• Publicationsclose
• SE close

Although the first sex-dependent differences in chemosensory processing were reported in the scientific literature over 60 years ago, the underlying mechanisms are still unknown. Generally, more pronounced sex-dependent differences are noted with increased task difficulty or with increased levels of intranasal irritation produced by the stimulus. Whether differences between the sexes arise from differences in chemosensory sensitivity of the two intranasal sensory systems involved or from differences in cognitive processing associated with emotional evaluation of the stimulants is still not known. We used simultaneous and complementary measures of electrophysiological (EEG), psychophysiological, and psychological responses to stimuli varying in intranasal irritation and odorousness to investigate whether sex differences in the processing of intranasal irritation are mediated by varying sensitivity of the involved sensory systems or by differences in cognitive and/or emotional evaluation of the irritants. Women perceived all stimulants more irritating and they exhibited larger amplitudes of the late positive deflection of the event-related potential than men. No significant differences in sensory sensitivity, anxiety, and arousal responses could be detected. Our findings suggest that men and women process intranasal irritation differently. Importantly, the differences cannot be explained by variation in sensory sensitivity to irritants, differences in anxiety, or differences in physiological arousal. We propose that women allocate more attention to potentially noxious stimuli than men do, which eventually causes differences in cognitive appraisal and subjective perception.

This thesis addresses the relationship between urban waste and agriculture using an interdisciplinary systems approach. The environmental, economic, socio-cultural and political potential for using municipal waste compost (MWC) in urban and peri-urban agriculture in Accra, Ghana, was explored from different stakeholder perspectives and scales of enquiry. A pluralistic methodology was used in order to address different parts of the research and a critical reflection was made by the researcher on the carrying out of interdisciplinary research using these approaches. Waste management and composting practices were studied, as was urban and peri-urban agricultural systems. A series of farmer participatory experiments were carried out with urban vegetable growers to test the effects of using MWC from two different composting plants in Accra alongside current farmers’ practices. The perspectives of different stakeholders were also assessed through a combination of methods, including semi structured and informal interviews, participatory appraisal techniques, formal surveys, group discussions and workshops. Compost quality assessments revealed that the compost from the small-scale James Town plant was of higher quality than that produced at the large-scale Teshie/Nungua plant. Compost applications had a positive effect on crop growth. However, vegetable producers primarily used chicken manure as a fertility input and compared to this, the compost was inferior, particularly in relation to crop establishment and in creating a higher water demand. The growers were happy with the crop performance from compost, but saw the watering issue as a potential problem. They agreed that compost would be an attractive alternative during the rainy season. They also liked the fact that they did not need to apply compost to each crop, as they did with chicken manure. Whilst, growers would be willing to use and pay for MWC, both composts were too expensive to represent a viable alternative to other fertility inputs. However, given an appropriate blend of public-private-community partnerships and scales of operation which could harness opportunistic alignments between the needs of different actors, composting and its use in agriculture has potential in contributing towards sustainable development in the urban environment of Accra. With some modest policy support, the possibilities for improving quality and financial viability are considerable. Providing quality and price can meet the needs of growers, there is a market for MWC in Accra.

Abstract The contact force development for two types of polymeric elastoplastic particles subjected to different triaxial loading conditions was studied experimentally utilising a unique triaxial testing apparatus. In order to evaluate the experimental results, a finite element analysis was performed. The experimental findings highlighted the importance of contact dependence, which manifested itself in two principally different ways. Firstly, a reduced stiffness was observed when plastic deformation ceased to be fully contained, which, depending on the loading conditions, occurred at an engineering strain of about 5–10%. Secondly, a markedly increased stiffness was observed when particle confinement inhibited further plastic deformation, making elastic volume reduction the predominant deformation mode. The experimental results could be well reproduced by the numerical simulations, provided that isotropic hardening was included in the elastoplastic model. In an attempt to invariantly describe the data, a nominal contact pressure was determined as a function of the volumetric constraint of the particle. This resulted in an adequate collapse of results obtained for different loading conditions onto a single master curve at large volumetric constraint. In summary, this paper should be considered as a step along the pathway towards our long term goal of introducing novel and improved contact models.

