1,131 research outputs found
Quantification of sleep in dairy cows in three different stages of lactation
The aim of this project was to quantify the total sleep time in modern dairy cows during
24-hour periods and to investigate whether the total amount of sleep as well as time
spent in different sleep stages varies between the dry period, early- and peak lactation.
The distribution of sleep time between night and day was also examined. Furthermore,
correlations between sleep and lying time, fluctuations in body temperature and heart
beat were included in the aim. Eight dairy cows of the Swedish Red breed were used in
this study, which was carried out between June and September 2010. In order to
quantify sleep non-invasive electrophysiological recordings were performed.
Simultaneously with collecting sleep data, body position and body temperature were
also recorded. No heart rate data was obtained due to difficulties of maintaining
electrodes for heart beat measurements attached to the skin. One 24-hour data
collection was performed on each cow in the three different stages of lactation. The
electrophysiological data was visually scored according to definitions of human sleep.
Electrophysiological data from one of the eight cows mainly contained artefacts and all
her data was excluded from the data set. Shorter sleep time was obtained in early- and
peak lactation compared with the dry period. The rapid eye movement (REM) sleep time
and REM sleep time in proportion of total sleep was higher in peak lactation compared
to early lactation. It could also be concluded that cows sleep during larger proportion of
the night compared with the day. Indications of a possible correlation between total
sleep time and total lying time was found, but no relationship between sleep and
fluctuations in body temperature. Possible correlations between sleep and heart beat
could not be investigated since no heart rate measurements was not obtained
Effects of cognitive tasks on car driversâ behaviors and physiological responses
The effects of driversâ engagement in cognitive tasks (i.e., non-visual, cognitively loading activities unrelated to the task of driving) are debated and unclear. Numerous experiments show impaired driver behaviors, yet naturalistic studies typically do not find an increased crash risk. In the future, autonomous driving (AD) is expected to improve traffic safety while allowing safe engagement in cognitive (and other) tasks. Having the opportunity to perform non-driving related tasks while traveling may then motivate drivers to use AD, provided they can actually engage in the tasks. Unfortunately, research on driversâ engagement in cognitive tasks suffers severe methodological limitations since reliable and unintrusive measures of cognitive load are lacking.The aim of this thesis is therefore to advance the understanding of task-induced cognitive load in the context of traffic safety. This aim is split into two objectives: A) to better understand how driversâ involvement in cognitive tasks can affect safety-relevant driver behaviors and decisions and B) to provide methodological guidance about assessing cognitive load in drivers using physiological measures.To accomplish Objective A, effects of cognitive tasks on driver behaviors were studied during routine driving and in a safety-critical event in a driving simulator. Also, driversâ ability to engage in a non-driving related task while using AD in real traffic was explored. In line with the cognitive control hypothesis (Engstr\uf6m et al., 2017), it was found that cognitive tasks negatively affected driver behaviors in situations where cognitive control was needed, for example in intersectionsâbut not in a lead vehicle braking scenario where responses were triggered automatically by visual looming. It was also found that although the number of off-path glances decreased during cognitive load, the timing of the remaining glances was unaffected. Clearly, cognitive load has different effects on different mechanisms. When using AD, drivers were indeed capable of engaging in a non-driving related taskâsuggesting that AD will be able to fulfill driversâ desire to perform such tasks while traveling, which may motivate AD usage and thus improve traffic safety (given that AD is truly safer than manual driving). Finally, a simulator study addressing Objective B showed that the measurability of cognitive load was greatly improved by recognizing that multiple coexisting mental responses give rise to different physiological responses. This approach can provide less context-dependent measurements and allows for a better, more detailed understanding of the effects of cognitive tasks.These findings can help improve traffic safetyâboth by being used in system development, and as part of the systems themselves
The mental work environment and social work environment on the senior workforce
Introduction: The Swedish Agency for Work Environment Expertise commissioned researchers atLund University, Kristianstad University and Malmö University to conduct a systematic reviewfocusing on the impact of the psychosocial work environment on the senior workforce (â„55 years ofage) in a Swedish context.Aims: To provide an overview of how psychosocial work environment and occupational healthfactors affect the senior workforce, and describe interventions designed to improve the workenvironment.Methods: The guidelines on Preferred Reporting Items for Systematic reviews and Meta-Analyses(PRISMA) were followed. The data bases: Pubmed, Cinahl, Scopus and Medline were searched forarticles published until 2021-07-10.Results: After deduplication 846 articles remained, of which 49 were selected for full text screening.After exclusion of studies with low quality 20 remained. The studies included in this literature reviewhave been thematized and analysed based on the nine determinant areas of the swAge model1, forthe ability and willingness to work in relation to ageing, to explain the complexity of predictors forthe senior workforceâs working life. These determinant areas are divided into predictors of: the workenvironmentâs effects on health; the personal financial situation; the social support, relationships,and participation; as well as the execution of work tasks and activities.Conclusions: Several of the articles included in the literature review did not consider the definition ofage in relation to the senior workforce, despite age being the factor that characterizes anddistinguishes a senior employee. However, there were articles highlighting the significance ofconsidering the senior workforce based on their biological age, social age, and cognitive age ratherthan just their chronological age (i.e. how many years had passed since they were born). Severalgeneral suggestions were discernable in the articles included in the literature review that will bediscussed
Are the Mediterranean countries competitive in fresh fruit and vegetable exports?
