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14305 Uppsatser om Difference- in- difference analys - Sida 9 av 954
Analys av kvalitet i en webbpanel : Studie av webbpanelsmedlemmarna och deras svarsmönster
During 2012, the employer of this essay carried out a telephone survey with 18000 participants and a web panel survey with 708 participants. Those who partook in the telephone survey were given a choice to join the web panel. The purpose of this work is to study the participants of the telephone survey and see if they reflect the Swedish population with regards to several socio-demographic factors. Also, we intend to investigate if the propensity to join the web panel differs for participants of the telephone survey with regards to various socio-demographic affiliations. It is also of interest to study if the response pattern is different for participants of the telephone survey that would like to join the web panel and those who reject.
Vidhäftning mellan prefabelement och pågjutningsbetong : Undersökning hur skrovligheten påverkar vidhäftningskapaciteten vid skjuvning
Self-compacting concrete has soon been around for a decade. Recently the prefabrication industry has started to use this fairly new concrete type in larger scales, mainly because of its distinctive properties. There are still certain areas that need to be thoroughly examined, such as bond capacity. There have been very few studies regarding shear capacity due to the fact that the procedure is complicated.This report will highlight a method to examine the shear capacity of different surfaces that have been prewetted as well as non-prewetted surfaces. The surface areas follow BBK 04?s and Eurocode 2?s demand for surface roughness. A smooth surface will be completed in order to confirm if the different shapes influence the bond strength by shear stress or not. The purpose of this essay is to measure the bond strength within the shear capacity as well as examine the impact it has on surface roughness and treatment for shear bond.The method used to identify the shear capacity is called L-shaped Push-Off Test.
Förekomst av Chlamydia/Chlamydophila spp hos gris med och utan konjunktivit.
ABSTRACTChlamydia and Chlamydophila are species of a family of bacteria (Chlamydiaceae) that cause a range of diseases, including conjunctivitis, in a variety of animals including pigs and humans. Some species cause zoonotic disease. This study examined the occurrence of Chlamydiaceae in samples taken from the lower eyelid conjunctiva in pigs with and without conjunctivitis. The study was initiated based on a herd investigation aimed to examine the experienced increase of conjunctivitis in some finisher herds. This study was conducted as a case-control study, by collecting samples from 62 case pigs (16-26 weeks old) and an equal number of controls, from three herds in Uppland, Sweden.
Bestämning av kroppssammansättning hos överviktiga och obesa ammande kvinnor. Validering av bioelektrisk impedans mot röntgenabsorption.
Introduction: Pregnancy, obesity, aging and certain diseases are examples of conditions thataffect the body, its constitution and composition. Simpler methods to estimate bodycomposition are needed to complement more advanced traditional methods to better identifythe health status without sacrificing accuracy and precision.Objective: To validate the results of body composition from bioelectrical impedancespectroscopy (BIS) against results from the study reference method, dual energy X-rayabsorption (DXA), in overweight and obese lactating women after childbirth.Method: The design of the LEVA-study (Lifestyle for Effective Weight loss during lactation)consisted both intervention and longitudinal follow-up, which gave the opportunity tovalidate the absolute values (accuracy) and the ability to detect changes (precision). Themean difference between methods was tested statistically by paired t-test. Bland-Altman plotsused to examine the degree of agreement between BIS and DXA, but also distribution andany systematic differences. Association between methods was measured by using Pearson´scorrelation coefficient.Results: Between BIS and DXA, absolute measurements of the variables fat-free mass (FFM)and fat mass (FM) showed a statistically significant difference (p < 0.001).
Nyemission. Var det värt det? : En studie om nyemissioners effekter på idrottsaktiebolag
This essay has examined the effects that new issues had on the four Swedish football clubs that are organized as sport limited companies. The difference between a limited company and a sporting limited company is that the clubs always have majority ownership by the 51% rule. Previous research on sport limited companies and on new issues has been associated with the agent theory and the pecking order theory in order to explain the effects.The thesis is a qualitative study with an inductive approach, where the interviews have been selected as the method of collecting data. Through the years the clubs have performed new issues several times. The study says that the clubs perform a new issue for two reasons, either for investment purposes or because they have a poor economy and must collect liquid assets.
Bulleremissioner från vertikalaxlade vindkraftverk
Wind power in Sweden is expanding in response to the government's decision that 49% of Sweden's power should originate from renewable energy sources by the year 2020. Problems with noise and sound emissions related to wind turbines are a constant argument against the wind power expansion and this paper means to examine if vertical axis wind turbines might be a viable alternative to the conventional horizontal design for noise sensitive areas. In order to determine factors like difference in frequency, noise propagation and noise emission level, measurements of both horizontal and vertical axis wind turbines have been completed and the data analyzed with MATLAB. It is shown that there is a difference in how the noise from the two types of turbines propagates due to avariation in the frequency spectra of the emitted sound. It is also shown that vertical axis wind turbines generate a lower sound emission with less intensity inthe lower frequencies..
Maktavstånd och kommunikation - en studie av upplevda och verkliga kulturella skillnader och deras följder
Hofstede constructed a culture dimension called Power Distance, measuring the inequality of Power. Germany and Sweden have relatively similar values according to his world-renowned research. But a series of interviews of Swedish entrepreneurs in Germany shows that these perceive a large difference in inequality of power in the two countries. This essay seeks to explain the difference between these subjective-qualitative experiences and the objective-quantitative data of Hofstedes Power Distance Index. We propose that a combination of differences in communication, exercise and visibility of power and formality influence the way Power Distance is perceived.