Neck pain is one of the most common musculoskeletal disorders, which causes sickness absence and early retirement. Manual labor, awkward postures and repetitive work are commonly reported as causes for work-related neck disorders. Both neck pain and heavy physical work have been linked to lower levels of work ability. The overall aim of this thesis was to gain knowledge of how work demands can influence the work ability and sickness absence of workers with neck and upper extremity disorders, and also investigate a method that measures work demands. One cross-sectional study, two longitudinal studies and one experimental study were included in this thesis. Papers I-III uses material from Statistics Sweden (SCB) “Work environment” and “Work related disorders” surveys. Sickness absence data from the Longitudinal integration database for health insurance and labor market studies (LISA) database were also used in these studies. The relationship between exposure to work demands (high or low) or work place interventions (yes or no) were compared to work ability or sickness absence. Paper IV investigated the inter-rater reliability of the summary scores and individual items of a method to measure work demands, the Quick Exposure Check (QEC), by comparing two simultaneous assessments of 51 work tasks. The results showed that a lower level of physically demanding work and having high control over ones work can result in lower levels of sickness absence and promote excellent work ability for workers with neck pain, especially among older workers (Papers I, II). In Paper III it was found that work place interventions that improves neck pain were associated with fewer number of sickness absence days. Paper IV found that the QEC has good reliability in total scores but a few of the individual items showed low reliability. The results from this thesis can be used in different work settings, to promote work ability and prevent sickness absence by employers and occupational healthcare professionals.

Atherosclerosis is an inflammatory disease that can be generalized, affecting more than one arterial bed simultaneously, or localized, manifested in one system. Ultrasound based measurements of plaque textural features, such as low grey scale median (GSM), echolucent (hypoechoic) plaque types and juxtaluminal black (hypoechoic) area (JBA) are manifestation of potentially unstable lesions. Conventional carotid IMT (intima media thickness) and the recently introduced IM-GSM (echogenicity of the intima media complex) are important measures of subclinical atherosclerosis and are used to predict future ischemic events. The aims of this thesis were to study, in detail, the systemic nature of atherosclerosis by evaluating the carotid disease burden contralateral to symptomatic arteries, determining the relationship between proximal (subclinical atherosclerosis) and distal segments (well established disease) of the same artery and comparing local plaque features with systemic burden of atherosclerosis disease. In addition, the effect of statins on carotid plaque echogenicity was evaluated in a systematic review and meta-analysis. Methods: We have measured ultrasound-based textural carotid plaque features (GSM, JBA, entropy, coarseness), surface morphology, as well as IMT and IM-GSM. An in-house custom developed research software package was used for plaque feature extraction. For the meta-analysis we used Comprehensive Meta-Analysis version 3 software. Results: Study 1. In 39 patients, the carotid plaques contralateral to symptomatic arteries had similar morphological and textural features to those in the symptomatic arteries and are more vulnerable than those in asymptomatic arteries; more often mildly or markedly irregular with more vulnerable textural plaque features (lower GSM and larger JBA). Study 2. In 87 asymptomatic patients, an increased IMT in CCA correlated with plaque irregularities in the bifurcation and ICA while IM-GSM was closely related to plaque echogenicity (GSM), and other textural plaque features. Study 3. In the same cohort in study 2, patients with previous disease in the coronary arteries had higher IMT and lower IM-GSM and those with prior stroke had lower IM-GSM. Neither IMT nor IM-GSM was different between patients with and without previous lower extremity disease. IM-GSM decreases significantly with increasing number of arterial territories p<0.001 (asymptomatic vs symptoms in one vs multiple arterial systems) but conventional IMT was not different between groups p=0.49. Study 4. In a meta-analysis of 9/580 identified studies including 566 patients with 7.2 months follow-up, a consistent increase in the carotid plaques echogenicity after statin therapy, was reported. The perpetual (over 12 months) effects of which were shown in a meta-regression analysis to be related to changes in hsCRP. Conclusion: Symptomatic patients have similar plaque morphology and textural features of vulnerability in the contralateral carotid system, compared with asymptomatic ones. In the latter, measurements of proximal disease reflect distal pathology and the number of affected arteries. Finally, statin therapy and the drop of LDL cholesterol result in better plaque stability and optimum control of arterial inflammation, shown by arterial wall echogenicity and hsCRP changes, respectively.

