last decades the fertility of dairy cows has declined in the same rate as the milk yield has increased. This is a result of the negative genetic correlation between milk yield and fertility, failure to show estrous signs and metabolic problems in the cow. The purpose of this review was to investigate the function of metabolites and hormones as markers for disturbances in fertility, health and production in the dairy cow. There are several metabolites that are suggested to indicate the cow?s energy balance.

Improvement of positive strand assay used in detecting positive and negative RNA of hepatitis E virus

Background: Hepatitis E (HEV) is a small, non-enveloped virus that belongs to the viral genus Hepevirus. HEV is a positive sense single-stranded RNA virus and there is insufficient information regarding its replication. This is mainly because the virus has low capacity to grow in normally used cell cultures. Many specific strand assay detection studies have been done in order to understand more about HEV replication. Unfortunately, these assays have the disadvantage of giving false positive results.Aim: The aim of this project was to improve the positive strand assay to increase specificity and eliminate false positivity which is due to high sensitivity of the polymerase chain reaction (PCR).

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