The Barcelona Agreement was signed in 1995, setting forth a structure with bilateral agreements between the EU and twelve Mediterranean countries. The agreement also foresaw the creation of a free trade area in the Euro-Mediterranean region by 2010. For many of the countries surrounding the Mediterranean sea, fruit and vegetables are very important products. In light of the increasing trade liberalization and thus increasing competition between countries, this paper aims to investigate further the competitiveness of Mediterranean countries with respect to fresh fruit and vegetables. The results generally show that the competitiveness of the investigated countries has deteriorated over the period. In only two cases, there is an increase in competitiveness.International Relations/Trade,
Salt transfer under irrigation with treated wastewater in semi-arid Tunisia
A continuously growing population in the world has resulted in more agricultural activity in arid- and semi-arid areas where it once was harder to cultivate crops. Due to the high evaporation and the lack of rainfall in these areas it is necessary to irrigate the fields. In some areas it has become more and more common to use treated wastewater as an alternative irrigation source. When the soil is irrigated with saline treated wastewater, some of the salt will be concentrated in the soil. Excessive soil salinity can e.g. limit the plant water uptake, thus decreases the crop production, and it could lead to sever soil degradation. However, it is possible to use moderately saline water for irrigation without a significant risk for severe soil salinization if certain rules for water and soil management are established, implemented and followed. Therefore the main objective of this thesis is to do an assessment of the soil salinity in agricultural soil as a result of irrigation with treated wastewater. This master thesis will also try to estimate the effects on the soil salinity after a major rainfall event. This will be done with a field study that was conducted outside the city of Nabeul in the north-east of semi-arid Tunisia during 2 months. The soil salinity assessment done in this thesis can only be considered a qualitative one and the result can only be seen as an indication of an increase or decrease in the soil salinity over this particular field. However, the indications can be a help when deciding the objectives and limitations on future studies in this area. It has been concluded that a general increase in the soil salinity after two irrigation events cannot be seen. However, it was concluded that a small decrease in soil salinity could be seen already after 57.5 mm of rain. This indicating that the Tunisian winter rains can leach the soil from the salts added during irrigation, and that there is no significant risk of soil salinization in this field
Thermal Stabilization of Polyhydroxyalkanoates by Washing with Acid
The main goal of this project was to investigate how the thermal stability of two different types of polyhydroxyalkanoates; poly(3-hydroxybutyrate) and poly(3-hydroxybutyrate-co-4-hydroxybutyrate) were affected when washing them with acid solution. Initially, four different acids were used: citric acid, hydrochloric acid, formic acid and acetic acid. Citric acid gave the best results for both biopolymers and was further investigated with respect to different concentrations and washing times to find the optimal parameters. Experiments where deionized water was used as the washing solution, and experiments where citric acid was mixed into the samples were also investigated. The analyzing techniques used to evaluate the results was thermogravimetric analyze, differential scanning calorimetry, rheometer and size exclusion chromatography. The degradation temperatures of as-received P(3HB) and P(3,4HB) powder were 279â and 247â, respectively, determined with TGA. After the citric acid wash (1 mM, washing time 30 min), the degradation temperatures increased with 16â (296â) for P(3HB) and with 48â (295â) for P(3,4HB). Higher degradation temperatures could not be reached with higher concentrations or longer washing times. However, further investigation of P(3HB) showed that a concentration of only 0.05 mM and a washing time of 45 s was enough to raise the degradation temperature to 296â. For P(3,4HB), a concentration of 1 mM and a washing time of 45 s was required to reach a degradation