Maximerande av ekosystemtj?nster i urbana kulturmilj?er: En fallstudie om tr?dval i Pommerska tomten i Mariestad
The purpose of this work has been to explore what ecosystem services a small green area in an urban
environment can offer and whether specific trees can be used to maximize regulatory ecosystem
services in a cultural-historical environment. Additionally, it investigates whether there is any
difference in ecosystem services depending on whether these trees, or trees that better fit into the
cultural-historical environment, are used. Through simulations and comparisons with existing trees in
Pommerska tomten, Mariestad, Sweden, a pocket park within a national interest area, different
hypothetical tree planting options are analyzed and evaluated. To measure ecosystem services, the
website My-Tree, developed by the US equivalent of the Department of Agriculture, was used. By
inputting data about the tree, such as location, species, vitality, stem diameter, and solar exposure,
My-Tree calculates some of the ecosystem services the tree provides.
Att gå en gyllene medelväg. Nio barnbibliotekariers resonemang kring Wahlströms långserieböcker på folkbibliotek
The aim of this masters thesis is to examine how some childrens librarians in public libraries reason about Wahlströms series books. During the 1970s, there was a discussion about the series books, and the general meaning was, among other things, that the books should not be available at libraries. Therefore, we also want to study if the arguments for and against the series books presented today are any different than those presented in the 1970s. For this examination, two methods have been used. We have done qualitative interviews with nine childrens librarians, and in order to find the arguments presented in the 1970s, we have studied the literature regarding the mentioned discussion.
Good cop - bad cop? : - en jämförelse i ilska och aggression hos polisstudenter och universitetsstudenter
The main purpose of this study was to compare the levels of anger and aggression between male and female Police Academy students (N=106) and male university students (N=100), using 2 psychometric anger instruments; Novaco Anger Scale-1998-S (NAS-1998-S) and Aggression Questionnaire-S (AQ-S). Another aim was to examine if there was a difference in anger and aggression between male and female Police Academy students. Questionnaires were handed out to Police Academy students in Växjö and the result was compared to university students from a previous study by Lindqvist, Dåderman & Hellström (2003). Analyses using a series of Independent sample t-tests showed a significantly lower level of anger and aggression in the Police Academy sample. There were no significant difference in anger and aggression between males and females with the exception of two subscales of the NAS-1998-S and AQ-S; females scored significantly higher on NAS Arousal and males scored significantly higher on AQ Physical aggression..
Tonala skillnader mellan en traditionell och en modern gitarrkonstruktion : En jämförelse mellan två klassiska gitarrer
During my studies to become a guitar builder at Carl Malmsten CTD, I have found an interest in the construction of the classical guitar. I am fascinated by the simplicity of its construction. A simplicity that becomes more complex when you start to study it in detail.In my final thesis I will not try to explain this complexity. The subject is to investigate two different principles regarding its construction. I would like to find out if the sayings concerning one of the principles will yield a guitar with greater ability to produce volume and projection.At a close distance the difference between the guitar?s volumes is not to speak of, but a significant difference can be seen regarding one of the guitars ability to project its sound.
Att bita den hand som föder en? EU-kritiska parlamentarikers arbete i Europaparlamentet
The study seeks knowledge about the Swedish euro-scepticism and about the work of the Swedish euro-sceptical Members of the European Parliament (MEPs). How do they work in an environment where the norm is to have a positive attitude towards a future federal state of Europe? How do they regard their own situation and possibilities to make a change?The study includes a debate on today's Swedish euro-scepticism as background. My finding about the MEPs? work is that their way of acting in the European Parliament does not distinguish from other MEPs? in large.
Fysisk aktivitet och fysisk självkänsla : Är det skillnad mellan elever på yrekesförberedande och studieförberedande gymnasieprogram?
Background: Students, at a secondary upper school, attending a practical programme have a lower physical capacity than students from theoretical programs. Our physical self-esteem has a great significance for our motivation in being physically active and thereby also for our health. The purpose: of this study is to find out if there is a difference between perceived physical self-esteem and objectively measured physical activity between students attending a practical programme and a theoretical programme. Method: Four classes, in a medium-sized town in the southeast of Sweden, participated in the study, two classes from practical programmes and two classes from theoretical programmes. All the students were in their final year at the upper secondary school, when they were part of the study during the autumn of 2011.
Detektion av mRNA från en cytokrom c gen belägen i genklustret för kloratmetabolism i Ideonella dechloratans
Abstract:In previous experiments with the bacterium Ideonella dechloratans a probable sequencecoding for a cytochrome c protein (cyt c) was observed, the sequence is assumed to have afunction in the bacterial respiratory chain. Detection attempts have been made to try to findthis protein, but have not succeeded. The purpose of this project is to detect the expressionof mRNA associated with the cytochrome c. And if it is detected, it will also be investigated ifthere is any difference in expression of the mRNA due to aerobic or anaerobic environment.Total RNA was purified from cultures grown under aerobic and anaerobic conditions. cDNAwas then synthesized using reverse transcriptase and subsequently amplified with thespecific primers in a qRT-PCR.qRT-PCR testing showed a distinct amplification of primer product, confirming that I.dechloratans expresses mRNA coding for the cyt c protein.
Truppgymnastik
According to recent research the basics for a good body posture is balance between the muscles, if unbalance originates this can be strengthen by gymnastics when most of the practise performs only in one direction. Because of limited research in the area was an explorative study conducted. The purpose of the study was to inquire if exercise adjusted to the individual contributes for balanced muscles and if it contributes for a positive or negative development for the team.On the basics of that the team is not equable an other team in the area has the results for two different periods been measured, during the first period the exercise continued as usual but during the second period each gymnast (n=9) received an individual strength- and stretch program that was performed during the teampractise twice a week. The gymnasts were tested in areas that are imported for them as body posture, balance between the muscles, vigour, range of movement, balance, the running and coordination. The results showed on that the difference is largest between test two and three, except the coordination and balance which did not show any particular change.