Uppsatsen ämnar besvara vilka aktiebolagsrättsliga skillnader det finns inom EU 25 för att starta och driva ett privat aktiebolag jämfört med den svenska aktiebolagslagens regler. Aktiebolagsrättsliga skillnader som undersöks generellt inom EU 25 är kapitalkrav, bolagsstyrning, aktieägare samt bolagsskatt. Utöver dessa fyra kategorier undersöks även bolagsbildning och bolagsstämma i fem länder som detaljstuderats. Sverige, Frankrike, Storbritannien, Tjeckien och Tyskland.

Familial hemophagocytic lymphohistiocytosis (FHL) is a rare and fatal disease of early childhood characterized by a non-malignant accumulation of activated T lymphocytes and histiocytes in the reticuloendothelial system. Moreover, immune system derangement, with prominent hypercytokinemia and low or absent cytotoxic T and natural killer (NK) cell activity, is a consistent feature of this autosomal recessive disorder. Recent work has demonstrated that the degree of spontaneous caspase activation in FHL lymphocytes is attenuated in vitro whereas Fas-mediated caspase activation and apoptosis induction remains unmitigated, and FHL can thus be distinguished from the related chronic disorder of immune regulation termed autoimmune lymphoproliferative syndrome or ALPS. However, subsequent studies have identified mutations in the gene encoding perforin, a cytotoxic granule constituent required for apoptotic killing of target cells, in a number of FHL patients. Hence, the underlying defect in FHL may be conceived of as a lack of apoptosis triggering within the immune system, rather than apoptosis resistance per se. These observations represent an important step in our understanding of the pathogenesis of FHL and also serve to emphasize the pivotal role of cellular (perforin-based) cytotoxicity in the regulation of immune homeostasis.

The autoxidation of the two mutagenic and antimicrobial sesquiterpenes merulidial (1a) and isovelleral (5) generates a number of bioactive products that are suggested to be partly responsible for the mutagenic and antimicrobial activities of the two compounds. The biological activities of the autoxidation products are, as far as has been possible to assay, of the same order as the parent compounds, and it is shown that they are formed in normal bioassay media. Merulidial (1a) is especially interesting, as its rate of autoxidation is considerably higher compared with non-mutagenic derivatives of 1a. In addition, natural isovelleral [(+/-)-5] was found to be twice as mutagenic as synthetic isovelleral [(+/-)-5], indicating that (-)-isovelleral is only weakly active or inactive, and supporting the suggestion that the interaction of isovelleral (5) and its derivatives with DNA depends on the absolute stereochemistry of the unsaturated dialdehyde moiety.

Context. Radiative association is a possible way of sodium chloride (NaCl) formation in interstellar and related environments. Theoretical studies are essential since laboratory experiments are unavailable and difficult to perform. Aims. The total rate coefficient was calculated for the formation of NaCl by radiative association at 30–750 K. Methods. We included two contributing processes for the total rate-coefficient computation. One of them takes the nonadiabatic coupling between the two lowest 1Σ+ states, Χ1Σ+ and Β1Σ+, into account. The other one was calculated conventionally as a single channel and started in the continuum of the A1Π state. The individual rate coefficients were calculated from cross sections obtained up to 0.8 eV, which enabled us to calculate the rate coefficients up to 750 K. The cross section was also calculated for a one-state process within the Χ1 Σ+ state. Results. The nonadiabatic coupling enhances the formation of NaCl by radiative association by two orders of magnitude at about 30 K and by around one order of magnitude at about 750 K. The single-channel process starting in the continuum of the A1 Π state starts to contribute above around 200 K. The one-state transition model, within the Χ1Σ+ state, is not an adequate approximation for collisions in 1Σ+ symmetry. Instead, these collisions are treated in the diabatic representation in the total rate-coefficient calculation. Conclusions. The calculated total rate-coefficient function at 30–750 K can improve the astrochemical reaction networks for the CRL 2688, IRC+10216, and Orion SrcI environments, where NaCl was detected before.