temperature of 295â. By washing P(3HB) with deionized water for 30 minutes, the degradation temperature became 294â, and for P(3,4HB) it became 271â. Due to the high increase in degradation temperature, more washing times were investigated. For P(3HB), a washing time of only 45 s was enough to raise the degradation temperature to 294â, and for P(3,4HB) 5 min was required to reach 271â. When citric acid was mixed into the homopolymer, the degradation temperature decreased with 27â, and for the copolymer the degradation temperature stayed the same. The increase in degradation temperature by washing the biopolymer powder indicates a significant increase in the thermal stability.Today, plastic materials play a very important role in our everyday life. Plastics are used in almost every manufacturing industry nowadays because their physical properties make them very useful in many different areas. They are very versatile and can therefore be manipulated to get a wide range of desirable properties. The major disadvantage with these plastics made by fossil sources is that they are non-degradable and thus, they accumulate in the environment at a rate of 25 million tons per year. Because of this, there is a strong desire for new polymers with degradability to replace the old plastics. A so-called biopolymer
Bokomslag i förÀndring: Omslagets roll i marknadsföringen av adapterade böcker
Books being adapted for film and TV are one of the most common trends in the entertainment business today. As a result, publishers have to take the adaptation into consideration when re-releasing titles after their premieres to increase sales and find new audiences. In this thesis, four book series that have been successfully adapted into film and TV will be examined with focus on their cover design before and after they are adapted in a new medium. This will be done by implementing Genetteâs theories about paratexts, and Hutcheonâs theories about adaptation audiences. The aim is to investigate if there are any trends and similarities in how the cover design changes, and if there are any common strategies used by publishers to reach a broader audience, and what part both the author and the design play in branding and marketing adapted books. The results show that the cover designs after the adaptations are genre neutralised by iconic simplicity to reach a broader audience. Actors on the covers are shown to be a problematic cross-promotional strategy that narrows the audience. The authorial brand-name is an important part of the branding of the books, and the authorâs presence is integrated in the adaptation to increase the cross-promotional benefits
Role of the FOXC2 -512C>T polymorphism in type 2 diabetes: possible association with the dysmetabolic syndrome.
OBJECTIVE: Overexpression of the human transcription factor FOXC2 gene ( FOXC2) protects against insulin resistance in mice and a common FOXC2 polymorphism (-512C > T) has been suggested to be associated with insulin resistance in humans. Here, we addressed the potential role for FOXC2 as a candidate gene for type 2 diabetes and associated phenotypes. MATERIALS AND METHODS: A case-control study was performed in 390 type 2 diabetic patients and 307 control subjects. The number of patients was increased to a total of 768 subjects for further study of phenotypic differences relating to the dysmetabolic syndrome relative to genetic variation. The FOXC2 -512C > T polymorphism was genotyped by a restriction fragment length polymorphism PCR assay. RESULTS: FOXC2 -512C > T allele and genotype distribution did not differ between patients with type 2 diabetes and control subjects, but the C/C genotype was associated with increased body mass index (BMI, kg/m(2)) (P-a = 0.03) among type 2 diabetic patients. The FOXC2 -512C > T polymorphism was a significant independent predictor of BMI (P = 0.001) in a multiple regression model including age, gender and affection status. We found no significant association with type 2 diabetes-related metabolic parameters but that the C-allele (P = 0.01) and C/C and C/T genotypes (P = 0.03) were significantly over-represented in type 2 diabetic males with a concomitant diagnosis of dysmetabolic syndrome. CONCLUSION: We conclude that FOXC2 is associated with obesity and metabolic deterioration but does not contribute to an increased risk for type 2 diabetes
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